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FINAL REPORT

of civil aviation safety investigation

CLASSIFICATION Accident

Operator Romanian Aeroclub

Manufacturer I.C.A. Brașov

Aircraft IS-28B2

Registration country Romania

Registration YR-3800

Location Aerodrome of Territorial Aeroclub “Al. Matei” – IASI

Coordinates: Latitude: N 47º09′47′′

Longitude: E 027º38′22′′

Date and time 02.10.2012 / 16:00 LT

No. : A 19 - 13 Date : 15.11.2019

Accident – Glider IS 28 B2 – YR-3800 – Iasi South Aerodrome – Iași County – 02.10.2012-

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AKNOWLEDGEMENT

This REPORT presents data, analysis, conclusions and recommendations

made by the civil aviation safety investigation Commission appointed by the General

Director of SIAA.

The civil aviation safety investigation was conducted in accordance with the

provisions of the Regulation (EU) no. 996/2010 of the European Parliament and of

the Council from 20 October 2010 on the investigation and prevention of accidents

and incidents occurred in civil aviation and repealing Directive no. 94/56/CE, the

provisions of Annex 13 to the Convention on International Civil Aviation signed at

Chicago on 7 December 1944, as well as with the Government Ordinance no.

26/2009, approved with amendments and additions by Law no. 55/2010, modified

and completed by Government Ordinance no. 17/2018.

The objective of the civil aviation safety investigation is to prevent the

occurrence of accidents and incidents, by determining the facts, causes and

circumstances that led to these occurrences and to issue civil aviation safety

recommendations.

The civil aviation safety investigation does not establish any legal guilt,

responsibility or liability.

Consequently, the use of this REPORT for purposes other than those

concerning the prevention of civil aviation accidents and incidents may lead to

misinterpretations.


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FINAL REPORT

Glider accident caused by the uncontrolled towing cable

self-releasing

Aircraft Glider IS 28 B2 / YR - 3800

Date and time 02.10.2012/16:00 LT

Operator Romanian Aeroclub,

Territorial Aeroclub “Al. Matei” – IASI

Flight type School flight

Persons onboard Student pilot

Victims The student pilot, male, seriously injured

Pilot in command Student pilot under license

Damages The aircraft was completely damaged

Location Aerodrome of Territorial Aeroclub “Al. Matei” – IASI

Coordinates: Latitude: N 47º09′47′′

Longitude: E 027º38′22′′

1. HISTORY OF OCCURRENCE

On 02.10.2012, during the training flight organized on Alexandru Matei – IASI

Aerodrome, the student pilot involved in the accident was planned to perform a solo

flight with the IS-28 B2 glider, registered YR-3800.

At 15:42, the student pilot, with the same aircraft YR-3800, performed a solo

test flight, using the take-off procedure by auto-towing. This take-off was interrupted,

because the towing cable, for indeterminate reasons, self-released from the glider

during the take-off run.

After this accidental self-release, the training flight was interrupted due to a

restriction imposed by the activity performed on the Iasi International Airport.

At 16:00, when the flight activity resumed, the first flight was also performed in

simple command by the same student pilot with the same glider. These flights in the

sequence presented were the first performed on that day within the training

organization.

During take-off after climb-out, when reaching the optimum towing speed of

approximately 100 km/h, the pilot commanded the aircraft to be aligned on the

climbing slope path in towing.

During this climb flight, the towing cable self released at a height of about 40-60

m, according to the statements of the eyewitnesses present on the runway where the


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aircraft took off. The glider, from the position where it was at the time of the cable

detachment, performed a descending flight, while entering in a left turn whose

inclination was accentuated with the slope increase. Near the ground, the glider

change its inclination to the right side, taking skid contact with the ground initially with

the right wing (see fig. 1) and the front of the fuselage (see fig. 2), and then the rear

of the fuselage impacted the ground. Due to the force of the impact, the left wing had

a point of rotation forward, which caused the fuselage to deform in the cockpit area,

and finally the glider rotated on the ground by pivoting toward the top of the right

wing, to the rear and right (see fig. 3). The aircraft made contact with the ground at

the coordinate point:

Latitude: N 47º09′47′′

Longitude: E 027º38′22′′.

As a result of the impact with the ground the aircraft was destroyed and the pilot

was seriously injured.

Fig 1: The glider's right wing in the ground contact area


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Fig 2: Glider fuselage destroyed on impact with the ground

Fig. 3: Traces of glider rotation, with skid on the ground


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2. ADDITIONAL INFORMATION

2.1 Pilot information

Student pilot Male

License Flight approval valid

Medical certificate CL.2, valid

Flight experience 14,25 flight hours on IS 28 B2

Working time Not applicable

Rest time Not applicable

2.2 Aircraft information

Aircraft category Two-seated glider

Manufacturer and aircraft type I.C.A. Brasov, IS-28 B2

Number and placement of wings Two high semi-wings

MTOW 520/590 kg

State and registration Romania, YR-3800

Owner Romanian Aeroclub

Operator Romanian Aeroclub

The glider IS-28B2 is a glider of Romanian design and manufacture, flying for

the first time in the beginning of 1975. The glider is of metallic construction, having a

high wing, classic construction, with a dihedral angle of 2,30°, provided with Hutter

aerodynamic brakes, which open only on the top of the wing, a fixed horizontal

stabilizer with classic rudder.

