Discuss the problems and solutions to all of the situations that Pilot X finds himself in.
By masterofnone
#1638608
So, it's my first time in the aircraft for a month or so, but I didn't feel really rusty. I was methodical on the pre take off checks, but I didn't get any sense something was wrong until I rotated. And then I sensed something was really wrong.

The overwhelming sense was that the aircraft did not want to fly . I had a momentary WTF? moment, followed by a very strong reluctance to raise the nose any higher, followed by a seat of the pants extrapolation of my position relative to the end of the runway and the A27 beyond. I can attest to the momentary sense of disbelief and confusion that pilots report in moments like this. It probably took 3 seconds to make the purely instinctive call to abort, about 10 or so feet off the ground. Even then, I was very mindful that there was still scope for the situation to end badly, being nose high and probably not far from the stall

I backtracked, wondering what the hell was wrong and whether I should attempt another take off. I figured it was worth another go, but only after a really thorough run through of the pre flight checks.

And what do you know, it was only running on one mag :oops: A combination of diminished currency and aircraft familiarity, and a mag switch that rotated in its housing just enough to make it look like it was on both mags when it wasn't, was almost enough to spoil my day. Subsequent take off was uneventful.

So, blushes all round, but some useful lessons learnt and things to take merit for. My instincts were pin sharp and my decision making was spot on. I didn't pancake the aircraft onto the deck during the recovery and if there was any danger of complacency creeping in, the episode firmly nipped it in the bud.

So, not exactly air crash investigation material, but definitely an incident that gave me a lot to think about, and one I learnt a lot from.
TopCat, dparnell, kanga liked this
By flyingyod
#1638615
Well handled. I was always taught to check that the RPM is at the expected value (a bit over the expected static RPM) once at full throttle. Would that have given an early warning in this case?
By masterofnone
#1638627
Yep! But I wasn't fully familiar with the aircraft. It was a 152, and amongst a few of those I have flown, not all of the have the same pitch prop, so there are variances amongst them. As I say, familiarity or lack thereof was a contributing factor.
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By Sooty25
#1638643
I do find it odd, that in an environment that demands dual redundancy on the ignition system, that often a common point of failure exists in a single MAG Switch assembly.

One of ours has a single slider switch 0, M1, M2, M1+M2 in each cockpit. I've had to strip and service both, and each time thought a mechanical failure in the switch itself could make life embarrassing, especially as they are both over 60 years old! Two individual toggle switches would give proper redundancy, but wouldn't be historically correct in our case.
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By Miscellaneous
#1638646
Sooty25 wrote:I do find it odd, that in an environment that demands dual redundancy on the ignition system, that often a common point of failure exists in a single MAG Switch assembly.

True, but then the single pilot is generally more prone to failure than the MAG switch, don't you think? :D
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By mick w
#1638647
Done it with Mags & Carb Heat , fortunately in Aircraft capable of climbing without one or the other , so once Brain has thawed , adjust & carry on . :oops: :wink:
By masterofnone
#1638722
Sooty25 wrote:I do find it odd, that in an environment that demands dual redundancy on the ignition system, that often a common point of failure exists in a single MAG Switch assembly

About as odd as having fuel tank guages that are universally accepted as having the utility of a chocolate tea pot. Or using a fuel metering device whose design makes it susceptible to icing under nearly all known atmospheric conditions. Or mandating maintenance protocols that were shown to be sub optimal during the second world war, and have been abandoned by virtually every other safety centric industry since.

Put mildly, there are numerous anomalies!

Two individual toggle switches would give proper redundancy, but wouldn't be historically correct in our case.

I get the whole "maintaining authenticity" thing, but I could never bring myself to use authentic kit when it is cr*p, especially when it doesn't incorporate the cumulative benefits from learned safety lessons over time. As a rule, we do things way better and safer nowadays.
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By T67M
#1638754
Sooty25 wrote:I do find it odd, that in an environment that demands dual redundancy on the ignition system, that often a common point of failure exists in a single MAG Switch assembly.


Ok, it's not 100% true, but it's very, very unlikely that a switch will fail to a double short circuit. It's much more likely that the failure will be a single (or double) open circuit, in which case the symptom is that you can't STOP the magneto, which is a fail-safe(r) option.
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By Paul_Sengupta
#1638761
masterofnone wrote:
Two individual toggle switches would give proper redundancy, but wouldn't be historically correct in our case.

I get the whole "maintaining authenticity" thing, but I could never bring myself to use authentic kit when it is cr*p, especially when it doesn't incorporate the cumulative benefits from learned safety lessons over time. As a rule, we do things way better and safer nowadays.


Well, the Tiger Moth used two toggle switches...

(four if you want to be pedantic!)
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By BirdsEyeView
#1638937
Well done Masterofnone...
Reminded me of a check flight with an instructor in a 172 I hadn't flown before. Understandably I was a little anxious as to the unfamiliar. Certainly not an issue as you faced though...
Echoing flyingyod's post: On power up rpm would only go to 2300 when I expected 2450+ or so. I nearly aborted (700m runway) but there was a feel to the aircraft that it was delivering full power - engine sound was also 'lively'. Lifted off to Vx and reached 1000fpm. Cruise was 2200, 100 rpm below. Subsequent findings likely to be static or under-reading tacho (I was told). Instructor thought it might have been prop pitch. But if you fly a particular aircraft on a regular basis then you 'have the feel for it' so well done on your recovery.
I spent my whole training on an aircraft with a mag switch showing the wrong positions due to slippage in the ignition barrel. Hence my own last checks at line-up before take off: Fuel, Flaps, Mixture, Mags... Brakes Off... "Off we go..."
Thanks for posting.
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By Rob P
#1639703
There was an incident in the Shiny Colt when a member, long since gone, who was a bit of a pie eater took his missus, also not the slenderest for a bimble from Knettishall.

The aircraft barely staggered into the air and crawled around the circuit at a little above the treetops to thankfully flop down again on the strip. Bear in mind that it took off quite happily with myself, 2D and some luggage + full fuel several times on the way to and from Italy.

He left the group shortly after having trailed around East Anglia looking for an engineer to condemn the aircraft. He was an R/C modeller and also developed a bee in his bonnet about aileron flutter. He was convinced the dear old Colt was going to kill him.

Our best assessment later was that his aircraft keys were on a largish bunch, which swinging as the aircraft accelerated, had switched off one of the mags.

I always use my FLYER lanyard now, from which the aircraft key and little else, bar the short streamer, detach simply.

Rob P