Turkish Airlines cargo 747 crashes in Kyrgyzstan

[short bus]

This may have been posted before but this video is from around the impact site. I found just after 5:00 to be of particular interest showing a concrete fence with sheared vegetation, what appear to be tire tracks, and the area around the red and white striped building. As a warning, note that the makeshift morgue is also shown but everything seems to be covered.

https://youtu.be/NBEJP-s7nHE

[despegue]

Regarding the possibility of setting-up a manual inserted approach into the fmc, let me give this theoretical possibility:
crew initially planned for an approach on rwy08, which is logical as this would be the preferential rwy according to current wind in the metar/atis, and had to change last minute for a setup for rwy26.
Runway and/or approach not in fmc database, manual entries in fmc. This caused the crew to be rushed.
As the aircraft showed problems with capturing ILS signals on previous sectors, which was not put in the techlog, (something that is a common occurence with ACT by the way), they followed a LNAV/VNAV approach, with a vnav path based on last point in fmc: threshold rwy08 where VNAV calculates to fly over at 50' .

This is by the way a rumour "on the ground"...

Totally unbelieveable obviously, but theoretically possible and an explanation that correlates with current information.

[Kulverstukas]

Originally Posted by short bus

This may have been posted before but this video is from around the impact site. I found just after 5:00 to be of particular interest showing a concrete fence with sheared vegetation, what appear to be tire tracks, and the area around the red and white striped building. As a warning, note that the makeshift morgue is also shown but everything seems to be covered.

https://youtu.be/NBEJP-s7nHE

Hmmm... what the heck they do at 3:36? Trying to rescue the crew?

[Airbubba]

Originally Posted by Icelanta

For some reason, IF date from FR24 is correct, the aircraft was flying a "phantom. ILS" around 4km. Offset to the West.
Now there is only one way I see this happening, and that would imply a total lack of procedures, and I will not put this on a public forum.

Originally Posted by scanelpan

My question: would it be possible to program the FMCs to perform a LNAV/VNAV approach with RW26 as active runway, but with final descent waypoint (mistakably) threshold RW08? I could not think of a good reason to use such a construction under the prevailing conditions, so I want to emphasize, its a technical question only.

Originally Posted by Icelanta

Scanelpan,

Yes, this is possible, and to be honest, I have already thought about this.
But surely no sane crew would do this...

Originally Posted by Machinbird

Would it be possible for this accident aircraft to set up an approach to the wrong end of the runway by keying in the wrong data? It wouldn't be a full ILS of course, but might use a combination of GPS and localizer data.

Originally Posted by despegue

Regarding the possibility of setting-up a manual inserted approach into the fmc, let me give this theoretical possibility:
crew initially planned for an approach on rwy08, which is logical as this would be the preferential rwy according to current wind in the metar/atis, and had to change last minute for a setup for rwy26.
Runway and/or approach not in fmc database, manual entries in fmc. This caused the crew to be rushed.

As the aircraft showed problems with capturing ILS signals on previous sectors, which was not put in the techlog, (something that is a common occurence with ACT by the way), they followed a LNAV/VNAV approach, with a vnav path based on last point in fmc: threshold rwy08 where VNAV calculates to fly over at 50' .

This is by the way a rumour "on the ground"...

Totally unbelieveable obviously, but theoretically possible and an explanation that correlates with current information.

The late runway switch scenario has set up a chain of events leading to a mishap many times in the FMS era. The 1995 American Cali crash and 2013 UPS crash at Birmingham are two examples that come to mind.

I've done the FMS drill of extending off a runway to build an advisory path for a visual landing on Boeing twins but I agree with everyone else that this would be suicidal in low vis to CAT II mins even if you did it right.

For the B-744 drivers, is it possible to select runway 08 and build a path in the wrong direction as some of the speculation implies? Doesn't the RW08 waypoint know the heading and plot a centerline on the ND? Or, can you just do an intercept to RW08 with an inbound course of 260 and a 3.0 degree path angle? Would LNAV and VNAV capture in this 'backwards' setup with a runway waypoint?

On some of the boxes I've flown with I don't think you can change the inbound course to a runway waypoint, i.e. go straight to the 'numbers', you have to do an intercept to a waypoint on the final course (e.g. RW08/-2). The idea is to prevent the path to the wrong end of the runway error on a 'homebuilt' approach.

