flyboyike

I'm afraid not, Don, and that AD certainly doesn't prove it. At best, it proves RAT was available. The electrical chapter of the systems manual (look it up on smartcockpit) makes not a peep about a RAT. The only thing mentioned is a hydraulic-driven generator for PW-powered birds. The chapter on RR-powered ones doesn't even reference that. Perhaps there was an STC of some kind, but if the manual is to be trusted, it wasn't standard equipment.

In fact, it appears it was optional on the 767 as well.

Turbine D

Boeing 757 RAT

I think some B-757s indeed had a RAT If you look at this FedEx B-757 landing after an aborted landing and go around, you will see the RAT deployed. Look carefully after the landing and the thrust reversers are activated and you will see the RAT. Going to full screen helps… I believe a division of Hamilton Standard manufactured the RAT.


TD

Winnerhofer

Myths and Training | Flight Safety Foundation

tdracer

For what it's worth, I checked 'generic' 757 AFMs for both PW2000 and RB211-535 and they both make mention of a RAT that will automatically deploy if both engines drop below 50% N2/N3 in flight or via a manual guarded flight deck switch.

BTW, I've never heard of Boeing certifying a RAT as "optional".

Tim

flyboyike

That's odd. The same generic manual I checked mentions only an hydraulic-driven generator.

tdracer

Flyboy, check Non-Normal procedures under Hydraulic Systems. It has a dedicated RAM AIR TURBINE (RAT) heading.

DozyWannabe

Makes sense - it would be a hydraulic RAT only, as electrical power would be supplied by the aforementioned batteries.

bubbers44

Thanks flyboyike, for a few posts it made me wonder if my memory was fading away. Our 767 had RAT but 757 didn't. Windmilling engine hydraulic pressure would get you down with total engine and electrical failure.

I made my example just a total electrical failure and was my plan if it ever happened. I usually was outside the 30 minute battery life of an airport over water so considered turning off the battery and navigating until approaching suitable airport and turning it back on to make the approach.

DozyWannabe

@bubs - check tdracer's posts at #628 and #630 - the Mighty 757 does indeed use a RAT for emergency hydraulics. Now - where were we regarding AF447?

B757 Hydraulics

(see pages 5 and 6)

Wally Mk2

This thread is becoming somewhat concerning. Does the B757 have a RAT or not? Checking quite a few sources via Google (smart cockpit for one) shows a RAT in the hyd system every time.
I'll ask again ( to anyone out there whom is B757 rated) upon an external insp of the A/C is there any evidence of a RAT? You know closed doors under the belly etc?



Wmk2

exeng

Talk about thread drift.

Mods where are you?


Regards
Exeng

DozyWannabe

Agreed, though I reckon the 757 RAT question and topic is worth hiving off into a separate Tech Log thread rather than simply deleting the posts, as there seems to be a considerable amount of confusion on the point.

In other words, it seems worth discussing, but not in a thread about AF447!

bubbers44

I was concerned with electrical not hydraulic systems. It is automatic for hydraulics so no training is required. That is why it was never taught except maybe in initial ground school once. It does not affect the electrical system.

From my memory over 10 years ago the 767 had a hydraulic driven generator that would be driven by the Hyd system. All my manuals drowned in Hurricane Wilma in 2005 so have no references to go to, only memory. If RAT would have taken care of total electrical failure I wouldn't have put my 'battery saving plan in my last resort checklist when I was current.

bubbers44

I agree, let's get back on topic. I am done. Hooray

john_tullamarine

Talk about thread drift. Mods where are you?

Watching on with interest, good sir.

Suggest we can tolerate a small digression on RATs for a few posts in however many thousands of posts we are up to in this sequence of threads.

If it persists, I'll hive the relevant posts off into a separate thread.

Not all will agree with me but, personally, I find the smaller digressions we see in threads part of the rich PPRuNe tapestry.

