Video Wanted - Interflug A310 Stall Incident

[Opositve]

Ladies and Gentlemen,

I'm looking for video of the Interflug A310 stall incident over Moscow back in 1991.

I saw amateur film of the incident on a documentary program years ago, but I can't find the video anywhere and can't remember which program it was on.

Anybody have a clue on where this was shown or, better yet, a copy of the video?

Thanks!
OPos.

[akerosid]

I have been trying to find information about this incident for years, but "unfortunately", because it was non-fatal, it's hard to find anything - even a report of the incident.

I did see a video about an A310 stall incident around that time, but it was actually a Tarom A310 at Paris.

[Gabriel]

I have been trying to find information about this incident for years, but "unfortunately", because it was non-fatal, it's hard to find anything - even a report of the incident.

Not a lot, but this is an intersting summary:

A310 Aerobatics
"Airliners Magazine", Winter 1992

Following an autopilot-coupled go-around, the pilot attempted to counteract the autopilot's programmed pitch-up by pushing forward on the control column. (In most circumstances pushing on the control column disengages the autopilot but automatic disconnect is inhibited in go-around mode. The autopilot should be disconnected or a mode other than go-around should be engaged through the FCU-Flight Control Unit).
As a result of the control inputs, the autopilot trimmed the stabilizer to 12° (nose up) to maintain the go-around profile, but the elevator was deflected 14° (nose down). After climbing about 600ft (to around 2100ft) the autopilot captured its preselected missed approach altitude and disconnected, as the go around mode was no longer engaged. In the next 30 seconds, the grossly mistrimmed A310 pitched up to 88° and airspeed dropped to less than 30kt. (The stall warning activated then canceled itself as the airspeed fell below usable computed values and the autothrottle system dropped off.) At 4,300ft, the A310 stalled, pitching down to -42° while pilot-applied control inputs showed full up elevator. Airspeed increased to 245kt then the aircraft bottomed out at 1,500ft, pulled + 1.7g, then climbed rapidly.
The second pitch-up reached 70° followed by a stall 50 seconds after the first. The nose dropped to -32° and airspeed rose to 290kt and the aircraft bottomed out at 1,800ft. On the third pitch-up (to 74°), the A310 climbed to 7,000ft then stalled again, about 60 seconds after the second stall. This time airspeed reached 300kt in a -32° nose down attitude before the aircraft leveled off at 3,600ft.
The fourth pitch-up reached 9,000ft but this time the crew's use of thrust and elevator control (and very likely retrimming the stabilizer) prevented a stall and the A310 leveled off at 130kt. Speed then increased accompanied by another milder pitch- up to 11,500ft where control was eventually regained.
All aircraft systems operated in accordance with design specifications. The reaction of ATC (the incident happened at Moscow) or the passengers is not recorded.

[Deadstick]

I bet there were some very messy underwear after that ride.

[Curtis Malone]

That's why I fly my go-arounds by hand and call for the AP once things are nice and stabilized.

[mzk49o1]

Around 2:20. But its just a FDR rendering. The Tarom incident follows right after.

[Opositve]

Thanks MZ!

That will work nicely.

It may be that this was exactly the show I saw and I just remembered the video as being from the same incident. In any case that clip shows exactly what I was looking for: a real-life example of why computerized systems need to do what the human end-users expect from them rather than what designers think is optimal for performance.

As the report Gabriel posted said, "All aircraft systems operated in accordance with design specifications." - which was exactly the problem in this case and what I'm trying to teach my people to avoid.

Cheers and thanks to all!
Opos.

[Deadstick]

Excellent! Thanks!

[mzk49o1]

No problem!

Here's a URL to a playlist for the entire series:

http://www.youtube.com/view_play_list?p=35C57BC6614125C2

[akerosid]

It just goes to show that a picture is worth a thousand words; I thought the text provided above was scary enough, but when you actually see the simulation, it is shocking. It's amazing, given the safety issues it raises, that no incident report was prepared (or maybe there was one and the Russians are keeping it secret? - seems unlikely).

