Yak42 crash, Russia
A couple of points to consider..
IF one were to discuss weight and balance as a possible factor (and I make NO comment at this stage as to the veracity of that being a factor, from what we know so far), I would make the following observations:
1. With the seating layout provided (IF it's accurate) it would seem that too much "weight forward" from seated pax would not be a reasonable possibility.
2. However... The equipment required by ice hockey players, and therefore very likely carried on this flight, is very heavy. Therefore the weight of baggage, per passenger, would be much greater than an "ordinary" flight -- even an ordinary flight carrying a team of large fellows playing a different sport. IF that baggage was not loaded (distributed) properly, then we could have the source of a significant weight and balance issue.
IF one were to discuss weight and balance as a possible factor (and I make NO comment at this stage as to the veracity of that being a factor, from what we know so far), I would make the following observations:
1. With the seating layout provided (IF it's accurate) it would seem that too much "weight forward" from seated pax would not be a reasonable possibility.
2. However... The equipment required by ice hockey players, and therefore very likely carried on this flight, is very heavy. Therefore the weight of baggage, per passenger, would be much greater than an "ordinary" flight -- even an ordinary flight carrying a team of large fellows playing a different sport. IF that baggage was not loaded (distributed) properly, then we could have the source of a significant weight and balance issue.
Last edited by grizzled; 15th Sep 2011 at 03:35.
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Here is a transcript which appeared in the media, roughly translated by myself.
Captain: 74, 76.
F/E: 74, 76.
Captain: time, headlights (on). We are taking off, threshold (V1?) 190.
Captain: 3, 4, 5, nominal (thrust).
F/E: At nominal.
F/E: Speed increasing. Parameters OK. 130, 150, 170, 190, 210.
Captain: Takeoff (thrust).
F/E: 220, 230.
F/O: Probably the stabilizer.
Captain: Takeoff (thrust). Takeoff (thrust), stabilizer
F/O: What are you doing?
Captain: Takeoff (thrust).
F/E: Takeoff (thrust).
Captain: (expletive).
F/O: Andrey!
Captain: 74, 76.
F/E: 74, 76.
Captain: time, headlights (on). We are taking off, threshold (V1?) 190.
Captain: 3, 4, 5, nominal (thrust).
F/E: At nominal.
F/E: Speed increasing. Parameters OK. 130, 150, 170, 190, 210.
Captain: Takeoff (thrust).
F/E: 220, 230.
F/O: Probably the stabilizer.
Captain: Takeoff (thrust). Takeoff (thrust), stabilizer
F/O: What are you doing?
Captain: Takeoff (thrust).
F/E: Takeoff (thrust).
Captain: (expletive).
F/O: Andrey!
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So that's what happened: they forgot to make the proper trim setting, aircraft accelerated to V2 (210-230) but refused to get off the ground, Captain ordered to increase thrust, F/O made a comment about trim, Captain agreed and still tried to take off. Looks like a situation where the takeoff should have been aborted even after V1...
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I am not shure what "nominal" power is. T/o thrust of Progres D-36 is 63.800N and max cruise thrust 15.700N.
http://www.motorsich.com/pdf/306.pdf
"рубеж" 190 could be transalted also as "limit" 190. I belive that it means V1.
http://www.motorsich.com/pdf/306.pdf
Captain: time, headlights (on). We are taking off, threshold (V1?) 190
Thank you for the translation vovachan. I realize your transcript is not official, but is appreciated just the same.
This dialogue concerning the stabilizer certainly appears to point in the direction of rotation difficulties. The Captain appears to be concerned with thrust, yet this could be explained by a desire to accelerate to make the elevator more effective.
The FO's comment regarding the stabilizer is made after the FE's 230 speed callout. (what would be a realistic rotation speed?)The Captain's repetition of "takeoff" and the addition of "stabilizer" seem like commands. As to what the Captain was doing to cause the FO to ask him "what are you doing", I don't even have a guess.
This dialogue concerning the stabilizer certainly appears to point in the direction of rotation difficulties. The Captain appears to be concerned with thrust, yet this could be explained by a desire to accelerate to make the elevator more effective.
The FO's comment regarding the stabilizer is made after the FE's 230 speed callout. (what would be a realistic rotation speed?)The Captain's repetition of "takeoff" and the addition of "stabilizer" seem like commands. As to what the Captain was doing to cause the FO to ask him "what are you doing", I don't even have a guess.
