Army Aviation Digest - May 1957

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UNITED ST TESARMY AVIATION

IGESTVolume 3 May 1957 Number 5

RTICLES

XH-40 Test Program. 5Mr . Hans Weichsel Jr.The Way t Used To Be . 11Brigadier General CarlL Hutton, USArmy Aviation Field Maintenance at Fort Eustis 15Major General Rush B. Lincoln Jr,. USA Method for Analysis of Pilot Error Aircraft Accidents 19Dr. Arthur C Poe Jr.Let s Modernize Artillery Aerial Observation 26Colonel Charles W Matheny Jr . r ty

DEP RTMENTSStraight and LevelNotes from the PentagonMajor General Hamilton H. Howze USMemo from Flight SurgeonThe Gray Hair Department

COVERThe XH-40 helicopter crUlsmg along on thismonth s cover is one of three experimental flightmodels of this aircraft which Bell HelicopterCorp. of Fort Worth, Texas, has completed to

date. It is anticipated that this six-place c1osedcabin model will be delivered to army units sometime in 1959. Its uses include inside litter evacuation cargo or troop transportation, command observation and many other missions.

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HEADQUARTERSUNITED STATES ARMY FORCES,

FAR EASTand

EIGHTH UNITED STATES ARMYREAR)

OFFICE OF THE COMMANDINGGENERAL

APO 343, San Francisco, California5 APR 1957Dear General Hutton:Inclosed for your information is acopy of a letter from Major GeneralR. L. Waldron, Commander, 315thAir Division, United States Air Force,as indorsed by General Laurence S.Kuter, Commander, Far East AirForces

We in this command feel justlyproud of the conduct of our officersand men in meeting a hazardous andtragic emergency with valor and expediency.Sincerely,

I D. WHITEGeneral, United States ArmyCommanding.

HEADQUARTERS315TH AIR DIVISION

COMBAT CARGO)UNITED STATES AIR FORCE

OFFICE OF THE COMMANDERAPO 323, San Francisco, California7 MAR 1957SUBJECT: Exceptional ServiceTHRU: CommanderFar East Air Forces

Advance)APO 925

TO: Commanding GeneralUnited States Army Forces,Far East and 8th United

States Army Forward)APO 301

1. On 22 February 1957 a C-124 air-craft of this command was forced toland in the Han river near Seoul,Korea. There were 10 crew membersand 149 passengers aboard therewere 137 survivors.

2 Certain members of your command gave exceptional service in therescue of survivors. I refer to thepilots and other crew members ofArmy helicopters who evacuated thesurvivors to nearby hospitals afew minutes after the aircraft accident occurred 26 Army H-13 and H-19helicopters arrived at the scene of theaccident. These helicopters, with theassistance of one Air Force helicopter,evacuated all survivors.

3. This evacuation was accomplished during the hours 9f darkness. Thehelicopters involved flew a total of81 hours. . . . Since there were 27helicopters participating in the res-cue operation, the resultant air trafficsaturation created an extremelyhazardous condition. The selfless andheroic actions of your helicopter pilotsand other crew members in evacuatingthe survivors to nearby hospitals unquestionably prevented the death tollfrom being higher. f evacuation fromthe sand bar had not been affected, therising tide and freezing water mighthave resulted in there being no sur-vivors. I recommend that these menbe given special recognition and highhonor.

4 According to available informa-tion, the Army helicopters and crewsinvolved were assigned to the following units:

Korea Military Advisory GroupK-16 Helicopter AmbulanceDetachment

8th United States Army AviationPlease turn t page 40)


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NOTES FROM THE PENT GONMaior General Hamilton H Howze US

Director of Army Aviation

There are rumors that our pilots are not the selfreliant hardy souls that they were back when . In1945 a pilot, by virtue of his training, could glue abroken L-4 spar, sew on a wing covering with properstitch, dope the job according to T.O., and then bebrave enough to fly it. ut we have very little sewingand gluing to do these days, and if the newly graduated aviator does not know what a sailmaker's needleis, it probably does not detract seriously from his professional value.Expanding use of aviation has imposed requirementsfor new training which more than replaces the timeformerly devoted to learning how to glue and to sew.Helicopter, instrument, and multi-engine qualificationsimpose a very appreciable load on schools. The manifold growth of air traffic and controlled air space requires today's pilot to be familiar with many rules andprocedures which were of no concern in 1945. Today'sreplacement for the 65 HP Continental engine is an efficient beast, but it demands more skill to keep it inbusiness than did its predecessor.The result is that a competent aviator today musthave many more talents than he had in 1945 and thenew graduate of the school, though his training hasbeen excellent, is a very basic Army aviator. Pinningon his wings has not made him a professional cropduster, airline captain or helicopter master. His training must proceed with planned progression throughouthis flying career. He is probably at the peak of hisskill in so far as manipUlation of the controls is con-


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U. S. ARMY AVIATION DIGESTcerned, SO it seems advisable to take this excellent rawmaterial and continue individual training to equip theman to contend with situations which, according to ouraccident experience, he will encounter. To be specific-

a Most tactical flying is low level flying-and inad-vertent stalls at low level can be tricky. Continue training in low work .b Ground loops are not lethal, but they indicate alack of finesse in the type of flying the Army bragsabout.c Inadvertent flight into instrument weather is in-evitable, and even if not instrument qualified, each avia-tor must be able to maintain control of attitude solelyby reference to instruments. Navigation can comelater. It is better to be lost straight and level than tobe a spiral over the homer.There has been no change in the requirement for atactical ability to operate from a cow pasture airfield.

Can we land and take off from fields like those used inItaly? Can we scrunch in with a crosswind and stopin:three lengths without clobbering? Or, have we be-come an airport outfit? To do aviation's job, we mustcontinually keep the tactical requirement in mindplus a growing requirement for weather operationfrom these same airstrips.; A very real responsibility is placed upon the unitaviation officer to train the new aviator so that heoperates effectively in the unit. The established proce-dure applies: Train the man-fit him into the u t-train the unit. Then continue training both the manand unit.The fledgling aviator has much to learn. He mustlearn it in his unit. The unit aviation officer must bea .professor of aviation techniques and tactics.


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many of these have been incorporated into the design.Following is the story of howBell and the Army are attempting to accomplish a thorough investigation of the helicopter scomponents before quantity production is begun. t is reportedthat this test program is one ofthe most extensive programsever mapped out for a helicopterprior to production.Set up to assure the Army anoptimum helicopter at the earliest possible date, the test program is being conducted by Bellunder auspices of the TechnicalLaboratories of Air Researchand Development Command andthe Project Office of Wright AirDevelopment Center, which inturn coordinates with theArmy sProject Liaison staff.At present, initial componentand helicopter tie-down testshave been completed. Exploratory shakedown flights h a v ebeen conducted and the PhaseII flight test program is scheduled to begin soon.TW XH 40S UNDERGO T STSThe XH-40 contract calls forthree experimental prototypemachines. Two of these helicopters, ships No.1 and No.2, areundergoing initial exploratoryflights of Phase 1 The initial exploratory Phase I flight p r ~gram consists of several hoursof ground running during whichtime the rotor is tracked andbalanced and checked with booston and off, and additional op-Top: Test bench where transmission and

drive systems are subjected to overspeedruns to determine life expectancy. Middle:Main rotor whirl tests simulate most flightconditions. Bottom: XH-40 is checked aftercompleting initial 50-hour ground tiedown run.

Photographs cou1tesyell Helicopter Corp


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erational functional checks areconducted. The special test instrumentation is checked out andthe helicopter is given a thor-ough shake-down inspection.This ground run is subsequentto the initial 50-hour ground tiedown test. The ground runs arefollowed by hovering and lowspeed flight investigations dur-ing which time the helicopter isflown with a neutral cg locationand flight handling characteris-tics are checked. Cooling checksare made as well as cabin carbon monoxide checks. Companytest pilots make a qualitativeevaluation of the machine withparticular emphasis on vibration and flight qualities.After the hovering and lowspeed flight tests the helicopteris taken through transition andlevel flight testing commences.Again the tests are conducted ata neutral cg, low gross weightand a systematic speed build-upschedule is followed. Prelim-inary controllability checks, including stick plots, are made,plus preliminary performancechecks. Particular emphasis isplaced on cooling, carbon monoxide, and engine operationalchecks.When the low altitude investigation is completed, the climband descent regime is investigated. Full power climbs andautorotation characteristics overa wide range of conditions areexplored; however. full autorotations to touch-down are notnormally conducted at this early

Top: Cabin view shows XH-40 photo paneloscillographs other test equipment in spacenormally occupied by passengers. Middle:Aerial shot of Bell s elaborate transmissiontest facility. Bottom: Tail rotor whirl testsrun in excess of design thrust.


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8 U. S. ARMY AVIATION DIGEST May

XH 40 landing gear was subiected to severe iolts and heavy loadsstage of the program.Once the hovering, low speed,transition, and level flight investigations have been conductedat a neutral cg, an incrementbuild-up is commenced to determine the fore and aft cglimitations by repeating theaforementioned exploratory testsin a systematic manner.OPTIMUM CONDITIONS SOUGHT

Following the initial exploratory flight program, an investigation is then initiated to adjustthe helicopter for optimum conditions. During this period manymitior changes are evaluated toobtain the optimum flight char-acteristics and minimum vibra-tion. For instance, the exact location, size, and control ratio ofthe synchronizer elevator are determined. Selection of the optimum stiffness for the vibration isolators is also made.