My feeling, for what its worth, has always been that the Interflug pilots, long used to IL62s and other Russian types with relatively sedate climb angles, probably hadn't experienced an A310 g/a in "real life" and found it a bit too much, which led them to try and override the system, with the results that followed.

It was circumstances such as this which led China Airlines to lose two AB6s - one at Nagoya and one at TPE: the flight crew attempting to override the aircraft's controls. This does not appear to have happened since, either on the A310/A300-600, or on any of the FBW types; presumably Airbus has redesigned its software to stop it happening?

[Leftseat86]

It just goes to show that a picture is worth a thousand words; I thought the text provided above was scary enough, but when you actually see the simulation, it is shocking. It's amazing, given the safety issues it raises, that no incident report was prepared (or maybe there was one and the Russians are keeping it secret? - seems unlikely).

My feeling, for what its worth, has always been that the Interflug pilots, long used to IL62s and other Russian types with relatively sedate climb angles, probably hadn't experienced an A310 g/a in "real life" and found it a bit too much, which led them to try and override the system, with the results that followed.

It was circumstances such as this which led China Airlines to lose two AB6s - one at Nagoya and one at TPE: the flight crew attempting to override the aircraft's controls. This does not appear to have happened since, either on the A310/A300-600, or on any of the FBW types; presumably Airbus has redesigned its software to stop it happening?

Software need not be redesigned here, but crew training definitely needed improvement, and likely has seen it. Those are just a couple instances in which automation was misunderstood by aircrews beginning to fly more advanced aircraft.

[Graham2001]

Sorry for bumping this old thread, but while poking around online I've found a scan of a German language article on the Interflug A310 Stall Incident and was wondering if anyone would be able to provide a translation? For that matter does anyone know what the flight number was?

http://www.interflug.biz/downloads/IF-Airbus_Incident_SVO_110291.pdf

I've also found a thread on another forum dating back to 1996 which suggests that there may have been an official investigation of some kind into this flight by the Luftfahrt-Bundesamt.

http://www.science-bbs.com/2-aeronau...1ac410cc06.htm

[Petertenthije]

Here's the translation. The article also refers to the official investigation which has been filed under reference 6 X 002-0/91. The article is not clear enough for me to say if this is the DDR reference or the unified Germany reference.

http://www.interflug.biz/downloads/I...SVO_110291.pdf

TOP SECRET
German Airbus out of control
The near-catastrophe in Moscow

Late april all 263 people died onboard an Airbus A300 near Nagoya (NOTE: referring to China Airlines flight 140). The investigations have ont been completed yet, but first indications are during the go-around the auto-pilot was used the wrong way. Three years earlier there was a similar accident in Moscow that was kept mostly quiet.

February 11th, 1991, 100 passengers had an unforgettable flight on the former DDR airline Interflug. They had boarded at Berline Schoneveld for a flight to Moscow. The flight was uneventfull, until they started the landing.

Just before 11 o'clock the flight is on approach to Sheremetyevo. The flight is on a ILS approach to runway 25L. The plane is on full auto-pilot.

As usual during such a landing the pilots are preparing the landing. That includes the second pilot setting the go-around altitude of 3.580 foot (1.090 meter) in the auto-pilot's computer. The plane is on approach wtih flaps and slats out at 1.550 foot (472 metres) when the pilots are informed by ATC that the runway is not clear. They are instructed to do a go-around. The pilots put the throttle in go-around mode and correct the settings of the flaps. They also change the altitude settings for the go-around computer tpo 1.640 foot (500 meter), the altitude assigned by ATC.

As the graphs indicate the Airbus climbed at 10:56:41 as expected on auto-pilot. The pilots believe the plane is climbing too steeply. Therefor they disconnect the auto-pilot. When they hear the stall alert they try to push the nose down. However, at this point the auto-pilot was not totally disconnected. Therefor the manual change in attitude is counteracted by a auto-pilot change of trim level.

