Army Aviation Digest - Aug 1955

8/12/2019 Army Aviation Digest - Aug 1955

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D I G . S I

ARMY AVIATION SCHOOL

CAMP RUCKER ALABAMA

AUGUST 955 VOLUME NUMBER 7


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V OLUME 1

ARMY AVIATIONIGEST

A UGUS T 1955

CONTENTS

N U M B E R 7

THE COMMANDANT S COLUMN ___ __________ ____ ____ ____ _ 3Brigadier General Carl I. Hutton USA

HURRICANES ____________________________________________ - _ 5

Major Joseph H. Hall USAF

RADIO HINTS FOR INSTRUMENT PILOTS _______________ 13N G Howell

A FIX FOR DOWNTIME___________________________________ 17

Raymond L. Chaney

FOOTNOTES FOR WRITERS_______________________________ 23

W. T. Burkett

BOOKS FOR THE ARMY AVIATOR ________________________ 30

GRAY HAIR _ _ _____________________________________________ 33

COVER: T h e H-34 A r m y t roop t r a n s p o r t i s a n en la rged versiono f t h e H-19 f ea tu r ing all m e t a l 4 b laded r o t o r systeIl ls fo ldi ng t a i l pylon a Wr i g h t 1820-84 eng ine wide t r e a d t r icycle

l and ing gear a n d is in t h e 100 Illile per h o u r class.

T h i s copy is n o t for sale. t is i n t ended for I l lore t h a n o n e reader.

PLEASE READ IT AND PASS IT ALONG


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EIJJTOR IN CHJEF

Cap ta in WeYlllan S. CarverASSISTANT EDITOR IN CHIEF

Capta in Richa rd W. Kohlbrand

EIHTOR

L e G e n e Lot t

The printing of this publication has been approvedby the Director of the Bureau of the Budget

3 August 1954.

The A R M Y A VIATION DIGEST is ari officialpublication of the Department of the Army publishedmonthly under the supervision of the Com m andanlArmy Aviation School. The mission of the A R M YA VIA TION DIGEST is to provide i n f o r n ~ a t i o nof anoperational or functional nature concerning safely andaircraft accident prevention training maintenance

_ operations research and developnwnt aviation m e d i c i n e ~and other related data.

Manuscripts photographs and other illustrationspertaining to the ahove subjects of interest to personnelconcerned with Army aviation are invited. Direct communication is u:uthorized to: Edilor-in-Chief AR.MYA VIATION DIGEST Army Aviation School CampRucker Alabama.

Unless otherwise indicated material in the A RMIT

A VIATION DIGEST m ay be reprinted provided creditis given to the A R M Y A VIATION DIGEST and tothe author.


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TH COMMANDANT S COLUMN

BrigadiC r Gf Ileral Carl l . I-Iutton, US

The v iews erpressed in this ariicle are the author s and are notTll cessariiy II/osp of thl Departmmt of fhe A r m y The Editor

Imbalance be tween Firepower and Mobil i ty

This column suggests a method of looking at recentmilitary history in terms of balance between firepower andmobility. I t is necessarily generalized and, therefore, maybe of linlited validity. Nevertheless, the method suggestsa line of experilnental approach for the imlnediate future.

Prior to the invention of repeat ing rifles, machine guns,and rapid fire artillery, Inobility and firepower were substantially in balance. Basic military tactics changed slowlyand the tactical lessons of military history had continuingapplicability. During World War I firepower surged aheadof mobility. This imbalance resulted in the static fronts of

that war. The soldier still nloved across country at the samerate he had been Inoving for centuries, but firepower (including the concolnitant industrial mobilization) laid downa beaten zone through which he could not advance. He wasforced to dig elaborate trench systems to live on the battle-field at all.

In World War I I the balance between firepower andmobility was restored momentarily, from the historical view.Tanks trucks and dive bombers increased mohility whilefirepower remained constant and, as a result, there weregreat movements of armies back and forth across Europe.Rapid and far reaching operations were again possible.

Then at the end of World War II the explosion of theatolnic bomb gave the signal that a new surge had carried


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4 ARMY AVIATION DIGEST

firepower enormously ahead of mobility. There is the pros-pect that warfare under present conditions would revert tosomething resembling the static trench warfare of WorldWar I. The possibility of movement would cease underatomic attacks or the threat of such attacks. The soldierwould go to earth in deep, protective dugouts.

This suggests that the problem which faces the soldiernow is how to rebalance firepower and mobility. Man stillwalks at about 7;2 miles per hour across country, and track-laying vehicles have about the same speed which they hadin World War II The 60 miles per hour tank has not beena decisive factor because the places on the earth s surfacewhere such speed across country is possible are extremelyrare.

Really great increases in mobility do not appear possibleas long as the fighting vehicle has to move through mountain-ous terrain, swamps, jungles, rice paddies, and rivers. Onthe other hand, fighting vehicles which can move throughthe air are not impeded by accidents of terrain. The paceof the soldier across the earth may be increased a hundredfold, or two or three hundred fold, if he can move in the airabove all obstacles. Therefore, if this method of looking atrecent military history is valirl, we should begin immediateexperiments to determinf the extent that air fighting mobilitywill balance atomic firepower.

This is the fifth in a series of columry s written by BrigadierGeneral Carl I. Hutton Commandant of the Army AviationSchool for the A R M Y AVIATION DIGEST. The Editor


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HURRIC NES

Major Joseph H. Hall, L SA F

The 11iews r.rpressed in this ar ficle arc fhe al/fhor s and are not w e( ssarily thoseof the Oeparlmrnl of flil t rmy or d The 'rm. i11iafioTl School . -Tlw Editor

BeCaUSl\ of its great size and intensity, the tropicalcyclone, when fully developed, is the 1l10St destructive of allstonl]s. Willds of the tornado blow ,yith greater fury hut theyare confined to a narro,Y path, 1 000 feet in average ,vidth,whereas it is not unusual for the violent winds of the tropi-cal cyclone to cover thousands of square Illiles.

Mountainous 'waves accoulpany intense tropical stOrInsat sea; their destructive forces are revealed in the appallingrecord of ships sunk or east ashore. They cause high tidesthat inundate low coastal areas. Storm waves b ~ e kon theshore, in some situations like a wall of water or a series ofgreat waves. Cities and towns have been 'wiped out, neverto be rebuilt. Though borne of the tropics, some of thesestorms move long distances and occasionally devastatesections far r,emote from their place of origin. In sonle of theI110st severe tropical stornls, loss of hUInan life has beenestimated at nlore than fifty thousand and property damageat many millions of dollars.

The above description of a fully developed tropical cyeIone was borrowed from the book '''Hurricanes,'' published in1942 by Ivan Ray Tannerhill, Chief of the Marine Division,U. S. Weather Bureau. I t is, in the opinion of t i ~writer, avivid description of the destructive power of nature's mostdestructive weather phenomena.

Tropical eyclones have their genesis near, but not direct-ly over, the equator. They fornl over all tropical oceans except the South Atlantic, but not over the continents. In thewestern North Pacific Ocean, they are known as typhoons; inthe Bay of Bengal and the northern Indian Ocean, as cyclones; in the South Pacific, eastern North Pacific, southernIndian, and North Atlantic Oceans (including the Gulf ofMexico and Caribbean Sea), they are known as hurricanes.Hurricanes of Australia are sonletimes called willy-williesand the typhoons of the Philippines, baguios. All are ofthe same general character and as a class are known astropical cyclones.


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6 ARMY AVIATION DIGEST August

The ternl cyclone',' (nleaning coil of a snake) ,vas firstsuggested about the lniddle of the last century by Henry

Piddington, president of the Marine Courts a t Calcutta. Theword has come into universal use as a ternl to designate allclasses of storms with low atnl0spheric pressure at the center.

