Originally Posted by
douglas.lindsay
That's what my instructor taught me, and great advice too. I've memorised the in-flight checks (and most of the other ones too, particularly the "oil pressure rise within 30 secs" stuff!) and rehearse them regularly (my poor wife is sick of them) - I guess my question was more "what sort of things do you all make a point of checking at different stages in flight?"
Great suggestions - thanks! Any other ideas?
The engine oil pressure rising is obviously a very important check but IMO an equally important check is to look at the ammeter. If the starter fails to disengage when the engine starts the starter will fight the engine and very expensive damamge will very quickly occur. This is called a "hung starter" and the first indication will be a massive electrical load. For the + 0 - type ammeters the needle will be buried at minus 60 amps and for aircraft with loadmeters (some Pipers) the needle will be hard to the right showing amximum load. I have never had an aircraft fail to show oil pressure on start but I have had a hung starter.
IMO flight schools often do not do a very good job of teaching how to do a good runup check. Some things to think about
1) Magneto Check: When checking the mags the difference in the mag drop between the the two mags is just as important as the maximum drop noted for each mag. A large difference in mag drop between the two mags indicates a problem with the ignition timing and should be investigated before further flight. The POH should have the limits for both maximum allowable drop and max difference allowed, which will always be considerably less (only 50 to 75 RPM). Similarly I have met many pilots that did not realise that no mag drop is actually bad as it indicates a fault of the magneto grounding circuit or mag switch and again is a reason to abort the flight
2) Mixture Control Check: Most pilots seem to just pull the mixture control out untill the engine dies and then shove the knob back in. This only proves the idle cut off works and does nothing to prove the mixture control can actually regualate the engine air/fuel ratio. It is also hard on the exhaust as the engine can backfire and blow out all the muffler baffles. A better way IMO is to start with full rich and apply carb heat for a period of 30 sec or so. The will RPM drop becasue the hot less dense air casues an excessively rich mixture. This proves the carb heat works and there is no ice buildup. Leaving the carb heat, lean the mixture slowly and note the RPM will slowly rise as the mixture is leaned from over rich to the best power mixture ratio. Continued leaning will cause the RPM to fall as the engine enters an over lean condition. This indisputably proves the mixture control is actually regulating the mixture and obviates the need to actually cut out the engine. Furhtermore if there is no significant rise in engine RPM when the engine is leaned with carb heat on this indicates the carburator has been set up much too lean and the aircraft should not be flown.
Finally I was so bold as to suggest on the instructor forum that I thought it ws a good idea to review the EFATO drills before every takeoff as part of the
pretakeoff check. I was thoughly beaten up by a few posters for this suggestion but I still think it is a good thing to do. I suggest readers review the "what happened to the EFATO thread" on the instructor forums (started 9 July) and make up their own mind.