Turkish Airlines cargo 747 crashes in Kyrgyzstan

[Airbubba]

Originally Posted by fepate

Someone else asked if there were aircraft approaching that runway prior to this one. If so, how did the FR24/FlightAware vertical profile compare? Is someone willing to dig that data up?

SU1882 turned onto the approach from the north, TK6491 came up from the south.

It looks like the 747 overshot the localizer slightly showing a 218 knot groundspeed on the turn to final.

TK6491 plots well above the path of SU1882 in the FR24 .kml files.

At roughly the same position on short final, TK6491 shows 3100 feet, 185 knots, heading 259 degrees and SU1882 shows 2040 feet, 140 knots and heading 259 degrees.

You can download these .kml files and open them simultaneously with Google Earth. You can also play with the tilt to check the vertical path profile.

Get the .kml files for January 15 here:

https://www.flightradar24.com/data/f...k6491/#c2d9d64

https://www.flightradar24.com/data/f...u1882/#c2da9c3

[Magplug]

Originally Posted by Icelanta

But then I would expect the GPWS to start shouting during the approach, resulting in an immediate G/A.
Also, your map on the ND would not coincide with your presumed position according to the glideslope.

I have never heard about such an occurence.

Me neither.... But.... Trying to capture the G/s from above in a B744 is really NOT a good idea. The GPWS will only give a 'Pull Up' if you are BELOW the glideslope. If you are still above the G/s trying to capture it from above there is no warning provided the aircraft is in the landing config. A crew that attempts to capture from above then fails to notice the lack of G/s capture, carrying on in V/s to 100' RA is in big trouble. My guess is that's what happened.

The Enhanced GPWS will call-out to trap an off-field landing but the 'safe-zone' around any airfield is not related to the selected runway in the FMC so the area around the threshold of FRU08 is also a 'safe-zone'...... Food for thought.

[peekay4]

Another possible factor is that the DME for ILS RWY 26 is actually measured from the opposite runway threshold (i.e., it reads 2.2nm at RWY 26 threshold, zero at RWY 08 threshold). This could've added to any confusion if the crew were chasing the G/S from above and looking at the DME to check distance to the runway.

[FIRESYSOK]

The Enhanced GPWS will call-out to trap an off-field landing but the 'safe-zone' around any airfield is not related to the selected runway in the FMC so the area around the threshold of FRU08 is also a 'safe-zone'...... Food for thought.

That's not quite correct. EGPWS does in fact have thousands of runways in its database. It matters not which is selected in the FMC, but rather a terrain clearance floor is tailored for each runway at every airport in the enhanced EGPWS database.

[Magplug]

So what did I say that was incorrect ?

[readywhenreaching]

You can download these .kml files and open them simultaneously with Google Earth. You can also play with the tilt to check the vertical path profile.

Get the .kml files for January 15 here:

FR24 commercialized the .KML's. Only $-members can see it.

[peekay4]

The TK6491 .KML and other data files can be downloaded for free from below:

https://www.flightradar24.com/blog/c...al-ads-b-data/

[FullWings]

Interesting discussion of a near accident involving ILS glideslope here (PPRuNe)

[FIRESYSOK]

Originally Posted by Magplug

So what did I say that was incorrect ?

Yes there would be a 'safe zone' at the runway threshold but mentioning FMC runway selection isn't relevant leading one [some] to believe EGPWS isn't runway specific.

I will say that if the information that this flight was higher than a previous arrival is correct, your suggestion that glide slope was never captured and the flight remained in a VS mode, is quite possible. This wouldn't be the first time recalling an Air Europa charter landing in Katowice that 'landed' short of the runway.

Additionally, a high descent rate from either a false glideslope or selected VS would result in low thrust and high inertia that, once GPWS Mode 1/2 became active, could result in an unexpected state from which a go-around would be more challenging.

All that said, I would hope either scenario would be trapped much earlier at the stabilisation 'gates', but a less-than-fresh crew is always a threat in any operation.

[Airbubba]

Originally Posted by readywhenreaching

FR24 commercialized the .KML's. Only $-members can see it.

Sorry, I didn't realize that. See if you can access these FlightAware logs to compare the speeds and altitudes on final, the 747 seems to me to be smoking down the glidepath (or above it ) for a low-viz approach, even for a whale:

Flight Track Log THY6491 16-Jan-2017 HKG / VHHH - FRU / UCFM FlightAware

Flight Track Log AFL1882 15-Jan-2017 SVO / UUEE - FRU / UCFM FlightAware

The A321 appears to have a stable approach on the turn to final for runway 26 with maybe a 10 knot reduction close to the runway.

[Icelanta]

FR24 has the vertical path as a steady 750ft/min. ROD?
That does not look at all like a crew that is trying to get onto the glideslope from above, but is a perfect 3 degrees glideslope.

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. So what can cause this "phantom ILS", knowing that aircraft have used the ILS before the accident without any issue it seems.

[Airbubba]

Originally Posted by Icelanta

FR24 has the vertical path as a steady 750ft/min. ROD?

It looks to me like they are descending on average at a higher rate than that. Wouldn't they have to be with that groundspeed to maintain 3 degrees?

[Avenger]

Bishkek can be hell on the approach, but in this case I doubt it was turbulence, the RVR seems on the "limits" and the missed approach is a right turn needing a hefty climb gradient. Like Katmandu, this will just be "pilot error", either attempting to line up with something other than the RW lights or botched GA, maybe executed too low to bulk the landing. In this part of the world the METAR is taken with a large pinch of salt..

[klintE]

Any chance this acccident was similiar to KAL801 which crashed on Guam?
They've decided to use localizer and DME when GS wasn't available.
However, their recognition of DME location was incorrect and finally they hit the Nimitz Hill.

[Icelanta]

No.
Only a Cat2 ILS was possible.
The MNS VOR/DME whose reading are mentioned on the ILS26 chart, is situated BEFORE the threshold by the way.

The Missed approach calls for a standard 2.5%.and is straightforward.

Approach speed would be between 150kts. And 160kts. If heavy.

[Pneumatix]

ILS Signal Interference

Originally Posted by Icelanta

For some reason, IF date from FR24 is correct, the aircraft was flying a "phantom. ILS" around 4km.

According to FR24 data flight path, a phantom ILS glide slope is a realistic investigation point. The signal may be deviated by a truck or an aircraft on ground. A mobile service equipment may have been in the critical ILS area during the approach.

Full case on French BEA web site / Report: Air France A318 and Transavia B738 at Nantes on May 25th 2010, loss of runway separation in low visibility, ILS disturbance

[Magplug]

@FIRESYSOK

Yes there would be a 'safe zone' at the runway threshold but mentioning FMC runway selection isn't relevant leading one [some] to believe EGPWS isn't runway specific.

I didn't say the FMC runway selection was relevent to EPGWS, I said it was completely irrelevent. Please don't chastise me for something I didn't say.

Can any of my fellow B744 pilots here imagine a crew going through 1000' for an autoland with G/S still armed in V/s without 'Land 3' staring them in the face ???

[Herod]

I don't know about modern installations, but in my day, intercepting the G/S was always to be done from below because of the possibility of a false G/S being propagated above the real one. Came up on the ATPL course in '76 IIRC.

[klintE]

Originally Posted by Icelanta

No.
Only a Cat2 ILS was possible.
The MNS VOR/DME whose reading are mentioned on the ILS26 chart, is situated BEFORE the threshold by the way.

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

[Icelanta]

Pneumatix,

Interference from. a ground based vehicule or aircraft will fluctuate the signal a couple of meters...not 4 km. ...

As I am a Captain on B744, I will follow this accident and investigation with great interest.