The exploratory flight program is followed by StructuralPerformance Phase I flight

tests conducted in accordancewith specifications agreed uponbetween the contracting agencyand the contractor.

The Phase I Flight Test Pro-gram is conducted by the contractor s test pilots and is followed closely by Phase II whichis conducted by Edwards AirForce Base personnel. The re-sults of the exploratory flighttests program indicated that theXH-40 far exceeds expectations.

Another example of the progress to date is the static testarticle. The static test article isa complete airframe minus theengine and dynamic components,i.e., transmissions, rotor, etc.The static test article is subjected to static design loads bymeans of artificial loadings, i.e.,sandbags, hydraulic jacks, etc.,to prove the structural integrityof the basic airframe.

The static test article wasscheduled for completion inMarch, 1957, but was actuallycompleted in November, 1956,


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1957 XH-40 TEST PROGRAMfour months ahead of schedule.The static test article was flownin a C 124 from Fort Worth,Texas, to Wright Field, wherethe actual tests were conducted.

BEHIND THE S ENESNow let's take a look behindthe scenes to see what has beendone in respect to componenttesting and tie-down testingprior to the initial flight testing

of the helicopter. The purposeof these extensive ground testsis to insure a safe flight testprogram and also to ascertainas nearly as possible that thenew helicopter will fulfill its design promises; particularly, inrespect to component life andmaintenance.Testing in fact, has beenmade the all-important key todevelopment of the all-new, nearrevolutionary H-40 presentlyscheduled to be the first turbinepowered helicopter to enter military service. Tests will provethe Army is getting all it hasbeen promised in the H-40 atthe earliest } X>ssible date. Theywill provide a basis for component life and prove the machinecan perform the missions it wasdesigned to fulfill.

TESTING THOROUGHExhaustive ground and flighttests supplement the componenttests to doubly assure that eachmajor dynamic component of

the new helicopter is perfectedbefore production is initiated.This comprehensive experimental test program is being conducted to assure the H-40 s dependability and minimize thelong, evolutionary product perfection process based on fieldservice experience.

Helicopter development testson the XH-40 include many ofthe familiar airplane-type testssuch as landing gear drop tests,fuselage static tests, and flighttests, plus very extensive dynamic component tests such asmain rotor, and tail rotor whirltests, main and tail rotor transmission deflection tests, transmission bench tests (dynamometer test stand), and extendedtie-down tests, of the completehelicopter itself.Coincident with all this is anextensive fatigue testing program where parts are vibrated,subjected to stresses and strainsfar in excess of those encountered in flight, and generally tortured until engineers have atrue picture of how the partswill stand up in service undervarious loading conditions.After initial fatigue tests aremade on components at highstresses, the actual anticipatedflight loads are measured andadditional fatigue tests are madeat loads comparable with thoseof flight.FATIGUE TEST RUNS 8 MONT S

Already the experimental fatigue test program for the XH-40 is more than a half year oldand will run another year.To insure the quality of itsXH-40, and all of its new helicopters, Bell Helicopter has builtup and operates an extensivelayout of test facilities andequipment. Included are a fatigue test building, a moderntransmission test building, twolaboratories, tie-down ramps,main and tail rotor whirl facilities, numerous s t t i test setups,and flight test hangars.In the fatigue test building,


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10 U. S. ARMY AVIATION DIGESTnumerous weird-appearing machines determine the life of helicopter structures under vibratory loadings. During fatiguetests, parts such as rotor blades,hubs, grips, and control systemcomponents are subjected to oscillatory deflections as well assteady static loads of millions ofcycles. The number of oscillations which can be tolerated atvarious load levels determinesthe life of a part under loads encountered in flight. Though timeconsuming, this phase of helicopter laboratory testing is onewhich yields a great amount ofinformation to the helicopter design engineer.

The XH-40 transmission benchtest is scheduled to run for morethan two years, involving morethan 2,000 hours of operation.Included will be runs at muchhigher loading than anticipatedin flight as well as loads comparable with expected flightloads. The XH-40 transmissionand tail rotor drive assemblybench test is driven by a 2,000HP P&W R-2800 engine througha fluid coupling to simulate aT-53 turbine power plant.

HIGH CLIM R TEBecause of the hi rh verticalrate of climb of tl te XH-40 (i.e.excess power availa')le over thatneeded for hoveri'1g, coupledwith ground effect), the mainrotor of the H .10 on tie-down

has been tested a.t a rotor thrustforce up to 8,600 oounds whilethe helicopter's oesigned grossis less than 5,500 ponnds. Thisis equivalent to 1.6 Gs, a loadfactor aviators don't normallyexceed in maneuvers. The groundtie-down test includes one 50-hour run and one 150-hour run,

in accord with stringent militaryspecifica tions.In flight test, the XH-40 prototypes will be filled with electrical stool pigeons (gauges,meters, oscillographs, m v icameras, etc.) to give engineersa true picture of what is happening. The data obtained arecorrelated wi t h engineeringanalysis ground test data, and.in turn, are fed into the fatigueand bench test programs.t is only fitting that the testing book should be thrownat the XH-40-a helicopter thatis expected to usher in a newera in helicopter operating economy, serviceability, reliability,and performance. This new utility helicopter will ce the first tooffer 1,000-hour overhaul periods

and is designed for easy fieldmaintenance, line inspection, andaccessi bility.Indicative of the advancements made in the XH-40 is thesmoothness and rapidity withwhich the 50-hour flight qualification ground tie-down run wascompleted. This test for newhelicopters is usually scheduledto require several monthselapsed time, allowing for redesign, replacement and rerun. Buton the XH-40 this gruelling 50-hour test was completed in theremarkably short period of onlytwo weeks without the necessityof replacing a single prime component and three weeks fromdate of receipt of the first XT-53turbine the first XH-40 was inthe air.

The XH-40 is being billed asthe helicopter that will give theArmy its first major breakthrough in helicopter operationand maintenance cost in recentyears.


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THE W Y ITUSED TO EBrigadier General Carl I. Hutton US

Commanding General he United States Army Aviation Center

T HE YEAR WAS 1947, and theArmy was taking FAF deliveries of L-17s. We were getting a few at Fort Sill, and indue course Luke* and gatheredone of the plums and headedwest to pick up two L-17s at theRyan plant in Los Angeles. Thetrip west was by C-54 freighter-OKC - SAT - ELP - RIV. Whendaylight came over SouthernCalifornia everything had beennormal, except to a light planeaddict those grinding long runsdown the runway were a trialand the cargo looked very insecurely lashed down with 4 inchrope. mentioned these to Luke.He said, I thought I was theonly one worrying about thosethings.

Southern California w spretty well socked in and apparently getting worse. One ortwo mountain tops were sticking up through the clouds ascalm reminders that there reallyare rocks. Sitting among thecargo (huge crates of airplaneand engine parts), not hearingthe radio, and not knowing whatwas in the pilots minds, we rodeLt. Col. H. I. Lukens, who is pres-ently assigned to the U S. ArmyLanguage School Monterey, Calif.

down without choice partly viaholes and partly through theclouds. t turned out that thiswas not an approach, but thatthe lumbering four-engine beastwas to be taken to March Fieldunderneath.Underneath there was notmuch room, although to give ourpilots their due, they tried.Three times we started down avalley, the clouds immediatelyoverhead, the walls of the valleydisappearing above us, and theground not very far below. Herewas demonstrated perfectly whythe 180 degree turn is not thepanacea it is sometimes creditedto be.On the third trip up the valleythe 180 was made in soup, andwhether the people in the drivers' seats knew where the rockswere is doubtful. The worst partis not knowing what they arethinking, but at last they quitthat foolishness, and we weretaken on top at about 12,000feet.We went to Long Beach andmade an approach. We brokeViews expressed in this article are theauthor s and are not necessarily thoseof the Department of the Army orthe U. S. Army Aviation School.-The Editor.


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12 U. S. ARMY AVIATION DIGEST Mayout something under 500 feetwith two steep turns to get linedup. The landing was in heavyrain. We left the pilot in operations having a long talk on thePlan 62 with Flight Service.Back at Fort Sill I had beengiven about one hour in theNavion. It was on old man srocking chair. We got our airplanes at the Ryan plant andtook them across the hills to VanNuys for a little shaking downbefore heading east.

W RNING LI HTS OHow much I knew about theairplane came out brightly whenthe red landing gear warninglights came on after takeoff. tseems that I had the impressionthat the red lights were sup

posed to come on when the gearwas either not locked up or notlocked down and the green lightonly wnen the gear was lockeddown.This required some conversation with the tower and I foundout that Luke who was ridingover to Van N uys with me didnot know any more about itthan I. His check-out had con-

sisted of the dual ride from PostField to Tinker on the way tocatch the C-54. We were ratherinadequately checked out for aferry flight from Los Angeles toFort Sill but the airplane seemed so simple that we spent onlyan hour or so around Van N uysin the traffic pattern.Flight plan was flight of twoLAX to PHX contact direct.Takeoff about 1000 hours inbeautiful weather. This was myfirst time with mountains thatsize so I climbed out over LosAngeles to 8 000 feet. Directlyover the city the engine wasrough as a cob. Carburetor heatmade it rougher, and finally Irealized that it required leaning out. This I did and the engine began to purr.

