jfw wrote:
Excellent question… Went through the documentation I had and all the documents edited by the club says 10° normal take-off…while the POH says no flaps…
Probably a fixed idea by some instructor. We used to have that in my club, too, many years ago. I ignored it completely and followed the POH. Our current crop of FIs are more sensible.
In situations where the PA28 POH does suggest the use of flaps for take-off it says 25°.
Airborne_Again wrote:
In that case, why not flaps 2…?I never got a straight answer to that question.
please find another “material” excuse
Huh? Why would anyone need an excuse? As far as my plane goes, it’s in conformance with the PoH, and it’s what I do. Why would I (or anyone else) need an “excuse”? If I prefer to eat my peas with honey (because it keeps them on the knife) why do I need an “excuse”, even if you prefer to mash them to pulp and suck them through a straw?
Just to throw some fun argument in here, it is claimed that takeoff leads to more tire wear than landing, see here
That is a nice argument but I would imagine useful load vs max weight?
1000lb is the typical useful load on 2500lbs 4 seaters, Jodel D140 being one 4 seater that takes 2*times it’s weight 
on typical trip, I would barely burn 300lbs fuel and I never throw the pax away from aircraft, we don’t weather parachutes like Trevor
What’s the typical ratio on airliners?
I believe most tyre wear on Jodels comes from using assymetric brakeing in gusting crosswind taxiing on hard surfaces.
Land into wind, turn 60° and taxi ~1000m to hangar was my norm.
I wonder why POH’s are so much second guessed here. Personally I think that they were most of the time written by those who know the airplane best, namely the manufacturers from data during flight test. If they indicate flaps should be used for take off, then I won’t second guess that without good reason.
I had the pleasure to discuss some rather ambigous paragraphs of the Mooney POH’s with some people who really knew those planes like Mike Miles, the long standing chief test pilot of Mooney. I also took pleasure in reading Bob Kromer’s articles about the series. Both of them were very open and clear on why certain things were done. Mike will forever be missed (he passed away a few years ago) and Bob’s articles have somehow disappeared in the void of the net, I hope some enterprising soul will find them back.
I am sure this goes for most airplanes. If we discuss why certain recommendations or actual instructions found their way into th POH, it should be the people who wrote them we should try to talk to.
They are mostly dead due to old age
Tire wear occurs in two different areas: The tread will obviously wear with contact, ground friction.. The sidewalls will wear with flexing. I have had two sets of tires “wear” to the point of being unairworthy with decent tread left, but cracked, flexed sidewalls. This being because those tires rarely saw hard surfaced runways, always grass. So after more than a dozen years, they needed replacement because of wear. The use of flaps, and shorter & lighter ground rolls will reduce such wear. I always use the greatest permitted flap setting for any airplane I fly. Flap use is free.
Pilot_DAR wrote:
The use of flaps, and shorter & lighter ground rolls will reduce such wear. I always use the greatest permitted flap setting for any airplane I fly. Flap use is free.
Absolutely.
I also wonder about tire speed. I read somewhere that in certain conditions (hot, high) take offs can end up very close to max tire speed, which could be another issue. I am not aware of restrictions in the POH’s on this for most types, but I wonder if our tires per se have a limitation set on them, which depend on the type. I know that airliners have max tire speeds which some times in such conditions lead to problems.
Not only but also for that reason I think it is prudent to use the recommended flap settings out of the POH. And in particular, it is imperative to use the flap setting with which the POH take off performance has been calculated, otherwise obviously ground roll and initial climb to flap retraction will be quite different. On short runways, this may well be a very important issue.