The tropical cyclone, in its genesis, differs from theex-tropical cyclone only in its geographical location. How-ever, as it develops it acquires a more circular nlotion, ahigher intensity of continuous windspeed, and a more intensedeepening of atnlospheric pressure. ' The average pressureof the tropical cyclone is above 28.00 inches of nlercury;h o w ~ e y e rin several individual stonns the pressure has heenrecorded below 28.00 inches and during the stonn that passedover West Palnl Beach, Florida, in Septenlber 1928, thebaronleter fell to a record lo w of 27/13 inches. This recordheld until 2 September 1935, when a hurricane of very smalldiameter but one of the lnost intense on record anywhere inthe world crossed the Florida Keys with its center on LowerMatecunlbe Key. The pressure recorded was 26.35 inches,

the world's lowest record of pressure at a land station. I t isreasonable to expect lower readings frolll ships than froinland stations, because tropical cyclones are usually nloreintense over water than over the land. F urthennore, nearly allships are equipped with baroineters, 'while they are fre-quently not available in the sparsely settled coastal regionswhere many tropical stornlS have 1110ved inland. Two suchlower readings were recorded on the Dutch steanlship,Sapoeroca, in the Pacific 460 Iniles east of Luzon (Philip-pines) on 18 August 1927 and the SS Al ethusa located1355' N .-13430 E. on 16 December 1900. The fornlerreading was 26.185 inches, the latter 26.16 inches.

,At the outer ,limits of the hurricane, the winds are light

iWajor Joseph H. Hall, Commander of Detachlneni 31,Third Weather Squadron, Ozark Army Air Field, CampRucker, A labama, graduated from Middle Georgia College in

1939. He is also a graduate of the VSAAF Aviation CadetSchool, the B 17 and B 29 instructor courses, the Air ForceForecaster s School, and the V SAF C 54 transition course.He is a senior pilot, instrument q u a l ~ f i e dwth ov r 3500 hOllrsflight t ime. The Editor


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955 HURRICANES

to moderate, and gusty. As the center approaches, they in-crease gradually, growing to squalls, then furious gales, and

finally, in the funy developed hurricane, the winds iIn-mediately surrounding the center blow with indescribablefury.

Words fail to present an adequate description of the furyof a great hurricane. A shipmaster, rho passed through thecenter of the hurricane which destroyed Santa Cruz Del Surin November 1932, wrote in his log a description of the rindshe experienced. His notations followed the Beaufort Scale,until he wrote that it was a full hurricane, force 12, thehighest number of the scale. Then finding no adjectives todescribe the violence of the winds which continued to in-crease, he wrote in his log, winds, infinite.

I t is very difficult to determine the velocity of hurri-canes' winds. On board ships at sea, w ~ i n dvelocities are esti-lnated by the effects of the winds upon the water. On land,measurements are lllade by instrunlents; however, there aretoo few instances where the center of the hurricane passed

directly over the instruments and in many such instances,the instrument was blown a\vay prior to the arrival of thecenter of the storm. There are, however, records which in-dicate that winds of the hurricane are sometilnes sustainedfor intervals of five minutes at an average rate of nlore than150 miles per hour. There is good reason to believe that thegusts of the hurricane represent air nlovenlents for briefintervals that may reach as high as 250 miles an hour in themost violent storms.

ye

In nearly all tropical cyclones the highest winds are thosewhich immediately encompass the calm center or eye of thestorm. The average diameter of the calm center is approxi-mately 14 llliles, though there are wide variations in individ-ual cases. There is sometimes a complete calm, though inmany instances there are light variable breezes. Over theocean, the seas are usually pyramidal, lllountainous, and ton-fused in the calm center. The clouds sometimes break a r a y ~sunlight succeeds the torrential rain by day and at night thestars appear. In contrast to the surrounding air there is agentle settling and drying of air inside the cahn area w ~ h i c h


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is usually acconlpanied by a sharp rise in telnperature.If a stOrIll is divided into four quadrants with the quad

rants labeled right front left front right rear and left rearas they would be o an observer looking forward along theline of progress froIlI the stonn center the stronger \vinds\voltld be in the right front quadrant since the wind speed issuperiulposed upon the forward nloveluent of the storm. The

~ e a k e s twinds will he in the left rear quadrant since the forward nlovement of the stonn is subtracted from the windspeed. Thus when a stOrIn of great force passes across a

coast line the area of greatest destruction will be to the rightof the center. This condition is reversed in the southernhemisphere.

Wind velocity in tropical storms of slnall diameter isprobably as high or higher than in the great stornlS of largediameter. Destruction is confined to a nluch smaller pathhowever and due to their size there is less chance for recordsto be obtained. In some of them the barometer at the centeris in the neighborhood of 27.50 inches and in rare instancesInuch lower -which compares favorably in that respect withthe greatest of hurricanes. Since the diameter of the smallstorm is much less the barometric gradient is much steeperand hence the wind velocities must be higher.

Tornadoes Wi t h i n t h e ur r i cane

There are few authentic records of tornadoes or violentlocal storms of tornadic nature occurring within a hurricane.The few reported in recent years were confined to the stateof Florida. When tornadoes do occur they are usually in thenorthern semi-circle of the storm.

Flying debris in hurricane winds has caused the death ofthousands of people. Thousands more have lost their livesin ships at sea. Yet Inore than three-fourths of all the lossof human lives in tropical cyclones have been due to inundations. The rise of the sea over low coastal areas not sub

ject to overflow by ordinary tides is sometinles sudden andoverwhelming and in some situations there is no escape.

T h e S t o r m Wave

The true stornl wave is not developed unless the slope of


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1955 HURRICANES 9

the ocean bed and the contour of the coast line is favorable.Like the gravitational tide, i t reaches its greatest height in

certain situations. If there is a bay to the right of the pointwhere the cyclone center moves inland, the waters are driveninto the bay. With a gentle sloping bed, the water is piledup by resistance and becomes a great wave or series of waveswhich lllove forward and to the left, the principle inundationusually taking place on the left bay shore. Great storm waveswhich have taken an enormous toll of hUHlan lives have, sofar as records are available, occurred in nearly every case ina situation of this kind.

Notable instances of inundation occurred at Indianola,Texas, on 16 September 1875 and again on 19 August 1886.A similar inundation occurred at Galveston, Texas, in 1900and Corpus Christi in 1919. The nlaximunl storms' wavesrecorded along the Gulf Coast have ranged from 10 to 16feet in height, while StOlilll waves on shores of the Bay ofBengal have been llleasured up to 4 feet and in the southernMarshall Islands on 3 June 1905 a storm wave at Millie was

reported to be 46 feet.Fortunately, along the Gulf and South Atlantic Coast ofthe United States, storm waves are not so readily developedas on the coast of India, probably due to less favorable contours of shore and ocean bed and because the tide from gravitational forces is of a smaller range so that its coincidencewith the hurricane tide does not result in such great rise.

Rainfal l in Tropical yclonesIn tropical cyclones, rainfall is nearly always heavy and

frequently i t is torrential, reaching on SOIne occasions to theproportions of what is commonly termed a cloudburst. A

~ l lof one inch of rain in a period of twenty-four consecutivehours is considered heavy in tenlperate latitudes. Yet, intropical cyclones there has been over 25 inches of rain recorded in a twenty-four hour period. This amount was re

corded on 13-14 September 1928 in the Luquillo Mountainsin Puerto Rico and at Adjuntas the fall was 29.60 inchesduring the passage of the sanle storm. Probably the world sheaviest rainfall in twenty-four consecutive hours was thatnleasured at Baquio in the Philippines in July 1911. The


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alnount was 46 inches. During the same storm an additional42 inches of rain fell at Baquio, totaling 88 inches in four days.