Only when the go-around altitude is reached is the go-around autopilot disconnected. However, the pilots fail to realise this. They are still trying to correct level of the climb. Due to this "fight" between pilots and auto-pilot the plane is at climbing at full power, but with very slow speed. At a height of 4.327 foot (1.318 meter) the speed is just 34 knots (63 kph). This is well below the stall speed and the wings barely provide any lift. The crew did not notice the stall alerts.

At this point in filght the plane dips to the left and goes into a nearly uncontrolled vertical dive. 23 Seconds later it's at 1.487 foot (453 meter) when at 10:57:46 it starts to climb again. This time is climbs for 29 seconds up to an altitude of 5.787 foot (1.763 meter). During the climb the speed again drops and again it dips to the left.

At 10:58:40 the process repeats. At an altitude of 1.775 foot (541 meters) it starts to climb again. This time for 31 seconds till it reaches and altitude of 7.355 foot (2.241 meter). This time it dips to the right.

These uncontrolled climbs and descents are repeated four times. Only after decreasing the engine power does the crew regain control and land safely at 11:05:58.

While the passengers and crew where terrified, there where no injuries. As was usual during those days (NOTE: cold war) no information was revealed about this incident. The accident investigators (FUS / Flugunfalluntersuchungsstelle) filed it under "flight disruption". In the investigation (file number: 6 X 002-0/91) the cause is noted as failure of the crew to notice that the auto-plot had disengaged. They where under the impression that the auto-pilot could not disengage, and paid insufficient attention to various warnings.

The pilots had not noticed that the auto pilot had changed trim level. This meant the plane was out of control between 10:56:50 abd 11:03:00.

Only after changing the power and trim level did the pilots, unwittingly, regain control. In desperation the captain had also pulled several fuses in an attempt to disable the auto-pilot. This did not work, as the wrong fuses where pulled!

No technical issues were found on the plane. The auto-pilot disconnected certain modules due to the strange flight path and resulting unreliable data.

That leaves the crew's qualifications. The captain had 6.399 flight hours including 5.699 hours on the Il-18 and 730 hours on the A310. The second officer 6.778 hours of which 5.509 on the Il-18 and 1.269 on the A310.

That the pilots had skipped two generations of planes between the Il-18 and the A310 was summarised as such by the FUS: "The crew did not follow essential rules of "Crew Coordination" and "Cockpit Resource Management". They lacked the required skills to operated a modern 2-man glass cockpit".

The lead investigator said: "The incident was caused by a disruption of communication between crew and plane. In a modern plane several safety controls are in place such as flight envelope protection. During a critical phase the pilots tried to override the auto-pilot, not fully realizing the potential consequences".

The alsmost crashed A310 is currently part of the Luftwaffe's VIP fleet, flying under serial number 10+23. The two other former Interflug A310s are now also part of the Luftwaffe.

[Graham2001]

Here's the translation. The article also refers to the official investigation which has been filed under reference 6 X 002-0/91. The article is not clear enough for me to say if this is the DDR reference or the unified Germany reference.

Thank you for providing that translation, that's more information on this incident than I've seen in the other accounts I've found online, provided of course the reporter didn't 'spice it up'.

But it is clear the investigation (in whatever form it took) is out there, this video (Which I linked another thread.) was made in 2013 and purports to depict the movements of the aircraft over Moscow.

https://www.youtube.com/watch?v=FJViilcDTyw

Later:Just checked the Bundesstelle für Flugunfalluntersuchung (BFU) website to see if I could pull up report 6X002-0/91, the downloadable reports don't go back any further than 1995.

A search using Google to see if it had been archived elsewhere turned up the fact that it was apparently referenced during the AA flight 587 investigation, which makes sense because the the way the aircraft flew during the Interflug Incident, must have put heavy stress on the airframe. However it did not turn up the report itself.