Discuss the problems and solutions to all of the situations that Pilot X finds himself in.
By johnm
#874608
No on else got their's yet??

Looks like out of currency IMCR holder with vacuum pump failure.

Edited to add:

Sorry I seem to have messed the thread up getting ahead of Ian :oops:

It seems that our chum had gyro failure possibly due to vacuum pump failure and he took off without any real checks of gyro serviceability, even though he had a squeaky turn co-ordinator.

He was well out of currency for Instrument flying even had all been chipper with the aircraft, he might even have had a touch CO poisoning as someone pointed out.

On exit from cloud his best plan was the one initially recommended by KNT. Close the throttle, roll the wings ever so gently back through vertical and start to pull ever so gently out of the dive rolling a bit then pulling a bit at a time one might just keep it together, but I don't think I'd ever fly that airframe again.
Last edited by johnm on Wed Jul 07, 2010 4:31 pm, edited 1 time in total.
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By G-BLEW
#875771
Sorry, have just posted copy here...

Ian
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By Keef
#875923
I read it in my copy, which arrived last week.

It sounded awfully familiar. Take your eyes off the AI for a few moments, and the aeroplane sets off to do its own thing :)

It might be a failure of something, or it may just be inattention and the inevitable spiral dive. Being a coward, I'm not into energetic manoeuvres in cloud, and would have chosen a nice, gentle descent rather than diving in with the airspeed in the yellow arc.

Keep the scan going! I have a simple rule - I say "I'm in IMC now, stop looking out of the window and keep things stable." If the scan shows that the instruments don't agree with each other, work out which one is lying and stop using that. Cover it up with one of the little disks that you keep on your kneeboard for this very purpose.

200 knots in a Warrior - oh dear! Should have pulled power off and levelled out a while ago. Let's hope he gets it down safely after a very gentle recovery from the dive, but it will need to go for a check after busting Vne by that much.
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By KNT754G
#875951
Which thread should we be using for the responses? Should a MOD merge the two??

Sounds like AI failure, usually a vacuum pump failure which could explain the DI spinning like a top as well.

Should have closed the throttle immediately, GENTLY rolled wings towards the nearest horizon and once within about thirty degrees of horizontal pulled gently out of the dive.

That all assumes that the wings are still attached at that speed.

In fact with the wings past the vertical I would wonder (aerobatic types might help here) whether there was mileage to be had in gently PUSHING to an inverted S&L while letting the speed bleed off. Sure the engine is likely to have failed by then but if sufficient height to subsequently roll upright again it should restart.

Actually his problems started long before that.

Squeezing back to increase the climb rate, very bad idea in IMC. Amply demonstrated by the stall warner which could have been the first real sign of an incorrect AI.

Clearly inadequate instrument scan, throughout the IMC phases.

On getting VMC on top how did he know that the wings weren't level?
A clear cloud top line is frequently not level and can provide a very confusing false and incorrect horizon.

A wingover just before entering cloud for the descent, does this guy REALLY have a death wish?? Nice way to confuse a fully serviceable AI without giving it enough time to restabilise prior to IMC.

Entering IMC with the speed in the yellow arc, another seriously bad idea. IMC frequently means turbulence, which means keep out of yellow arc.

Continually having to "regain" wings level. With a fully failed AI he would never have been able to regain wings level on the AI, it just wouldn't respond to the attitude change. Wonder if there is a more subtle failure inside the instrument that it is partially reacting but to a false and continually deteriorating "wings level"??
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By CaptChaos
#876055
I agree with the comments here and have added my thoughts FWIW.

It started on the ground, an aeroplane that had not been looked after or flown for quite a while and just back from maintenance with a battery down on power and an admitted dodgy turn coordinator (thereby taking away ones braces or belt depending on your point of view). Also the aggressive cleaning regime ending up with a pressure hose blowing muck and grime around could easily block static ports, etc.

The mental state of the pilot was not conducive to safe flight; major business and cash worries, angry at being told off twice and the emotions of losing the plane.

With illegal and non-current flight into IMC conditions which he just got away with to then conduct flight likely to topple gyros which were not showing great stability anyway set up the final act.

A dive into IMC and potentially turbulent conditions above manoeuvring speeds and possibly above VNE with the extra push, even if pitot static system was not compromised put the aircraft into a spiral dive agressively, as although he thought he was levelling wings he no longer had any reference to judge that by as he solely focused on the seemingly failing AI without a look at the compass, etc. The fuel imbalance was symptomatic of the mismanagement of the flight.

His actions should have been to close the throttle, roll the wings level and start a gentle pull to level out from the dive. The pull needs to be sensitive to the high loading caused by excessive speed and as the speed reduces the pull could be increased. However being 40 Kts above VNE it may be too late but you have got to try. I would also try to hold the controls firmly to try to prevent flutter but not sure if that would help.

The pilot was not receiving any kind of service (so was unaware of other traffic) and no mention made of navigating to keep out of CAS. Hopefully no other traffic was transiting under the cloud layer when he dived out of it.

It seems the Darwin principle was at work again!

KNT754G wrote:In fact with the wings past the vertical I would wonder (aerobatic types might help here) whether there was mileage to be had in gently PUSHING to an inverted S&L while letting the speed bleed off. Sure the engine is likely to have failed by then but if sufficient height to subsequently roll upright again it should restart.



My though on the recovery is that it was only just past the vertical and aircraft such as the PA28 are designed with greater strength in positive g, so I would not continue to inverted. Our pilot was inexperienced in any case and not strapped into an aero harness to push the kind of g needed for recovery. The issue is the nose is down at high speed and needs to be raised.
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By Charles Hunt
#876091
A while since I read it, but wasn't he feeling a bit unwell. Some poor decision making, carbon monoxide poisoning?
By AttorneyAtLaw
#877516
Sounds like an toppled gyro from the wing overs coupled with a failure of the electric turn coordinator. That might explain why in both the climb and the descent he did not realise that his wings were not level. Is the spinning DI indicative of a vacuum pump failure, a toppled gyro or just that he was in a tight spiral dive? The article is not clear who much it was spinning. He is clearly out of currency or he would have derived some clue that hie was ascending or descending in a turn (with the wings not level) even if it was only from the compass.
By mixsfour
#877900
There's so much going on here including some possible human factors.

Agree with the comments about inappropriate/agressive cleaning methods causing blocked ports (couldn't make sense of the mixed messages from the ASI & VSI), and the whole thing ending in a spiral dive for which the first action is to close the throttle. Vne on a P28 is 160 KIAS I believe? - so pulling on the yoke at 200 KIAS will certainly result in structural overload. CO poisoning could generate the euphoria to make some of the reckless decisions taken during the flight, although there's plenty of evidence of poor decision making before then.

Dirt and dust in the interior - could this have blocked the suction system filter and caused erratic behaviour of the AI?

He had worked on the plane most of the day - what did he have for lunch? (thinking of hunger causing irrational behaviour)

He hadn't flown for 5-6 months - perhaps it would have been wise to go with an instructor after such a long break?

"focussing intently on the AI" - what about continuous radial scanning of the primary instruments? That would have picked up the spinning DI and increasing AS sooner.