First Giant, second plane, couple of questions!

[Desertdualsport]

I got in about 10-15 flight hours on my Avistar trainer before the elevator stuck, and I turned it into a pile of splinters. I was pulling off loops and rolls regularly, and cross-wind landings nicely.

I then went to a local RC Swap Meet (Lebanon, PA) and picked up an old Maule Sky Rocket with a new ZDZ 40 engine on it. The aircraft is OLD, but solid. Huge, and heavy. I have spent the last three weeks rigging and fixing all the little issues that come along with someone elses old stuff. The guy even sent the original plans with it, and the N-number actually reflects a de-registered Maule in the FAA registry!
Questions;
--This will be the first time I will fly with a flap equipped plane........do I want to use them for initial take off? If so, should I leave them at full deflection? or set them to 50% or so (romote only has switch, I would need to program less than 100%)
--I re-did the fuel system with the correct parts (tygone etc....) and kept the original 3 line set up with two clunks, one for filling/emptying, one for engine, and a vent line. is this ok?
---ground runs are going well with the 19-10 prop, should I stay with this size prop, or change? engine manual calls for a 20-10.
--This is the first time running an ignition system.....it runs fine off my old 4 cell ni-cad 4.8volt, 600 mAh pack......and 600 mAh is all it calls for, should I run a higher output battery just in case? (bought a 3600mAh pack to try)


Thanks!

Nick

[Edgeman 540]

First off bud I'd definitely go with a bigger ignition battery somewhere around 1200mah or higher.Second I've never run a 3 line system.Third the flaps will give you additional lift but I wouldn't use full flaps on takeoff.Usually 15% - 20% is good.

[astrohog]

Love that plane!!

I've always wanted a giant-scale Maule!

Is this an IKON Nwest kit?

What are the specs? (w.s, weight, etc)

Might you be interested in selling the plans?

Regards,

Astrohog

[Desertdualsport]

Astro,
Wingspan is 96" measured, weight= heavy, didn't weigh it yet. Sorry, gotta keep the old plans! Doesn't look like a kit at all, hand built suspension and everything. I assume he did it all from the plans.


Edge,

I corrected my original post, I bought a 3600 mAh pack to try....I will run it vice the little packs on the ignition.

[2walla]

Three line tank is the safest way to go as you don't have to worry about a filler valve in the carb line leaking and killing your engine. I usually put barbs on all tank lines so that the tygon can't come off. If you have never had flaps, don't mess with them untill you have a few flights on it, then deploy them in stages at altitude so you can recover if it gets out of hand. Flaps usually make the nose pitch up and a small mix of down elevator may help- I usually put in 10% down mix to start. The flaps probably don't need more than 45degrees of deflection max. You will need to carry power with the flaps deployed as they create a lot of drag. Good Luck..

[jack01]

Don't use flaps for takeoff. The primary purpose of flaps is to increase drag and allow an airplane to make a steeper approach. Obviously, the increase in drag isn't a good thing for takeoff... lol.

The 3600 pack is pretty overkill. I've got a 2200 on my 150cc... Like Edgeman said, I'd go with something in the 1200 range. That will help to lighten the plane up some, and still give you plenty of flying time. Typically single cylinder ignitions draw a little under one amp, while two cylinder engines draw a little over 1 amp.

That 19X10 prop should be OK. If the plane is really heavy, try finding a 20X8 or 20X6.

[BasieB]

	Quote: Originally Posted by jack01
	Don't use flaps for takeoff. The primary purpose of flaps is to increase drag and allow an airplane to make a steeper approach. Obviously, the increase in drag isn't a good thing for takeoff... lol. The 3600 pack is pretty overkill. I've got a 2200 on my 150cc... Like Edgeman said, I'd go with something in the 1200 range. That will help to lighten the plane up some, and still give you plenty of flying time. Typically single cylinder ignitions draw a little under one amp, while two cylinder engines draw a little over 1 amp. That 19X10 prop should be OK. If the plane is really heavy, try finding a 20X8 or 20X6.

You can use flaps for take-off, if you are careful - we use flaps on light aeroplanes all the time for a short take-off. The flaps are used at max 20%, which increase the wing area which then creates a bigger lift. BUT be careful, no need if you have enough runway!

Have fun!!!
Basie

[jack01]

	Quote: Originally Posted by BasieB
	You can use flaps for take-off, if you are careful - we use flaps on light aeroplanes all the time for a short take-off. The flaps are used at max 20%, which increase the wing area which then creates a bigger lift. BUT be careful, no need if you have enough runway! Have fun!!! Basie

True, but that's usually for soft field takeoffs where the increase in drag from the flaps is less than the increased drag from the grass. Use the flaps to get it off the ground and into ground effect, speed up, clean up, go up!

[imhooked]

Flaps increase lift due to increased wing area.The use of flaps signifacantly decreases stall speed therefore allowing for slower flight and steeper angles of decent. They are not speed brakes.

[jack01]

I shouldn't have started this...

Here we go:

Flaps do not increase the lift of a wing. However, they do allow the wing to generate the same amount of lift at a lower airspeed. They do this primarily by increasing the camber of the wing. Some flaps, such as fowler flaps found on airliners, also increase the wing area by moving rearwards as they extend. With the increase in camber and wing area, the wing can now generate a given amount of lift at a lower airspeed without reaching it's critical angle of attack. In basic aerodynamics, the wing on a 2000 pound Cessna 172 cruising along is generating 2000 pounds of lift. It does this regardless of flaps up or flaps down.

