Scottish Information .. Pan Pan
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Scottish Information .. Pan Pan
Hey thaks to all you guys on my frequency earlier that remained quiet whilst I dealt with the Pan call............
.....Pa28 over lowther Hill announced that throttle was stuck on max and engine RPM red line...thankfully instructor aboard and despite some grotty weather over the hills he managed eventually to get back to Prestwick and land safely.....to anyone that called me and never got an instant response sorry but i was a wee bit busy!! 
.....Pa28 over lowther Hill announced that throttle was stuck on max and engine RPM red line...thankfully instructor aboard and despite some grotty weather over the hills he managed eventually to get back to Prestwick and land safely.....to anyone that called me and never got an instant response sorry but i was a wee bit busy!!
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Well, there's a floatpane trick for when idle gives you too much power - turn one mag off ...
(I had "throttle stuck open" on a car once. I turned the ignition off, put it in neutral, put on all lights and hooter, and forced my way to the hard shoulder. Can't do quite the same thing in an aircraft, unless it happens to you overhead an airfield.)
(I had "throttle stuck open" on a car once. I turned the ignition off, put it in neutral, put on all lights and hooter, and forced my way to the hard shoulder. Can't do quite the same thing in an aircraft, unless it happens to you overhead an airfield.)
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A single engine aircrafts throttle system is normally designed so that it fails to fully open (as opposed to fully closed like in cars). In case of a failure, you let the engine run until within safe gliding distance of your chosen field, then cut the fuel and glide to safety.
If the engine is redlining, in addition to the trick of Gertrude, you can also pull the mixture to reduce the RPMs.
In fact, the POH of the PA-28 Cadet has this as the recommended leaning procedure: Mixture and throttle both full forward. Reduce mixture - RPMs will climb initially then reduce. Set desired cruise RPMs with the mixture, leave throttle wide open. Do not operate above 75% power with a lean mixture for more than 15 seconds.
Oh, and you can also put the aircraft in a climb attitude to prevent redlining. But that's perhaps too obvious...
If the engine is redlining, in addition to the trick of Gertrude, you can also pull the mixture to reduce the RPMs.
In fact, the POH of the PA-28 Cadet has this as the recommended leaning procedure: Mixture and throttle both full forward. Reduce mixture - RPMs will climb initially then reduce. Set desired cruise RPMs with the mixture, leave throttle wide open. Do not operate above 75% power with a lean mixture for more than 15 seconds.
Oh, and you can also put the aircraft in a climb attitude to prevent redlining. But that's perhaps too obvious...
Last edited by BackPacker; 4th Oct 2009 at 19:27.
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trick for when idle gives you too much power - turn one mag off
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What have leaning procedures got to do with anything?! You wouldn't be leaning as per the POH (in order to get best power/economy etc)... you're just leaning to a level where the power drops sufficiently. Would make for some interesting pops, bangs and the like, but would get the job done.
Does it? I've never heard of this, so how does it work? Are you suggesting that, in carbureted engines, there is a set position to which the throttle valve will go? Or are you saying that they never fully open? I'm not trying to be smart, just after some clarification, as I never knew about such things. What about on fuel-injected engines?
In all the PA28 POH's I've seen, it says to refer to the engine manufacturer's handbook for leaning procedures.
Thanks
A single engine aircrafts throttle system is normally designed so that it fails to fully open
In all the PA28 POH's I've seen, it says to refer to the engine manufacturer's handbook for leaning procedures.
Thanks
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Obvious now you say it, but duly filed for future reference.
It's a recognised trick when taxying a floatplane to the dock, and on idle with both mags on it's moving faster than you feel comfortable with. I haven't a clue whether it makes sense with the throttle stuck open in the air!
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Backpacker....
Well I reckon the instructor on board ( Dr in Aeronautical Engineering ) knew that as well as when at first Prestwick radar told me they could not see him on radar i aked him if he could climb and he said yes as he would probably have to do that anyway to keep the rpm below red line!!!...
