[kip51035]

I bought this .60 size Spitfire off ebay. I t came in a plain box with no markings. The only label is "ARF" on the back page of the instructions. It is a well made model that comes with retracts and flaps. The recommended setting for the flaps is 8MM, about 10 deg. On most models setting up the flaps is usually a waste of time. Many models have really weird reaction when you lower the flaps. Should I set the servo arm so when the flaps are full down the pushrod and the servo arm form a straight line, thus taking the strain off the servo. Does anyone out there regularly fly an aircraft with flaps? What did you do to make it fly right on approach. I know that aircraft with flaps down require a lot more power to keep them in the air.

[voyager_663rd]

Others will chime in if this is in error but: From what little I know, set up the flaps with slight down (as you've done @ 10%). At the same time, set a slight down elevator as well (mix with the elevator being slaved to the flaps). The dropped flaps (without elev) will cause it to pitch up so the down elev helps keep it level flight (albeit with increased drag so you'll need to speed 'er up a bit).

You can always do it first without the down elevator input to observe what happens. Just at all times be ready to raise them if there's an issue.

Go fly and try dropping flaps. Make sure you're 3-4 mistakes high and about half throttle. Note planes reaction and adjust when you're back on the ground.

[Max]

Kip, it depends on the plane whether flaps are useful or not.

For example, I have a CG SuperChipmuk that has flaps. It's pretty much useless, I can land with flaps up or flaps down and i couldn't honestly tell you the difference. (other than a pitch-trim change, which I will mention below)

Some warbirds particularly benefit form the use of flaps, others not.
Years ago I built a corsair that was a real brick, but it would float across the runway from one end to the other when it came time to land. I replaced it with a corsair with flaps and now landings are a breeze with it. I recently acquired a GP corsair ARF with no flaps, and while t does land a little better than my Brick-of-a-Corsair used to, some days I wish it too had flaps.

In all cases, any airplane will have a pitch-up tendency when you lower the flaps. As you lower the flaps, the plane wants to start climbing under the same trim conditions. In the old days pre-computer radio, you had to drop the flaps up high and fly a circuit to get the trims dialed in before you tried to land.

Today, with the advent of computer radios, flap-to-elevator mixing is a real boon. You may need to play with your plane/radio on the ground a bit before you can get the mixing order correct, but basically what you want is the elevator to be moved slightly downwards as the flaps are lowered. The exact ratio will have to be determined(fine-tuned) in the air.

What you want is that when you dial in the flaps, the pitch doesn't change. This may take several flights, but once you have it set right, you will find that dropping the flaps has minimal effect in your pitch.


In summary, I would say that some planes can benefit from flaps, others not. In our case, you wont know until you fly it for the first time. If it were up to me and I had the option to put the flaps in, I would put it them on and maybe not need them than to not put them on and need it.

[Ron Marwood]

Hi Kip, I have a Top Flight Piper Arrow with flaps. This plane is fairly heavy and lands fast without flaps. This is damaging to the gear as our field is grass and not too smooth. The flaps are on a 2 position switch which deploys them at either 25 degrees or 40 degrees.
When the flaps are deployed (at about 2/3 power) the nose pitches up and the plane starts to slow down. I cut the power a little bit and the plane levels out without any elevator input. I proceed to land by reducing power and control with elevator as required to keep from stalling. This plane if stalled at 2 or 3 feet will nearly drive the wheels into the wing, so be careful that you fly it to touchdown.
This is my only experience with flaps and I find that I like them very much.

[stegl]

Originally Posted by Ron Marwood

Hi Kip, I have a Top Flight Piper Arrow with flaps. This plane is fairly heavy and lands fast without flaps. This is damaging to the gear as our field is grass and not too smooth. The flaps are on a 2 position switch which deploys them at either 25 degrees or 40 degrees.
When the flaps are deployed (at about 2/3 power) the nose pitches up and the plane starts to slow down. I cut the power a little bit and the plane levels out without any elevator input. I proceed to land by reducing power and control with elevator as required to keep from stalling. This plane if stalled at 2 or 3 feet will nearly drive the wheels into the wing, so be careful that you fly it to touchdown.
This is my only experience with flaps and I find that I like them very much.