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Time stamps:
11:58:37 Captain: 74, 76.
11:58:40 F/E: 74, 76.
11:58:41 Captain: time, lights, taking off, limit 190.
11:58:53 Captain: 3, 4, 5, nominal (thrust).
11:58:58 F/E: At nominal.
11:58:59 F/E: Speed increasing.
11:59:04 F/E: Parameters OK.
11:59:07 F/E: 130
11:59:12 F/E: 150
11:59:15 F/E: 170
11:59:19 F/E: 190
11:59:27 F/E: 210
11:59:28 Captain: TOGA!
11:59:31 F/E: 220
11:59:34 F/E: 230
11:59:37 F/O: Probably the stabilizer
11:59:41 Captain: TOGA! TOGA! HS
11:59:47 F/O: What are you doing
11:59:48 Captain: TOGA!
11:59:49 F/E: TOGA
11:59:56 F/O: Andrey!
After 11:59:19 acceleretion decreased. Between first instruction instruction TOGA! and F/E confirmation seems to be interval 21 sec! It look like the first command was omited and TOGA was set after the captain secound command.
11:58:37 Captain: 74, 76.
11:58:40 F/E: 74, 76.
11:58:41 Captain: time, lights, taking off, limit 190.
11:58:53 Captain: 3, 4, 5, nominal (thrust).
11:58:58 F/E: At nominal.
11:58:59 F/E: Speed increasing.
11:59:04 F/E: Parameters OK.
11:59:07 F/E: 130
11:59:12 F/E: 150
11:59:15 F/E: 170
11:59:19 F/E: 190
11:59:27 F/E: 210
11:59:28 Captain: TOGA!
11:59:31 F/E: 220
11:59:34 F/E: 230
11:59:37 F/O: Probably the stabilizer
11:59:41 Captain: TOGA! TOGA! HS
11:59:47 F/O: What are you doing
11:59:48 Captain: TOGA!
11:59:49 F/E: TOGA
11:59:56 F/O: Andrey!
After 11:59:19 acceleretion decreased. Between first instruction instruction TOGA! and F/E confirmation seems to be interval 21 sec! It look like the first command was omited and TOGA was set after the captain secound command.
Last edited by Karel_x; 16th Sep 2011 at 17:07.
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"informed speculation" now tends to point to dragging brakes as the culprit either because someone was inadvertently riding the brakes, or because of some hardware problem. That would create enough nose-down force to prevent it from unsticking.
11:59:19 F/E: 190
11:59:27 F/E: 210
11:59:28 Captain: TOGA!
11:59:31 F/E: 220
11:59:34 F/E: 230
11:59:27 F/E: 210
11:59:28 Captain: TOGA!
11:59:31 F/E: 220
11:59:34 F/E: 230
Very interesting !
That would be 15s from 190 kph to 230 kph.
That's an eternity.
and that with TOGA thrust.
Definitely something wrong here.
Stuck brakes would indeed create a strong Nose Down moment as long as they were on concrete. Only after getting on the grass and 'jumping' a bit downhill, the Nose of the Aircraft starts to rotate. Given the fact that the factor of adhesion would be very much reduced at that moment and considering the bounce after the bump when leaving the runway a subsequent rotation seems plausible.
The story with the breaks seems to match most of the known.
A Nose Heavy CG would also match many of the facts but the acceleration with TOGA thrust should rather have been higher in that case.
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Very interesting !
That would be 15s from 190 kph to 230 kph.
That's an eternity.
and that with TOGA thrust.
Definitely something wrong here.
That would be 15s from 190 kph to 230 kph.
That's an eternity.
and that with TOGA thrust.
Definitely something wrong here.
Stuck brakes would indeed create a strong Nose Down moment as long as they were on concrete. Only after getting on the grass and 'jumping' a bit downhill, the Nose of the Aircraft starts to rotate. Given the fact that the factor of adhesion would be very much reduced at that moment and considering the bounce after the bump when leaving the runway a subsequent rotation seems plausible.
Further, some earlier quotes from the investigators say there were no visible skid marks found on the runway. If the parking brake was applied, as the aircraft gained speed, and the wing gained lift, things would reach a point where the wheels would lock and there would be obvious skid marks on the runway.
The story with the breaks seems to match most of the known.