Oh, and you can also put the aircraft in a climb attitude to prevent redlining. But that's perhaps too obvious...
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I don't want people taking that as serious advice!
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Could you not just put the mixture leaver to starve the engine of enough fuel? I don't mean cut it totally, but you'll get to a point where there's not enough fuel to burn, and the RPM will come back.
So long as you'd pulled it far enough back to be below 75% power (which should be obvious from your resultant straight and level speed) everything should be all right.
I seem to remember Deakon advocating this as best normal operating practice some time back.
Have I got this wrong? Would it not work so simply?
So long as you'd pulled it far enough back to be below 75% power (which should be obvious from your resultant straight and level speed) everything should be all right.
I seem to remember Deakon advocating this as best normal operating practice some time back.
Have I got this wrong? Would it not work so simply?
Well done to those who left ATC and the urgency aeroplane to sort their problem out.
Regarding a stuck full throttle, presumably in a fixed prop aeroplane - the obvious thing (to me) to do is climb to somewhere in comfortable gliding range of a useable runway, then shut the engine down and glide to land.
Assuming that you can do it without climbing into cloud! - which is where having an instructor with an IR on board is helpful, but I can't imagine any sane pilot then shutting the engine off without sight of the surface.
Failing that - accept probably damaging the engine, stick the nose down and overspeed it; there are safety margins in everything, including RPM limits.
G
Regarding a stuck full throttle, presumably in a fixed prop aeroplane - the obvious thing (to me) to do is climb to somewhere in comfortable gliding range of a useable runway, then shut the engine down and glide to land.
Assuming that you can do it without climbing into cloud! - which is where having an instructor with an IR on board is helpful, but I can't imagine any sane pilot then shutting the engine off without sight of the surface.
Failing that - accept probably damaging the engine, stick the nose down and overspeed it; there are safety margins in everything, including RPM limits.
G
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Mechanical jam following full-power climb. And I mean jam - absolutely rigid. Further climb to >4000' brought rpm onto red line in cruise, but speed in yellow arc in slightly turbulent conditions. Weather precluded direct track to PIK hence lengthy divert. Little in the way of forced-landing options in the NGY area.
Student did very well indeed. I just helped with R/T and analysis to decide what he could and couldn't do. Throttle unstuck south of PIK. But that's a worry too - did the stuck throttle indicate a linkage problem that would become apparent when throttle was advanced? Again, I didn't touch the controls once. Student managed it all, right up to landing.
Apologies fisbang for pan pan as initial call. As always, a nice warm feeling in this part of the country when on R/T!
A really nice problem for de-brief what-if scenarios
Student did very well indeed. I just helped with R/T and analysis to decide what he could and couldn't do. Throttle unstuck south of PIK. But that's a worry too - did the stuck throttle indicate a linkage problem that would become apparent when throttle was advanced? Again, I didn't touch the controls once. Student managed it all, right up to landing.
Apologies fisbang for pan pan as initial call. As always, a nice warm feeling in this part of the country when on R/T!
A really nice problem for de-brief what-if scenarios
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What have leaning procedures got to do with anything?!
I've never heard of this, so how does it work?
I don't know about fuel injected engines. But I would assume the same design principles apply.
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India-Mike...
Hey thats no problem thanks for the call thats what were here for....sorry for asking you if it was actually a practice as you just sounded too dam cool..!!
Anyway glad all turned out well in the end....speak again soon...
Paul.
Apologies fisbang for pan pan as initial call. As always, a nice warm feeling in this part of the country when on R/T!
Anyway glad all turned out well in the end....speak again soon...
Paul.
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Student did very well indeed. I just helped with R/T and analysis to decide what he could and couldn't do. Throttle unstuck south of PIK. But that's a worry too - did the stuck throttle indicate a linkage problem that would become apparent when throttle was advanced? Again, I didn't touch the controls once. Student managed it all, right up to landing.