PDA

View Full Version : Boeing 737 stalled on go-around Bournemouth UK Sept 2007


Centaurus
22nd Oct 2017, 03:14
In 2007 a Boeing 737-300 stalled on go-around at Bournemouth, England. The crew were very lucky to get away with it. Automation dependency strikes again:rolleyes:
Summary:

Early in the ILS approach the auto-throttle disengaged with the thrust levers in the idle thrust position. The disengagement was neither commanded nor recognised by the crew and the thrust levers remained at idle throughout the approach. Because the aircraft was fully configured for landing, the air speed decayed rapidly to a value below that appropriate for the approach. The commander took control and initiated a go-around.

During the go-around the aircraft pitched up excessively; flight crew attempts to reduce the aircraft’s pitch were largely ineffective. The aircraft reached a maximum pitch of 44º nose-up and the indicated airspeed reduced to 82 kt. The flight crew, however, were able to recover control of the aircraft and complete a subsequent approach and landing at Bournemouth without further incident.

Full report below:

https://assets.publishing.service.gov.uk/media/5422eab5e5274a131700001f/3-2009_G-THOF.pdf

rog747
22nd Oct 2017, 07:57
fly Dubai 738 ROV

Emirates 777 DXB
Asiana 777 SFO
Turkish 738 AMS

all similar in the landing phase and Fly Dubai did a GA with extreme pitch up?

wiggy
22nd Oct 2017, 08:42
Not sure why this Bournemouth near accident has resurfaced now but without dong a search I'm pretty sure it has surfaced on Pprune before...it even made the popular press in the U.K...

Thomsonfly passenger plane continued to fly for 11 days after stalling - Telegraph (http://www.telegraph.co.uk/finance/newsbysector/transport/5357482/Thomsonfly-passenger-plane-continued-to-fly-for-11-days-after-stalling.html)

I think the issue of underslung engines and stalling/pitch up is hopefully a bit better understood these days and is one reason why the manufacturers (well at least some) changed their published stall recovery actions.

Musician
22nd Oct 2017, 13:32
Not sure why this Bournemouth near accident has resurfaced now but without dong a search I'm pretty sure it has surfaced on Pprune before....
Yes it has, here it is: http://www.pprune.org/rumours-news/300235-tom-stall.html

Love RAT5's post: "I would have expected the elevator to have been as useful as wet fish at this speed."

Centaurus
22nd Oct 2017, 15:12
Musician. Quite correct. It was in Rumours and News ten years ago. Long enough for the present generation of Australian pilots to not have known about it and therefore the lessons learned. Hence the idea of re-visiting the incident in this forum.

KRviator
22nd Oct 2017, 21:10
Musician. Quite correct. It was in Rumours and News ten years ago. Long enough for the present generation of Australian pilots to not have known about it and therefore the lessons learned. Hence the idea of re-visiting the incident in this forum.Working in an entirely different industry these days (rail vs aviation), this mindset is commendable, and not just restricted to pilots. The vast majority of railway rules are written in blood, and there are very few new ways to stuff up so, like flying, it is best to learn from those that have gone before you.

Sadly, a lot of driver's these days have no interest beyond the bare minimum they need to get their job done on the day - you tell them about the ATSB/OTSI/NTSB investigation reports and they just look at you like you have 2 heads.

ViPER_81
23rd Oct 2017, 00:50
I'm just a lowly GA pilot, but from everything I've watched online, the correct recovery from an extreme nose high attitude would be to roll left or right and let the nose drop and then recover. Is this what they would have done in this situation?

Centaurus
23rd Oct 2017, 02:18
I'm just a lowly GA pilot, but from everything I've watched online, the correct recovery from an extreme nose high attitude would be to roll left or right and let the nose drop and then recover

That's about it. It is good to read there are those like yourself who are prepared to spend time on various excellent online websites to increase their airmanship knowledge :ok:My guess is very few flying school instructors are taught this during their own instructors course and therefore do not pass this info on to their own students. Same problem often seen during simulator training on airline types

ViPER_81
23rd Oct 2017, 07:26
I assume its not taught in GA as an aircraft with a much lower inertia, combined with the thrust vector from the engine being further forward and higher elevator authority, pushing the nose down is the quickest way back to lower attitude? I stand to be corrected.

