No T/O flaps on longer runways?

[Steve]

Paul:

I certainly agree with pulling the prop RPM back (we can't 'Feather' on a DA40) on simulated engine failure practice landings. It makes a significant difference in glide range. In an engine failure right after T/O, it wouldn't be my first action. I pitch for best glide (usually up, then down), turn (either for open area, or if above about 750 AGL, a hard turn back for the runway), then run my engine failure emergency checklist if I have time.

Just what I practice...

Steve

PS: Good luck on the FAA medical!

[tjgoddard]

Our primary job as pilots is to limit our exposure to those things that will kill us! With altitude comes options. Simply put, I can always make an airplane come down but it takes power to go up. Speaking as a Gold Seal CFII who has had 4 engine failures in over 9k hours, I climb at Vx until 250 agl and then Vy until reaching 1000 - 1500 agl (or more depending upon terrain). Once a safe altitude is reached a cruising climb of 90 - 100 kts is established. With this departure profile, anytime after reaching 500'agl a turn back to the departing runway is very easy to make in fact allowing for full flap landings. The shallow "high speed" take-off profile only puts me farther from the airport at a lower altitude for a longer period of time reducing my options. Altitude is your friend (unless you're on fire) and one should look to add it to their available resources as soon as practical. BTW, safe landings with all 4. One was helicopter.

[Gary]

I use T/O flaps always, unless I forget, which only happened once. It happened of all places at a 2,600' grass field 6Y9 with some rather tall pine tress at both ends. For reasons I can't remember I did things in different order than from my usual take off routine from the 11,000 foot long runway at my home airport. I did the checklist before taxi but delayed the run up until I reached the end of the runway. I normally extend flaps after the run up to reduce the risk of damage from debris kicked up during the run up. I did not refer to the checklist during or after the runoff, probably since I was so nervous. Fortunately I was light and cleared the trees easily. The take off was noticeably different but I attributed that to the grass take off. If I had been flying any of a number of other aircraft I might not have made it. There was a fatal accident on the same runway about 10 years earlier when a Cessna 172S didn't clear the trees.

[Fred]

I have concerns intentionally increasing your takeoff roll by using no flaps on take-off. Per the POH the flaps can be retracted upon positive rate of climb is established (200-400 ft for me when I'm on a stable climb out). If you were to loose your engine at 800ft - 1000 ft extending your rollout by 40% can in some cases place you further from the airport environment and less likely an option to perform a 180 degree turn which if executed properly can be done at 800ft - 1000ft AGL consistently.

I always use first notch of flaps to reduce T/O roll and clean up the plane on climb out sometime before 500-600ft. If I were to loose my engine down low (below 700) I would be landing with-in 20-30 degrees of my heading at minimal airspeed; not many other options. The whole idea of pulling back the constant prop back sounds great, but don't see the benefit.

Our constant speed props maintain a RPM. It is not a mechanically change pitch and feather regardless of RPM. A windmilling prop I expect would be a very low RMP outside the range the prop governor impacts. I could be mistaken, but a few prop A&P's that perform rebuilds explained how this was more of a myth and confusion between a constant speed prop, and a constant speed prop that could feather or go beta. With that said I don't see a downside to pulling the prop all the way back, but don't expect it to change my outcome. I also would only touch the prop when EVERYTHING else possible was done like pushing the nose down on climb out to preserve airspeed and control, boost pump on, switching fuel tanks, and attempt to restart the engine.


Keep the blue sky on top and always leave yourself an option if your plan doesn't work out like you expected.

Fred

[rwtucker]

I'm with Fred and the others on using T/O flaps in all situations. As I think I mentioned earlier, it seems like there are a few situations in which a no-flaps T/O might have some advantages or at least no big disadvantages. However, there are always some disadvantages to mechanic types like me. The extra 500 feet on the ground (or whatever it turns out to be) is that much more vibration transmitted to the G-1000 stack, that much more wear on the tires and bearings, that much more potential for gusts, potholes, and ridges in the runway to nudge our non-steerable nosewheel off track, and that much more post-rotation time in which a gust can drive one of our super long wingtips into the ground. On the last point, I occasionally practice no-flap takeoff scenarios along with short-field, etc. When I do, it seems like I have less aileron control when I am critically low and slow. When you add these considerations to the fact that in most cases you will be better off situationally in a take-off engine failure, the FAA and POH guidance for T/O flaps seem spot on.