Falls exceeding 20 inches in twenty four consecutivehours have been recorded in hurricanes in the lTnited States.In 1916 a hurricane caused the greatest floods known in thesouthern -\ppalachians. At Altapass. N. C., the rainfallaccolnpanying the hurricane anlounted to 22.22 inches. Thegreatest twenty four hour rainfall of record in the UnitedStates resulted from a tropical storm in September 1921.I t nloved -westward across the southwestern Gulf of Mexicoand

passed inland over Mexico,after

which i tturned north-

ward and crossed the Rio Grande Valley into Texas. Afterpassing inland the stornl rapidly dissipated and by the timeit reached Texas could scarcely be identified as a cycloneexcept by the torrential rains which continued northwardinto Texas. Within twenty four consecutive hours, 23.11inches of rain fell at Taylor, Texas. Torrential rains accOlllpanying this disturbance caused the most destructiveflood in the history of San Antonio. Water rose so rapidly inthe streets that autonlobiles were deserted and the occupantssought safety in the high buildings. Five to nine feet of waterstood in the large hotels, theaters, and stores. Fifty onelives were lost and property danlage anlounted to 5,000,000.

Rainfall in a single day in tropical cyclones jn the instances cited equals or exceeds the average annual rainfall atParis, 21 inches; London, 25 inches; Chicago, 33 inches; andSan Francisco, 22 inches. These amounts also include rnelted

snow nleasurelnents. 'Distribution of Rain Intensity in the Hurricane Studiesshow that the maximulll rainfall iiI a moving hurricane is inthe right front quadrant and that there is relatively littlerainfall in the rear half of the stOrIn. On the other hand thereis a lllaximum of lightning and thunder after the center ofthe storm has passed. This has led to a belief among nativesof tropical clinlates that when a thunderstorm occurs thestorn} is dinlinishing.

Signs o t he pproaching Hurr icaneOne of the first signs of an approaching tropical cyclone

is the storm swell. The \vinds in the distant storm createwaves on the sea. Moving outward froll} the storm area, they


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1955 HURRICANES

traverse great distances and break upon shore 4 to 5nliles away. When the wind is light, the boolning sound ofthe surf at fairly regular intervals is ominous.

Winds create ,yaves which rnove with a speed a littleless than the speed of the wind which produces thenl. Wavesquickly outrun the tropical storm in which they are fornled.The West Indian hurricane nloves at an average rate of about12 n1iles an hour while the waves move at rates sOlnetiInesexceeding 3 Iniles an hour. As the wave lnoves ahead of thestornl it takes on the Slllooth characteristics of a swell and

arrives at the shore hours and son1etimes days ahead of thestonn.Intenuittent breaking of heavy s\vells on shore when the

wind is light is one of the signs of the hurricane. Ordinarywaves produce a 1110re or less continuous sound.

A s a precursory sign the tide is noteworthy. Ordinarily,a continuation of offshore winds will result in a tide belo,vthe nonnal and \vinds blowing for a considerable period to-ward the shore will cause a high tide. When a tropical stormapproaches the coast, the tide rises even \vhen winds areblo wing offshore.

In the tropics \vhere there is very little change in at-lllospheric pressure, except for the diurnal variation, a fallof 0.1 inch or 1110re of pressure, exclusive of the diurnalchange, is significant. In temperate regions, the barometeris of little value until the storn1 is close at hand.

Cirrus clouds extend outward to the limits of the stonn

and sonIetinIes beyond. Shortly after the appearance of thecirrus clouds, a veil appears, gradually increasing in density,so that the high clouds are distinctly seen through it. Solarand lunar halos are s o n ~ t i n I e sobserved after the appearanceof the veil.

There next appears on the horizon, at about the pointwhere the cirrus clouds diverge, an arc of dense clouds. \vhichis the body of the hurricane itself. Its color is w ~ h i t i s horgrayish at first. changing to dark gray, sometimes with acopperish hue. At this tinle low clouds appear in the di-rection from which the hurricane llloves, gradually extendingover the entire sky. They are broken clouds llloving swiftlyat ahnost right angles to the cirrus clouds, so that the ob-server, directly facing the hurricane, sees the clouds move


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fronl his left to his right. The outline of these low clouds,called fractostratus or scud, are indistinct through the haze.If they appear early the observer nlay not be able to see thebar of the hurricane.

If the hurricane is moving directly toward the observer,the bar of the hurricane will relllain at the same point on thehorizon, gradually rising. If the hurricane is llloving to hisleft or right, he will see the bar nlove slowly along the horizon.

Hurr icane Tracks

If all known tracks of West Indian hurricanes were as-sembled on a chart it would exhibit an intricate and densepattern covering practically every part of the Gulf of Mexicoand Caribbean Sea and Inuch of the North Atlantic Ocean.The outstanding feature of any chart of hurricane tracks fora considerable period of years is the presence of many sweep-ing curves which extend \vestward or northwestward, thenturning northward or northeastward. While a large per-centage of these tracks are described as . parabolic, thereare many exceptions.

There is, however, a decided variation in the movenlentof hurricanes from one month to another. This variation isrevealed in an examination of tracks by nlonths.

During the early part of the hurricane season. in Juneand sometimes July hurricanes originate in the westernCaribbean Sea. From that region nearly all of thenl move ina northwesterly direction into the Gulf of Mexico, crossing

the coast line into Mexico or the Gulf States. During Augustand September. hurricanes develop over the eastern NorthAtlantic Ocean south of the Cape Verde Islands. The lllajor-ity of these move in a westerly direction across the Atlantic,sOlne of thern reaching the coast of the United States beforethey recurve to the northward and northeastward.

O In the latter part of Septenlber. and in Octoher and_Novelnber, hurricanes are again found originating in thewestern Caribbean Sea. Those of the latter part of Septemberfollow much the sanle paths as storms froln that region inJune but in October and Novenlber they are more likely toturn northward and northeastward in lower latitudes,sweeping out over Florida or the Greater Antilles.

Continued on page 39


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R DIO HINTS FOR INSTRUMENT PILOTS

N. G. lIowell

The l il l(1s e.rprl'ssed in Ihis arliC/( are flie authur's and af(' nut W Cl . I.wlrily thosoj the /)ppartml Tlf vf fh rmy ur of The trmy .,1viafioll SC /Uol.-The Edit.or

The follow-ing hints on use of radios while flying instru-IllE'nts include techniques often used by experienced pilots,but usually overlooked by the authors of instrument text-books. Perhaps these hints ,,,ill lllake your instrument fligh tseasier and safer.

Use the conllllunication receiver to receive conllnunications. This appears to be a trite and obvious statelnentIs t ~ Receiving l\ TC instruction on the primary navigationfacility frequency is sOllletinles a convenient and easy systemto use, but i t nlay involve complications. Suppose a pilotIllakes a position report on a victor airway and requests achange in altitude, asking that reply he Illade on VOR frequency. The operator to whom the report was made will nodoubt acknow edge the transmission and request the pilotto stand by for further clearance. The operator will then tryto call his A TC center to get clearance for the change inaltitude. If lines to ATC are busy this could take severallninutes. All the ,vhile the pilot is moving closer to his nextVOR station and lllay Tant to tune to i t rather than relllainon the frequency of the station last passed in order to receivethe clearance. Had he used an assigned communication frequency, he would have felt free to tune the navigation receiver at will. Perhaps this presents only a lninor problemin instrument flying, but minor problems add up to formlnajor probleJns.

