flaps reduce the rate of climb
Well sure, but that’s why you retract them as soon as you’re off the ground (well, at 50 feet).
That is not 100% true “flap reduce rate of climb”, I think I posted two POH that says the opposite, I think if 0 stage flaps is a negative setting then 1 stage flap is likely to enhance L-to-D and max available power
Lot of flaps do reduce rate of climb, especially drag & landing flaps
In gliders it’s a whole new game, you throw lot of positive flaps in strong thermals and lot of negative flaps in fast glide in sink to maintain best L/D and increase RoC or reduce RoD
johnh wrote:
Well sure, but that’s why you retract them as soon as you’re off the ground (well, at 50 feet).
Still the loss is more than zero. A small piston aircraft is typically not constrained by tire rotational speed or ground roll length, so I would say flap operation is more of a training routine than necessity.
Ibra wrote:
That is not 100% true “flap reduce rate of climb”, I think I posted two POH that says the opposite
I think you need to revisit principles of flight.
I think you need to revisit principles of flight
Indeed, I did mention in a previous post it’s puzzling, it does not make it wrong though 
I think, I understand the logic behind but it’s less obvious unless you fly gliders or have advanced degree in aeronautical engineering 
https://www.euroga.org/forums/flying/13707-flaps-for-take-off-why/post/311210#311210
OK. Sorry for not reading in detail and being rude.
No worries, it’s not the most obvious detail, I tried on M20C: I think it’s a mistake to climb with any sort of flaps, maybe a typo in POH? but the PA32 seems to climb better with 10deg flaps but I have lot of doubts about 10deg flaps near 18kft ceiling
Whether it’s flaps up or flaps down most aircraft, I have flown, tell you when they are ready to fly.
That does not necessarily mean they are telling you they are ready to climb, although they will tell you that too, if you are listening.
The point at which they are ready varies with weight, drag and lift. Flaps usually mean they are ready to fly a little before they would be with no flaps. The difference depends on many things but is usually reasonably fixed all things being equal and can therefore be published in a POH.
Meanwhile the PIC has to decide if s/he is ready to fly or ready to climb at the same time as the a/c. And example of this would be in a lightly loaded light twin in strong winds where the aircraft might be like an excited puppy ready to leap into the air long before Vmca is reached.
It is for the PIC to decide whether to let the puppy have its head and leap into the air or whether the risk of it coming down splat and getting seriously injured is too great.
The choice of flaps or no flaps is a pilot decision (outside the training environment) and should never be made mandatory, there are far too many other considerations to be taken into account to do that, surely.
I have never seen a flight manual refer to a “stage” of flap. Is this an authoritative term? Might it be dramatic?
I have most commonly seen flap settings referred to in either degrees, or a fraction of full flap extension.
Some airplane types (Some Cessna 3xx and 4xx twins, and DC-3) use split flaps, so they are great for drag, less beneficial for lift, so less useful for takeoff, though a little may be specified for takeoff, it seems to have a very slight “vectored thrust” effect. I used 10 degrees of flap when I used to fly the 310, just because the POH said to for the runways I used.
The Lake Amphibian specifies full flap for takeoff (because the flaps are either up or down). This, like many floatplanes, is the optimum flap setting to place the hull in at an angle in the water which gets you out of the water fastest. With the wrong hull angle, you’ll never accelerate to get out of the water. For the flying boat I own, flaps were added as a design improvement after the first 17 airplanes were built, as it was found beneficial for pitch attitude in water takeoffs. The use of flap shortened the takeoff, not so much as making the wing fly better, but rather spending less time and distance trying to accelerate. For a number of Cessnas converted to floats, the 40 flap setting is limited to 30, owing to the difficulty in getting the nose high enough during a power off water landing.
Otherwise, for other types, it is what has been found to work best for general handling, without getting the plane into a undesirable configuration in other phases of flight (like a go around). If you are going around from a full flap landing, particularly in a retractable, unless the flight manual says otherwise, fly the plane first, change configuration later. If you have decided to go around, fly whatever is needed to manage that situation, the plane has demonstrated that a takeoff while configured with full landing flap will still work safely (or it would not have been certified). Fast hands in the cockpit can lead to disappointment, particularly in twins and RG’s take you time, do vital actions only when you change a phase of flight. Flap reselection is rarely vital.
In Canada, non certified planes are prohibited to have flaps designed to extend further than 45 degrees. With only one exception I can think of, those GA types with flap settings greater than 45 degrees have been limited to maximum 45. The SM1019 is approved landing 60, takeoff 30 flap. I have done the flight testing, those flap settings are excessive for the operational needs, and unsafe in the hands of an untrained (on type) pilot.
I was checking out an owner on his new plane last week, we did not use flaps, as there were none. It landed faster than I’m used to, but, it’s supposed to.
to help this popcorn 🍿 thread, one more variation:
On the RVs with manual plain flaps (-3, -4, -6) short or bad surface runways, one technique is 0 flap take-off, partial extension during the roll…
Here goes:
- line up, apply the brakes and add as much power as possible without lifting the tail (about 2300 on mine)
- let go the brakes, push the stick forward to level attitude
- extend the flaps one notch (about 15°)
- let the aircraft levitate and accelerate in ground effect
- retract the flaps
The whole procedure results in a short ground roll, and is over before you’re even 1/2 thru reading that text
