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Old Sep 26, 2005, 12:24 PM
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Crash, help me figure out what happened

I was flying my PTS mustang at the field the other day in 35 MPH gusts and managed to bring it down. However, yesterday with calm conditions and clear skies I crashed. I took the speed brakes off before the flight and took off. Did some loops, low passes etc, the plane was ALOT faster. I brought it in for landing and lined it up with the runway. I eased back the throttle to zero and started coming in. About 5 feet off the ground the plane started lurching to my left, (its right). I tried to use the ailerons to correct but instead it just dumped all the way over, cartwheeled in, ripping the wing off and crushing the fues. Well it's being repaired, but I'd like some helpful pointers I guess on maybe something to do different? My alpha has no problem coming in, but I thinnk it's because I feel safer with the longer legs than the low to the ground stance of the stang.

Thanks in advance.
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Old Sep 26, 2005, 12:46 PM
Naturally altered
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The problem you encountered is called stall speed. Below it, the airplane ceases to fly and control surfaces are not effective because of not enough airflow (or disrupted) over them. Keep the speed up a bit during your approach, cut the throttle to zero only at touch down. Put the extra flap servo if you want to land slower than the plane could without flaps.
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Old Sep 26, 2005, 03:47 PM
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I agree with Cubber. You're probably scared of breaking your Mustang, so you're coming in too slow, and stalling. In that circumstance, trying to lift a wing by using aileron just makes it even worse because it spoils what little lift the wing had.

The calm day just accentuates things because you probably approached the runway on each occasion at what looked to you like the same speed. But with headwinds up to 35 m.p.h. on the previous occasion your model had up to 35 m.p.h. more flying speed than when the wind was calm. So, on the bad day you were probably getting buffetted, but you had plenty of flying speed to avoid a stall and to keep the ailerons effective.

The solution is that you have to fly a faster (ground speed) approach when the wind is calm.
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Old Sep 26, 2005, 03:51 PM
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The PTS needs some spped to land properly. It is heavier (mine weighs close to 7 pounds) than most other trainers (most are 5 to 6 pounds and a bigger wing) and therefore needs some airspeed to keep it flying. It rolled due to loosning lift on one wing tip before the other (tip stall), the NACA droops are there to try to counter this, and the forward CG is supposed to dip the nose in a stall.

A good landing whth this plane will be with the main gear only. Fly the plane to the ground and flare to gently bring ing in with some speed. Putting the planes left gear down first should help limint the bouncing. Adding a servo for functional flap is a good choice also, you can have your faster fun then srop the flaps for a good slow landing. With the flaps deployed the wing maintains a more level flight at slower speeds, helping keep aileron effectiveness a bit longer.

I bought one of these for a new sport plane, and flew it in the beginner progression just to see it's characteristics. It now has the brakes and NACA droops removed, the flaps are functional and it has an APC 11x5 2 bladed prop. The new prop makes it a fun sport plane, with some good fast speeds (not a racer yet) and nearly unlimited vertical. I was surprised with the change in the prop, but the inclueded tree blade is there to make it a good slow trainer.
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Old Sep 26, 2005, 04:44 PM
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We have some newbies at our feild and one had the same happen to him. The P-51 is really 3 different planes. I have helped the guys fly theirs..w/ all the training gear on, speed brakes removed, brakes and droops off w/ original engine & prop (kinda scary), and w/ brakes and droops off w/ a T.T. Pro .46- 11x5 master airscrew prop(fast and Pretty darn agile) Flaps are a big help, all I can add other than the good points mentioned above is before you start removing parts or "upgrading" have an experienced flyer w/ you the first time you fly it after making changes just in case you are not as ready as you thought you were. And remember...we were all in your shoes once. Good luck!
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Old Sep 27, 2005, 01:30 PM
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When you are flying too slow and the plane stalls and begins to roll to the right (or left) apply opposite rudder to the direction of the roll, as mentioned before when you try to use your ailerons there is not enough lift under the wing to bring it back up, so remember to use rudder and most of the time you can save the plane with little or no damage
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Old Sep 28, 2005, 04:30 PM
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Hmm ok, that makes alot of sense, it just has a harsher stall than the alpha even with all the training gear. So next time, I'll leave 3 or 4 clicks of throttle until im over the end of the runway and then chop it and keep the nose down until it's just a few inches over the deck. This should prevent that stall.. correct?