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CYR audio recording
Tripped over this on YouTube. Supposedly the audio from the CVR, though the time intervals don't match, so it is likely a reenactment. Note the different transcription and translation than was posted previously in this thread. Someone who knows Russian will have to comment on the differences.:
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Thank you all for being gentle, I get that main undercarriage braking will put weight on the nose-wheel and I do not know what V2 is on this, but I assume that if V1 is 190(somethings) then 230 exceeds V2. So, if the wings are flying then there is no downforce on the mainwheels, hence no braking on the mainwheels, hence no nose-down moment caused by breaking (of the mainwheels)?
Perhaps we should first clear up what V2 was for this weight, both properly configured and clean?
Perhaps we should first clear up what V2 was for this weight, both properly configured and clean?
Lift = essentially angle of attack * speed squared. you need both angle of attack AND sufficient speed to generate the lift.
So if the aircraft doesn't rotate to angle the wing into the airflow, it ain't gonna fly.
I've watched a fair few russian aircraft take off, and some of them do seem to accellerate slowly and use alot of runway. (ever wonder why most russian airports seem to have 4000m of tarmac!). I can't comment on whats normal for a yak42 but if those timestamps are correct than thats a very very slow accel. 50 secs from 75 to 190 kph (40 to 105 kts) ! My car is significantly quicker than that! and another 15 secs from 190 to 230 (125kts) - and we can surmise that they went off the end of the strip round about that point - thats 65 secs to get to 125kts - even an old russian klunker can't be that slow. Gotta be something wrong with that.
Probably reading too much into an unoffical transcript, but I don't know about you but If i'm heading off the end of the runway and either of us call for Full thrust and nothing happens I ain't gonna call for it agian. I assume either pilot or the FE can firewall the thrust levers in a yak42? why wait and ask for it again when you are going grass cutting?
EDIT to add that I'm reading the 74, 76 bit at the beginning as speeds - but you could read it that the 'speed increasing' comment was the start of the roll in which case accell looks pretty normal. Who knows. No doubt someone will come up with an answer soon. Unless the laws of physics have changed recently theres only a handful of things that make an aircraft go off the end of the runway like that.
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I'm reading the 74, 76 bit at the beginning as speeds
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Supposedly the audio from the CVR, though the time intervals don't match, so it is likely a reenactment. Note the different transcription and translation than was posted previously in this thread. Someone who knows Russian will have to comment on the differences.
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Here is a cablegram from MAK which appeared on the web, google-translated with some light edits by me. I left out the boring parts
Telegram number 140 635 from the MAC, the 09/14/2011
DATE, TIME EVENTS (LOCAL, UTC, time of day): 09/07/2011, 15:59
Moscow time (11:59 UTC), DAY
PLACE EVENT: RUSSIA, at a distance about 800 m about 240 AZIMUTH
Degrees from the exit end of runway 23 AERODROME Tunoshna (Yaroslavl)
COORDINATES scene of the accident 57 deg 33.029 'N, 40
Deg 07.336 'E
Event Type: CATASTROPHE
Type of aircraft: Yak-42D
AC REGISTRATION NUMBER: RA-42 434
CERTIFICATE OF STATE REGISTRATION: NUMBER OF 4565 19.09.2007,
Issued by Federal Service for Supervision of TRANSPORTATION
MoT RUSSIA
Certificate of Airworthiness: NUMBER 2082101871 FROM 14.12.2010, ISSUED
….
INFORMATION ABOUT THE CREW:
CPT: total flight time - 6954 on the Yak-42 - 1312, AS
CPT Yak-42 - 686 , meteorological conditions - 60 x 550m, 200M TAKEOFF
The co-pilot: the total flight time - 13 492 H, on the Yak-42 - 613
Mechanic: the total flight time - 568 h, on the Yak-42 - 568
Technical staff on board: 2 engineers,
CABIN CREW
….
NUMBER OF CREW / PASSENGERS: 8 (including 2 GROUND ENGINEER) /
37
KILLED CREW / PASSENGERS: 7 / 37
INJURED CREW / PASSENGERS: 1 / 0
ABOUT AC: SERIAL NUMBER: 4520424305017, manufacturer, date -
SAZ (Saratov), 1/10/1993, HOURS AC - 6482, 3109 .,
LIFE UNTIL TO-10000 - 18 years, until 10/01/2011, CAPACITY - 15,000 H,
….