Green 5 I was on course onthe east leg of LAX low freq.t looked like a piece of cake.Passing Riverside I watched aflight of four of those newfangled jet fighters in handsomemaneuvers. The air was smoothand solid. I could not see Lukewho had been cleared for takeoffimmediately after me. I checked

passage of the north leg of Ther-Brigadier General Carl I. Hutton graduated from the U. S. MilitaryAcademy in 1930 and was commissioned a second lieutenant in the Field Artillery. After six years of troop duty with the Field Artillery, he was detailed tothe Quartermaster CorpS for another six years.During World War II, he served in NorthAfrica, England, France Belgium, Holland andGermany. In March 1944 he commanded the 14thArmored Field Artillery Battalion which enteredcombat a short time later. In August of 1944, he as-

sumed command of the 2d Armored Division A rtillery remaining in that post until September, 1946.In October 1946, he attended the Army Aviatorscourse at San Marcos Air Force Base and FortSill graduating from the latter school in June 1947.A 1952 graduate of the National War College heattended helicopter school before assuming commandof the U. S. Army Aviation School in July 1954.Since September, 1954, he has commanded the U. S.Army Aviation Center and the U. S. Army AviationSchool at Fort Rucker Ala.-The Editor.


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1957 THE WAY IT USED TO BE 3mal range and turned towardBlythe.

SUDDEN UMPSuddenly there was a bumpand the airplane began to yawto the right the gear warninglights went off and the rightmain gear green light came onbright and clear. Now what didthat mean? Presumably itmeant that the right main gearwas locked down ready to land.I turned on the hydraulic pumpand the green light went off andthe airplane stopped yawing.Hydraulic pump on the gearcame up. Hydraulic pump offthe right main gear went down.How much damage would it doto leave the hydraulic pump onworking all of the time againstthe weight of the gear? I hadno idea but I decided to let ityaw and to land at Blythe forrepairs.Blythe radio said that the oldAir Corps training field west oftown had no facilities but therewas a small commercial field justeast of town where I could probably find a mechanic. The fieldwas small all right. One blacktop runway looking to be exact-ly one-half of a section line long.One-half mile. When the gearwent down the horn went offand the green lights came on.I put the flaps all of the waydown and bumped the runway apretty good lick. This shouldhave made an impression uponme but it did not at the time.On final I heard Luke callingPhoenix radio and I assumedthat everything was normalwith him.

TROU LE FOUNDThere was a mechanic there

and the trouble was easily found.The stopnut on the bolt whichcatches in the hook which holdsup the gear was not properly adjusted. A couple of turns movedit out of the way. There was nocharge but the mechanic said hewould be repaid amply if hecould make a test hop with me.Lined up for takeoff the mechanic pointed at the propellercontrol and asked how I checkedthat. With embarrassment Ichecked propeller operation.The gear worked fine. Comingin on final gear and flaps downfat dumb and happy I kept aneagle eye upon the power lineswhich crossed right at the endof the runway and nothing else.Suddenly and powerfully theairplane began to sink. The passenger was eagerly waving atthe airspeed indicator which Inow saw said something undersixty. I opened the throttle andcame up over those power linesand down onto the end of therunway in a sensational shortfield landing. Very exciting. Ihad the impression that themechanic was glad to get out.

FLIGHT SERVICE NOTIFIEDI got Flight Service on thetelephone and told them whereI was and attempted to file contact for PHX. This was turneddown because of thunderstormsin the hill country in betweenand I was forced to eat a phil

osophical lunch. N ext I waswanted on the telephone andthe thought occurred to me thatFlight Service was really on theball to call me back like that.But it was Luke on the otherend. He was at the old Air Corpsfield west of town and BlytheRadio had told him where I was.


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4 U. S. ARMY AVIATION DIGESTHe brought his airplane overand landed. His story was thathe had run into the thunderstorms and had had to turnback. He remarked that therewas a good deal of scramblingaround, recovering sectionalcharts from the back seat wherehe had nonchalantly tossed themas he used them up. His ideawas that from now on he wouldhave somewhat more orderlyhabits in flight.The next morning Flight-Service was hopping mad. t seemsthey had lost me and Air Searchand Rescue was on alert to findone lone L 17 in that wild country. In positive terms they announced that a violation wasbeing lodged. After recallingthat I had talked to Flight Service three times the afternoonbefore I could not regard aviolation too seriously. HoweverI had only talked to the filingout desk and not to the closingout desk. When filing ro mPhoenix, this was talked overwith Flight Service. They cooleddown and finally did not file theviolation but I gathered thatthe alert had been real fromremarks I heard at Phoenix.

We filed PHX-TVS-E.LP contact and I followed the airwaysfor awhile uneventfully. Thereis a lot of that kind of countryout there, but the low freqranges brought me along precisely on course and the landingat EI Paso was hot but routine.HALF WAY TO ORT SILLt was mid-afternoon by thetime we got off contact for Lubbock somewhat more than halfway to Fort Sill. For this legthere were no beams, no ADF,

no VOR. There was only themanual lOOp which would nothelp much until the last fiftymiles. I was lacking the sectional chart showing the areafor the first 5 miles or so eastof EI Paso. This did not seemimportant since I would soonrun onto the charts I did have.But it was strange how nothingon the ground appeared to matchanything on the map.At one point I decided to giveup and did a 180 to head backfor EI Paso. When I got headedback in that direction therewere the EI Paso mountains seventy miles away, a visual homerlike Mount Scott or the BalloonHangar at Fort Sill. That revived my courage and I returned to my course. t was simple

enough to pick out a river-andrailroad feature ahead which Icould not miss even in this wildand featureless terrain. I forcedmyself to hold on course fortwenty minutes more and surely enough I came to the riverand-railroad not five miles offcourse.O NIGHT FLYING

Ferry flights in those dayscould not be made at night, andso we were nighted-in at Lubbock. The next morning, stillCAVU it was a short jump.Across the Red River I startedhoming on the Wichita Mountains. Runway 18 was just likehome. Luke landed immediatelybehind.

There it was a flight madewith some overconfidence and atouch of ignorance. When askedabout what kind of flight wehad had we said Nothing toit.


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Army AviationField Maintenanceat Fort Eustis

Maior General Rush B Lincoln Jr. USCG Transportation Training Command

WHEN IT COMES T ARMY Avia-tion Field Maintenance, boththe school for teaching techniques and a model shop for putting them into effect are foundat Fort Eustis, Va. home of theArmy Transportation Corps. TheTransportation School offers avariety of specialized courses todevelop the skills of aircraftfield maintenance; the Transportation Field MaintenanceShop is a model of how theseskills can be utilized.Cognizant of the TC responsibility to keep Army aircraftready for duty with third andfourth echelon maintenance, thispost has naturally taken a vitalinterest and part in the Armyaviation program.The Aviation Department ofthe Transportation School provides resident instruction in 14courses including a course forofficers covering all phases ofArmy aviation field maintenance.These courses do not overlap themaintenance courses taught at

Fort Rucker, but rather pick upthe Transportation Corps fieldmaintenance responsibi l i tywhere organizational maintenance must stop.The actual operational side ofthe TC s mission however, isnot overlooked. An aviation fieldmaintenance shop is operated at

Fort Eustis Felker Army Airfield. This model setup has thepractical mission of keeping intop shape more than a hundredaircraft assigned to installationsin the Second U. S. Army area.TRANSPORTATION SCHOOL

The school has adequate shopfacilities and classroom spacefor teaching more than 1500students annually. In fact, thedepartment offers more than 150weeks of instruction covering allphases of Army aviation fieldmaintenance, both fixed wingand helicopter.The Aviation Department isone of the major instructionaldivisions of the r a n s p o r t a t i o nSchool. The department is headed by a senior Army aviator,Lieutenant Colonel Edwin L.Harloff and has approximately250 military and civilian instructors.

The school keeps right up withthe latest in the Army aviationprogram. For instance, as theH-37 helicopter is now makingits debut into the Army aviationprogram, the TransportationSchool is developing its coursesof instruction to cover fieldmaintenance of this craft. A rigging trainer, engine installationtrainer, hydraulic trainer, andtwo electrical trainers have al-


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6 U. S. ARMY AVIATION DIGESTready been received as trainingaids for this new craft.

An important course at theschool is the Aircraft Maintenance Officers Course, a comprehensive 15-week course of instruction for officers and warrant officers. The course coversboth fixed- and rotary-wing aircraft, training officers to supervise organizational, field and depot maintenance including technical inspections of all Armyaircraft.Officers in this course are concerned with the management ofa T AAM Transportation ArmyAviation Maintenance) Companyor TAAHM S Heavy Maintenance and Supply) Company;they learn to control the workflowing through their organization and to check the quality ofthe completed maintenance.

3 REP IRM N COURSESThe 3 other courses taughtat the Transportation Schoolare repairman courses for enlisted personnel. TheGe coursesvary from 9 to 16 weeks inlength, each covering a specialized field. Quite varied in

their instruction, the coursesteach everything from fieldmaintenance on a particularca egory of aircraft to fieldmaintenance on a particular component of an aircraft.For example, r e p i r m ncourses in the MOS 670 seriesare taught for the airplane, reconnaissance helicopter, singlerotor utility and transport helicopter, and tandem rotor utilityand transport helicopter. Thenthere are nine component repaircourses in the MOS 680 series.The Aircraft Component RepairHelper Course is the entry orbasic course in this field, whileother courses of instruction usually follow.Specialization is available inthe repair of engines, carburetors, powertrains, rotors andpropellers, electrical systems,airframes, hydraulic systems,and instruments.

