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For notifications regarding civil aviation accidents and serious incidents: Phone: +40 751 192088 (24/7) E-mail: [email protected]
1-3 Walter Maracineanu Square, 6th floor, District 1, Bucharest – postal code 010155, Romania
Phone: +40 21 2220535, Fax: +40 378 107106 E-mail: [email protected]
Website: www.aias.gov.ro
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.
Accident – Glider IS 28 B2 – YR-3800 – Iasi South Aerodrome – Iași County – 02.10.2012-
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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
Accident – Glider IS 28 B2 – YR-3800 – Iasi South Aerodrome – Iași County – 02.10.2012-
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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.