Atlas 747 Landing Incident - Shanghai

[Three Lima Charlie]

Date: 04-AUG-2020
Time: 18:05:00Z
Regis#: N408MC
Serial#: 29261
Aircraft Make: BOEING
Model: 747-47UF
Flight#: Atlas Air 8939
Type: INCIDENT
Highest Injury: NONE

AIRCRAFT SUFFERED POD STRIKES TO THE #1, #2 AND #4 ENGINES ON LANDING, SHANGHAI, CHINA. (PVG)

[Ray_Y]

Atlas Air on behalf of DHL
Seoul to Shanghai Pudong
Pod Strikes on Landing rwy 17R
No further incident during rollout

19013G20MPS 8000 -SHRA

[Intruder]

It must have been a REALLY dynamic landing (lots of roll rate) to get #2!

[Longtimer]

More at: Incident: Atlas B744 at Shanghai on Aug 5th 2020, triple engine pod strike (http://www.avherald.com/h?article=4daee036&opt=0)

[Pilot DAR]

The report says:

The aircraft rolled out without further incident

Considering the pod strikes, I can't help wondering if the roll out was on the runway, or the roll axis!

[pattern_is_full]

I'll be interested to see what dynamics led to an inboard pod strike.

Seems like the outboard would act as a pogo wheel to hold the inner engine off the ground - but I guess wing flex, or gear flex, or extreme damage to the outboard, or a semi-excursion such that the #2 hit an edge light, each could explain it.

[Australopithecus]

Is it just me or is the incident rate higher than normal with a small fraction of the normal flying?

[DaveReidUK]

I can't see this staying classified as an "incident" (per Annex 13) for long ...

Seems like the outboard would act as a pogo wheel to hold the inner engine off the ground - but I guess wing flex, or gear flex, or extreme damage to the outboard, or a semi-excursion such that the #2 hit an edge light, each could explain it.

The 747's geometry is such that a combination of wing flex (particularly if an outer engine is already in contact with the ground), and/or wing gear oleo compression, doesn't leave much clearance between the runway and the inner on the same side at best:

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/606x220/b744_front_view_c867452ca5990fe5c651f413992d8b9acb55c844.jpg

[Pugilistic Animus]

Here is a little aviation news letter that I subscribe to.

https://simpleflying.com/atlas-air-747-engine-strike/amp/

[anxiao]

I no longer have the Boeing equivalent of the POH for the -400 with me, it has been a few years since I flew them, but I seem to remember it had a diagram showing the roll and pitch angles and oleo compressions for particular pod strikes.

What struck me at the time and is apparent here is that at a certain roll angle and nose down pitch (7 and 3 degrees?, my memory fails me) it was the inboard pods that struck before the outboards with full oleo compression. The rate of descent for full oleo compression was not stated but would have been near the limit, around 600fpm.

[vilas]

the aircraft suffered engine pod strikes on the #1, #2 and #4 engines (outboard left, inboard left, outboard right). The aircraft rolled out without further incident.
To strike double pods on one and the other side outer takes some doing. What further could happen?

[Banana Joe]

It must have been similar and worse than this:
https://www.youtube.com/watch?v=oRScivHIH10

[Havingwings4ever]

anxiao

you are correct, it was like that on the 747-2 and the 747-4 , our airline always focused on roll angle control since they had a pod strike incident long time ago. 7-8 degrees roll looks like a lot from the cockpit but it can happen quick. I rather landed crabbed wings level during wet strong xwind landings than trying to de-crab. The gear takes it easily, unlike eg an MD11(i have flown those 3 types, no arm chair)

[DaveReidUK]

What struck me at the time and is apparent here is that at a certain roll angle and nose down pitch (7 and 3 degrees?, my memory fails me) it was the inboard pods that struck before the outboards with full oleo compression.

Well remembered.
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/388x643/b744_pitch_roll_angles_for_engine_pod_strike_2__102ac3850b50 5ac498a82a811df22ebfb7acbfb5.jpg

[DCS99]

Is it just me or is the incident rate higher than normal with a small fraction of the normal flying?

Not just you. Common theme on the WhatsApp Groups for the grounded / part-time / pay cut / survived the latest round of dismissals colleagues.

[MarkerInbound]

Haven’t seen the 3rd quarter numbers but Atlas was running about 10 extra sections a day during the 2nd quarter. While passenger operations have suffered during this outbreak the cargo world has gone crazy.

[pattern_is_full]

anxiao and DaveReidUK - yes, thanks. As I suspected. Ain't 3D trigonometry wonderful!

[lomapaseo]

I thought it was geometry :)

[anxiao]

Nothing so cerebral. It was playing with my -400 Manila model on a table top that set me searching for the answer :)

[Check Airman]

Not often that you see that much rudder deflection on a jet.

[hans brinker]

Watched video again after your comment. Maybe someone with a better monitor can confirm, but it looks like full rudder at 0:07, and again at 0:16. I don't see aileron deflection. Aside from cross-wind landings in high wing turbo props and during ground roll in the A320 I don't think I've used that much rudder in 20 years.

[3Greens]

you don’t need full rudder even in max x-wind landings on a 747, that DHL is being grossly mishandled. Doesn’t even look like much, if any, x-wind. In fact it looks like the pilot flares a touch early and tries some kind of “wing dip” like in a light aircraft to get a bogey down. Huge no no in a “wings level” aeroplane like the 747.

[Capt Fathom]

Wake turbulence.

[misd-agin]

It looks like the DHL might have even had the left aileron down, inducing a right roll? That much rudder? There's a big rudder input at the 0:07 mark. Ugly, poor, flying. Can't blame the plane if it's mishandled.