13.10.17 UT588 KRR-VKO

[Kulverstukas]

Performing GA:

bank 96 deg
pitch 45 deg
IAS 60 kts
stick shacker

https://img-fotki.yandex.ru/get/893240/6154164.2a7/0_bf049_99e3db58_orig

[fox niner]

Ehh...holy *£{$}|!§>&€%*%.

Thanks Kulverstukas for that. You always seem to have access to really really interesting occurrences coming out of Mother Russia. Another 737 incident to be followed carefully...

[Kulverstukas]

Info from FDR:

Pitch 45, right bank up to +33, then left to -34.8, pitch reduced to 30 speed dropped to 60 KIAS, plane goes into right banking up to +96(right wing stalling), pitch reduced to -14 (nosedive), banking left to -45, plane came out off stalling, speed rises to 150 KIAS, banking to 0, pitch up and plane begin to climb.
Height loss was about 300 m.

[ManaAdaSystem]

Only 300 m loss of altitude after a stall from 60 kts speed?
Is this FR24 info only, or from other sources?

[Kulverstukas]

Is this FR24 info only, or from other sources?

Figures are from inside source. Quite similar to tatarstan at KZN and FlyDubai at ROV minus weather

[Less Hair]

Must be the fastest 737 ever.

[ManaAdaSystem]

I accept your information, but I thought I would be impossible to save a 737 in 1000 ft from an upset like that.
What does the graph say? Did he land right after that exercise?

[bloom]

Good pilots is all it takes!

[ManaAdaSystem]

Good pilots would not have found themselves in a situation like that in the first place.

[RVF750]

One good pilot, the other possibly getting into that situation. Until more comes out, it's hard to speculate.

[Kulverstukas]

I accept your information, but I thought I would be impossible to save a 737 in 1000 ft from an upset like that.

I think it's integral height loss, take in account that she was on TOGA climbing at the beginning of incident.

Did he land right after that exercise?

Yes and even paxes thanked pilots afterwards in social media ;)

[ManaAdaSystem]

One good pilot, the other possibly getting into that situation. Until more comes out, it's hard to speculate.

Speculate is what we do here. :)
With both pilots in the loop, this will not happen.

[Jet Jockey A4]

Scary... Must have been a heck of a ride for the passengers.

[Kulverstukas]

https://aviation-safety.net/wikibase/wiki.php?id=200545

[FLEXJET]

I heard that:

CATII could not be performed as the FO was very new.
Captain was busy with the change of RWY.
PF set IAS 110 instead of HDG 110.

[RAT 5]

Ouch. That might be the case; been there done that and/or vice versa, the effect was instantly noticeable as an error and immediately corrected. If the data in the opening post is correct that would suggest the error was left in affect for far too long, even for a newbie. I hope there is more to this than that. Mind you, in this day and age of teaching (did I say teaching, sorry, instructing), when newbies make an error via the automatics they often are startled, wonder what/why and then try to correct it via the automatics which often can take too long. if it is a power/pitch couple problem then it's not the first or last.

[underfire]

wake encounter?

Edit: Wasnt there an elevator jam issue with the 737's (not sure about 500's)

[standbykid]

Must be the fastest 737 ever.

650 knots at 2000ft. Nice.

[Herod]

Underfire.
It was a rudder hard-over issue, and has hopefully been solved with a couple of mods and a change in procedures.

[slip and turn]

https://aviation-safety.net/wikibase/wiki.php?id=200545
"Airplane damage: None" ... Ehm ... well not so's you'd notice by kicking any tires!

[Kulverstukas]

http://archive-server.liveatc.net/uuww/UUWW2-Oct-13-2017-0600Z.mp3

[underfire]

It was a rudder hard-over issue, and has hopefully been solved with a couple of mods and a change in procedures.

Okay, was just looking at the sudden 45 degree pitch and then a -33 pitch, not sure how that is a rudder hard over issue. Combined with the stall, roll angles, this is more like a tumble, no? Seems reasonable for a wake encounter.

[Herod]

underfire. I wasn't making any comment on this event, but responding to your query about the historical ones. There were aircraft lost due to the rudder hardover, but Boeing's fix has, we hope, sorted it.