NATURE OF MISSION: CHARTER FLIGHT
FLIGHT ROUTE: Yaroslavl - Minsk
LAST POINT OF DEPARTURE: Yaroslavl
DETERMINED POINT LANDING: Minsk
NUMBER OF PASSENGERS AND THEIR NATIONALITY: 37, 26 - RF, 3 - CZECH REPUBLIC, 2 - CANADA
1 EACH (Germany, Slovakia, Sweden, Latvia, Byelorussia Ukraine)
IMPACT EVENTS, INCLUDING FOR OTHERS object known: 7
CREW AND PASSENGERS KILLED 36, 1 GROUND ENGINEER
and 1 passenger (later died in Hospital) RECEIVED Serious injuries. FELL A few trees, FUEL SPILL over a wide area, destroying ANTENNAS COURSE
SYSTEMS APPROACH LIGHTS DAMAGED
Takeoff weight, CENTERING: Take-off weight 52 816 KG, CENTERING 4.24
Percent, is within the RLE
Weather conditions: wind 360 - 03 M / C, visibility 10, Cloudy
SIGNIFICANT Stratocumulus 990 M, temperatures of 17.8,
PRESSURE 747.9 mm Hg, 0.6 COP
BRIEF DESCRIPTION OF EVENT: operate charter flights AKY OF 9633
ROUTE Yaroslavl - Minsk.
On board were two pilots, flight engineer, 3 flight attendants, 2
ENGINEER'S GROUND MAINTENANCE AND 37 PASSENGERS.
Takeoff from runway 23 AIRCRAFT TERMINAL Tunoshna OVERRAN
Runway, collided with Antenna COURSE SYSTEM, APPROACH LIGHTS
TREES, damaged and caught fire.
DESTROYED PLANE FOUND distance of about 800 m from the exit
Runway 23, LEFT AXIS about 100 m. Scattered COMPONENTS
Over a large area partially in the water.
The extent of damage the aircraft: AIRCRAFT DESTROYED
INFORMATION ON THE STATUS Flight recorders: NO DAMAGE,
decoded
PHYSICAL characteristic of scene of the accident: the river bank
Flat terrain, stand-alone trees up to 10 METERS
RECOMMENDATION: Conduct classes with flight crews YAK-42 TO CORRECT
Position of the feet on the pedals at various stages of flight, and THE
PROCEDURE ADJUSTMENT pilot SEATS.
(END)
DATE, TIME EVENTS (LOCAL, UTC, time of day): 09/07/2011, 15:59
Moscow time (11:59 UTC), DAY
PLACE EVENT: RUSSIA, at a distance about 800 m about 240 AZIMUTH
Degrees from the exit end of runway 23 AERODROME Tunoshna (Yaroslavl)
COORDINATES scene of the accident 57 deg 33.029 'N, 40
Deg 07.336 'E
Event Type: CATASTROPHE
Type of aircraft: Yak-42D
AC REGISTRATION NUMBER: RA-42 434
CERTIFICATE OF STATE REGISTRATION: NUMBER OF 4565 19.09.2007,
Issued by Federal Service for Supervision of TRANSPORTATION
MoT RUSSIA
Certificate of Airworthiness: NUMBER 2082101871 FROM 14.12.2010, ISSUED
….
INFORMATION ABOUT THE CREW:
CPT: total flight time - 6954 on the Yak-42 - 1312, AS
CPT Yak-42 - 686 , meteorological conditions - 60 x 550m, 200M TAKEOFF
The co-pilot: the total flight time - 13 492 H, on the Yak-42 - 613
Mechanic: the total flight time - 568 h, on the Yak-42 - 568
Technical staff on board: 2 engineers,
CABIN CREW
….
NUMBER OF CREW / PASSENGERS: 8 (including 2 GROUND ENGINEER) /
37
KILLED CREW / PASSENGERS: 7 / 37
INJURED CREW / PASSENGERS: 1 / 0
ABOUT AC: SERIAL NUMBER: 4520424305017, manufacturer, date -
SAZ (Saratov), 1/10/1993, HOURS AC - 6482, 3109 .,
LIFE UNTIL TO-10000 - 18 years, until 10/01/2011, CAPACITY - 15,000 H,
….