The school has many excellentfacilities for instruction in aviation field maintenance. Classrooms and shops are located inthe Transportation School's technical shop buildings, with plentyof hardstand space outside forMajor General Rush B. Lincoln , Jr., graduated from the United StatesMilitary Academy in 1932 as a second lieutenant in the Corps of Engineers.He later received his Master of Science degree in civil engineering from theMassachusetts Institute of Technology.World War II service included assignments in the Office of the Chief ofTransportation as well as in the Middle East, NorthAfrica, Europe and the Pacific Theater of Opera-tions. After V J day, he served as Chief of Transportation, Army Forces Western Pacific, until his

return to the U. S. in 1947.He attended the first class of the Armed ForcesStaff College and is a 1950 graduate of the NationalWar College. Transferred to the TransportationCorps in 1951, General Lincoln has been in com-mand of the Transportation Training Command atFort Eustis, Va., since December, 1954.The views expressed in this article are theauthor s and are not necessarily those of the Department of the Army 01 of the U. S. Army AviationSchool.-The Edit01


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other work. The school has manyaircraft which are useful in therealistic training program. Airconditioned shops are providedfor instruction in the repair ofinstruments and helicopter rotorblades as temperature and humidity control is a necessity inthis type of work.Enrollment in these coursesna urally is not limited to Transportation Corps personnel. Alliedofficers Army personnel fromvarious branches and even civilian employees of Army fieldmaintenance activities attendthese courses at the Transportation School. A one-week courseis taught to National Guard officers who are orientated on thelatest maintenance techniques.

MO EL SHOPThe model Army AviationField Maintenance Shop is likewise an interesting activity atFort Eustis. This shop with thelatest in equipment and operational know-how shows how thefield maintenance of Army aircraft can be accomplished in a

most efficient manner. This shopdiffers from other field maintenance activities in two respects:it has complete equipment tohandle all of the necessary jobsand the men in the hangar mustconcern themselves with onlythe bare minimum of paperwork.The shop operates with 57 personnel but handles field maintenance for more than 100 aircraft. Since the shop was established in November under theTransportation Division at FortEustis it has streamlined itsoperations to a point where thecrew working on an aircraft canalmost forget paperwork. Hereis how the operation works:

L 20 Engine est StandWhen an aircraft either fixedor rotary-wing comes into theshop for repair an inspectioncrew checks it out. Inspectorsfind the deficiencies on the craft

then list them breaking themdown as to organizational maintenance and field maintenancerequirements. This shop willonly concern itself with fieldmaintenance except where organizational maintenance mustbe performed to put the aircraftinto safe flying condition.After this preliminary checka repair crew takes over. Thiscrew made up of no more than

H 37 Rigging Model


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18 U S. ARMY AVIATION DIGESTfour men, will see to the repairof this aircraft from start tofinish.

OPER TION STRE MLINEDHere is where the streamlined operation comes into play.If this crew needs any spareparts to accomplish the repairof this aircraft a repairman hasonly to ask for the parts he needsat the supply shop. All necessary paperwork is handled bysupply personnel, allowing mechanics to concentrate on theactual maintenance of the aircraft.Specialized shops, with thelatest in tools and equipment, tohandle particular problems, arelocated alongside the hangar.These shops can handle any jobfrom instrument repair to rotorblade patching from sheet metalwork to flaw detection, fromwelding to hydraulic system repairs. These shops are availableto all of the crews working onaircraft.Hence, this field maintenanceshop is a model, combining a

specialized system for specialized jobs with a crew system formaking sure that the right jobis done on each aircraft. In thesame way, paperwork is keptoff the hangar floor. The simplicity of the operation makesit efficient: repairmen can obtain with ease, anything fromneeded parts to specialized repairwork. They merely tell thespecialized shops what they needto get the job done.This model shop at Fort Eustis offers a wonderful opportunity for officers and enlistedpersonnel attending the Transportation School to see a fieldmaintenance shop in actual operation-at work in a top-efficiency manner. Students regularly visit the model shop in thecourse of their instruction.As the Army aviation program grows, Fort Eustis and theTransportation Corps will continue to develop the field maintenance program both at theschool and in the shop, to meetthe challenge of keeping Armyaircraft flying.

Transportation chool oursesThe following courses are offered by the aviationof the Army Transportation School at Fort Eustis:MOS COURSE4823 Aircraft Maintenance Officers671.2 Airplane Repairman672.2 Observation Helicopter Repairman673.2 Single Rotor Helicopter R.epairman

674.2 Tandem Rotor Helicopter Repairman680 Aircraft Components R.epairman Helper681.1 Aircraft Engine Repairman682.1 Aircraft Carburetor Repairman683.1 Aircraft Powertrain Repairman684.1 Aircraft Rotor and Propeller Repairman685.1 Aircraft Electrical System Repairman686.1 Airframe Repairman687.1 Aircraft Hydraulic System Repairman688.1 Aircraft Instrument Repairman

departmentDURATION15 weeks11 weeks12 weeks13 weeks

13 weeks8 weeks8 weeks8 weeks16 weeks12 weeks16 weeks10 weeks9 weeks16 weeks


21/44

Metho j.o.lz M ~ U 1Pilot Error ircraft ccidents

Dr Arthur C Poe Jr

CURRENT ROUTINE INVESTIGA-TION of in-flight aircraft accidents reveals that three factorsca use the great majority ofthem. In-flight accidents occurbetween the start of the takeoffand the end of the landing. Thethree factors are pilot error, mechanical or structural failureand maintenance error. Pilot error and mechanical or structuralf a i u r e are self explana ory.

Maintenance error refers to themistakes made by mechanicswhile servicing or repairing aircraft. t is possible for pilot errors to occur subsequently tomechanical failures or maintenance errors.Pilot error is the cause attributed to most in-flight air-Dr. A r thur C Poe , J r., is Education Advisor in the Office of the Dir ec tor of Instruction, the U. S ArmyAviation Schoo l For t Rucker , Ala-bama. He cam e to Army aviation withprior experience as Aviation Tr ainingAnalyst on the S taff, Chief of NavalA ir Tr aining. V iews expressed in thisar ticle ar e the author s and are notnecessarily those of the Depar tmen t0/ the A rmy or of the U. S A rmyA viation School.- The Editor

craft accidents. Weather conditions are routinely checked whenan accident occurs but involvement in inclement weather, except in rare instances contributes to a finding of pilot error. It is commonly believed thatan alert pilot would avoid suchconditions.The purpose of aircraft accident investigation is to preventthe recurrence of similar accidents. This must be accomplished by determining the basiccauses of accidents and establishing effective safety procedures through knowledge ofsuch causes. Establishing safetyprocedures upon anything lessthan basic causes is similar tothe procedure of a physicianwho treats the symptoms of adisease. He affords some temporary relief to his patient, but hedoesn t cure the malady.Continued treatment of asymptom may prevent the recurrence of the one particularsymptom but the disease willmanifest itself in other ways.Similarly the pilot involved in apilot error accident may be cor-


22/44

2 U. S. ARMY AVIATION DIGEST Mayrected on the particular mistakehe made but the same mistakeswill keep recurring in other pilots or in the same pilot in adifferent form until the cause iscured or removed.Techniques for the determina-tion of basic causes of in-flightaccidents involving mechanicalor structural failure and main-tenance error have been estab-lished. These are based upon engineering analyses to the extenttha wrecked aircraft are takenapart piece by piece. Each pieceis checked examined and testedby experts to determine thecause of mechanical or structur-al failure or maintenance error.When the cause is determinedeffective steps are taken by revising the details of construction the maintenance procedures or the operating limita-tions of the aircraft to preventsimilar recurrences.

The determination of the basic causes of pilot error aircraftaccidents has not been as successful as the investigation ofmechanical failures or mainte-nance errors. The probable rea-son for this comparative failureis that the investigative tech-niques of psychology the scienceinvolved in pilot error analysesdiffer from engineering analysesbased upon the physical sciences.

T SK DIFFICULTThe real problem seems to bethe difficulty of classifying piloterror accident data into a f wcategories wh n th specific cir-cumstances for each accidentdiffer s radically t is prac-tically impossible to conduct significant analyses to determinebasic causes when there are onlyone or two similar accidents in

each of a great many differentcategories.In current pilot error accidentinvestigations it is determinedwhether pilots misused powercontrols brakes, equipment orflight controls; if they exceededstress limits were inattentive tofuel supply didn't lower landing gear, selected unsuitablelanding areas, or misjudged dis

tances; whether they failed tocompensate for wind to noticeother objects to maintain air-speed or rotor revolutions to useequipment or to perform an adequate pre-flight inspection; or ifthey continued visual flight rulesinto instrument conditions operated the aircraft recklessly orlost control. t is suggested thatthese are mistakes which causein-flight emergencies.

t might be desirable to distinguish between the occurrence of in-flight emergenciesand in-flight accidents. Suchemergencies may develop intoaccidents or they may not. t depends upon what the pilot does.Use of this distinction may beof assistance in the preventionof accidents.Analyses of the mistakesmade by pilots would go far toeliminate emergencies and re-duce the number of resultant accidents if effective preventativemeasures could be devised.Though there has been little suc

cess in this endeavor every effort should be made to accomplish it. However it should benoted that the expression toerr is human is as true today asit was in Shakespeare's time. Sosome emergencies caused by pri-or pilot mistakes, by mechanicalor structural failure or by maintenance error will continue to


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957 PILOT ERROR AIRCRAFT ACCIDENTS 2occur despite the possibility offuture establishment of even them 0 s t effective preventativemeasures. This suggests the necessity of additional accidentprevention measures.Perhaps something could bedone to prevent accidents by assisting the pilot who is confronted by an emergency. If emergencies could be held to emergenciesand not develop into accidents,the present accident situationwould be alleviated and procedures could be developed thatwould be always useful. There-fore, it seems desirable to examine that area between the occurrence of an emergency and thesubsequent accident to deter-mine if there is any way to assist a pilot in such a situation.This would be a humane enieavor.