Musician
23rd Oct 2017, 09:14
From post #63 on the old discussion (emphasis mine):

Nose high speed decreasing unusual attitude/upset.

You can use roll to aid lowering the nose if you have a very high nose attitude but only if you have sufficient speed in hand in the first place. Interestingly Boeing advocate up to full nose down elevator and a REDUCTION in thrust to aid recovery. The order is elevator, trim, thrust, roll and the roll has a caution attached as does the use of trim. By using the elevator aggresively your decreasing your angle of attack and making a stall due to roll much less likely (you can't stall at 0G) and reducing power will aid the pitch down initialy.

If your 40 nose up in the stick shaker then I'd reckon you don't have that speed in hand and by rolling your going to increase your angle of attack on one wing so could easily induce the stall you wish to avoid and make your subsequent recovery harder as the stall on one wing could induce even more roll. If you want to see that in action then look at the video of the Nimrod crash during an airshow in Toronto, I imagine its on U tube. Not exactly the same as they were in an established turn with G on but it gets the point of Mvr stall accross in a very tragic and poignent way.

With 40 nose up and stick shake you'd be doing the approach to stall checklist I would imagine. That and praying to whichever God you happen to believe in.

jonkster
23rd Oct 2017, 21:36
I assume its not taught in GA as an aircraft with a much lower inertia, combined with the thrust vector from the engine being further forward and higher elevator authority, pushing the nose down is the quickest way back to lower attitude? I stand to be corrected.

In the discussion (particularly when aimed at GA training) I think there should be a consideration between the differences between standard stall recovery that involves a high nose attitude and a recovery from an extreme nose high attitude (with power) where the aircraft does not enough elevator authority to substantially change pitch (and in most GA type aircraft) before the aircraft potentially starts to tailslide.

The technique for extreme nose high in that situation changes from the standard stall recovery technique taught as part of PPL training.

Typically GA training covers recovery from stalls that do not involve extreme nose high attitudes - the idea as I understand it the pilot should be trained to be aware through exposure of the symptoms of a stall (or approaching stall) before it gets extreme.

Extreme nose high attitudes should not be encountered as they would not enter such a state because they would have recovered well before this situation happens.

I think that is reasonably appropriate for PPL level training.

Of course for those doing aerobatics or wanting UA training, they will do recovery from potential tailslide attitudes but it is not commonly taught otherwise in GA as far as I am aware.

Not saying it couldn't happen - I have had a PPL doing a TW endorsement in an aircraft with a very powerful trim operated by a knob located near your left hip. He reduced throttle to idle (he thought) prior to turning base by rapidly pulling the trim knob fully back (mistaking it for the throttle) then released the stick in panic because he was so surprised at the strong stick force. I was caught fat dumb and happy with arms crossed in the back :( result was a very rapid and extreme pitch change up. I assumed it was a deliberate action by the pilot and was very confused and thought he had perhaps gone mad - trying to do a stall turn onto base is not a standard procedure. I know of another instructor in the same type who encountered exactly the same situation some years later.

The Green Goblin
24th Oct 2017, 00:39
Viper 81

A roll left or right command in a TC jet is a last resort if other recovery techniques fail. You wouldn’t use it as a first order of recovery.

It was originally a technique for when your nose attitude is high blanketing the tail plane with turbulent flow off the wing, preventing suitable airflow for elevator authority. (Rear engine jets were very prone) The roll command was to use secondary control effects to provide yaw which would lower the nose, increase elevator flow and provide suitable control. This was a jet test pilots bread and butter. If you’ve ever read David Davies work.

In a modern jet with multi crew ops you follow the recall items and the standard trained recovery technique.

If this doesn’t work, then you’re on your own.

In my outfit it’s a 3 part recovery. Plus it’s a recall

nose down pitch control apply
Bank wings level.

Then

Thrust increase smoothly (to prevent pitch up)
Speed brake check retracted
Flight path recover smoothly (don’t aggressively pitch up and enter secondary stall)

Then

If in clean config below FL200 config 1 select (slats)

I would assume in step 1 ‘nose down pitch control apply’ if you’re not getting a nose pitch down with elevator, you’d use some roll to get it.

ViPER_81
25th Oct 2017, 02:06
Thanks for the extra info :-)