There isn't much room for error in the "how it is supposed to be done though.

Stall at >1g trying to pull though as there was not enough room?

"Only in Russia"

There is a YT of a formation of AT-6's "water skiing" on a lake.
It's cool, and stupid.

In the "do it this way" clip, doesn't look "close" at all to me. Push Nose down, roll right, level out. Good timing, no tears.

I don't think there was Stall. "Pulling through" isn't what our pilot needed. He needed to arrest his descent, and he appears to have begun to input correct controls just as his left wings snagged the turf.....

In a turn with roll at or near ninety degrees, "Up" is sideways. We got a glimpse of correct controls just as the right wings caught the airstream after cartwheeling, a bit late....?

imo

Kulverstukas put a video of a prior routine in post #28. https://m.youtube.com/watch?v=Ud1RFzJ34sw

In the #28 video the pilot finishes the left diving turn rolling the aircraft right to end up flying wings level aligned parallel with the crowd line then does a climbing turn. Going off the Kulverstukas comments it appears it is a well practised routine.

In the accident vid the aircraft actually looks to be verring to the left of the parallel display line with no right roll even initiated before ground impact ?





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Spatial disorientation or distraction in the cockpit?
I can't imagine any other reasons for flying into the ground in such a controlled way :(

rnzoli. Yes CFIT. Hence my muse about his "plan". Flying Binghi, I referenced post 28 above, the maneuver looks pretty vanilla, and not that risky when done with good timing.

You also brought up right rudder at impact. I saw that also, so a conclusion of "late" timing would be a reasonable explanation for the accident?

Inexperience may have allowed him to get too low, misjudging the rate of descent in knife edge. Assuming his plan was similar to Kulver's surmise....

Concours77, you may very well be right, though the right rudder input suggests to me a possible jammed control. (Note, my AN2 cockpit time is under an hour flying level around a circuit at slow speed, and that were a long time ago. I did own a Yak52 for a number of years so have some Russian equipment exposure)


I don't like blaming pilots for anything unless there is an accident report suggesting otherwise, so...

Looking again at the #28 video of a prior airshow: As the aircraft recovers from the turning dive and rolls right to the wings level altitude the smoke from the exorst stays close to the fuselage - the ball would be centred. Suggests to me a co-ordinated rudder and aileron input. What i carn't see is if the exorst outlet is the same as the modified extended one shown in the accident aircraft video.

In the accident video it appears to me that the exorst smoke trail gradually veers further away from the aircraft as it would entering into a controlled 'knife edge' flight. (AN2 would probably need another ten thousand horse power to do full knife edge) Going off the videos of prior airshow displays the pilot was not doing anything near a knife edge flight at that part of the display though was doing a rolling right turn to fly wings level and parrele to the flight line before entering the next manoeuvre.

As the AN2 is not designed for aerobatics as such (It is a heavyweight ag plane though) I would surmise that the flight controls would get fairly heavy as the airspeed increases. The accident pilot would from prior display experience expect to be 'strong arming' the controls as the aircraft came out of the left turning dive doing a right roll. If the controls were jammed in any way, because of prior expectations of heavy control inputs it may not become immediately apparent that there is a problem - it would likely be several seconds of confusion before the issue became apparent.

I'd suggest that the gradually veering smoke trail indicates the pilot was attempting to do the normal co-ordinated aileron and rudder right roll recovery though did not pick up on a jammed aileron until it were to late.






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The jammed control theory has 2 weak points

1) the a/c is a fully coordinated diving turn down to 2 feet between wingtip and grass, when it's already way too late to recover. If you have an aileron jam, you would notice the turn becoming uncoordinated (smoke detaching from the fuselage) at a much greater height, because you get your independent right rudder input responded by the a/c, but no response to the aileron input. There is no sight of anything like that.

2) Jammed controls typicall result in an uncontrollable high speed, high angle impact with the ground, with small impact crater radius. On the other hand, crashes due to misjudged height above terrain result in high speed, but low angle collisions with the ground, resulting in the long trail of debrish along the crash path. This crash fits into the latter category.

For me it's more interesting, why the pilots made this mistake. I have seen a MiG-23 crash resembling this one. High speed flying towards spectators, perpendicular to the runway, and high bank turn in the last seconds. The result was similar, that aircraft actually bounced from the ground, engine fire occured and crashed 1 km away eventually.

So somehow this type of crash is intrinsic to, "coded" into the manouver. If you turn early, it is not spectacular enough, you can't scare the crowd. But if you turn late, you lose more altitude than originally planned, gain higher speed in the process. Turning at that point will require more than the usual control forces, higher G loading etc. The safety rules say that the aircraft cannot overfly the crowd, but in case of the pilot already making the mistake and missed the regular point of turning parallel with the spectators, it would be actually much safer to allow the aircraft to stay level, climb and fly over the spectators.

Heh, ..just two?..:) Since posting I've thought of several more weak points in my theory.

I do note though that the aircraft had sufficient height to actually veer left of what i take to be the display line (pararelle to the crowd line) before impacting the ground. If the pilot had miss-judged the height would not the aircraft impact the ground before attaining the display line (i.e. Heading to the right of the display line) or actually on the line? In one of the videos posted by Kulverstukas the aircraft looks to be heading almost 30º away to the left of the display line before impact.






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FB,

I think the Ruddering issue is not too germane; the impact was more or less concurrent with what I saw as rudder deflection. It suggests a late attempt to stop deviation from flight path, which I assume aligns with the runway, or was intended to.