N W C TEGORIES NEEDEDIn order to do this it is necessary to develop new categoriesfor pilot error analyses. The useof such categories is not intended to change current accident investigative procedures. As pointed out above they should be carried on. The new categories willmerely permit scientific analysesof the period between the occurrence of an emergency and anaccident.They will point out that piloterror can occur after an emer

gency develops as well as causethe emergency. Such analysesmay permit the establishment ofnew safety procedures. Suchprocedures could reduce thenumber of accidents by properhandling of the aircraft subsequent to the emergency. t isessential to investigate this areabecause accidents are so numer-

ous and because present procedures have not prevented theirrecurrence.The purpose of this article isto develop such categories foranalyses of the period betweenthe occurrence of the emergencyand a subsequent accident. Theone common denominator inevery such accident is the human pilot.All other circumstances, theweather other environmentalconditions, the type of aircraftinvolved, its equipment, the ma-neuvers being performed, etc.,may vary considerably. But,w h t eve r different circumstances exist in each specific accident, involvement of the pilotis the one constant. t is proposed that pilot involvementshould be the basis for establishing these categories.Whenever a pilot encountersan in-flight emergency, the possibility of an aircraft accidentexists. Whether the emergencydevelops into an accident or notdepends upon what the pilotdoes. t therefore seems logicalto base the categories for analyzing such aircraft accidents onthe tasks that confront the pilotwhen an emergency occurs.These tasks will be the same forall emergencies and comparatively few in number. See Fig-ure 1)The next step in accident classification is to define the taskswhich confront a pilot when anin-flight emergency occurs. Thesequential nature of these tasksis indicated in the diagram. Thedefinitions are accompanied bytitles which describe the task.

PERCEPTU L T SKFirst of all, the pilot is con-


24/44

22 U S ARMY AVIATION DIGEST MayTHE FOUR SEQUENTI L TASKS WHICH CONFRONT

A PILOT WHEN N EMERGENCY OCCURS

n Emergency Occurs

~

l The Perceptual Task Task.....

An AccidentBecome ware That an Emergency Exists Failure .. Occurs

Task Successt2. Th e Problem Solving Task Task An AccidentDetermine Proximate Cause of Emergency Failure / Occurs

Task Success

3. The ecision aking Task Task An ccidentDecide on Correct Procedures Failure . . Occurs

Task Successl4. Th e Performance Task Task An AccidentDoing the Procedures Failure Occurs

Task SuccessJNo Accident Occurs

Figure 1


25/44

957 PILOT ERROR AIRCRAFT ACCIDENTS 23fronted by a perceptual task Hemust notice, as soon as possible,the cue or cues which indicatetha an emergency exists. Theperception of such cues may occur through anyone or anycombination of the five senses.few examples of perceptualcues are: aircraft attitude, itsmaneuverability, the feel of thecontrols, the smell of burningmaterial, changes in engine power, or changes in instrumentreadings. Many others exist.

t is possible for a pilot notto notice these cues because theyare beyond his physical abilityto perceive, perhaps such as instruments failing, or because heis not aware of their importancefor indicating that an emergen-cy exists. The classic example ofthe latter is the pilot, after awheels up landing, complainingthat he couldn t hear the towertelling him to lower his landinggear because the horn was soloud. A pilot is not aware thatan emergency exists until henotices such cues. The sooner henotes them the better are hischances of recovery.

PROBLEM SOLVING T SKThe second task that confronts a pilot is a problem solv-ing task t is possible, even ifa pilot is aware that an emer-gency exists, that he can t determine the cause of the emergency from the cues that he per-ceives. He must, at the veryleast, ascertain the proximatecause of the emergency. This isnecessary because the decisionhe has to make in the next taskwill vary according to this cause.The term, proximate cause, isused in the legal sense. Theproximate cause may have oc-

curred by itself or it might bethe culmination of precedingevents. However, it is the nearestor latest phenomenon that causesthe emergency. The pilot mayhave time to determine earlierevents that led to the proximate cause. f so, the decision inthe next task would be differentthan if no time were available.In the latter case, it could bepilot error to spend too muchtime trying to determine earlierevents in the chain of circumstances. There is nothing myste-rious about this job.Certain symptoms (cues) exist; the pilot must determinetheir proximate cause. If he doesthis correctly he has providedthe basis of the next task. fnot, he must make his decisionfrom a faulty basis. t is believed that training in the earlyperception of cues and in inter-preting them will prevent manyemergencies from becoming accidents.

DECISION M KING T SKThe third task confronting

the pilot when he has determin-ed the cause of the emergency isa decision m king task He has todecide what corrective action hemust take to prevent the emergency from becoming an accident. If he decides to performthe proper procedure, good; ifnot, an accident will occur. Heretoo, training and experience withmaking decisions on proper procedures will help prevent accidents.PERFORM NCE T SK

The fourth task, after deciding upon the correct procedures,is the performance task The pilot must be able to accomplish


26/44

24 U. S. ARMY AVIATION DIGEST Maythe procedures that he has decided are necessary. If he is notable to perform them successfully, the accident will happen.

These four tasks may be usedfor categories to classify thatpilot error which occurs after anemergency, but they will notcover instances where pilot errorexisted prior to the occurrenceof an emergency or caused theemergency. Therefore, additionalcategories are necessary.A fifth category for the classification of accidents would involve the existence of pilot errorprior to the occurrence of anemergency. This error could consist of any mistake made by thepilot from planning the flight tothe time the emergency occurs.t could have caused the emer-gency or contributed to the likelihood that the emergency wouldbecome an accident. The 17 possible mistakes made by pilots thatare mentioned in the eighth para-graph and are currently investigated would fall into this cate-gory. This category would benamed prior rror and every ef

fort to determine basic causesof such mistakes should be continued.It is believed that these fivecategories would include all piloterror accidents that could beclassified. However, it may benecessary to establish s u bclasses in some of them as dictated by experience. A sixth category would be necessary for accidents that could be definitelyattributed to pilot error. Thiswould be an uncl ssified category to include those accidents inwhich data from survivors, spectators, or equipment inspectionwould not be sufficient for properclassification.

t should be noted from thesecategories that there could be amultiplicity of pilot errors contributing to an accident. It isalso important to understandthat a pilot error prior to or onecausing an emergency can berectified if the emergency tasksare performed correctly. Thehope for immediate accident reduction lies in the proper performance of the emergencytasks.It is not proposed that correctperformance of the four taskswill prevent every emergencyfrom becoming an accident.There will be cases of structuralfailure, impossible landing ter-rain, poor visibility, or otherconditions that will make acrack-up inevitable when anemergency occurs. However, inthese instances correct perform-ance of the tasks should improvethe chances that the pilot wouldescape injury. In such cases correct performance could be the useof the parachute or perhapslanding the aircraft in that par-ticular attitude which wouldgive the best chance of ~ r v i v a lThe need for knowledge onperformance of the four sequential tasks may be questioned bysome pilots. One has questionedthe need for practicing emergency procedures in training. Hemaintains, The best emergencytraining is to have an actualemergency. This could be true,but the pilot should have substi-tuted the verb to survive forto have . Implementation ofsuch a practice could be fairlyexpensive in loss of life andequipment. This reasoning, carried to extremes, would indicatethat flight training is not necessary.


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957 PILOT ERROR AIRCRAFT ACCIDENTS 25The best pilots would be thosewho without instruction couldsurvive learning to fly. Complexas these four tasks may seem toa pilot confronted by an emergency each must be performedsuccessfully or an accident willhappen. Even though it is possible to luck through by chanceprior training on how to do thejob should assist achieving successful performance.