Adding flaps for takeoff allows the airplane to lift off the runway at a lower airspeed not because the wing can now magically generate more lift, but because it can generate that same lift at a lower airspeed.

According to the FAA's own test bank and several aerodynamics books I've read, the "primary" purpose of flaps is to allow the pilot to make a steeper approach by increasing drag. It just to happens they do have other uses too. I wish I still had my Gliem books from studying for FAA writtens. I'd scan the pages with those questions on them and upload them here. After I passed the checkride I got rid of them since they publish new ones every year...

I'm not saying you're going to crash and burn if you use flaps on takeoff. I'm just saying that on a rediculously overpowered model, comparatively speaking, you don't need them and they stand a good chance to hurt your overall takeoff preformance.

[imhooked]

.

[Edgeman 540]

	Quote: Originally Posted by jack01
	I shouldn't have started this... Here we go: Flaps do not increase the lift of a wing. However, they do allow the wing to generate the same amount of lift at a lower airspeed. They do this primarily by increasing the camber of the wing. Some flaps, such as fowler flaps found on airliners, also increase the wing area by moving rearwards as they extend. With the increase in camber and wing area, the wing can now generate a given amount of lift at a lower airspeed without reaching it's critical angle of attack. In basic aerodynamics, the wing on a 2000 pound Cessna 172 cruising along is generating 2000 pounds of lift. It does this regardless of flaps up or flaps down. Adding flaps for takeoff allows the airplane to lift off the runway at a lower airspeed not because the wing can now magically generate more lift, but because it can generate that same lift at a lower airspeed. According to the FAA's own test bank and several aerodynamics books I've read, the "primary" purpose of flaps is to allow the pilot to make a steeper approach by increasing drag. It just to happens they do have other uses too. I wish I still had my Gliem books from studying for FAA writtens. I'd scan the pages with those questions on them and upload them here. After I passed the checkride I got rid of them since they publish new ones every year... I'm not saying you're going to crash and burn if you use flaps on takeoff. I'm just saying that on a rediculously overpowered model, comparatively speaking, you don't need them and they stand a good chance to hurt your overall takeoff preformance.

Thanks for the education on flaps.I stand corrected from my intial reply to the thread starters question pertaining to the usage of flaps on takeoff.

[Desertdualsport]

Thanks for the responses. I got the plane set up pretty tight....I thought.... and took it out to my club field last weekend for some airstrip length hops. Low and behold, I get it to gether, and a flap does not work. Come to find out later that the signal wire to that servo was worn out near the connector.
It was also VERY windy that day, I did manage to get it off the ground to about 10' and flew about 50' a few times. It handles nicely at low speeds and altitudes. The power seems ridiculous.......if it has a fast idle issue, I wouldn't be able to stop it. I am sure it will fly around at 1/4 throttle, and full speed would tear it apart in a hard bank.
I spliced in and soldered a new connector on that flap servo, and batteries are charged. Weather is gloomy today, but I will load up and see what we can tdo this weekend.

Nick

[Desertdualsport]

BACK FROM FIRST FLIGHT
Couldn't take letting it sit on a day off. Headed out to the field, and got it going. Was a bit breezy so I figured I would just do some more field hops with the flaps working. After a few, the plane was always pulling to the right on the ground so I brought it in to find one of the home made strut assemblies had slid down and was stopping the wheel hub. A quick fix later and I was back for more taxxing around and hopping.........
That is until I had nervouisly throttled too hard, and absolutely had to commit to a take off, or run off the field and trash the plane. Up she went at less than 1/2 throttle, no flaps and mild elevator input.
In the first bank, I easily noticed that the somewhat small ailerons did not roll the aircraft near as easily as my Avistar trainers' did. The plane looked like it was totally out of control.......well I guess it was! I finally found that 1/3-1/2 throttle vested the best reults for getting it dialed in. Then I realized it didnt even need dialed in. With all surfaces eyeballed level, it flew straight......it was only my overzealous inputs that made me constantly correct.
I almost slammed it into the ground 3 or 4 times, coming out of banks, and nose diving. Luckily the huge elevator surface and gobs of power allowed my to save it at the last minute.......only to head up too fast into a stall, needing to add even more power. I just didnt feel comfortable running it fast....seems like the wing struts would pull out, maybe I am being too careful, I don't know.
Time to try flaps. I had dialed them into 25% of thier throw before taking off. I got some altitude and hit the switch....ALOT of balooning, needed 10% at least down elevator to fly level, and more power than I was comfortable with. Flaps up.
Circled and landed nicely, in fact this thing floats down at idle. The winds were picking up,so I packed up and headed home.

Nick

[Tired Old Man]

Climb into the front seat of a C-182 or 210 someday and drop 20 degrees of flaps in level flight, then say flaps don't increse lift. They most certainly do, with some types generating more lift than others. They also frequently induce as much drag as they do lift.

The more wind you have, the less flaps you use. Unless you are using a short or soft runway flaps serve little useful purpose for takeoff. The only increase the workload for the takeoff. Use them for slower and steeper approaches, but remember to add power and uptrim to overcome the drag and pitch associated with their use. If you have a nice long runway why use them at all?

Depending on the ignition battery an 800 mAh 4.8v would be enough for a days flying.