The separated smoke trail and "veering left" suggests to me a slipping (or sinking) aircraft, which is not at all desired....

Aircraft heading looks quite left of (desired) heading to me also. The debris trail, seemingly more aligned with the runway, tells us the actual flight path at impact, and also suggests an uncoordinated condition....(nose left of heading).

One last thing is the arc (veer) of the last portion of the flight. It suggests to me an aircraft losing lift, not in control. Even had it been corrected with Rudder, it would have entered an even more aggressive slip. Recovery was not possible well before impact, IMO.

(Because of the extreme roll, "slip" and "skid" must be considered with a grain of salt....)

It was here, but vimeo video was removed for unclear reason. This is the training flight two days before accident, 31/08/17, but at the base airfield (Severka) not at the actual one.

Information about the pilot: Gender male, 10.07.1968.

The following pilot certificates to the FAC are presented to the commission:
The certificate of the pilot of commercial aviation III P No. 007510, issued VKK FAVT MT of the Russian Federation on 15.12.2004. Admitted for: Yak-18T (30.12.2003), Cessna-208 (22.12.2005) (all as PIC and pilot-instructor).
Certificate of Aviation Specialist No. 002065, issued by CA ROSTO 25.04.2005. Admitted for: the Yak-52 (2005), An-2 (2005), Cessna-172 (2005). Mi-2 helicopter (2005). (All as a PIC and pilot-instructor).
The certificate of the amateur pilot III P No. 002282, issued by the VKK Rosaviatsii 30.08.2011. Admitted for: Cessna-172 (2011) as a PIC.
The certificate of the linear pilot № 0043187, issued by the VKK FAVT MT of the Russian Federation 11/06/2015. Admitted for: Boeing-747 (pilot- instructor).
The certificate of the linear pilot (first class) I П № 013767, issued VKK FAS of Russia on 17.07.2007. Admitted for: Yak-42 (13/10/2000, PIC), Falcon 20/2000 (15.04.2004, Pilot-instructor) Boeing-757 (12.03.2010, PIC, instructor), Boeing-747 (26.07.2011, PIC).
Certificate of the pilot of transport aviation No. 3193771, issued July 18, 2008 by the US Air Administration. Admitted for: Сhallenger-650, Embraer-145 (PIC).
The validity of these certificates and the availability of qualification checks are being refined.
The total flight time is 14600 hours (according to the records in the flight book), total hours on type / of them as a PIC are being refined, meteorological minimum category III A ICAO 15X200X150

Who was PF? The "amateur" had only C172 time? Is total time an aggregate of all these airmen? That seems odd.

This accident does most closely resemble CFIT. That means our pilot was distracted, incapacitated, unfamiliar, or experienced mechanical issues.

More of a puzzle. Suggest a placard: "Fly wings level below two hundred feet AGL"

All this documents belongs to one man, PF at the accident. Second seat occupant at this flight was only a photographer and doesn't even mentioned in accident report of MAK (IAC).

Type of aircraft: An-2T
State and registration badges: RA-35171
Certificate of State Registration: No. 7378, issued by UIBP FAVT MT of the Russian Federation 02.09.2015
Information about the owner of the aircraft: Private person

Information on aircraft: Manufacturer PZL-MIELEC (Poland), date 30.12.1969, Serial No. 1G 11310, Certificate of Airworthiness No. 2132100181, issued SZ MTU Rosaviatsii 15.11.2010, valid until 15.11.2012,
operating time 19721 h (as of 05/05/2015, further data are absent),
assigned resource / service life 20000 h / not established, overhaul
resource / service life 2000 h / 5 years, number of repairs 12, date and place
the last repair 04.04.2008 OJSC "MARZ DOSAAF", working time after repair
466 hours (as of May 28, 2015), the remainder of the designated resource / service life
279 h (as of 05/28/2015) / is not established, service life and resource are not prolonged.
The remainder of the overhaul life / service life of 279 hours (for
05/05/2015) / The overhaul period has expired on 04/04/2013

Engine: АШ-62ИР, manufactured by WSK PZL Kalisz S.A. (Poland),
date 16.05.1986, factory No. K 1642620, the operating time of SNE 3684 hours (on
28.05.2015), the designated resource / service life of 6000 h / not established,
overhaul life / service life 800 h / 6 years, number of repairs 4,
date and place of the last repair 17.03.2008 OJSC «MARZ DOSAAF»,
operating time after repair 466 h (as of May 28, 2015), between the overhaul resource left / service life 334 h (as of May 28, 2015) / time between repairs
service expired on 03/17/2015

So I reject Pilot Error. My best guess, especially with an errant rudder, is the seat track or seat support broke, and pilot had no fixed position to articulate controls.

The Rudder may have reacted to an attempt by the pilot to gain a position from which to use controls.

It's happened before, more than once. It happened to me. It was a challenge to maintain straight and level...let alone knife edge...

Respect

It will be interesting to see what the investigation comes up with. At least when the accident happened there were a field full of AN2 drivers watching so there will be no shortage of expert witnesses to the actual flight.

From the Kulverstukas post i see the aircraft had near 20 thousand hours airframe time. The AN2 job description is to operate in the rough field ops so i imagine those 20K hours would have been hard work.





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I passed this thread along to a friend, also a pilot, who may have figured this out.

He believes that at the last moment to pull out, the pilot figured that on his current heading, he would likely fly into the audience. Hence the pull on the stick, and the change of heading, which led to the impact and fatal cartwheel.....

Works for me.

Preliminary report was published by MAK (IAC) (Russian)

A translation of the summery would be helpful..:)






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