757 inflight instrument problem

[BANGHER]

Apparently a 757 out of Africa had a high level stall a few months ago due some technical problem, luckily it was recovered and returned OK with some insects in the Pitots, normal proceedure for the crew to be put in sim etc, how common is this type of event? and do we ever get to hear about it other than in the sim coffee lounges!

[rubik101]

Apparently not, is the answer to your question.
The reason being, that to publish these 'incidents' in this era of instant communication is to invite rabid press speculation with lurid headlines with which we are now so familiar.
Years ago, a precis of the previous months incident reports were posted on the back of our rosters. The practice had to stop when details were leaked to the press and a regular column of 'near death' experiences appeared in the national press.
For this reason, the essential dissemination of flight safety information amongst and between pilots has virtually ceased.
Now, all we get to read are the accident/incident reports, once published by the Accident Investigation branches around the world.

[Gulfstreamaviator]

Prompt: "I learned about flying from this", would ensure that we do not learn from the accident, but learn from the incident.

Chirp was a good outlet for this (in the civi world), but is getting PC.

glf

[Kirks gusset]

Your'e absolutely right guys, while ASRs and CHIRP is the vehicle for highlighting these events, most airlines, particularly in the current climate, don't want or need the bad press of A/C potentially falling form the skys!

[Magplug]

With the prevalence now of many competing 24hr news channels editors are desperate to fill air time. Airliner incidents are an editor's dream because the layman does not understand them so... the news channel can fill extensive air time with ill-informed experts and speculation.

Whilst the banks have behaved in an appalling profession manner with irresponsible lending, the news channels are to blame for 2/3 of the financial fallout due to their incessant reporting and the damage it has had on market confidence.

[Rainboe]

I think some of you aren't reading what actually happened judging by the peculiar nature of the comments. One side of the instruments were out due to pitot blockage. the situation was well recovered by an extremely competent pilot despite the usually screaming horns and ambiguous and false displays. I can think of 2 almost exactly identical incidents where the outcome was final for all concerned. There wasn't a stall for the hell of it, or for the neglect of it, and as far as I know the pilot is commended.

[aztruck]

Still under investigation by AAIB, and as far as I am aware the crew actions were exemplary. The causes are far more interesting than the beetle that had crawled into a pitot tube and died, and which, incidentally, did not manifest as a failure till the aircraft was well into the climb.
When the report is issued, I'm sure we can all learn something that we never knew about the 757 pitot static system from the folks at Farnborough.

[Rainboe]

What are you peope talking about? There was a potentially very dangerous and lethal problem that has caused a fatal outcome in several recent incidents. The crew recovered the situation safely and are still happily flying. New rules about parking planes in 'exotic' locations are being introduced. It must be terribly disorientating to find your flight instruments feeding you bizarre information with warnings going off everywhere. It was dealt with quietly and competently by the pilots who are flying still. No 'hero to zero' or 'back in the sim', just another problem dealt with safely.

[Avenger]

I don't think anyone is disputing the potential for disaster here and the prompt actions of the crews, and no doubt management have a role to play, having said that.. It certainly looked like the sim, smelt like the sim and drove like the sim when they were in the sim.. that's the facts, not speculation.:=

[aztruck]

Well Mr Gusset, I'm sure the AAIB were in that sim too, trying to reproduce the event, and comparing the sim data to the actual data, and the outputs of the various alternate sources, with the acual outputs of various alternate sources on the real aeroplane.
Its a bit more mature a process than your "hero" or "zero" oversimplification.

[4eyed spotter]

Birgin Air springs to mind.

[latetonite]

I had a blocked pitot years ago, on a ferry of a A310 out of Filton, together with an air/ground sensor failure. 400` overcast, tops 10.000. I can assure you, the combination of the view of the speed tape, sound of bells and whistles of the slat/flap, speed, and for some reason the gpws, distracted me a little bit from trying to figure out what was wrong and fly this thing "pitch and power" until out of the clouds.
It is definately not for the faint hearted.

[brakedwell]

Many years ago the RH altimeter remained static after take-off from Nairobi in a Hastings. Close inspection revealed a largish spider clinging to both needles. Around 10000 feet the spider's grip was overcome by torque and the needles span round to our cruising altitude, chopping the poor creature into many pieces. Carnage on the flight deck. :eek: :eek:

[Captain Airclues]

Many simulators in the UK do not have the facility to simulate a blocked pitot and therefore many crews have not been trained for this. I have seen it demonstrated in a (non-UK) sim and it required a great deal of skill and concentration to overcome either a single or double blockage. It would seem that the crew concerned are to be commended.

Dave

Edit; Just to confirm, many UK sims do have this facility. However, many do not. When using one UK sim we had to fail the ADC which did not give the correct indications.

[Regulation 6]

Pitot / Static failures are, as already said, particularly nasty. Even when an exercise of this nature is pre-briefed in the sim for training, the 1st attempt often ends in a mess, so if this event did not end up with aircraft exceedances and proper control was maintained throughout, - very well done to the crew.

Interestingly, this is one of the few areas where corporate aviation has safer practices than airline ops. Almost all corporate pilots fit pitot covers (and, depending on climate, often engine covers as well) even for single night stops. In my experience, this never happened in airlines.