PSYCHOLOGIC L EFFE TThe psychological effect of anemergency upon a pilot is alsoimportant to consider when discussing the tasks he has to perform. Flying an aircraft hasbeen jocularly described ashours and hours of sheer monotony interrupted only by moments of stark terror. Accidentprevention data may be derivedfrom the expression if its humorous aspects are disregarded.First of all emergencies are thecauses of these moments ofstark terror. Second terrordescribes a mental conditionthat is not conducive to logicalreasoning at the moment it ismost needed. The terror, withaccompanying stress and amdety produces mental rigidityjust when flexibility is most necessary.This rigidity must be considered in relationship to the foursequential tasks confronting apilot in an emergency. The performance of the tasks undersuch unfavorable conditions indicates that if the tasks are tobe successfully completed theymust be done automatically.There is little time for creativereasoning processes in emergencies. Automatic performance inthese situations is the result oftraining and practice. t is be-

lieved flight emergency trainingbased upon performance of thesequential tasks would be moreeffective than current emergency training.However since instruction inall aspects of flying is desirable limited training time makesit mandatory to select only themost important procedures andmaneuvers for the training program. Therefore it would befirst necessary for accident analyses to indicate which taskswere most failed. Then specificprocedures could be establishedfor training on the correct performance of such tasks.t is probable that current investigative personnel or boardscould not initiate the programof classifying pilot error acci

dents into one or more of thesix named categories. It is suggested that a psychologist whois familiar with aviation safetyproblems obtain the classification data during nondirectiveinterviews with the pilot othersurvivors and /or spectators.In a nondirective interview theinterviewer puts the person atease and encourages him to talkabout the incident with appropriate guidance until a set ofpre-determined questions havebeen answered. When the psychologist has established techniques and procedures for obtaining such data he could teachthem to selected investigativepersonnel. Then implementationof this classification program inthe routine investigation of pilot error accidents using information from the interview andother investigational sourcesshould permit meaningful analyses that could result in the establishment of effective accidentprevention procedures.


28/44

Let s ~Artillery AerialObservationColonel Charles W. Matheny Jr. rty

HE FIELD ARTILLERY must con-tinually improve its aerialobservation methods and techniques concerned with target acquisition and adjustment of fire.Present methods of aerial observation with organic artillery aircraft have been developed andproved in combat during twowars; however these methodsmust be modernized to functionon battlefields employing modernweapons. Observation aircraftwith improved capabilities -andperformances are required to adequately perform this mission.Although this discussion isconcerned primarily with aerialobservation the artillery obser-

Colonel Charles W. Matheny, Jr.is Assistant Director Department ofTactics and Combined Arms, Researchand Review Division The Artilleryand Guided Missile School Fort SillOkla. He became an Army Aviator in1952 and is qualified in all types ofrotary- and fixed-wing aircraft. Viewsexpressed in this article are theauthor s and are not necessarily thoseof the Department of the A rmy or theU. S. Army Aviation School. - TheEditor

vation system should be outlinedto provide a better understanding of why aerial observation isan integral part of this system.The field artillery observationsystem exclusive of the observation battalion consists of: forward observers who are primarily concerned with the close-inimmediate surroundings of thesupported infantry or armoredforward elements; battalion observation posts established ondominant terrain when suitablelocations can be found to provide observation of greaterdepth into enemy territory; andaerial OPs in Army aircraft toprovide observation to a distancebeyond the extreme depth of artillery fires.

FL XI L OBS RVATIONThis aerial observation possesses great flexibility augments ground observation exercises general surveillance overthe battlefield throughout theentire sector of responsibilityand is a primary means of locating targets and adj usting artil-


29/44

LET S MODERNIZE ARTILLERY AERIAL OBSERVATION 27

HIGH PERFORM NCERTILLERY OBSERV TION

HELICOPTER

ME NS OF OBSERV TIONRTILLERY ERI L OBSERVERERI L C MER

TELEVISION C MERELECTRONIC DEVICESINFR RED

, ; g : ~ ~ ~ ~ - ~ ~ ~ \~ - - ~ J " .MORT RS 8: RMOR ~ _ ~ . - : . . - : .


30/44

28 U. S. ARMY AVIATION DIGEST Maylery fire. The greater ranges ofnew weapons, both missile andgun types, and new concepts ofground operations place new requirements on artillery aerialobservation. To meet these newrequirements it is apparent thattwo general fields of aerial observation are developing: shortrange observation to a depth ofsome 20 miles into enemy terri-tory (light, medium, and heavyartillery and long range observation into enemy territory(long range missile artillery .Aircraft best adapted to the performance of each of these twotypes of observation must beutilized to provide effective andefficient aerial observation.What kind of observation air-craft will the artillery need tomeet these new requirements?A tomic warfare is characterizedby dispersed units, wider front-ages, longer range artilleryweapons, and atomic explosives.New, powerful, long range missiles may well make the operation of any type of airfield with-in their lethal range infeasible.These factors will no doubtcause changes in the tactical op-

eration and employment of ourobservation aircraft; point toward a decentralized system ofoperation; may make it necessary to do away with air stripsin the forward area which can bereadily located and destroyedalong with their concentrationof fixed-wing aircraft.DV NT GES OF VTOlThese factors also point to the

operational advantages to begained through the use of VTOLaircraft (vertical takeoff andlanding aircraft , high perform-ance helicopters, and convertiplanes. These vertical takeoffand landing aircraft have operational characteristics w h i c hmake them particularly adapta-ble to artillery observation.1. They can operate withoutairfields from the immediatearea of artillery units.2. Maximum dispersion andcamouflage can be effected.3. Close coordination can beeffected with facility betweenthe artillery pilot, artillery observer, artillery staff, and artil-lery commander.4. Local security, messing, andIl lustrations by nald R Smith based on concepts of Col Matheny

j;:

HIGH PERFORMANCEARTILLERY OBSERVATION HELICOPTER

f ~ ~ / L . " " " . ~ ; ; ; ; : : ~ ~ ~ ~ ~ t ~ ~ ~ ~ U I ~TWIN GAS ARMOR CANOPY. 360 OBSN INSTRUMENTS

~ ~ : ~ I ~ ~ E ~ ~ ~ ; : O ~ R TuRBINE RETRACTABLE VISIBILITY . PRESSURIZEDENGINES AND A IRCONOI T IONEOPOSSIBLY ELIMINATE LANDING GEAR COCKPITTAIL ROTOR.)

PERFORMANCE DATASPEED - - - - - - - - 0 - 200 KNOTS PAY LOAD - - - - - - - 600 POUNDSRATE OF CLlMB- - -10,000 FT / MIN OBSERVER - - - - - 200 POUNDSRANGE - - - - - - - - - - - - - 500 NM RADIO aeSNENDURANCE - - - - - - - - - 4 HOURS EQU IPMENT - - - - - 600 POUNDS

SELF SEALINGF UE L CO TAINERS


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1957 LET S MODERNIZE ARTILLERY AERIAL OBSERVATION 29administration of the aviationsection is facilitated.5. The performance of developnlental aircraft with verticaltakeoff and landing capabilitiesthat are now flying is equal toor greater than present fixedwing observation airplanes.

6 These types of aircraft canbe used in present standard artillery units, airphibious artillery units, and other types oforganiza ions.The general characteristics of

the two types of aircraft considered necessary for artillery observation are shown here.High Performance rtilleryObservation and ReconnaissanceHelicopter Two-place)This helicopter should be capable of performing short-rangeartillery observation light, medium, and heavy artillery), alsobattlefield surveillance and reconnaissance. t should have thefollowing operational capabilities: speed 0-200 knots, rate ofHIGH PERFORM NCEVERTIC L T KE OFF

ND L NDINGRTILLERY OBSERV TIONIRCR FT

ME NS OF OBSERV TIONRTILLERY ERI L OBSERVER

TELEVISION C MERELECTRONIC DEVICESINFR RED

L NDING FIELDS

/ \1\1

~ J J i J 6COMMUNIC TION

CENTERS

SITES

TOMICDELIVERY ME NS


32/44

30 U. S. ARMY AVIATION DIGESTTWO GAS TURB INEENGINES SWING VERT .FOR L IFT a HO R IZONTA L

HIGH PERFORMANCEVERTICAL TAKE OFF a LANDING

ARTILLERY OBSERVATION AIRCRAFTFOR FORWARD F LI GHT - - - - .

INSTRUMENT 4 - f R : : ; : ; ; ; ; ; ; ; ; ; ~ : : : - . ,OBSERVERISEAT ADJUSTABLELL DIRECTIONS)

PANEL : : : r i ~

LANDING GE AR

TRANSPARENTLIGHT ARMORCANOPY, 360 0VISIBILITY.PRESSuRI ZED ANDAI R CONO ITIONEDCOCKPIT PERFORMANCE DATA

SPEED 0600 KNOTS LOAD 1.000 POUNDSRATE OF CLIMB ZU.00030.ooo FT MIN PI LO T . . . . . . . . zoo POUNDSRANGE OO NM OBSERVER zoo POUNDSILNOURANCE 4 HOURS RADIO II OBSN

EQUIPMENT 500 POUNDS

climb 6,000-10,000 feet per minute, range 500 nautical miles, endurance four hours, and payloadcapacity approximately 800pounds observer, observationinstruments, radio, and otherequipment) .The only helicopters under development which might approach this requirement withmodification or redesign are theXH-39 Sikorsky) and XH-40Bell). The XH-39 has a maximum speed of 156 mph and holdsthe helicopter altitude record of24,500 feet. One of the Armyconvertiplanes such as the XV-lMcDonnell) or XV-3 Bell)presently under developmentmight possibly meet this requirement. The XV-l has flownat speeds of 200 mph.High Performance VTOL r-t l l e r y b servation A i tcr aft(Two-place)

This VTOL aircraft should becapable of performing longr n g e artillery observation(heavy gun and long-range missile artillery ), also battlefieldsurveillance and reconnaissance.This aircraft should have thefollowing operational capabilities : speed 0-600 knots, rate ofclimb 20,000-30,000 feet per minute, range 800 nautical miles, endurance four hours, payload capacity approximately 800 poundsobserver, observation instruments, radio, and other equipment).Artillery observation aircraftwith greatly improved performance and vertical takeoff andlanding capabilities are requiredto keep pace with the development of new weapons and newtactical concepts. Let s modernize field artillery aerial observation.