Wally Mk2

ok answer me this you thread drift haters what possible HARM can it do?
Is there a law we are breaking here? So what if a thread drifts off it happens all over PPrune everyday it can hardly hurt a soul. Most subjects drift off, ALL conversations go off on a tangent at some point or another but generally drift back. If anyone finds it offensive then simply don't read it or reply. This particular thread drift seems (well to me anyway) somewhat important & if it makes some out there whom fly these Boeings increase their knowledge base then good & well NO HARM done.....sheez I know the Mods love to dictate but boy it must be a personal agenda they have!!

Wmk2

DozyWannabe

Likewise - I certainly learned something today. In fact I think I'm right in saying that despite being of dubious relevance to the thread subject, we're looking at the first honest-to-goodness new information to be discussed since several threads ago - shame it's tangential!

So, returning - albeit with a somewhat heavy heart - to the subject:

@bubs - I know you were referring, at least in part, to electrical power in your post #614. The tangent occurred because you said in your next post there was no RAT, period, on the 757, which I thought was iffy.

Getting back to that first post, and acknowledging that you seem to have performed some very useful preparation and experimentation for total electrical failure, I ask again - as did vilas and a couple of others - why all this talk of automation, and what relevance does that post of yours have to the subject?

Also, given that the AF447 PF was a sailplane pilot, and that there are to the best of my knowledge no, or at least very few, automated sailplanes - it's a bit of a stretch to assume he was across-the-board dependent on automation, do you not agree? Not to mention that to fly sailplanes one has to be able to manage the flightpath by handflying and managing pitch, roll and energy - understanding stall - and particularly how to recover from it - is a prerequisite because gliders don't have TOGA power.

What we don't know is how recently he'd been practicing those skills, but it's fair to assume that he was proficient in them at some point, and remained proficient for some period of time. The recurrent training and practice both the F/Os lacked was of *high-altitude* manual handling only.

The airline industry previously made a dubious move to focus on stall *avoidance* in recurrent training and stopped practicing recovery which, to say the least, didn't help - but the continuing bafflement remains as to how they got themselves into that position in the first place!

I know there's an issue with automation dependence in the industry, and I don't think that anyone posting on this thread seriously supports the notion that increased use of automation is a good idea. What I was trying to understand from you is - why the continued assertions that the F/Os didn't know how to handfly at all and were automation-dependent, when the evidence suggests otherwise, and why you insist that Airbus was the prime mover behind increased use of automation, when the evidence is clear that it wasn't?

mm43

DW,

You'd have to accept that their automation dependance was to a degree revealed when following the initial "we've lost the speeds" that the PF didn't call for the FDs to switched off, and their no apparent attempt to follow SOPs or to call for the QRH guidance.

Put it down to a one-off CRM problem, but there may have been some other Human factors involved here, which may surface with the passage of time.

DozyWannabe

@mm43 - That's one interpretation. Another is that he was so startled that he lost focus from the start of the sequence and never recovered. There was no call to turn off FDs, but there was no call to initiate UAS procedure either.

I've said it before, even if you're among the best pilots in the world, a mistake - even a small one - which causes you to lose SA, can kill you with frightening ease.

vilas

mm43&Dozy
Our underlying likes, dislikes, attitudes and suspicions about automation go to form our opinions. We may be entitled to them but for the truth to emerge if we keep ithem aside what we see? Lets take a case where a pilot has regularly hand flown normal approaches and is profficient in it. But he was never explained the principle of the UAS procedure nor was he current or profficient in it. Another pilot who practices minimum handflying but is knowledgeable and had recently practiced UAS at high altitude. Who do you think would have managed the situation better? The human factor here is lack of proper knowledge or misunderstanding of UAS and stall recovery procedure. This particular abnormality is not straight forward and calls for investigation first, memory items and then paper procedure. If 447 pilot knew the procedure but was not very profficient in it might have saved the situation, may be he would have stalled 3 times on the way down but the flight would not have ended in 3 mts.