Tuning

The proper tuning of radios is of vital illlportance. Concentrate on the radio being tuned; turn the volume down


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14 R ~ I YAVIATION DIGEST August

mOlnentarilv on the other radios to elhninate confusion andprovide for clear reception of the proper signal. Once that

signal is accurately tuned and identified, readjust the variousvolume controls as required. Re-check the tuning occasional-ly. This is especially important when a radio has been tunednear the transnlitter and the distance frolll the transmitter isincreasing. The OFF flag of the VOR or ILS receiver maystart up as the distance froIn the translllitter increases,leading you to believe that the signal is becolning too weakfor accurate track guidance. In many cases the flag can bemade to go down by re-tuning thus providing lllany llloremiles of accurate track guidance. The quadrant signal of alow frequency range can be reversed near a beam by im-proper tuning. The calibrated tuning dial is not always ac-curate. Tune above and below the assigned frequency inorder to get a bracket on the best position of the dial.

Tune every radio that can be of service. If you are flyinga low frequency clearance under conditions of poor recep tionand desire to receive the scheduled weather broadcast, tune

in any BVOR station within range, preferably one along theroute of flight because that station will probably report theweather of stations you are most interested in. Leave thevolume down on the ,FOR station until scheduled broadcasttime, and then turn the low frequency volume down and theVOR volume up until the broadcast has been conlpleted.The transmitting station reports its weather at the beginningand end of the weather transmission and thus you are pro-vided with two opportunities to receive enroute weather.

Another reason for utilizing enroute stations in manycases is to take advantage of their signals for secondary

Mr. Nolen G Howell is th Flight Edu.cational Advisorfor the Office Director of I nstrnction the Army AviationSchool Camp Rucker Alabama. He served in the British andAnwrican forces as a flight and ground school instructor duringlVorld War I I and has been with th Army Aviation School

since 1949 as a fixed and rotary wing flight instructor. Duringthe two years prior to receiving his present assignnwnt h wasan instrument flight instructor. He has logged over 9 000 hoursflight iinle in all types fixed and rotary wing aircraff.-TheEditor


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1955 RADIO HINTS FOR INSTRUMENT PILOTS 15

track guidance or to check progress along a low frequencybeanl. These stations can often be used to help you identify

a cone of silence by setting the proper radial on the courseselector and noting nlovelllent of the deviation indicator asthe cone is crossed. Tune your radios early when approachingan area containing several navigational facilities. If you arecleared to the station on a victor airway and expect to lllakea VOR low approach, why not tune the ADF to the low frequenc) station in that vicinity This procedure offers differentadvantages under varying situations, but i t always offersyou the advantage of being set up to renlain oriented in casethe primary navigational system fails.

The practice of tuning radios early as you approach acongested area is commendable, but some stations can besatisfactorily tuned much farther out than others. Forexample the middle marker and outer marker compass 10cator stations are low-powered and have a serviceable rangeof fifteen to twenty five miles from the station. I t is generally, a waste of time to t ry and tune in one of these stationswhile fifty miles from the transmitter. The ADF couldprob-ably be put to better use by tuning it to a more powerfulfacility or to a closer facility until within about fifteen Inilesof the compass locator.

Vo l u m e ont ro l

Use of the volume control takes on added importance asmore and more radios are used simultaneously. Audible volumeon all results in good reception of none. VOR and ILS usuallyprovide v o i ~ transmissions on the facility frequency. Theaccuracy of the ground track on these systems is independentof the volume so either system can be used for track guidancewith no audible signaL When one of these systems is beingused as a primary navigational aid it is good procedure tokeep the volume just high enough to lllake you aware of any

signal interruption. The signal will then bel o , ~

enough notto cause irritation or fatigue, yet it will be high enough toalert you if a voice broadcast is lllade.

Getting to a VOR station from an unknown positionwhen close to the transmitter sOlnetirnes presents a confusing


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16 AR1V1Y AVIATION DIGEST

problelll. Nearness to the translllitter is indicated when thecourse selector Illust be rotated alnlost constantly to keep the

deviation indicator centered or when the deviation indicatorrapidly nloves fronl thc ccnter to an extrellie position with aconstant course selector setting.

Close-; n Procedure

The confusion of a VOR close-in problem can be elinlinated by use of the folIo-wing procedure. Rotate the course

selector to center the deviation indicator with the-

FROM indicator reading TO. Start turning the aircraft inthe proper direction to turn to the heading indicated by thelarge arro w of the course selector. As this turn progressesthe deviation indicator will move frolll the center position.As it starts to move rotate the course selector to keep thedeviation indicator centered. When the heading of the aircraft approaches the value indicated by the large arrow of thecourse selector start rolling out of the turn. This will placethe aircraft on a heading alnlost directly toward the VORstation and corresponding very closely with the value set onthe course selector. Only slight changes in heading willnormally be required fronl this point to the station.

Microphones

Carbon type lllierophones are subject to deterioration

with age. The carbon granules may become packed to theextent that the transmitter signal is weak or garbled. If youhave trouble lnaking transmissions readable cease trans-mitting and gently tap the lllicrophone against the palm ofyour hand several times. Subsequent transmissions may beimproved because of the loosening of packed carbon granules.

Conclus ion

These are but a fe w hints to improve technique in radioinstrument flying. Perfection is the goal and it can be attain-ed only by the pilot who thoroughly understands the capabilities and limitations of his radio equipment and who iswell trained in its use.


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FIX FOR OWNTIME

Raymond L. Chaney

The views expressed in this article are th author s and are not necessarily thoseoj th Department oj the Army or oj The Army AI,ialion ,School.-The Editor

For discussion purposes, this fix will be defined aslllaxillullll utilization of ease of rnaintenance concepts.

The 111 st chronic and, therefore, the 1l1 st critical downtiIneis caused by 11lechanical failures which render the aircraft

out of cOTnnlission. fix can be applied in this case tominimize downtime by effectively reducing the maintenanceman-hour input and the skill levels required to repair, adjust,or replace those items experiencing Inechanical failures.

Experience with Army aircraft in combat has emphasizeda rEquirement for maintenance which can be perforrned quickly and easily under difficult and often hazardous conditions.Recognizing this requireInent, the Chief of Transportationhas assigned the ArlllY A viatioll Division, TransportationResearch and Development COllnnand (TRADCOM) theresponsibility of aircraft lnaintenallce operations evaluations.Within this responsibility, the Arnly Aviation Division

pursues ease of lllaintenance for Arnry aircraft as one ofi ts objectives.

Ease-o j -Main tenance Program

Ease of 11laintenance is a measure of the relative tinleand effort required to service, adjust, and repair nlachineryproperly. I t is not a nleasure of the amount or frequency ofmaintenance, but an index of the ease and nliniIllUIll tinle in

which each lnaintenance operation can be accoInplished.Most of us agree that, at times, it appears a deliberate attenlpt was nlade to lllake the lliaintenance of aircraft difficult.Some of these difficulties are evidenced by poor installation.designs and arrangeInent of cOlnponents. Fronl a rnaillte-


20/44


nance viewpoint it is axiomatic that for maximum or mostefficient equipment performance provisions must be made

for simple and easy performance of lllaintenance.Any inaccessible area which requires frequent or regularlllaintenance attention is vulnerable to neglect. n suchareas it is self-evident that easier and simpler preventivelllaintenance features will allow maintenance personnel toperform their functions with reduced skill requirements andless supervision. n addition. the aircraft is more assured ofreceiving the tiInely and adequate maintenance required forsafety.

Not only does the foregoing represent large savings indollars but, more important, it provides for a combat lllissionthat life insurance which guarantees on-target, on-time, withthe required nUlnher of aircraft.