Or, did they build an ad hoc approach using the wrong NDB?

Originally Posted by klintE

Yes. But NDB for RWY08 is situated almost exactly where they crashed. Suppose this is just coincidence (no irony)

[Kulverstukas]

Short translation from leaked IAC preliminary report
Seems its a kind of letter sent to pilots by Rosavia or some big carrier...

1) While landing at Manas airport, rwy26 (CAT II ICAO) crew doesn't performs distance/altitude control which led to the situation when FAP was reached at 650 ft higher at 200 kts with LOC CAPTURE and G/S/ ARMED. Because of wrong height, there was no glideslope capture and a/c switched to ALT HOLD at 3400 ft.
2) At 1.5km from rwy accidental capture of false glideslope (~1 sec) happened which activated GS CAPTURE and a/c begin automatic descend parallel to glideslope
3) Exactly at this point crew doesn't evaluate situation and don't make decision that it's impossible to land safely from 3400 ft (aerodrome elevation is 2055 ft) and 1.5km distance. G/S pointer at PFD was at the bottom all the time but crew was not aware either.
4) With A/P engaged a/c overflew all rwy until decision height 100 ft where Cpt. announced GA because no visual contact with rwy. But TOGA was activated at 52 ft only.
5) While performed TOGA a/c touched ground 900 m from rwy end and 60 m to the right of the centerline with 6 "points" (?) accel
6) After bouncing a/c hit concrete fence and rolled out to the village, where separates with fuel spill and ground fire started.

[Bleve]

Originally Posted by Kulverstukas

... accidental capture of false glideslope (~1 sec) happened which activated GS CAPTURE and a/c begin automatic descend parallel to glideslope ...

I always thought capture of a false GS still took you to the same point on the runway but at a steeper angle. Rather than a 'false' GS, I wonder if they captured an 'erroneous' GS just like an Air New Zealand B767 did into Apia in 2000.

[oicur12.again]

Some false gs captures have occured where a path parallel to the correct slope has occured. Depends on the combination of failures.

Which is why we should be doing 2 gs/alt checks on the way down.

[747-8driver]

Originally Posted by Bleve

I always thought capture of a false GS still took you to the same point on the runway but at a steeper angle.

That's probably only when you stay on this false glideslope.

3) G/S pointer at PFD was at the bottom all the time but crew was not aware

[RichardN]

So the false G/S signal at 9° for ~1 sec. caused the G/S switch from ARMED to LOCKED.
What ROD is A/P flying after the false G/S was lost again?
Isn't there an alert when the G/S is lost on G/S LOCKED?

[Kulverstukas]

Page #2 of the letter

[RAT 5]

Could this be another of those 'I don't understand why some guy's self survival circuits are not active?' Who drives high speed down a motorway in the fog at 03.00 assuming no other idiot is going to be there? Who hurtles towards the ground, knowing it's LVP's on the ground, without being 100% certain where they are and it is all under relaxed control? And there is more than one guy at the sharp end of this train wreck. I just don't get why the "where the are we?" and the "is everything all OK?" questions don't tweak the hairs on the back of necks. Toss it away and try again with more certainty. It's a real human behaviour curiosity and it keeps happening?

[Jockel76]

I guess that's what happens when you have two ex-military in the cockpit. Not much CRM going on.

[Airbubba]

Looks like the FR24 (and FlightAware) data was correct. As Kulverstukas observed three weeks ago:

Originally Posted by Kulverstukas

If we take in account FR24 height data (including last recovered points) it seems that they aim in the point ~900m right after the further end of the rwy, which is marked 0 on the graph

Smoking in to capture the glide slope, crossing the final fix at 200 knots, 650 feet high for a low vis approach?

Getting a momentary false glide slope capture at only .8 nm (1.5km) from the runway?

Continuing to a 100 feet DH with the GS pointer pegged off the bottom of the PFD scale?

There should have been even more clues on the ND unless it was prone to map shifts and not trusted in close to the runway. Some older Boeings see the same GPS data as the ADS-B, some don't in my experience.

This reminds me of the UPS 1354 cargo crash where the vertical path was misconfigured on a non-precision approach, the pointer was pegged off the top of the screen and they flew into the ground short of the runway using vertical speed. Any semblance of a cross check or stable approach SOP would have saved them.

