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-   -   Power Attitude Trim. PAT vs APT (https://www.airlinepilotforums.com/hangar-talk/15819-power-attitude-trim-pat-vs-apt.html)

wmupilot85 08-13-2007 10:45 AM

Power Attitude Trim. PAT vs APT
 
I am having a debate with someone, who claims Attitude, Power, Trim is the proper order to deal with level flight. I tell him that once you change power settings, you changing lift also (either airspeed or prop), so another pitch attitude is required. Since he doesn't believe me, what your opnions on here. Who teaches what method?

Ewfflyer 08-13-2007 11:37 AM

I'm confused on exactly what are you trying to say? What do you mean "deal with level flight?"

Yes, when you change power, you'll gain/lose airspeed, assuming you correct with pitch and trim corrections for the speed change, you can maintain altitude. Now say you pull the power, but don't change pitch, well you descend, vice versa with a power addition. In the end, there's not really a specific order, because most of these are done simutaniously as far as pitch/trim are concerned.

I'm just throwing out scenarios' to make sure we're on the same page, or maybe I'll cover it with all the randomness.

LeoSV 08-13-2007 11:40 AM

I set my power before trimming. if you trim and then set power, you will either climb or descend because of changes in lift. your power setting at cruise is different than your climb/descent power settings.

FlyerJosh 08-13-2007 12:04 PM

Ummm- can I say that in the whole scheme of things it doesn't matter? Flying isn't an exact science.

You're debating TECHNIQUE. What works for one person isn't necessarily the best for another depending on personal flying style and preference.

Personally I often trim simultaneously as I change pitch or power. Right way, wrong way, doesn't matter as long as you get the job done and your student understands what the primary concept is of the maneuver.

mcartier713 08-13-2007 02:12 PM

i always understood it as you adjust pitch and power together simultaneously, then trim it out.... granted it all depends on the stiuation

the King 08-13-2007 02:35 PM

I teach Pitch, Power, Trim. When I do it, it comes out closer to simultaneous though. I'd suggest Pitch before Power on the principle of sight picture. Even in IMC, you know where the approximate position of straight and level is. Pitch for it, set the power to the proper setting, and begin trimming to relieve pressure. Then double check the instruments or visual reference and make fine adjustments.

the King 08-13-2007 02:39 PM

Oh, the reason I don't do power first is because you usually want to get somewhere fast. By pulling the power back first, you lose some airspeed while pitching. If you pitch first, the airspeed increases momentarily until you pull that power back. That would be especially bad if leveling out from a nose-high unusual attitude or recovering from a climb is slow-flight.

Cubdriver 08-13-2007 04:34 PM

That's also a good habit to use in the pattern. Pilots will pull the power back then pitch down abeam the numbers, but if you keep it in and adjust pitch first you get there quicker and waste less time. The typical thought is, if you are trying to deploy some flaps and you are near the top of white arc, you will make airspeed too slow to reduce without removing power, so most people prefer to pull that first and let the airspeed reduce. On the other hand, coming off cruise for a gradual, 500 fpm descent the easiest thing to do is ease back the power a bit and let the airplane naturally descend. It depends on the particular situation.


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