[Kulverstukas]

https://img-fotki.yandex.ru/get/509739/6154164.2a7/0_bf055_416ee76f_orig

[wiedehopf]

@kulverstukas
could you or someone else tell me what the lines are?
i would presume from top to bottom:
altitude in m (edit: actually in feet)
bank angle?
pitch angle ??
power setting ?? (edit: actually heading)
Calibrated Airspeed (as in the label)
v2
vref
flap setting ?

[Kulverstukas]

Alt AGL ft
Bank °
Pitch °
Direction °
CAS kt
v2 kt
vref kt
Left flp °
Shaker
AP

[pattern_is_full]

Altitude in meters or feet?

Aviation Herald says feet MSL, which is more consistent with 5.3 miles from threshold - but I won't argue with a Russian about an FDR readout in Russian! Just asking.

Referring to the mechanical stall warning device, in English that is the "Stick shaker." "Shacker" means - something else.

[wiedehopf]

it's feet, i just assumed because it's Russia :)

the time code fits with the flightradar24 trace.
0617 with the upset quite some speed change can be seen. that's at about 1000m, the altitude dip doesn't show well on the granularity of flightradar24, but it's enough to see it's feet not meters in the FDR readout.

[Kulverstukas]

but I won't argue with a Russian about an FDR readout in Russian! Just asking.



Thanks, edited. Alt is AGL (said "above RWY lvl" in parenthesis).

[TRW Plus]

Does anyone have any thoughts about what the spike to 650 knots really means? It would seem physically impossible to accelerate and decelerate that quickly (keeping the aircraft intact at least).

[F-16GUY]

I heard that:

CATII could not be performed as the FO was very new.
Captain was busy with the change of RWY.
PF set IAS 110 instead of HDG 110.

So now the skills of the magenta generation have degraded so much that they can not even punch the correct value into the correct box.

And the captain was "busy" punching the runway change into the FMC.....

https://www.youtube.com/watch?v=pN41LvuSz10

From min 3:30 to 9:30 basically sums up this scary incident.

Unbelieveable...

[slip and turn]

Great instructional video, F-16GUY.

Back to the incident (incidents?) in question, is it worth noting that none of the visible fun started until coming off a 40 minute hold? One might wonder what stresses the crew may have carried forward with them from that.

So the upset in the FDR readout shown occurred immediately after the GA was "initiated" on the first approach, but what happened thirteen minutes later on the second approach?

That's when FR24 showed a momentary reported GS of just 41kts at 2400 feet and then two minutes later the unexplained momentary reported 637kts at 2300 feet (that last plot coincident with momentary VS+17536fpm)? Have we got the FDR readouts and/or more detailed ADSB data for those too?

[Nemrytter]

I'm amazed that people are still trying to use FR24 data to analyse these types of incidents. the most simple explanation for an anomalous value in FR24 speed/altitude graphs is that FR24 has it wrong. We see this in pretty much every thread on here.

[slip and turn]

I'm not amazed, just curious. The underlying FR24 data is, as I know you know, just data broadcast from the aircraft. That data isn't "wrong" - if it is reported accurately by the aircraft systems, broadcast to anyone who cares to receive it, and if it is faithfully recorded with known context and margin for error and shared, it just exists as valid public domain data and in cases like this it feeds healthy curiosity.

Obviously interpreting it in the wrong context, and blindly ignoring how errors may occur can lead to completely wrong conclusions. So it is sometimes (often?) misleading to rely on simply joining all the ADSB dots and getting the wrong lines of course, and to that extent FR24 graphs which do join dots however anomalous, do need to be taken with a pinch of salt!

Yours is of course fair amazement if you think many reading this thread still labour under the notion that the crazy-looking 637kts number was associated with the apparent stall recorded fifteen minutes earlier in the FDR:ok:

[DaveReidUK]

Yes, the relevant caveats in this case are:

a) Like most surviving B735s, the aircraft in question has non-GPS ADS-B, and so lateral positions are automatically suspect

b) Reported altitudes may or may not be corrected for QNH (you can't tell from FR24)

c) Timestamps come from FR24 and may not match those in the FDR readout that was posted.