Thanks for all the insight.
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Old Sep 28, 2005, 04:51 PM
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Just remember to control your altitude on your approach more with throttle than with elevator. Just fly it all the way to the ground. If it looks like it is loosing alt too quick, ""ease on"" the throttle or if it wants to maintain alt ""ease off"" the throttle. Now you will still have to hold a little up elevator but do not move the elevator up and down to make the plane go up or down. Just hold a little up to keep the nose up slightly. You can get away with a lot more coming in just a little "hot" than you can coming in too slow. As long as you keep the wings level and hold a little up elevator and a little "finesse" on the throttle, landings should become easier and easier. Good Luck and Happy Landings!
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Old Sep 29, 2005, 12:06 PM
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Quote:
Originally Posted by foofinator
Hmm ok, that makes alot of sense, it just has a harsher stall than the alpha even with all the training gear.
. . .
Yes, that's why most of us do not consider low wing planes (especially warbirds ) being trainers. Most high wing trainers (properly balanced) have very mild stall characteristics - they usually just drop the nose down and self recover from the stall unless too much elevator is fed constantly. OTOH, low wing planes usually drop a wing tip followed by total loss of aileron response (lack of airflow through the aileron surface) and they do not recover from the stall by themselves.
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Old Sep 29, 2005, 07:48 PM
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So. Texas
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Quote:
Originally Posted by foofinator
I was flying my PTS mustang at the field the other day in 35 MPH gusts and managed to bring it down. However, yesterday with calm conditions and clear skies I crashed. I took the speed brakes off before the flight and took off. Did some loops, low passes etc, the plane was ALOT faster. I brought it in for landing and lined it up with the runway. I eased back the throttle to zero and started coming in. About 5 feet off the ground the plane started lurching to my left, (its right). I tried to use the ailerons to correct but instead it just dumped all the way over, cartwheeled in, ripping the wing off and crushing the fues. Well it's being repaired, but I'd like some helpful pointers I guess on maybe something to do different? My alpha has no problem coming in, but I thinnk it's because I feel safer with the longer legs than the low to the ground stance of the stang.

Thanks in advance.
I had a similar experience yesterday. The plane was hard to keep level in flight. As I made my approach the plane dipped to the left from about 50 ft and nose dived into the ground. Wings suffered a small amount of damage but fuselage was demolished. When we began to check why this happened we found the glue that holds the ailerons servo to the wing cover plate had come loose. This was not because of the crash as you could see there was hardly any glue on the plate , no wood splinters at all.
This plane is designed to be stable a slow speeds. The first few times I flew it I made power off approach with no trouble at all. When I made the flaps movable and removed the speed brakes I began to do power approaches.
No matter what people say with this plane you do not have to do power approaches.
Hope this helps.
.
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Old Sep 30, 2005, 04:46 PM
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No. You do not have to make power approaches. But remember most people flying these p-51 have little or no experience landing. The power on landing is an extremely useful tool to learn as early as you can, and w/ this plane it is very easy to master. It will help you as you advance to more agile and somewhat "twitchy" planes that are sure to come. Also power on will help keep a slightly miss-tuned engine running and not as likely to quit on approach. Nobody wants to learn dead-stick landings at the same time they are just learning to fly. I am not saying you can't chop the throttle and glide her in but you need to be comfortable w/ the planes handling characteristics at slow speeds and what speed or lack thereof you can get away w/ before she snaps. To a fairly experienced flyer power off landings are easy but for a "newbie" it more often than not spells C-R-A-S-H. I train a half dozen people a year to fly and more often than not they say power on landings feel more comfortable than "gliding her in". They also pick up power landings quicker. Jeez I'm rambling. Foofinator, hope we're not confusing you even more than when you first post.
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Old Oct 01, 2005, 06:30 PM
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Haha, it's ok guys.

I'm going to check that aileron servo.

Thanks for all the replies, I had some very successful flights today, using throttle to control altitude helps ALOT and I am getting good at it. I hold the elevator to a little up until i'm flaring to land. I also have been leaving 3 clicks of throttle all the way in, cutting to idle to descend if im too shallow then getting back in it, or giving it a couple more clicks if im coming in too steep. Thanks for all the help, and when the mustang is repaired in a few more days, I'm sure i'll be ready!

BTW the alpha trainer is a great airplane!
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