33/44

EROTITIS MEDIA and aerosinus-itis are Latin labels for thesevere earache or sinus pain cre-ated by a partial vacuum that

might happen to you. Here s thes toryThe barometric pressure ofthe outside air and that in themiddle ear cavity is normallyequal. o long as a path (Eustachian tube) is kept open be-tween them, nothing serious willhappen. You may climb into thesky and every 400 or 500 feetyour middle ear will spontane-ously expel a puff of air with asizzling sensation to allow your

Views expressed in this departmentare not necessarily those of the e-partment of the Army or of the U S.Army Aviation School. The Edttor

bellying ear drum to click backinto place. The Eustachian tubefunctions similar to a ball valvepromoting free passage of airrrom the middle ear cavity intothe upper area of the throat.During the descent the barometric pressure builds up on theouter surface of the ear drumwhich gradually changes from aconvex to a concave surface.This change will produce severepain in the ears if the pressureis not constantly equalized byforcing air back through theEustachian tube into the middleear cavity. This is accomplishedby the acts of swallowing yawn-ing yelling or by holding thenose closing the mouth andblowing.In the presence of a commoncold the tissue lining the nosesinuses and throat swells to va-rying thickness. The degree ofobstruction in the nose is a goodindex of the swelling in theother areas of the upper respiratory tract. Such swelling in thethroat produces obstruction ofthe opening of the Eustachiantube thus increasing the diffi-culty of getting air back into themiddle ear cavity to equalize thepressure, and break up the partial vacuum that has developed.

f during descent in an air-


34/44

32 U. S. ARMY AVIATION DIGEST Maycraft, an earache develops and itcan not be controlled by theabove measures of positive ac-tion, climb back to the altitudewhere the pain is relieved. Nowbegin your descent at 250 feetor less per minute, and constant-ly use the above maneuvers tokeep the barometric pressureequalized on each side of the eardrum. If this fails, land the air-craft and immediately go to theflight surgeon's office or theE,NT clinic for treatment whichonly these sections are equippedto administer.Prevention of injury to theear and the loss of time relatedto the problem can be easilyaccomplished by each individualpilot as follows:

1 Obtain an inhaler from yourflight surgeon and carry it inyour flying clothes so that itwill be available when needed.2. Chew gum while flying topromote swallowing.3. Do not avoid the flight sur-geon for fear of your flight pay.He is not gunning for you.

4 Before the let down isstarted, use the inhaler liberallyto shrink the nose to where itwhistles like a wind tunnel. Thisalso takes care of the areas of thesinuses and the throat and willnormally permit aeration of themiddle ear cavity by the swallow-ing secondary to chewing gum.The production of a partialvacuum in the middle ear cavitywas described above. In the samemanner a partial vacuum can de-velop in any of the accessory na-sal sinuses. When such a vacuumis developed in the sinuses ofthe forehead (frontal) or cheek

(maxillary), the individual mayhave a sensation similar to thatof being stabbed by a knife inthe area of the sinus involved.This can be extremely seriousand lead to a protracted illness.The answer to this problem isthe availability and use of aninhaler. Keep one in your flying


35/44

957 MEMO FROM FLIGHT SURGEON 33clothes and use it in flight asneeded. Do not use preparationscontaining antihistamines; useonly that obtained through theflight surgeon.

They say Oxygen is the pilot'sstaff of life. So the busy HumanEngineers have come up with a setof limiting altitudes for this aeronautical bread. Like to memorizethem?5,000 feet-Maximum for normalnight vision without supplementaloxygen.8,000 feet-Altitude at which supplemental oxygen should be used forroutine flights.10,000 feet-Maximum w t h 0 u troutine use of oxygen.

18,000 feet-Maximum for emergency without use of oxygen.23,000 feet-Altitude at which depressurization sickness may develop.25,000 feet (L-23D ceiling)-Approximate time of consciousness without oxygen is 116 seconds. This iscalled the LETHAL zone.

That extra weight you'rewearing this season may beenough to give you the bends oreven kill you at the higher altitudes you can fly in the L-23D.Here's how:

At sea level you'll store upnitrogen in your tissues. As youfly high into the area of decreased barometric pressure,this nitrogen expands, entersthe blood stream from the bodytissues and gradually escapesthrough the lungs. All is well solong as it leaves at a regularrate.The trouble is, fatty tissuesstore up a lot more nitrogen thanany other tissue-five or sixtimes as much as an equalamount of blood. And worse, itis least supplied with a bloodsystem for drainage. At altitudethe nitrogen expands into bubbles of gas and tries to escape.If crowded out by excess gas orby too few ways to freedom, youmay pick up an attack of thebends (decompression sickness)a very ugly way to suffer.But worse, that extra fattytissue may kill you because theentering, bubbling nitrogen maydislodge a bit of fat from thewalls of the blood vessels andcarry it along to your heart orbrain.Excessive weight carries ahazard for everyone. We allknow it means declining vigor,appeal and resistance to disease.But for you, it may result in animmediate and complete declinein longevity.

Illustrations by nald R Smith

+ PROP RIET -


36/44

4 U. S. ARMY AVIATION DIGESTAnd then, there was the student

who flew his L-19 into the good brownearth a little while ago. Inexperienced? No doubt about it. But coupledwith a great big morning after.Quoting from the magazine, -proach

Restrain your convivial enthusiasm, gents, particularly for the'drinking' in Eat, Drink and beMerry For regardless of howmuch or little you drink, alcohol iseliminated from your system at therate of only one-third ounce an hour.

So it takes 12 hours to get rid ofall the alcohol from half-a-dozen goodhighballs. Five 12-ounce bottles ofbeer have even more alcohol.

Do you have an AviatorStomach? As an Army Aviatoryou are so carefully selected thatyou seldom develop a cripplingemotional illness, no matterwhat.As a young pilot you're adventurious, even reckless, withlittle thought for danger. But asyou grow older you naturallygrow more conservative, moreinterested in security. Add to

this, the rubbing wear of theones that nearly happened. Orthe big ones that did happen toothers. That harrowing low levelphoto mission you pulled twiceweekly in Korea. Or the airlineryou read about in the news-theone that got it in Colorado orNew York or California.Is it any wonder, then, withmild but constant tension tugging you one way, and pride andthe monthly bills tugging theother-is it any wonder you develop that gnawing pain in theupper belly.Do you have one? Well cheerup, it probably won't get worsebecause you were originally selected for high immunity to abad breakdown. t may get better-perhaps by itself-from aduty change or a switch to lessflight time.Regardless of what is in thecards for you, see your flightsurgeon. Take a little groundtime; rest; get some exercise,erase your Aviator's Stomach,and become a more compatibletype at home and on the flightline.

New Jep anual Covers uropeO JUNE FIRST, Army Aviators on the continent will receive thenew European edition of the Jeppesen Airway Manual. Printedin the offices of Jeppesen and Company, GmbH, in Frankfurt, Germany, the manual will mark the beginning of a world-wide expansion.The new edition, designated TM 11-2557-4, will offer Europeanflight information in the same form as that now used in theUnited States.A one-volume edition. the manual will cover the new area withten Avigation Charts. Following the establishment of the new plant,the company plans to further extend its service into the WesternPacific and South America.


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OPERATING FROM AN AIRFIELDin a tropical zone an ArmyAviator loaded two passengersand their luggage into his H-13Gfor a routine survey mission. Athorough pre-flight was completed and a hovering check wasmade. The helicopter required28.5 inches of manifold pressureto hover. The pilot recalled thatthis was the same helicopter inwhich he had performed a testflight eight days previously andthat it required 28.5 inches toclimb at 45 mph airspeed withonly one passenger.He chose to make a maximum

performance takeoff from hisparked position on the airfieldinto a five-knot wind. The onlyobstacle in the takeoff path wastelephone wires 100 yards away.He over-revved the engine andmade what he considered a sat-isfactory execution of the maneuver. As the helicopter approached the wires the airspeeddropped off and the rate of climbdecreased. Rotor rpm was alsodecreasing and a landing becameimperative. But the close proximity of the wires would necessitate a vertical descent. His decision under the circumstancesColonel Jack L. Marinelli the Senior Army Aviator above is

presently assigned as the Chief Special Projects Branch DCSLOGDA and is charged with the logistics monitorship of Army Avia-tion Guided Missiles and Atomic Weapons. Upon entering theArmy in 1940 he attended the Cavalry School both horse (J.nd mechanized. After graduation he was assigned to the 113th Cavalryand later joined the 4th Division as Aide-de-Camp to the Commanding General. After completion of the Field Artillery Pilots CourseNo. 12 he went to Europe as the Aviation Officer of the 71st .FieldArtillery Battalion. II Corps and 5th Army. He was one of thefirst Arm l Liaison Pilots to be awarded the DFC.