That said, here's the FR24 track that corresponds to the two-and-a-half minutes of the FDR trace:

http://www.avgen.com/UT588.jpg

The heading/track appears to match the FDR values.

The lateral positions are clearly offset, as can be seen from the final approach and landing.

The altitudes differ from the FDR readout by about 1000', but appear to be broadly in step.

Obviously none of the other FDR parameters appear on FR24. :O

[slip and turn]

Nice one Mr Reid.

As an aside, ADSB data, including a complete lack of it in recent days, indicates that the aircraft flew pretty much daily until 13th October, but appears not to have moved since!

[Nemrytter]

According to FR24 (:rolleyes:) it was flying yesterday and today...

[slip and turn]

My goodness Nemrytter, that'll teach me not to rely on getting my gaps in ADSB data from an unreliable source (https://flight-data.adsbexchange.com/activity?inputSelect=registration&registration=VQ-BJP) - remind me to rely on your preferred FR24 for that from now on :}

[Kulverstukas]

zmg-tLuMmJo

https://cdn.aviaforum.ru/images/2017/11/892136_384c505aeb02fec671afbbca55f2b209.pdf

[DaveReidUK]

Hmmm.

I'd be sceptical about the ability of even a full OEM simulator to replicate the extreme flight regime that the aircraft appears to have encountered, let alone the capability of a PC simmer enthusiasts' app.

[PENKO]

That looks like an actual FDM playback, not flight sim :)

[CargoOne]

Playback claimed to be based on FDR readout and visualisation looks similar to those produced by WinArm - russian software for flight data analysis which is also used by Russian NTSB (MAK) for incidents/accidents illustration

[derjodel]

I ran parts of the pdf through an ocr and google translate. Results are poor, but better than nothing.

I don't know what a "traction automaton" is. It's called "автомат тяги" in russian. Russian wiki mentiones it as a part of ABSU: "ABSU functionally consists of a servo drive system (SSP), a steering control system (SSU), an automatic control system (ACS), an automatic and a director approach system (trajectory control system - STU ), integrated control systems (ICS), a traction automaton )." Bing translates it as "thruster's machine".

"from itself" means forward, away from the pilot

steering wheel - yoke


Translation:

When the speed of 133 to 134 knots was reached, the traction automaton increased the mode
engine performance up to 75% M! with a further increase in the regime (by the time
autopilot off) to 95% M]. When approaching the aircraft to the entry point in
glissatsu, at a speed of about 130 uclov. The crew began to release the flaps 30 °.
The increase in the operating mode of the engines was accompanied by an increase in tanto,
the transition of the aircraft to a smooth climb and a drop in the instrument speed.

During the release of flaps at 30 °, a trip was made
autopilot. By the time the autopilot was turned off, the pitch of the aircraft was 19 °,
speed 128 knots. Disabling the autopilot and deflecting the steering wheel "from itself"
was accompanied by the transfer of engines of engines to reduce the mode of operation,
without switching off the traction automat.

Thereafter, the steering wheel was alternately turned
This pitch has increased to 45 ° (the maximum achieved value). what
accompanied by a warning shaking npturvala (triggering sgik-
shaker), the drop in the instrument speed is less than 100 knots, the roll
reached 95? The engines of the aircraft due to the operation of the traction automat on
the maximum mode is up to 95% MP.

After increasing the pitch to 45 °, the steering wheel was deflected "from itself" and
was held in this position (with a smooth decrease in deviation) to the conclusion
plane from a complex spatial position. The withdrawal of the aircraft from
complex position (pitch and roll) was produced without
exceeding the restrictions on overload and flight speed in the landing
configuration. In the process of developing a special airplane, the aircraft gained a height of 750
meters and was put into normal flight mode (completion of the decline, the beginning
missed approach) at an altitude of 350 meters.

Re-entry and landing did not take place. AT
As a result of a serious incident, no one was hurt. aircraft damage is not
got. A serious incident is being investigated.

[Kulverstukas]

I don't know what a "traction automaton" is. It's called "автомат тяги" in russian. .

It's Auto Thrust.

[fab777]

Auto throttle here...