Maybe 30 years ago in a 727 you might try to 'salvage the approach' if you came in high and fast over the marker for an ILS. Some idiots would brag about how they never had to do a go around and there was no approach they couldn't salvage.

But any place I've ever worked since then, you would go around or take vectors for another try if you passed the fix at 200 knots and 650 feet high for an ILS down to minimums.

If they had ALT HOLD at 3400 feet and no GS capture, how did they start down? FL CH or V/S? Did they really wait until .8 nm from the runway to start down with the false GS capture? As others have noted the descent path closely parallels the glideslope with a vertical offset above. Is this a coincidence?

I realize that this latest information is preliminary, unofficial, translated from another language and quite possibly subject to change.

[aterpster]

airbubba:

This reminds me of the UPS 1354 cargo crash where the vertical path was misconfigured on a non-precision approach, the pointer was pegged off the top of the screen and they flew into the ground short of the runway using vertical speed. Any semblance of a cross check or stable approach SOP would have saved them.

Had they not busted minimums, they could have followed the VGSI as required on the approach chart. That would have saved them, too.

Maybe 30 years ago in a 727 you might try to 'salvage the approach' if you came in high and fast over the marker for an ILS. Some idiots would brag about how they never had to do a go around and there was no approach they couldn't salvage.

At my company even 45 years ago they read out every approach, whether on the 727's old FDR or on the L10's DFDR. If you weren't on speed and vertical speed below 500 feet, you would get a note from the chief pilot with a copy of the read-outs. The second time a given PIC did this, he was "invited" to have a chat with the chief pilot.

[cappt]

At my company even 45 years ago they read out every approach, whether on the 727's old FDR or on the L10's DFDR. If you weren't on speed and vertical speed below 500 feet, you would get a note from the chief pilot with a copy of the read-outs. The second time a given PIC did this, he was "invited" to have a chat with the chief pilot.

Today at most every western airline this is called FOQA (flight operational quality assurance). It is an automatic download of every flight parameter that goes into a data base at the flight completion. The airline will set the parameter specifics that flag events which can then be reviewed by the airlines FOQA gatekeepers. After reviewing a flagged area you may get a non-punitive chance to de-brief the flight with a member of the FOQA team to find out why you did what you did. More severe deviations from SOP's might get you a trip to the SIM for some training but this being the exception in most cases.
Overall it's a great program that can spot airline and industry specific problems which can then be addressed through SOP changes and future focused training events.

[despegue]

Situational awareness Zero
Procedural compliance Zero
Technical knowledge Zero

It is very saddening to see these things happening and unfortunately this does not surprise me at all, having colleagues that already dealt with ACT.
Appallingly bad standards, in Operation, Training, Maintenance.

This crew did not crash on purpose but were a byproduct of the mentality of the Airline involved.

[no sponsor]

Capturing a false lobe (6, 9, or 12 degree lobe) on the G/S will have the opposite effect. The result will be a dramatic pitch up if captured from above, potentially leading to a low speed event.

There are several examples in the public domain.

[747-8driver]

As explained here.

[Icelanta]

No Sponsor,

The 6 degree false glideslope has indeed an opposite indication due to the 90hz. Lobe under the 150hz. Lobe. ( the intersecting line gives the glideslope as we know)

The 9 degree glideslope however IS correct in indication as the 150hz. Lobe is below the 90hz. Lobe.

In reality, most false glideslope incidents happen by catching the 6 degree slope. Where the Autopilot might indeed start a pitch-up manoeuvre.


On B747-400,When the AFDS senses a glideslope within the established criteria, it will capture. A thing that is not that well known by some Airlines crews however, is that if there is interference or loss of signal of the UHF glideslope signal, the AFDS will continue the remembered glidepath. This should happen only below 200ft. Agl though. Strangely enough, this is not mentioned in the Standard Boeing issued FCTM or OM of the -400.

It is almost impossible to understand why a crew is following a LVP without checking the G/S during the whole approach, being so high, not knowing what they were doing at all.
We all make mistakes, and we endeavour to learn from them, but this smells of a deeper problem within the Company Culture.

[747-8driver]

Not according to THIS video... (0:36)
Might depend on the type of glide slope antenna on the ground?