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36 U. S. ARMY AVIATION DIGEST May

was to attempt to fly over thewires. As the tail rotor clearedthe wires the rpm dropped from3000 to 2700 and the airspeeddissipated to zero. The area below was a swamp with surfacewater standing 12 to 18 inchesdeep. The helicopter toucheddown in a level attitude thenrocked forward causing the mainrotor blades to strike the waterand shatter and the aircraftturned over on its right side.There were no serious injuries.t is fairly common knowledge

among Army Aviators that thepilots engaged in the topographical surveys have been pushingtheir helicopters beyond the limits recommended by the manufacturers the technical ordersand the Army Aviation School.This practice has been necessaryin some mountainous terrain inorder to accomplish the missionat all. In other cases-such asthis one - the overload in thehelicopter cuts down flying timeby fifty per cent. The troubleseems to be that the practiceUpon Colonel Marinelli s return to the U S., he became the firstDirector of Arm?) Aircraft Tests at AGF Board No.1 now knownas The Army Aviation Board. During the ensuing period he attended the Advanced Artillery Officers Course, and became the Avia-tion Officer for the Office, Chief of Army Field Forces, DA; Headquarters, Far East Command; and Headquarters, Army ForcesFar East.Colonel Marinelli has held an instrurnent rating since 1951 andis currently rated in all Army rotary-and fixed-wing aircraft. Inhis 15 years with Army Aviation, he has accumulated over 3,600hours of flight time.


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1957 THE GRAY HAIR DEPARTMENT 37develops a certain amount ofcarelessness or over-confidencein the machine. This is the onlylogical way to explain this aviator's actions in flying as no inexperienced pilot would dare.

OUT OF G S Y INDECISIONA 3-2 'aviator in an L-23 wascleared for a VFR direct flightwhich he listed on Form 175 as400 miles (it measures 346), as

3 hours enroute at 150 knots (itcomputes for 400 at 02 40 andfor 346 at 02 24). From thisstart, there continues to be acurious aura of uncertaintyabout the flight right up until itended three miles from thethreshold lights of the destination runway.Takeoff time was 1412 on aFebruary day. Before reachinga fix 45 miles from the destination, the flight plan was changedin flight to another destination96 miles from the fix. After thechange, the total flight distancewould be 394 nautical.Shortly af.ter this, I ran theauxiliary tanks dry, writes theaviator. This would compute tobe a little over 2 hours fromtakeoff, and suggests that normal fuel m'anagement procedures were being followed. Ifthe auxiliaries ran dry in 0115, as opposed to the normal01 30 to 01 45 {dependingupon the individual airplane andpower settings) the length oftime, it could be expected to continue would be between 75% and90% of normal, or between approximately 03 45 and 0430, using the DD Form 175 figure of 5 hours of fuel instead ofthe more usual 05 30.The aviator, noting the abnormal fuel consumption, decided

to return to the fix. Subsequenttimes are from the CAA Incident Report. Starting at 1702various requests were made forweather within the area of thedestination. At 1825 (time inthe air 04 13) the aviator declared an emergency and requested approach to the airfieldnear the fix. Before receiving theemergency clearance, he changed his mind and requested clearance to his original destination.At 1845 (04 33 after takeoff)the aviator asked for approachclearance at the destination, andrequested as little delay as possible because his gasoline gaugesindicated empty. He receivedimmediate appro'ach clearance.At 1857 (04 45) he reportedhe was contact and inbound onone engine. At 1900 (04 48)the airplane lights disappearedand it was later learned that theaviator had made a successfulnight forced landjng, wheels-up,without injury to any of the occupants.The facts indicate then-thata 2 to 3 hour flight was stretched to 4 hours and 48 minutes, andit ran out of gasoline less thantwo minutes from destination.

TEST fliGHTTechnjcally, the carrying of

This marks the final Gray Hair De-partment to be compiled by CaptainRichard W. Kohlbrand Inf. Associated with the U. S. ARMY AVIATION DIGEST since its beginningearly in 1955, Captain Kohlbrand hasserved as assistant editor in chiefcontinuously except during the summer of 1956 when he was the editor-in chief. A Senior Army Aviatorqualified in both rotary- and fixed-wing aircraft Captain Kohlbrand hasbeen assigned to duty in France.The Editor


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38 U. S. ARMY AVIATION DIGEST

No azard Involved to Passengers on This Test Flight

passengers on a test flight constituted a vioJation of TB AVN-1 However, no hazard to per-sonnel aboard was involved inth execution of this type test.The above statement, extract-ed from the accident report, whenassoci8lted with the accompany-

The Gray Hair Department is pre-pared by the U S ARMY A VIA-TION DIGEST staff with informationobtained from the files of the U S.Army Aviation Safety Board Viewsexpressed in this department are notnecessarily those of the U S ArmyAviation School or of the Departmentof the Army. The Editor.

ing photographs provides theGray Hair Department with anexcellent opportunity to mentionagain our habit of attempting tominimize or justify factors inaccidents by smoothing over thefacts.How it happened: A T AAMcompany test pilot loaded thecrew-chief, five passengers andtheir luggage aboard an H-19prior to taking off on a mainte-nance test flight. The flight wasto test the tail rotor control system which had been repaired.If the test proved satisfactory,


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the aviator intended to ly thehelicopter and passengers to thehome unit. n takeoff the helicopter grossed 7,350 pounds witha payload of 1,330 pounds in thecompartment.

He performed the hoveringtest, checking right and leftpedal action and found the hovering test satisfactory. He thenexecuted a normal climb to ap-proximately 500 feet, made a 180degree turn to the right andheaded back toward the airfield.Permission was granted by thetower operator for a low, downwind pass over the heliport. Theaviator established a long shallow descent and passed over theheliport 'at about 100 feet thenclimbed quickly to approximate-ly 450 feet. At zero airspeed, hemade a pedal turn to the right,but he ran out of left pedal andcould not stop the turn. The helicopter spun around 480 degrees,entered a spiral then momentarily held its course. The aviatorflared the aircraft and it crash-ed. Moments later it burst intoflames; pilot and passengers escaped without serious injury.If his purpose was to check leftpedal travel, the test was per-formed at too Iowan altitude.Accepted practice is for a minimum altitude for an H-19 of1500 feet . and many test pilotsprefer 2000. If the purpose wasto frighten the passengers,doubtlessly, the aviator succeeded.

SAFETY FIRSTAn aviator focused his atten-tion on the left wheel of the L-19as he taxied it slowly toward a

Unsafe afety top

gas trailer in the refueling area.He was watching and waitingfor the 'accustomed bump of thetires against a log, used to stopaircraft a safe but convenientdistance from the trailer. Beforethe wheels contacted the log, thepropeller struck the trailerhitch.E'arlier in the day, the gastrailer had been towed to thePOL dump for refilling andwhen returned had been spottedcloser to the safety log thannormally. Servicing personnelfailed to notice the reduced distance, and the pilot relied solelyon the log to stop the aircraft.The log was not anchored tothe ground and there were nospotting marks or tire stops provided for the proper placementof the trailer. In view of thesefacts, both supervisory and pilot error contributed to this accident. The accident, however,resulted in action by the aviation section to provide spottingmarks for the gas trailer, anda s,afety stop log secured to theground.


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Continued f rom page 2DetachmentA-9 Unit of 24th Infantry Division3rd Light Aviation Section of 1stCorps2nd Engineer Group Air Section13th Transportation Company5. There were many individuals who

gave aid and assistance on the nightof the accident and during the recovery and salvage operations whichextended over several days. Many ofthese persons should be singled outfor special praise. However, we haveno information as to the names ofmost of these people. I regret thateach of them cannot receive the honorand recognition due him.

6 . Personnel of the 121st ArmyHospital did their utmost to relievethe suffering of the accident survivors many of whom had sustainedcuts and burns We also desire toexpress our special thanks to all yourpersonnel who assisted in the recoveryof No.3 engine from the accident site.This was almost a superhuman taskbecause of the icy water and tideconditions. Only by examination ofthis engine will the cause of the accident be determined.

7 There are seven individuals Iwould like to commend for theirprompt and valuable aid in the re covery efforts following the accident.They are:

Colonel John W. Maxwell TheQuartermaster, AFFE / Sth ArmyColonel K. W. Dalton, U. S. ArmyOperating GroupColonel Thatter P. Leber, 2nd Engineer Construction Group

Major Kilcauley TransportationCorps U. S. Army Port, InchonCaptain John P. Denham, 5th Quar-

termaster Detachment, PetroleumLaboratory

Captain William J. Roof MOthQuartermaster CompanyCWO Mielnik Harbor Master,Inchon Port.

S I t is requested that a copy ofthis favorable communication be filedin appropriate records of each individual concerned.

R L. WALDRONMajor General,United States Air ForceCommander.

HEADQUARTERS, FAR EASTAIR FORCES, 9 MAR 57TO: Commanding General, UnitedStates Army Forces, Far East

and Sth United States ArmyForward), APO 301:

1. The foregoing letter by GeneralWaldron has my wholehearted endorsement. t is a most deservingtribute to the Army personnel, eachof whom so willingly and courageously risked his life to assist in the rescue of his fellow serviceman.2. The indomitable courage demonstrated by the personnel who tookpart in this operation is surely acredit to the United States Army.Their efforts will undoubtedly be asource of pride to the organizationsrepresented.

LAURENCE S. KUTERGeneral United StatesAir ForceCommander.

Letters of constructive criticism arewelcomed by the U. S. ARMY AVIA-TION DIGEST. To appear in thiscolumn they must be signed. - TheEditor


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Army Aviation Digest - May 1957

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Transcript of Army Aviation Digest - May 1957