NATURE OF MISSION: CHARTER FLIGHT
FLIGHT ROUTE: Yaroslavl - Minsk
LAST POINT OF DEPARTURE: Yaroslavl
DETERMINED POINT LANDING: Minsk
NUMBER OF PASSENGERS AND THEIR NATIONALITY: 37, 26 - RF, 3 - CZECH REPUBLIC, 2 - CANADA
1 EACH (Germany, Slovakia, Sweden, Latvia, Byelorussia Ukraine)
IMPACT EVENTS, INCLUDING FOR OTHERS object known: 7
CREW AND PASSENGERS KILLED 36, 1 GROUND ENGINEER
and 1 passenger (later died in Hospital) RECEIVED Serious injuries. FELL A few trees, FUEL SPILL over a wide area, destroying ANTENNAS COURSE
SYSTEMS APPROACH LIGHTS DAMAGED
Takeoff weight, CENTERING: Take-off weight 52 816 KG, CENTERING 4.24
Percent, is within the RLE
Weather conditions: wind 360 - 03 M / C, visibility 10, Cloudy
SIGNIFICANT Stratocumulus 990 M, temperatures of 17.8,
PRESSURE 747.9 mm Hg, 0.6 COP
BRIEF DESCRIPTION OF EVENT: operate charter flights AKY OF 9633
ROUTE Yaroslavl - Minsk.
On board were two pilots, flight engineer, 3 flight attendants, 2
ENGINEER'S GROUND MAINTENANCE AND 37 PASSENGERS.
Takeoff from runway 23 AIRCRAFT TERMINAL Tunoshna OVERRAN
Runway, collided with Antenna COURSE SYSTEM, APPROACH LIGHTS
TREES, damaged and caught fire.
DESTROYED PLANE FOUND distance of about 800 m from the exit
Runway 23, LEFT AXIS about 100 m. Scattered COMPONENTS
Over a large area partially in the water.
The extent of damage the aircraft: AIRCRAFT DESTROYED
INFORMATION ON THE STATUS Flight recorders: NO DAMAGE,
decoded
PHYSICAL characteristic of scene of the accident: the river bank
Flat terrain, stand-alone trees up to 10 METERS
RECOMMENDATION: Conduct classes with flight crews YAK-42 TO CORRECT
Position of the feet on the pedals at various stages of flight, and THE
PROCEDURE ADJUSTMENT pilot SEATS.
(END)
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RECOMMENDATION: Conduct classes with flight crews YAK-42 TO CORRECT
Position of the feet on the pedals at various stages of flight, and THE
PROCEDURE ADJUSTMENT pilot SEATS.
Position of the feet on the pedals at various stages of flight, and THE
PROCEDURE ADJUSTMENT pilot SEATS.
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Flight Crew Toxicology Status
Captain too ill to fly...
Brakes set or not set...
CVR - F/O to Captain "What are you doing?"...
Now a refresher course on correct foot on pedal placement during flight???
Has there been any postmortem information released on the toxicology status of the flight crew? Will there be?
Brakes set or not set...
CVR - F/O to Captain "What are you doing?"...
Now a refresher course on correct foot on pedal placement during flight???
Has there been any postmortem information released on the toxicology status of the flight crew? Will there be?
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MAK info 17.09.2011
Here's what MAK published today, translated by Google and polished with the help of my very deficient Russian, English and aviation knowledge. Any corrections are welcome.
Original here: MAK: Yak-42 RA-42434
Original here: MAK: Yak-42 RA-42434
- Takeoff weight and center of gravity aircraft did not exceed the permissible limits
- Before take-off flaps were set at 20 degrees (take-off position), the stabilizer -8.7 degrees pitch up, which corresponds to estimated 24-25% of the alignment of the MAR (?)
- Before take-off the crew double-checked all channels of control of the aircraft, including the channel of the elevator, the elevator was deflected cleanly. The maximum recorded deflection of the elevator pitch up was 21 degrees, which corresponds to a constructive stop. Last check was performed 1 minute and 40 seconds before takeoff.
- Weather conditions at the time of the accident: wind 360 - 3 m/s, visibility 10 km, clouds significant stratocumulus lower limit of 990 m, the temperature +17.8° C, 747.9 mm Hg pressure. Art., friction coefficient of 0.6.
- Take-off from runway 23 was carried out. Taxiing aircraft to take-off was carried out by RD (taxiway?) 5. Distance from RD 5 to the start of runway 23: about 300 meters. Total runway length: 3000 meters.
- The crew decided to take off at nominal thrust settings. Preliminary simulations showed that the rate of up to ~ 165 km/h acceleration rate corresponded to the set engine thrust.