Consideration of these facts gives rise to the logicalquestions of how and hen this ease-of maintenance program is going to come about.

TRADCOM has within its Army Aviation Division a

group of engineers and maintenance technicians highly experienced in the field of aircraft nlaintenance. This grouphas carefully exalnined the many previous studies written onease of maintenance and investigated the ease-of-maintenanceprogralns presently in effect by other nlilitary agencies.Based on this information TRADCOM personnel havedeveloped an ease-of-maintenance program which theybelieve will effectively nleasure and systematically improvethe maintainability of the - , , ~ r n l y saircraft.

TRADCOM s treatment of ease of maintenance prescribes both inlmediate and long range objectives-each ofwhich should be considered separately.

]Vlr Raymond L. Chaney is Chief of the Army Aircraft~ a i n t a i n a b i l i t yProgram Transportation Research and Devel-opment Command. He received his B. S. degree in aeronauticalengineering fronl the rrniversity of OklahOlna in 1950. During

lYorld lFar he served as a pilot in the Army Air Corps andas an Arnly A ialor during lhe [{orean War. Subsequent tohis Korean tOllr he was enlployed by lhe Bell Aircraft Corpo-ration as a rotor analyst and in September 1954 joinedTRA DCOM as a m.echanical engineer.-The Editor


21/44

1955 A FIX FOR DOWNTIME 19

mmedia te Objectives

The imnlediate objective is to establish practical easeof-nlaintenance features for incorporation on the Anlly sadopted aircraft and those new aircraft being phased intothe systenl. Due to their relative complexity and inlmediateurgency the AnIlY s lllore recent helicopters will be subjectedto these evaluations first. Detailed nlaintenance data isbeing collected from AF Phase VI Functional Developmenttests and selected Army TC Helicopter Battalions. Thisdata will provide a basis for determining which areas of theaircraft are requiring the most maintenance attention. Thecorresponding type of helicopter will be subjected to a COIll-prehensive maintenance evaluation at TRADCOM to llleasure this lllachine s lllaintenance requirement. Specialenlphasis will be given to the investigation of those areasdelllanding excessive lllaintenance with an objective towardsreducing the time, tool, and personnel required. Whereverpossible, ease-of-maintenance principles will be applied to

achievethis

objective. Based on results of thesetests

allfeatures deemed practical and economically feasible will berecollllllended for use in the field. However, the time lagbefore aircraft in the field will incorporate these featureswill be necessarily dependent upon the cOInplexity of themodification required.

In all probability, the filore complex lllodifications willbe accomplished at depot installations. However, it is anticipated that lllOst of the approved ease--of-Illaintenancefeatures can he incorporated on the aircraft at field lllaintenance level.

Long Range Objective

Long range objective of the ease of Inaintenance progranl is to estab]ish a maxilllum nunlber of sound, provenease-of-lllaintenance principles. lTltilllately, these provenfeatures should be incorporated as maintenance design

criteria in military characteristics and specifications developed for the Army s future aircraft.The possibilities of sinlplifying and improving Inainte

Hance in the field appear unlinlited. At present, it is COllservative to say that there are few, if any, aircraft in the


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Army system that would not profit if subjected to impartialtests and evaluations. Some of the ohvious areas that require

ease of Inaintenance attention can be brought to light byasking SOllle pertinent questions.I s access to fastenings 01 nwunting del ices of specific as-

selnblies 01 structures undnly restricted? For exalnple: Whatabout the fuel pUlllp installation of a certain helicopterExaluination of. the installation reveals it takes eight lnanhours to complete this task, which consists of removal of otherasseInblies, replacement of the punlp, and re-installation ofrenloved assemblies. Yet, to rmnove and replace the pumpafter gaining access takes only twenty Ininutes. Relocationof the fuel pUlllP may be the obvious solution to this problelu.Another classic example is the renloval of a helicopter engineto permit repairs on the accessory drive installation. Thereare, obviously, nlany other such cases.

Anything other than productive lIlan-hours on an itemrequiring repair is lost lllotion and serves to keep the aircraftgrounded for a longer period of tinle. This should luake an

ease-of-maintenance principle evident: ' All assemblies andsub-assemblies requiring regular service and Inailltenanceshould be positioned so as to he replaced ,yithout re11loval ofother assemblies or structures.

Are technical nstructions complete understandable andusable in the field by maintenance personnel? Do not ask amechanic in the field this question unless you are preparedfor a lengthy, impassioned discourse in the negative. Arecent survey disclosed that a very slnall percentage of theA.TlllY S aircraft lllechanics could understand the technicalinstructions as presently written. Vhen one considers thatthese mechanics possess at least average intelligence andhave Inechanical and technical experience, the inadequacy ofpresent technical instructions is alarnling. If additionalfeatures were provided in the technical instructions, such asa listing of the complete tools required for an engine change,the tiIne saved could nlean the difference between one and

possibly twenty trips to the tool crib for tools, and, theti11le

could be applied to-wards getting the aircraft back in the airthat 11luch earlier

.Another ease-of Inaintenance feature can no,y he described as All technical instructions should enlploy the basic


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1955 A FIX FOR DOWNTIME 21

principle of writing worklllan's words for working people.Can aligning devices quick disconnects color coding

seclionalizafion or other modern engineering practices beel1lployed to speed up lnaintenance tasks? Make a job easier todo and the possibility of error is llliniulized; also, the jobcan be performed by less skilled personnel ,yith Ininhnulnsupervision. An exalnple can be cited in applying this basicthought to aircraft lubrication. A requireillent exists forthree grades of lubricants at various locations for this nlachine. Paint all grade 5 lube fittings blue; grade 15 yello,,';and grade 25 green. Further paint each of three availablegrease guns a color corresponding to each of the three gradesof lubricants required. Now to lubricate all fJttings requiringgrade 5 lubricant the blue grease gun is Inerely applied to allthe blue grease fittings. Very little instruction is requiredeven for an inexperienced mechanic to insure that the job isdone quickly, easily, and without error.

A_nother area notorious for violation of simplified maintenance is the engine installation. Visual study of this C 111

plex nlaze of wires, hoses, tubes, attaclunents baffles, etc.,rell1inds one of a well decorated Christmas tree. Is i t illogical to aSSUlne this could be an efficient, cOll1pact packagethat could be con1pletely disconnected and relnoved andre-installed in forty-five minutes or less. ntilizing less skilledpersonnel and one or t yO C0I11n}On t o o s ~

Visualize the following possibilities:a. ~ f \ lifting eye permanently installed on the top center

of the power package.b. Color coded, self-sealing, quick disconnects for all

oil, fuel, and hydraulic lines. These lines tenninate at ajunction box on the fire wall.

c. Electrical lines possessing plugs chich connect toa polarized junction block on the fire ,vall.

d. The engine lIlount using double safety, quick disconnect fasteners of the lever and eccentric type.

e. The use of tapered do,vell tracking devices and hlanksplines to ease alignnlent and eliluinate error of enginere-- installation.

The foregoing indicates that the next axioln lending itself to ease of lnaintenance is: Maxiullull use of modern


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25/44

FOOTNOT S FOR WRIT RS

W. T. Burkett

The views e.cpressed in this article are the author s and are nol necessarily thoseof th Deparfment of th Army or ~ r The Army Aviation School. The Editor

A t one time or another lnost officers in Army aviation

are asked to write inforrnative articles about their work,specialties, or experiences. Written reports about accidents,training activities, administrative details, training projects,command functions. and flight procedures are also oftencalled for. Occasionally they must provide technical in-formation for a manual, or forlllulate the scope and plan of anew subject to be taught, or describe for a visiting VIPcertain areas of command, doctrine, or flight. Now and thenthey may want to express some highly original idea, hopingi t will meet a unique need or inlprove some unhandy sit-uation. method, or technique.