According to the aircraft documents, it had a valid certificate of airworthiness,

and the maintenance was performed in accordance with the approved maintenance

schedule.


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Fig. 4 Image of the YR-3800 glider

2.3 Aerodrome data

„Iasi South” aerodrome is located in the south-east of Iasi city and is managed

by the "Alexandru Matei" Iasi Aeroclub. The aerodrome operates during the daytime

and is intended exclusively for VFR traffic. It is located in the vicinity of Iasi

International Airport.

The aerodrome has a take-off/landing runway with grassy surface, oriented on

140° and 320° headings, having a length of 650 m and a width of 40 m (fig. 5).


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Fig. 5 Iasi South Aerodrome

2.4 Towing vehicle information

The towing was carried out using a Romanian type 34 AL towing car.

The body of the towing vehicle is mounted on a "Bucegi" truck chassis, which

allows it to move from one place to another by its own means. The towing vehicle has

a 258 HP engine, which drives one of the 2 drums with which it is equipped. The fuel

used is diesel.

The 4.5 mm diameter towing cable is wound on the drum; the cable is made of

multiwire steel and has a length of about 900-1500 m, length that varies depending on

the length of the take-off field.

Each drum is equipped with a scissors for cutting the cable (at the command of

the towing operator) and with a distributor that has the role of laying the cable on the

drum, by spinning.


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Fig. 6 : AL 34 towing vehicle

To make the functional connection during the towing between the towing cable

and the glider, the parachute kit and TOST rings are used.

The towing vehicle and its operator held the operating certificate and the

authorization within the validity period.


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Fig. 7: TOST type connection system

2.5. Meteorological information

Weather conditions at the time of the occurrence were as follows:

- Wind from SSE (1500) with an intensity of 10 knots and 5m/sec.; - CAVOK; - Temperature/ Dew point temperature: 22⁰C / 14⁰C; - QNH 1014 hpa.

The weather conditions did not influence accident occurrence.

2.6 Additional information

In the contractual documents under which the student pilot performed the flight

activity, no details regarding the theoretical training and the conditions for performing

the practical training are included.

In the ” Training manual ” of the glider training organization , Part 2, in chapter

2.1 “Practical training program on the ground and in flight in order to obtain the glider


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pilot's license, the glider / motor glider pilot class qualification and the qualification for

the launch method of vehicle towing / airplane towing / self-launching”, point 2.1.1

“Practical flight training program for pilot students in order to obtain the glider pilot

license, the glider class qualification and the qualification for the method of towing

vehicle launching (Method M)”, at exercise no. 6 it is mentioned: “special cases in

free flight and at least three cases of breaking the cable towing will be simulated”.

In part 5 “Annexes”, in the content of Annex no. 8 section “Practical training in

flight”, at exercise no. 6 it is mentioned: “special cases will be simulated in airplane

towing (minimum 4) / vehicle towing (minimum 6) as well as checking the waltz

removal in plane towing will be simulated”

In the “Timetable file for gliding flight”, for the date of 10.09.2012, there are 3

flights performed by the student pilot, which had flight duration of 5 minutes each.

In the student pilot “Flight evolution sheet”, 3 flights with duration of 5 minutes

are registered on 10.09.2012, with the mention "simulated special cases".

3. ANALYSIS

The flight on Iasi South aerodrome was opened by informing A.O.C. (Air

Operations Centre) in accordance with the provisions of the Government Ordinance

no. 912/2010. The flight activity was performed based on the "Operational

Procedures" provided in the "Operating Instructions" of the Iasi South Aerodrome.

Analyzing the evolution of the aircraft, in the opinion of the investigation

commission, from the moment of self-launch, the student pilot performed a maneuver

that determined the aircraft to enter a descending evolution, and at the same time

with the descent, he also initiated a tight left turn with steep inclination, which led to

the rapid loss of speed and consequently to the aircraft loss of control in flight.

The instructor on the ground, observing the evolution of the glider, repeatedly

communicated to the student pilot to pull the control stick, but he had a late reaction.

When the student pilot pulled the control stick diagonally to the right, trying to recover

the glider and reduce the inclination angle of the turn, the glider responded to the

command by lowering the descent slope and at the same time switched from the left

turn to a right turn. At that moment, given the very low altitude, the right wing came in

contact with the ground, determining the further evolution of the aircraft.

When examining the flight instruments it was found that the speed indicating r

needle was blocked indicating the value of 120 km / h (see fig. 8), and the variometer

needle had exceeded the maximum limit, so the vertical descent speed was over 6 m

/ sec. (see Fig. 9). From the calculations, a vertical descent velocity of about 10-12

m/sec results, which, compared to the time elapsed since the termination of traction

and until the impact, of about 4 seconds, resulting in a gliding evolution characteristic

for the stalling on the wing with an increased flight speed. The evolution time of the

glider after completing the towing and until the moment of impact was determined

after analyzing the audio recording existing at the air traffic controller.