- Command to rise of nose wheel began at approximately 185 km/h. The elevator was set to pitch up at values of 9-10 degrees (about half way), but increase of pitch angle did not happen. After 6 seconds thrust settings were put in take-off mode. Despite increases take-off thrust, acceleration slowed significantly, which may be explained by the appearance of additional braking force. The actual value of an additional braking force will be established based on the results of mathematical modeling and field experiment. The braking systems of the aircraft were sent to be studied by a specialized institute. These study started on 16 September.
- The maximum speed reached by the plane: approximately 230 km/h. In spite of continuing increase of elevator pitch up, separation from the runway did not happen. According to the traces on scene (?), the actual separation of aircraft took place at a distance of 400 meters after exiting runway 23 end at deflection of elevator at 13-14 degrees and the relocation of the stabilizer to 9.5 degrees pitch up. After separation of the aircraft from the ground followed an encounter with the antenna system localizer and the rapid growth of the pitch angle to 20 degrees for 2-3 seconds. Maximum recorded height: 5-6 meters.
- Then followed an intensive roll of the plane to the left and its collision with obstacles and the ground.
- Measurements of fragments of the aircraft revealed that at the time of the accident flaps and slats were set in take-off position, the spoilers were retracted, the stabilizer in position about 10 degrees pitch up. Wiring layout elevator control showed that at the time of the accident there was not disconnection of wiring.
- The Technical Commission investigates all possible versions of occurrence of additional braking force during take-off and the reasons why the aircraft failed to make timely detachment from the runway.
- Before take-off flaps were set at 20 degrees (take-off position), the stabilizer -8.7 degrees pitch up, which corresponds to estimated 24-25% of the alignment of the MAR (?)
- Before take-off the crew double-checked all channels of control of the aircraft, including the channel of the elevator, the elevator was deflected cleanly. The maximum recorded deflection of the elevator pitch up was 21 degrees, which corresponds to a constructive stop. Last check was performed 1 minute and 40 seconds before takeoff.
- Weather conditions at the time of the accident: wind 360 - 3 m/s, visibility 10 km, clouds significant stratocumulus lower limit of 990 m, the temperature +17.8° C, 747.9 mm Hg pressure. Art., friction coefficient of 0.6.
- Take-off from runway 23 was carried out. Taxiing aircraft to take-off was carried out by RD (taxiway?) 5. Distance from RD 5 to the start of runway 23: about 300 meters. Total runway length: 3000 meters.
- The crew decided to take off at nominal thrust settings. Preliminary simulations showed that the rate of up to ~ 165 km/h acceleration rate corresponded to the set engine thrust.
- Command to rise of nose wheel began at approximately 185 km/h. The elevator was set to pitch up at values of 9-10 degrees (about half way), but increase of pitch angle did not happen. After 6 seconds thrust settings were put in take-off mode. Despite increases take-off thrust, acceleration slowed significantly, which may be explained by the appearance of additional braking force. The actual value of an additional braking force will be established based on the results of mathematical modeling and field experiment. The braking systems of the aircraft were sent to be studied by a specialized institute. These study started on 16 September.
- The maximum speed reached by the plane: approximately 230 km/h. In spite of continuing increase of elevator pitch up, separation from the runway did not happen. According to the traces on scene (?), the actual separation of aircraft took place at a distance of 400 meters after exiting runway 23 end at deflection of elevator at 13-14 degrees and the relocation of the stabilizer to 9.5 degrees pitch up. After separation of the aircraft from the ground followed an encounter with the antenna system localizer and the rapid growth of the pitch angle to 20 degrees for 2-3 seconds. Maximum recorded height: 5-6 meters.
- Then followed an intensive roll of the plane to the left and its collision with obstacles and the ground.
- Measurements of fragments of the aircraft revealed that at the time of the accident flaps and slats were set in take-off position, the spoilers were retracted, the stabilizer in position about 10 degrees pitch up. Wiring layout elevator control showed that at the time of the accident there was not disconnection of wiring.
- The Technical Commission investigates all possible versions of occurrence of additional braking force during take-off and the reasons why the aircraft failed to make timely detachment from the runway.
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Despite increases take-off thrust, acceleration slowed significantly, which may be explained by the appearance of additional braking force.
11:59:47 F/O: What are you doing
RECOMMENDATION: Conduct classes with flight crews YAK-42 TO CORRECT Position of the feet on the pedals at various stages of flight, and THE
PROCEDURE ADJUSTMENT pilot SEATS.
PROCEDURE ADJUSTMENT pilot SEATS.
Toxicology may reveal a lot.