Often they are unprepared, either in experience or innatural talent, to meet and further the writing challenge.Usually though, if they are willing to put forth the effortand if other responsibilities are not too urgent, they pro-duce a fairly comprehensive and finished product. What issaid hereafter is not a criticism but is merely an effort to

point out a few connnon faults in writing.First of all, very f w ~individuals can transfer frolIl theirbrains to a piece of paper the precise duplicate of theirthoughts. Even to approxiInate such an exchange of mediulllrequires the 1l10st difficult and tiring of all lllental efl ort.However brilliant the writer s mind, however much he haswrestled with grammar, language, and style, he cannotexpress his notions or knowledge without SOllle slight con-fusion, some degree of inexactness.

h i n k

Ohviously, the first requirenlent, in order to write withclarity, is to think. An individual cannot afford an excess


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27/44

955 FOOTNOTES FOR WRITERS

during the nlaneuver and in order to facilitateeconolny of fuel after lnaking the turn the pilot

,, ill insure that he has previously conlpleted hisestinlates of theBETTER: The pilot conlpletes his estimatesof the before beginning the lualleuver. Hethus maneuvers corrE'ctlv and saves fuel afterlnaking the turn.


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29/44

955 FOOTNOTES FOR WRJTERS

the prinlary navigation facility within their re-spective control zones and are the prilnary in-

strument letdown facility of the airfield at,vhich located. These radars may also be usedas a secondary navigation facility by ArnlYaircraft on airways to the limits of their sur-veillance range and spatial coverage.

27

The antecedent of the first italicized pronoun is sinlpleenough to find, although the reader's original ilnpulse whenhe begins the second sentence with these before reachingradars. is to attach the plural pronoun to the last pluralternl in the previous sentence, corps corps artillery andfield army base airfields. That inlpulse is corrected by radarsinunediately after the pronoun.

The second pronoun in our example, their can refer toeither of the plural antecedents used in the first sentence;hut the reader is more likely to choose the proper one,radars since the term has been repeated and fixed by theprevious pronoun. The final pronoun italicized in the

example probably makes its reference clear to the reader inthe same manner; nevertheless, in this case he is nlorestrongly tempted than before to attach their to the wrongantecedent since two separate plural terms, aircraft andairways have just been passed.

The writer should have been Inore careful; he shouldhave reviewed his work and nlade changes sinlilar to these:

BETTER: Arnly airfield surveillance/ ap-proach radars are established at corps, corpsartillery, and field army base airfields as thep r ~ m r ynavigation facility to control prinlaryinstrument letdown. Radars of this type mayalso be used as a secondary navigation facilityto the extent of their surveillance range andspatial coverage.

Why primary is repeated should deternline whether ornot its repetit ion is essential. Offhand, the first use of the

rord seems to be enough.One last word about pronouns, the indefinites. Withvery rare exception such as I t is raining or They saybrain cells work like electrical units, the indefinite use of apronoun is weak. The second inserted exception has less to


30/44

28 ARIVIY AVIATION DIGEST August

offer than the first because they could have an antecedentbut it cannot. Other exanlples:

POOR: It is our job to sec that they keep at it.The sentence should begin with our job. The last phrase,keep at it, is an idiolll of speech, lneaning to continue it orstick to it or keep it up. Such idioIlls are pernlissihle if notout of tune with the Titing and if not overused.

POOR: It is our intention to sho,v that .BETTER: Our intention is to show that or,

'Ve ,viII try to s h o \ J ~that

Do not worry too lnuch about ,vhether to use shall orwill with I or we. OPOOR: It is at this phase thatBETTER: At this phase This is our plan

Ordinarily, the construction is inlproved by beginningwith the subject of the statement, in this case our plan;but brief introductory sentences sonletimes get a paragraphunderway with effectiveness. Just keep them very brief ifyou use the indefinite pronoun or the pronoun ahead of itsantecedent.

Spli t lnfiniti ve

Quite often a writer finds himself in the dilemma of de-ciding whether or not to split an infinitive. Do not, if yougain nothing by doing so; do, if readability and meaning areimproved. Split infinitives absolutely insult some people;students used to be schooled to NEVER split an infinitive.To ne ver split is a spl it infinitive. An infinitive, by the way,is the verb form made up of to plus the verb: to be, to runtfo fly . You split one by inserting a word or phrase betweenthe to and the verb:

To never in any way at all succeed isThe never split ,,, auld hardly grate on the purist's ear.

The split -with in any way at all which should properly followthe verb, rubs against the grain of even the least formal of

readers.Military writers, even the more experienced ones, cOlllmita grosser writing sin than splitting infinitives when theycompile a list of activities or items carelessly. Each item inthe list should follo Y a single fonn. When the first iteln


31/44

1955 FOOTNOTES FOR WRITERS 9

begins with a verb, so should the others, or at least with averbal construction:

1. To keep the orderly roonl in2 To check the sign-out sheet beforeDecide ahead of the actual listing ho,,- to shape the

items. Will nouns or noun phrases be better than verbals(infinitives and ing verbs) In the introductory statement can a substitution of words or phrases prevent itsrepetition in each i t m ~For example, The Officer of theDav will:

O

1. Insure that accidents are .2. Insure that firearms are .3. He will insure that quarters are .4. Insure that retreat fornlation is

This is an unbalanced listing; and the repetition of tnsurcan be avoided by including it in the introductory statelnen t - The Officer of the Day will insure that:

1. Accidents are . . .2. Firearms are . . .3. Quarters are . . .4. Retreat formation is . . .

Conclus ion

To conclude this brief treatment of a highly complexsubject, realize that no one expects a writer to be letterperfect every time. But the reader deserves the fair play ofclarity and unity of thought. We write for his benefit, notfor our own. The fact that he nlust, let us say, read what wewrite to receive credit for a course of training is all the nlorereason for exerting our best writing effort. Ease the reader'sburden by making the conlpulsion less disagreeable. HeInight even want to read nlore if the writer:

1. Plans his subject.2. Thinks through his plans.3 Writes a first draft.4

Proofreads once for unity and rearranges.5. Proofreads again for clarity, corrects and tightens.6. Eliminates negative asides.7. Accents positive approaches.8 Rewrites into final form.


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BOOKS FOR THE RMY

VI TOR

DEVELOPMENT OF T H E G UIDED M I s s I L E - G a t l a n d K e n n e t hW., F. R. - ~ . S (The Philosophical Library, Inc., 15 East4.0th St., Ne,v ~ o r k16, N. Y. 1954. 4.75)

This is the second edition of a book which presentsfactually the lllain inforlllation available on the contemporarydevelopment of guided weapons and rockets for lnilitary andpeaceful purposes. The author, ,vho is an aircraft design.engineer and a founder-lllelnber of the British InterplanetarySociety, describes the potentialities of the rocket as aweapon of ofl'ense or defense, as an instrulllent of researchinto the upper atmosphere and outer space, and eventuallyas a vehicle of interplanetary travel.

The first edition has been cOlllpletely revised and anumber of useful features have been added. New chaptersdeal with problellls of propulsion, research into rockettechniques and requirelllCnts, and postwar work on guidedbombs. Of particular importance is the detailed survey ofRussian potentialities for long range rocket development.An appendix reveals SOllIe details of the telellletering equipment used in British lllissiles, and another appendix shows

photographs, to scale, of over 4 0 notable rockets from variouscountries. The table of characteristics, which was an inlportant fe{:lture of the first edition, has also been enlargedand now provides data on l ~ t powered rockets from eightcountries.

