flaps down for the pre-flight walk-round, but when does the checklist tell you to bring them up, if at all? Many official Cessna Pilot’s Operating Handbooks (POH) don’t put the flaps down for the walk-round checks and so don’t have a need to raise them during/after the starting checks. The only reference is in the pre-take-off checks – ‘Flaps set for take-off’. There are commercially produced
checklists available for each type of aircraft and they might have differences which include when you raise your flaps, some before starting the engine, some after starting to help save draining the battery. Flying schools/clubs often produce their own checklists for their members. If you’ve been flying with manual flaps
these are often raised before the master switch has been turned on, but it doesn’t work in a Cessna with electric flaps, you need the master switch on. So be careful, don’t amend a checklist to be similar/ familiar with a previous type of aeroplane, the flaps may well stay down.
DISTRACTIONS It’s a common issue. When passengers start talking and asking questions while you are doing your checks, items get missed. Likewise, if ATC calls or you’re rushing because you’re in a hurry. Or, you just missed it, we can all be guilty of occasionally missing a check and that’s why we should double check. The number of times I have seen Cessnas taxying out with their flaps still fully down...
SETTING FLAPS FOR TAKE-OFF Have you got the correct amount of flap? Do you actually need any for take-off? While the 150/152 POH recommend 10° flap for a short-field take-off, several 172 POHs say no flap for short-field take-offs because if you have an obstacle to clear the reduced climb performance outweighs the benefit of using flap. But, then some do recommend flap for a soft-field take-off with no obstacle issues. Is the gauge reliable and accurate? Have
you even thought about it or just assumed that they are where you think they should be? I’ve known a case where the pilot didn’t hear the motor whirring, so he recycled the flaps a couple of times and accidentally left them fully down. He survived to tell the tale, the aeroplane didn’t and the end hedge had a big hole in it. If you’ve missed all the precautions and not visually checked your flaps are set correctly for take-off are there any further
warning signs? Yes. During the attempt at taking off, the aircraft will be a lot slower to build airspeed, you’ll be using a lot more runway, it just doesn’t feel right... That’s when to abandon the take-off — now! (Always do the take-off checks properly and always be prepared to abandon a take-off.) Are there any further considerations with the flaps when flying? Yes, be aware of the handling characteristics when lowering or raising the flaps. The pitch changes required to maintain airspeed are relatively small when lowering the first 20° of flap, but they increase significantly with more flap and going from 30° to 40° requires a very prompt and positive pitch nose down to avoid losing the speed. Your rate of descent will also be significantly greater. Raising the flaps can also produce
considerable pitch changes and the potential for a large amount of sink if all the flap is raised in one go. Hence bringing flaps up in stages. On a go-around with full flap, having applied full power, as soon as the aircraft is stable bring the flaps back up to 20° and establish a positive climb. They will climb quite reasonably with 20°. Touch-and-go’s — yes, we all do circuits
practicing different types of approaches that involve the flaps being brought up during the roll. Have they come up? it’s a bit late to discover they haven’t when you are airborne, staggering over the hedge and not climbing very well. An electric motor can fail at any time. I mentioned earlier that the 152s having only 30° of flap is a significant change. I said
at the time that the extra 10° on the 150 made it different; in reality it’s the 152 that is different. If you learn on a 150 and go onto 172s the flap handling characteristics are similar. If you learn on a 152 and go onto a 172 the extra flap is usually emphasised on your checkout and it is a noticeably different aeroplane all round, bigger, four seats, so you are prepared for it to be different. 152 to 150? Not so, because, to all intents and purposes, they appear to be similar, just that one has a slightly bigger engine and is an inch or two wider in the cockpit, they are both basically a two-seater Cessna. But the flaps give them very different characteristics, a 152 will climb, although not brilliantly, with its full flap of 30°, will stagger off the ground on a touch-and-go and doesn’t have the large pitch changes.... but will a 150? They are different and need to be treated and respected as such. Finally, back to where we started “Check
Your Flaps Visually!” – If you always visually check your flaps are set for take-off when doing your pre-take-off vital actions… If you always glance at the flaps when you raise the lever during a touch-and-go to make sure they are moving up before you get airborne… Again, if you always check they are on the way up during a full flap go around… Then you shouldn’t have that unintentional full flap in any critical phase of flight.
Jennie Lyons has been actively involved in the aviation industry for more than 40 years and has owned and managed her own school. She gained her instructor’s rating in 1975 and is both a Flight and RT Examiner.
Summer 2018 CLUED UP 13
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