I am flying a Hanger 9 twin otter and can land with or without flaps ; but like the real one landing is definitely improved WITH FLAPS if set up right.( the same with my Deuces twin) Like most said fly up high and try flaps and see how the airplane responds. a lot depends on just how much flap you put in. (flap drop) . It can drop the speed down quite noticeably; but the trick will probably be that you will have to mix in some down elevator to get the nose down. The big thing is the more you drop the flaps the more the nose will pitch up .Once set up properly, it will be an improvement. If not sure maybe get someone with your club help out.

[Flypaper]

I have a 10 yr old Cap 10B with flaps that are very necessary. Like Max, I come across the threshold at about 10 ft and at the end of the runway, I'm at about 5 ft. I've found the best way for this plane to land, is to slow the plane down first, then lower the flaps. If you're going to fast, you will get an abrupt pitch up. If done after slowing down first, there is very little pitch up. I don't mix with elev. as the pitch will change as you change speed. The slower you go, the less elev. you need. You will also need to come in with a lot of throttle on as the flaps make great air brakes. Once you lower the flaps past about 15 degrees, the lift does not increase, just become brakes. The throttle becomes your altitude control. If your coming ito short, throttle up a bit to hold your altitude. Not up elev, as that will shorten even more. The real Spitfire flaps come down almost 90 degrees, with no in between. In the Biography of Buzz Burling, Canadas top WW2 ace, he mentions about going with some new Spitfires to Malta on an aircraft carrier, and when the got to Gibralter they wouldn't take the carrier any further as it would be in range of German bombers. To take off from the carrier, they dropped the flaps, put a 2by4 or equivalent in the opening, then put the flaps back up. Now they had about 10 degrees flaps. Enough to get off the carrier without falling into the ocean and being run over. A good biography if you run across it. He was one of our unsung heroes.

[stegl]

Originally Posted by Flypaper

I have a 10 yr old Cap 10B with flaps that are very necessary. Like Max, I come across the threshold at about 10 ft and at the end of the runway, I'm at about 5 ft. I've found the best way for this plane to land, is to slow the plane down first, then lower the flaps. If you're going to fast, you will get an abrupt pitch up. If done after slowing down first, there is very little pitch up. I don't mix with elev. as the pitch will change as you change speed. The slower you go, the less elev. you need. You will also need to come in with a lot of throttle on as the flaps make great air brakes. Once you lower the flaps past about 15 degrees, the lift does not increase, just become brakes. The throttle becomes your altitude control. If your coming ito short, throttle up a bit to hold your altitude. Not up elev, as that will shorten even more. The real Spitfire flaps come down almost 90 degrees, with no in between. In the Biography of Buzz Burling, Canadas top WW2 ace, he mentions about going with some new Spitfires to Malta on an aircraft carrier, and when the got to Gibralter they wouldn't take the carrier any further as it would be in range of German bombers. To take off from the carrier, they dropped the flaps, put a 2by4 or equivalent in the opening, then put the flaps back up. Now they had about 10 degrees flaps. Enough to get off the carrier without falling into the ocean and being run over. A good biography if you run across it. He was one of our unsung heroes.

Yes I heard about the 2 by 4 in the flaps but don't remember which aircraft.

About the flap at speed ; I don't seem to have the problem with either my Twin Otter or Deuces both twin motors and both with flaps. I know I have the flaps operate at slow speed with my SD-10G Airtronics radio and the elevator compensation also matches the speed of the flaps dropping and haven't seen any balooning. Works great ! Flypaper ; do your flaps drop quickley or are they slowed down ? as that may be part of the problem and yes compensating elevator mix is also the way to go..

[Guest]

i had a h9 spitfire with flaps and they worked great..they were about 10 to 20 degrees.

[Flypaper]

The Cap has a fairly wide speed range. So I have to slow her down before I drop the flaps so it's no problem, just a matter of knowing/ learning your planes traits.. Poor old DX7 only has one flap speed, fast.!! This is the old girl. Had a Quadra 42, now electrified with the same power.

[stegl]

Originally Posted by groundcrew

i had a h9 spitfire with flaps and they worked great..they were about 10 to 20 degrees.

The twin otter works out to about 20 degrees at flap 1 and then 30-32 degrees at flap 2. The really nice thing is the servo slow feature and especially the matching slow elevator mix. Can't really tell that you are using flaps other than the airplane really slows down nice for landings . Have floats built up, covered and mounts done. Just need rear mount fairing and floats painted.