The book is illustrated by over 100 photographs anddrawings of exceptional interest. Anyone who wishes tounderstand the significance of the guided missile-boththe threat it holds as a weapon of war and its promise ofMan s adventuring 'into space-should read Mr, Gatland sbook.T H E AMERICAN TRADITION IN FOREIGN P O L I C y - T a n n e n

baum, Frank (University of Oklahoma Press, Norman,Oklahollla, 1955. 3.50)


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BOOKS FOR THE ARl\1Y AVIATOR 31

T\yo sharply divergent doctrines of foreign policy arebeing debated today in AnIerica. One doctrine, calledrealpolitik, insists that relations bet\veen nations be builtupon a balance of power and po\ver politics, \vhile the o t h e rthe principle of the coordinate state-holds that the bestrelations can be nIaintained hy friendship alllong nations,the right of the little nation to survive without fear, and theenhancelnent of lnunan dignity and freedoln.

Mr. TannenbaunI, a professor at Colulllbia University,states the case for the coordinate state. His conclusionsare based upon study of the progress of nations in the pastand the ethical and constitutional foundation of the UnitedStates. Whereas the exponents of realpolitik adhere to theprinciples of Machiavelli, Richelieu, Clemenceau, and Bismarck, believing that \vars are inevitable and that the individual is the servant of the state, the author points out thatthe T nited States and its governnlent (along -with the BritishComnI0nwealth and the S\viss Federation) are founded onthat

revolutionary principle ofthe state s

beingthe servant

of the individual . Such a foundation philosophy made possible the equality of Texas and Rhode Island.

He further states that nations subscribing to a policyof power politics (the Gernlan EnIpire under the Kaiser andHitler, Italy under the Borgias and Mussolini, IllIperialJapan, Richelieu s France, for exalllple) have usually endeddisastrously.

The debate b e t w ~ e e nthese opposing policies will come toour attention nlore and more. Anyone would do well to readthis book \\I-hich advocates Christian principles and lllutualsovereignty anlong nations ill the face of the COllllllunistthreat.Two YEARS IN T H E ~ t \ N T A R C T I c - ~ - a l t o nE. W. I ~ e v i n(ThePhilosophical Library, I n c ~15 East 40th St., New York 16,N. Y., 1955. -1.75)

Considerable publicity has been given in recent yearsto the conflicting claims of Britain, Chile, and the Argentineto the area of _Antarctica south of Cape Horn. The yearly

This department is prt pared by the A R M Y A V I AT I O N DIGEST staff .Views e.rpressed are nol necessarily those of the Department of the Army or of

The Army Aviation School. The Editor


34/44


departure of the Survey ship John iscoe receives increasingpublicity in the press and on the airwaves.

This is the first personal account of two years spentin that area of British Antarctica since the war. KevinWalton went to the Antarctic as a meluber of the newly form-ed Falkland Islands Dependencies Survey which has beenengaged ever since in exploring the region. The Survey partyestablished the first base inside the Antarctic circle atMarguerite Bay in Graham Land, and spent their first yeartraining both themselves and their dogs to live and travelin this difficult country.

The next year, an Anlerican expedition arrived, andlater both parties combined to complete a survey of theEast Coast of the Graham Land peninsula. At the same timea party from the Survey s northern base at Hope Bay sledgedover 500 miles southwards to a pre-arranged rendezvous,and were escorted over the formidable plateau to MargueriteBay.

These journeys lnarked the clinlax of two years work,and it was a measure of their success that they were ac-complished without dralnatic incidents. The expedition asa whole did not lack excitement, however, for their air-craft crashed seventy miles from base, and the occupantshad to walk home; and on two occasions a member of theparty was rescued from the depths of a crevasse, once by theauthor himself.

Some of the most interesting chapters of the book arethose that describe how the Expedition actually lived inAntarctica, how they organized their base, trained theirdog teams, and worked out a sound routine for polar sledgejourneys, based in large nleasure on the recorded experienceof previous polar travellers. Mr. Valton enlphasizes thelogical approach to polar l i fe-how every accident mustteach a lesson, and the value of careful planning and meticu-lous attention to the preparation of equiprnent. I t is acountry where success, and life itself, may depend on thestrength of a dog trace or the \veight of a ration box.The book evokes the wildness and beauty of the Antarctic, the combined isolation and close companionship ofExpedition life, and explains why the author left detcrnlinedto return.


35/44


36/44


in a hover then attelllpted a slope landing. The left skidwas placed on the slope and at this lllOInent the helicopter

began drifting and turning sio,vly to the right. With theintention of re-aligning the helicopter for another attemptat a landing, the pilot brought it to a hover, but the rateof turn increased rapidly. The instructor pilot shouted tothe student, What are you d o i n g ~The student answered,' I believe we have a tail rotor failure. The instructorsaid, Cut the power and get it on the ground.

The student cut the power and the helicopter rotated180 degrees heading down wind and down slope. I t hit theground and bounced. The lnain rotor struck the tail boomand upon second contact with the ground the helicopternosed into an almost vertical position, then rolled over onits right side.

Fortunately, neither the student nor instructor wasinjured. Due to the extent of dalnage there ,vas not enoughevidence available for the accident investigation board todetermine the cause or contributing factors of the accident.

Poor judgment on the part of the instructor pilot wasconspicuous. He gave responsibilities to the student -whichwere beyond the student's ability and experience. The tagof instructor pinned on a pilot also pins on him responsibility. U nit instructor pilots should be well versed in theiraircraft and especially adept in recognizing serious situationsin order to prevent accidents. In this case, the IP shouldhave acted first and asked questions later.

Unbalanced

No matter how extenuating the circulllstances, an aircraft cannot be flown safely ,,,hen the center of gravitylimitations are exceeded. I t is especially critical in helicopters.The following accident was a result of a pilot being too

The Gray Hair departnwnt is prepared by th AR_MY

A V I AT I O N DIGEST staff with infornlation obtained fromthe files of the world wide aircraft accident safety review boardThe views expressed in this departnwnt are not necessarilythose of the Department of the Anny or of The Army AviationSchool. The Editor


37/44

1955 GRAY HAIR 35

anxious to expedite his lnission and failing to exercise goodjudgment.

During field lnaneuvers a reginlent&l pilot was flying thecommanding officer in an H-13E. In the course of theirflight they were informed that a soldier with a broken legneeded evacuation. The colonel directed the pilot to pick upthe patient and fly him to the collecting COlllpany. They proceeded to the pick up point, placed the patient on the lefthand litter, and took off for the collecting COlllpany.

Upon arrival at the designated grid coordinates theydiscovered the COlnpany had displaced to an unknown location.The colonel then decided that the best lllethod of locatingit was to return to the regimental P for information. Thepilot, after arriving at regiment, had flown approximately2 hours and 10 lllinutes -without refueling.

While the colonel \vas in the P obtaining the information, the pilot, because of his suffering patient and the factthat darkness was coming on, decided to hover to a refueling point 150 yards away. He realized that the center

of gravity would be critical without the colonel's weight inthe right seat so he hovered the helicopter in order to determine whether there would be enough cyclic control.

Weather was clear with wind approximately 30 nliles perhour and extremely turbulent. The helicopter was broughtto a hover and after a few monlents the pilot became satisfied that he had enough cyclic controL L ~ She llloved forwarda strong gust of wind struck frolll the right, resulting in thepilot using up what little right cyclic he had; also, he ranout of pedal and the helicopter began turning to the right.Unable to control direction and lateral movement any longerthe pilot lowered pitch. The helicopter touched down moving to the left then, according to the pilot, struck the onlystump in the area which caused the helicopter to turn over.He further stated, I aln confident that if I had missed theone and only StulllP in the area that I would have successfullylanded the helicopter.

