A380 wake upset: business jet at 34,000ft, lost 8,700ft in 32s, plane written off

[RAM]

Interesting/alarming report on an incident involving a Sydney bound Emirates A380 and a Bombardier Challenger business jet in January.

https://www.flightglobal.com/news/a...t-inquiry-offset-not-permitted-on-rou-437303/

I cannot imagine how it would feel (even if safely/firmly) strapped in to your seat to drop around 300 feet a second for around 30 seconds.

In the following second vertical acceleration changed to -3.2 g.

By all reports everyone on the plane is lucky to be alive - the air frame has been declared a write-off.

During the descent the aircraft's airframe exceeded the design certification load limits. Although the aircraft landed safely at Muscat, with no apparent external damage, BFU says Bombardier determined the airframe "could not be restored to an airworthy state".

An Emirates Airbus A380-800, registration A6-EUL performing flight EK-412 from Dubai (United Arab Emirates) to Sydney,NS (Australia), was enroute at FL350 about 630nm southeast of Muscat (Oman) and about 820nm northwest of Male (Maldives) at about 08:40Z when a business jet passed underneath in opposite direction. The A380 continued the flight to Sydney without any apparent incident and landed safely.

The business jet, a MHS Aviation (Munich) Canadair Challenger 604 registration D-AMSC performing flight MHV-604 from Male (Maldives) to Abu Dhabi (United Arab Emirates) with 9 people on board, was enroute at FL340 over the Arabian Sea about 630nm southeast of Muscat when an Airbus A380-800 was observed by the crew passing 1000 feet above. After passing underneath the A380 at about 08:40Z the crew lost control of the aircraft as result of wake turbulence from the A380 and was able to regain control of the aircraft only after losing about 10,000 feet.

In the following second vertical acceleration changed to -3.2 g.

The German (English version) interim report - an interesting read to say the least (24 pages).

Interim Report (PDF, 7MB, Not barrier-free file.)

 

[juddles]

I will leave it to expert pilots to make their assessment, but from a layman's understanding, this appears to be a scenario where wake turbulence caused a relatively minor hiccup (error in reaction?) from the autopilot, but the intervention by the pilots successfully resulted in a complete loss of control of the aircraft.

I do not think that the wake turbulence 1000 ft below a passing "heavy" will by it self cause such dramatic acrobatics.

I am not bagging the pilot here, but a casual observer of this incident may get an entirely incorrect idea of the realities.

 

[Quickstatus]

I think the wake turbulence exceeded the ability of the autopilot or pilot to correct. It spun about the longitudinal axis a few times before the pilot regained control. The report suggests that despite the correct corrective inputs the Challenger still spun out of control
Presumably because the diameter of the wake vortex off an A380 would be greater than the wingspan of the challenger
This was discussed previously I think?. But I can't find it.

See this one at 2:20 onwards.
https://m.youtube.com/watch?v=h8fV36OtrJw

And this one is very dramatic
https://www.youtube.com/watch?v=KXlv16ETueU

Though as you say there have been instances of pilot inputs exacerbating the effects of WT :See AA587


and here is a dramatic wake vortex
https://www.youtube.com/watch?v=uy0hgG2pkUs

 

[jb747]

I think the wake turbulence exceeded the ability of the autopilot or pilot to correct. It spun about the longitudinal axis a few times before the pilot regained control. The report suggests that despite the correct corrective inputs the Challenger still spun out of control
Presumably because the diameter of the wake vortex off an A380 would be greater than the wingspan of the challenger
This was discussed previously I think?. But I can't find it.

The wake is just one of the holes in the cheese. Looking at the graphs at the end of the report, and I'm pretty suspicious of the rudder input. A wake induced departure should have been relatively clean, in that the core isn't very big, and he was well out of it for about 99.9% of the event.

Though as you say there have been instances of pilot inputs exacerbating the effects of WT :See AA587

The way the controls were manipulated in that accident is right up there with AF447. Roll is a secondary effect of rudder...using it as the primary control in a normal situation is extraordinary. That's what the ailerons are for....

 

[Skrambled]

Mock up video of the event under related videos of those links above https://www.youtube.com/watch?v=UJ8MJm8xWyY