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The investigation commission considers that the self-releasing occurred

because the pilot, after performing the moderate climb flight (as needed to increase

the glider speed in the climb), put the glider in a more pronounced ascending slope,

causing the tow cable system to reach the self-release angle. The slope imposed by

the pilot in relation to the power developed by the towing vehicle at that time did not

allow the acceleration and evolution of the glider to climb, favoring the fulfillment of

the conditions for the self-release of the tow cable.

Fig. 8 Image of the speedometer blocked on the flight speed of 120 km/h

Fig. 9 Variometer locked to the maximum possible indication


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The investigation commission analyzed the history of the flight activity of the

student pilot in order to determine whether he had the necessary experience of flight

training, and especially of the part on how to deal with emergencies (special cases)

that may occur in take-offs made with towing vehicles.

From the documents regarding the flight activity records of the student pilot

and the documents of daily registration of the flights, the commission found

inconsistencies regarding the real situation of the special cases performed with take-

off by towing vehicle.

The flight duration in case of performing a special case when the glider is

towed by a towing vehicle is of 1-3 minutes, depending on the altitude at which the

completion of towing is simulated.

This time is also confirmed by the analysis of other timekeeping records,

where similar special cases appear, performed at altitudes between 50 m and 100 m,

and the flight duration is of 2-3 minutes.

Also, the first flight test from 02.10.2012, where, as a result of the towing cable

self-launching in flight, the registered flight time was of one minute.

The investigation commission found that a runway-lap flight performed by the

towing vehicle method has a duration of about 5 minutes, of which the duration of

towing up to an altitude of about 250 m is of almost 30-40 seconds.

The flight time to simulate the special case (cable self-release on towing) at an

altitude of about 150 m will be 3 minutes, at an altitude of about 100 m will be 2

minutes, and at an altitude of about 50 m will be one minute.

Considering the flight time registered in the student pilot's record sheet (3

flights x 5 minutes), it can be assumed that the simulations of these special cases

were performed by executing the solving maneuvers at an altitude of 250 m. Learning

these maneuvers at an altitude of 250 m created the student pilot a sense of security

and, mistakenly, the illusion that in a real situation he will have more than enough

time available.

In the case of a front wind of 5 m/sec and with a completion of towing at an

altitude of 40-60 m, on Iasi South Aerodrome, according to the applicable

regulations, the glider is placed in the normal gliding slope of free flight through a

safe and determined maneuver by pushing the control stick forward. After

establishing the normal gliding flight speed, it may be performed the landing in a

straight line with deviations to avoid any obstacles (according to the Operating

Instructions of the Iasi Aerodrome in force at the time of the accident).

In this case, the student pilot initiated the turn that prevented him from solving

the emergency situation, a solution that normally the glider pilots must know and

master very well.


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As a conclusion to the data analyzed above, in the opinion of the investigation

commission, the student pilot did not know how to solve this special case, he acted in

a way that raise doubts on the assessment when it was considered that during the

training process he had acquired the necessary skills and was ready for a solo flight.

Also, the investigation commission considers that in the case of this student

pilot the training organization failed to identify the gaps in his training before it was

planned to perform a solo flight.

No malfunctions were found in the operation of the towing vehicle and towing

system, but in the opinion of the investigation commission, it would be appropriate if

the flight instructor had performed a flight to verify the functioning of the glider –

towing vehicle assembly, given the first accidental towing cable self-launching.

4. CONCLUSIONS

4.1 Findings

- The pilot student fulfilled the conditions for performing the solo flights

according to the regulations in force;

- The medical certificate and the flight approval were valid;

- The weather conditions were favorable for the solo flight;

- No elements that indicate a malfunction or abnormal functioning of the glider

or the towing vehicle have been identified;

- After the first self-release of the towing cable in flight, the flight instructor did

not perform a flight to verify the functioning of the glider – towing vehicle

assembly;

- The student pilot did not know how to solve this special case.

4.2 Cause of the accident

The most probable cause of the accident occurrence is the improper learning

by the student pilot on how to solve the emergency situation produced at an altitude

of 40-60 m and with a front wind of 5 m/sec.

Favorable cause: the erroneous appreciation of the altitude at the time of the

emergency occurrence in relation to the turn maneuver initiated.


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5. SAFETY RECOMMENDATIONS

1. It is recommended to the Romanian Aeroclub, as a training organization, to

review the Training Manual of the Gliding Training Organization in order to upgrade it

with a procedure that prevents the student pilots from performing solo flights before

they have the necessary skills for solving special cases.

2. It is recommended to the Romanian Aeroclub, as a training organization, to

identify the solutions by which, at the beginning of the daily flight activity, the first

take-off to be performed by a pilot holding a valid license, in order to check in flight

the functioning of the glider – towing vehicle assembly.

Note: The documents and analysis objects used for the issuance of the flight safety

investigation Report are confidential and are archived at the Civil Aviation Safety Investigation

and Analysis Authority, according to legal provisions.

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