Lady Luck was riding this ill-fated flight and the pilotfortunately emerged unhurt and, amazingly, the patient didnot receive further injury, although pinned under the-wreckage.

,The pilot, having a patient on board, being lo w on fuel,


38/44

36 ARl\1Y AVIATION DIGEST August

and faced with approaching darkness was no doubt underSOll e strain and very anxious to cOlllplete his Tllission. o \ ~ -

ever there is no excuse for failure to use good judglnent andespecially no excuse for taking UIlnecessary risks.Ballast on the right litter prohahly would have pre

vented the accident hut better stilL hauling a couple offive gallon cans of gas fronl the refueling point 150 yardsaway would havcprevcnted it.

ont r ibu t ing Factor

Fauli) naz igation has long been a prominent contributingfactor leading t aircraft accidents. Examples of this type ofaccident. picked al rand01n from the world wide accident Jiles,are gillen below.

One

A pilot was flying a passenger in an L 19 on a nightadnlinistrative cross-country. Prior to take-off the pilotplanned the course of the flight filed his flight plan andthoroughly checked his aircraft and radios. All were in goodorder. Shortly after becoming airborne they left the localflying area and the pilot turned all radios off.

The first check point was passed on schedule but a fewminutes afterward a bird came through the propeller andstruck the lower portion of the right windshield and rightwing. An inspection was made by the pilot and passengerfrom the cockpit with flashlights and no damage to the aircraft nor unusual vibrations of the propeller were detected.

Shortly after the bird incident the passenger fell asleep.Some time later he awoke and asked the pilot where theywere. The pilot pointed out a small town they were flyingover and stated its name. The passenger being familiarwith the terrain near their destination and over this particular route disagreed.

The pilot pointed out a rotating beacon ahead of them

to substantiate his belief and gave the name of a nlilitaryair base. However upon checking closer i t turned out to bea civilian field and although there was activity on the fieldthe runway \vas unlighted. The pilot rechecked his map thenattempted to use radio aids but was unsuccessful. He checked


39/44


40/44


down and check a highway sign in an effort to deterrnine hisexact location. There was a layer of condensation on the inside of the bubble, which made it ilnpossible to read the highway sign; also, the aircraft was not equipped with a heater ordefroster to renlove this condensation.

The pilot decided to land in a nearby plowed field andsend his Illechanic to read the sign. He circled the fieldseveral times in order to ascertain the presence of obstaclesor other hazards which would impair his approach and landing. The field appeared to he clear of all obstructions and the

pilot established a HOflnal approach.Approximately 50 feet fro In the ground and with 25miles per hour air speed, the pilot suddp1l1y saw that he wasletting down into wires. In an attenlpt to avoid t l ~ mhe applied full throttle and pulled full pitch, hut too late. Thewires caught the vertical stabilizer and the helicopter pitcheddownward, ahnost 90 degrees. The pilot applied back cyclic,cutting the tail boon}, and the helicopter fell to the gronnd,crashing on its bubble then turning over onto its hack. Thepilot and passenger walked away without injury.

e could give a long dissertation about errors made in theabove accidents but the primary Inistake and contributingfactor was a lack of self discipline among pilots in the obser-vance of good navigation practices.

In the first accident, the pilot was not Inaking use ofhis radio aids, at least not until he was hopclessly.lost. Hethen discovered that the static was so great that he could not

receive anything, nor did he know if he was translilitting.By failing to utilize his radios, he used poor judgment andviolated regulations which require a radio listening watchof appropriate radio facilities, and which also require atleast one position report every hour Flight Regulations for

rmy Aircraft, par. 21, R 95-8). A position report, whichwas due over the first check point, would have indicated thecondition of his radios.

In the second accident there were several contributingfactors but the one which started the chain of events thatled to an accident was faulty navigation.

In flight planning a pilot must study weather conditionsalong his route, consider the wind and figure it into headings,calculate thne between check points, and record the in-


41/44

1955 GHAY HAIR 39

forrnation ill his flight log. An exanIple of a simple flightlog can be found 011 page 8, May 1955 issue of the ARMYAVIATION DIGEST.) Further, a pilot should use all radiona vigational facilities available. Finally, he should followhis flight plan accurately, and if he does become disoriented, he should not let pride cause him to hesitate. Heshould inlnleciiately tune his radio to 121.5 and announce hispredicalnent in order to get help. This is using good judgment, and it is the type of action that gains respect.

I-Ianger fliers sonwtilnes grin when a gray haired pilot

walks to the plotting Lable in operations, pulls out maps,blank paper, W cenlS plotter, and his E6B conlputer to plana sinlplc 50 Inile


42/44


Types o f Warnings

1) Warnings-Area s) forecast to be in or near path oft )e tropical cyclone during the valid time of the bulletinbut the surface winds will be less than 34 knots,

2) Gale Warning-Cited area(s) forecast to be affectedby w,inds of 34 to 47 knots during the valid time of thewarnIng.

3) Storm Warning-Cited area(s) forecast to be affectedby winds of 48 to 6 knots during valid time of the warning.

4) Hurricane Warning-Cited area(s) forecast to bef f e c ~ e dby winds of 64 knots or nlore during valid time ofwarnIng.

The above advisories are issued each six hours that astorm is in progress with special bulletins issued whenwarranted.

The United States Weather Bureau maintains hurricanewarning centers in all major sea coast cities. Air WeatherService maintains a Hurricane Liaison Officer at all majorcenters and the Air Force and Navy maintain weather reconnaissance units in all areas that might be affected bytropical storms.

The tremendous record of deaths and property damagecaused by tropical eyclones in the past was due primarilyto the lack of hurricane warning service. This is no longertrue. Today, with the combined team of the Weather Bureau,Air Weather Service, and the U. S. Navy forecasting, tracking, and escorting the storms, it is improbable if not impossiblethat a tropical storm could approach any land mass in thewestern hemisphere without the population bei,ng forewarned.

A FIX FOR DOWNTIME continued from page 22 Tosummarize: ease-of-maintenance evaluations are for thepurpose of minimizing the time, tools, and mechanical skillsrequired to perform maintenance of Army aircraft. Anurgent requirement exists that specific, well-defined maintenance design criteria be developed and clearly expressed inmilitary characteristies and design specifications. Thesemaintenance design criteria must be enforced without compromise by either the military or industry if the Armyaviation program is ever to receive aircraft that are inherently easy to maintain.


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DISTHIBUTION:ACTIVE AR \IY:

G l 5)G2 3)G3, ATTN: Army Avn Div 5)D E P LOG 5)Tee Svc, DA (5)Hq, CONARC (25)CONARC Bd 5)OS Muj Comd (50)

NG: State AG 2)USAR: ~ o n

OS Base Comd 10)Armies (CONUS) 1)Armies OS) (25)Corps OS) 10)Div OS) 10)Brig OS) (5)F t Cp (COl'iUS) 1)F t Cp (CONUS) M / F Librarian (1)

For explanation of abbreviations used see SR 320-5()-1.


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RMY VI TION SCHOOL CREST

When reproduced in full color, the colors red, blue, and yelloware used in the crest to indicate representation 0 all branches 0the rmy in The rmy Aviation School. The school s aviation

training mission is symbolized by the perched falcon denotingthe art of falconry with its patient training of swift, keen birdsfor hunting. The mailed fist depicts the military ground armwhich exercises the control, training, and direction of the flight.

Army Aviation Digest - Aug 1955

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Transcript of Army Aviation Digest - Aug 1955