Cheers all

[aztruck]

Ah.... you will be pleased to hear that fitting Pitot covers is now a mandatory procedure with Astraeus for anything longer than a few hours on the turnaround.
Lest you think this is some third world problem, I once tried in vain to programme the FMC at a certain French location before air testing a 757. Various anomalies cropped up including a 135 knot speed variance between the ASI's on the ground, resulting in the aircraft logic assuming it was airborne!
The FMC responded by only allowing inputs as if the aircraft was in the air.
Turned out that a swarm of bees had crawled into the Pitot system and died. The seal that resulted trapped air that merrily expanded in the heat of a Southern French summer, interpreted by the ADC as 135 knots.
We enquired of the well known pan european maintenance organisation whether thay had fited covers to the Pitot system.
"Of course" they replied

[stilton]

It strikes me as odd that in the year 2009 we are still using Pitot / Static sensing for Airspeed / Altitude / Vertical speed.


Along with the potential for disaster after repainting, leaving Pitot covers on and so forth..there are other pitfalls like operating in cold weather, 'high to low, look out below' flying an approach with an innacurate altimeter setting etc.

Why not use an input immune from the above errors, GPS ? It can display all of the above.

We could keep all of the standby instrumentation as pure Pitot / Static driven.
I think the idea has merit.

[HundredPercentPlease]

Why not use an input immune from the above errors, GPS ? It can display all of the above.

We could keep all of the standby instrumentation as pure Pitot / Static driven.
I think the idea has merit.

And how, exactly, do you know what ground speed to fly when there is a wind? (Not bothering to even mention the whole not-autonomous problem).

[757_Driver]

I'll let you reithink that one stilton! Groundspeed is utterly irrelevent to the airplane, it only cares about airspeed. Indeed i've seen a cracking airshow trick onc an aircraft with a 20 odd knot stall speed flying 'backwards' in 25 knots of wind!

Anyhoo, completely co-incidentally, I have recently experienced a pitot static blockage in the sim (it can be done in UK sims - this was in a well known sim buidling in gatwick) both ASI's reading normal during the take off roll, and then captains pitot getting blocked during climb out. It was a 'simple' captains pitot blockage in which the press of one button (capts alternate air data ) resolves the problem ,but that wasn't the point. It was extremely disorientating, and removes your trust in many if not all of the instruments! In the end I flew pitch and power to a sensbile level off and then worked the problem, I even talked myself into flying a raw data VOR appraoch as I didn't trust the autopilots, even though they worked perfectly - it is very disorienting.
I suggest that those of you that think this is an Anglophile issue, try a blocked pitot / static in the sim (two fatal 757 accidents have occured for exactly the same reasons).
It is a real issue. The turkish accident was 3 people not paying attention to a perfectly servicable aircraft. Completely different kettle of fish.

[RAT 5]

Lateonite: "PITCH & POWER". Now there's a blast from ther past, more's the pity. I fly with F/O's who can't fly visual approaches. They allow the A/P to be sued for radar intercepts and then disconnect at 1000' and steer the a/c towards the runway. They must have been able to fly visual circuits for base training, but that was month ago. Visual descending approaches on a severe clear day are not in their portfolio. Sadly, the company doesn't seem to propmote the idea, whereas 25 years ago in the Greek island charter days of needles & dials a/c it was the standard. And if you couldn't do it efficiently and safely you didn't get command.
This is not a "it weren't like that in my day" tirade, it is just a comment that when I see F/O's fly visual circuits on the autopilot I wonder where we are going with aviation. I know this topic has been discussed many times before, and I am not opening the debate again, but where will the astute commanders be who can save such a scenario as this B757? Once every 3 years in the sim doing a few simple unusual attitude recoveries is not the answer. it ticks a box, but.........

[Waqavukatau]

I am brand new to PPRuNe tonight, a real oldie, and I just read your tale of the pitot and beetle.

In a DC3 full of pax (I said I was an oldie), descending IFR in cloud through 6000ft at night, all - and I mean all - flight instruments on both sides suddenly went ape or just froze, iced up, with me at the pole. Pitot heat didn't hack it.

I can understand your feelings: it is a most horrifying experience. We broke out at 1000 feet in a total sweat, still with no flight instruments. On the ground the engineer reported a beetle jammed in the mouth of the pitot and the drain holes blocked!

For those who scoff at such tales, you want to hope you never get the chance to have it happen to you. You'll wonder how your uniform trousers suddenly changed color.

[stilton]

My mistake, in terms of ASI we are stuck with Pitot-Static for now, but GPS can give you an altitude readout free of errors.

[411A]

...but GPS can give you an altitude readout free of errors.

Yes, but....haven't you heard, GPS is 'supposed' to go tango uniform any day now.:ugh::ugh:
Shock, horror...whatever will we do?:}

You'll wonder how your uniform trousers suddenly changed color.



Mine never changed color, just got soaked from the leaking windshield.:eek:

[IRRenewal]

GPS can give you an altitude readout free of errors.

Unfortunately, altitude is the least accurate part of your GPS readout.

[HAWK21M]

Out here Halt exceeding 2 hrs & the Pins & pitot covers are installed.
regds
MEL.