Lean of peak

[Thomas]

Fully agree with Antoine. Especially first part, this has nothing to do with DA40, it`s pure airmanship.

[rwtucker]

I agree with Antoine as well. I would be especially afraid of retracting flaps at 100 AGL. As we all know, their transition effect on ROC is not that smooth under certain W&B configurations. I guess prop speed is more of a matter of preference. Under certain conditions, I don't mind climbing at 2350. However, this is after I'm 1000 AGL and have the option to accept a less aggressive rate.

[CFIDave]

His recommendation is that the prop be pulled back to 2400 before leaving the pattern; and that this should be the default setting for everything not involving pattern work. When in doubt, put it there. If you don't have a good reason to change it, leave it there.

Flaps should come up at about 100' AGL (sometime before reaching the end of a middling-sized runway, in other words). I love the feeling when they come up: suddenly, we're in bat-out-of-hell climb mode, which is a lot of fun.

I agree only with the "when in doubt, put it there" recommendation for 2400 RPM. 2400 is the "default" RPM for flying a DA40 in cruise, cruise climb, or descent (prior to entering the pattern).

But the idea of raising flaps at 100 feet AGL, and pulling the prop back to 2400 before leaving the pattern is wrong in my view. Instead, the idea is to gain as much altitude as quickly as possible after takeoff -- providing the pilot with more options if the engine malfunctions. This means holding 2700 RPM (where the engine makes 180 hp at sea level) instead of 2400 RPM (where it makes only 160 hp) early in the climb. And since raising flaps tends to make the DA40 settle, you need to be clear of obstacles and closer to pattern altitude before touching the flaps.

[Colin]

I keep my hand on the throttles (previously throttle, mixture and prop), holding them against the firewall until I can glide to somewhere safely. Engine failures (and a lot of other bad things) happen more often when a change is made. And, as Antoine points out, sometimes when you make a change you make a mistake, introducing an uncertainty. Here at home (SMO), I don't touch anything other than the gear lever until I can glide to the beach. Then I start messing with things.

[Colin]

One of the guys that trained at the same flight school I did raised his flaps to do a go around at L35 (Big Bear). The plane settled onto the runway instead. Unfortunately, he had already raised the gear on his little Piper. Of course, there was some sort of airshow at the airport and there happened to be a television crew there, so he has video of his poor plane sitting on the runway.

Amazingly, his insurance paid every dime and he said his rates did change. When he questioned that the company said he was now VERY unlikely to have another runway issue.

[rwtucker]

. . . Engine failures (and a lot of other bad things) happen more often when a change is made. And, as Antoine points out, sometimes when you make a change you make a mistake, introducing an uncertainty. . .

This is a point to make more broadly, especially to those who are not mechanics or particularly interested in engines. Changes, especially abrupt changes, can increase stresses to the point of breaking parts that have undetected weaknesses (AKA: Damn! What was that?). IMO, it is inadvisable to make optional changes in engine parameters anytime your aircraft is in an especially critical environment. Even when I'm flying over the Grand Canyon, I set up the engine for minimum necessary stress well before the Canyon and do not change until I'm in a "landable" environment (I've often wondered about those long river bars down there . . . )

[BlueYonder]

Appreciate the feedback, Antoine. It's precisely the kind of alternative perspective I'm looking for.

When I'm flying on my own, my own preference is to get somewhere closer to pattern altitude (after the crosswind turn, at any rate) before fiddling with the flaps. Interesting about engine failure -- the reason I was given for pulling them in early was to maximize the climb, so you'd have more altitude to work with in that same case....

I'd read (here and elsewhere) about keeping the prop all the way up in climb, and prefer to fly that way when that CFI isn't riding the right seat. <g> My recollection is that this was due to European noise abatement requirements, which aren't generally operative in the US.

Went up today and tried Colin's suggestion for keeping the prop under 2350 in cruise. The effect on the fuel burn was amazing (high 8/low 9); and if there was a performance cost, it was minimal. Thanks -- will adopt that as my new policy, too.

Y'all will make a pro DA-40 pilot out of me yet....