Staudacher S-300D Help Needed
06-04-2007, 10:27 PM
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Staudacher S-300D Help Needed
Several weeks ago, I took my newly completed Staudacher ARF to the field for its maiden flight. Being a lower intermediate pilot, I entrusted the club’s most experienced pilot, over 30 years flying, to flight test it. It did not fly well!
It’s flying good at straight & level, climbing and diving, and does not try to stall when flying straight up. He tried to get it to stall, and it wouldn’t. But, when he banked the plane for a turn, it would start out banking fine, then suddenly the wing would dip and the plane would dive.
He thought that the 50% rudder-to-aileron mix I gave it was causing problems. He barely landed it without damage. He also thought it was behaving like it is was tail heavy, but I had used a CG Machine to set it after construction, taking ten weights on the tail, but he double checked this after the first flight, and confirmed it was good, according to the measurements in the manual (110 mm from LE). Even though this seemed like a lot of balancing weight for an OS.46, we couldn't argue with the manufacturer's specs. We also checked the left-right balancing and it was level.
So, I took the mix out, and we had a chance to refly it this weekend, same experienced pilot at the controls. But the problem was not resolved.
He almost crashed it several times, but managed to get about three-mistakes high and flew it for a few minutes. Each time he banked, though, the plane did this again. Then, the engine died. Not out of gas, but possibly overloaded.
On the dead-stick approach, he kept it in control until about 20 feet off the ground and in turning to land, the wing dipped, and it nose-dived. He managed to barely get it leveled so it didn’t go straight in, but the stalled, hard landing in the grass ripped out the landing gear and put a hole in the wing (from the wheel pant).
Several of the other club members joined us in checking out the control surfaces and the servos, and they all look good, as they did before we took off. All the electronics were still functioning correctly after the crash. The batteries were all fully charged and I had it set for low rates, somewhere around 60% for each control.
One of the club members said that tapered wings like the Staudacher tend to stall at the wing tips. Are we talking about a “tip stall” here? If that’s what it is, how do you correct it? This plane is not sufficiently controllable to be flown by ANYONE at this point.
Is anyone in the RC Universe familiar with this plane and its flying characteristics? What is the problem and how do I fix it? What could we expect to happen if we moved the CG a little toward the nose (maybe 5 or 10 mm)? Any suggestions would be appreciated.
It’s flying good at straight & level, climbing and diving, and does not try to stall when flying straight up. He tried to get it to stall, and it wouldn’t. But, when he banked the plane for a turn, it would start out banking fine, then suddenly the wing would dip and the plane would dive.
He thought that the 50% rudder-to-aileron mix I gave it was causing problems. He barely landed it without damage. He also thought it was behaving like it is was tail heavy, but I had used a CG Machine to set it after construction, taking ten weights on the tail, but he double checked this after the first flight, and confirmed it was good, according to the measurements in the manual (110 mm from LE). Even though this seemed like a lot of balancing weight for an OS.46, we couldn't argue with the manufacturer's specs. We also checked the left-right balancing and it was level.
So, I took the mix out, and we had a chance to refly it this weekend, same experienced pilot at the controls. But the problem was not resolved.
He almost crashed it several times, but managed to get about three-mistakes high and flew it for a few minutes. Each time he banked, though, the plane did this again. Then, the engine died. Not out of gas, but possibly overloaded.
On the dead-stick approach, he kept it in control until about 20 feet off the ground and in turning to land, the wing dipped, and it nose-dived. He managed to barely get it leveled so it didn’t go straight in, but the stalled, hard landing in the grass ripped out the landing gear and put a hole in the wing (from the wheel pant).
Several of the other club members joined us in checking out the control surfaces and the servos, and they all look good, as they did before we took off. All the electronics were still functioning correctly after the crash. The batteries were all fully charged and I had it set for low rates, somewhere around 60% for each control.
One of the club members said that tapered wings like the Staudacher tend to stall at the wing tips. Are we talking about a “tip stall” here? If that’s what it is, how do you correct it? This plane is not sufficiently controllable to be flown by ANYONE at this point.
Is anyone in the RC Universe familiar with this plane and its flying characteristics? What is the problem and how do I fix it? What could we expect to happen if we moved the CG a little toward the nose (maybe 5 or 10 mm)? Any suggestions would be appreciated.
06-05-2007, 02:03 AM
#2
RE: Staudacher S-300D Help Needed
G'day John,
Use this CG calculator to check the CG for your particular wing, manufacturers have been known to make typo's when it comes to balance points (CG).
http://www.palosrc.com/instructors/cg.htm
Also, these planes need to be flown faster than it may have been flown, I dunno, but usually balance point differences, will NOT cause tip stalls, but loss of airspeed can.
Have you you ever heard of a thing called, downwind stalling, it happens when the aircraft is flown down wind, then banked, & elevator is applied, but no additional throttle is used to keep the airspeed up, & because the plane is flying too slowly through a sideways moving airstream, in relation to the plane, most of it's airspeed has been lost, because it has slowed too much, this could be your problem, tip stalls occur when the wing tip stalls, easy as that, the only way to stop it, is to keep the wing flying, in other words, keep the speed up.
Use this CG calculator to check the CG for your particular wing, manufacturers have been known to make typo's when it comes to balance points (CG).
http://www.palosrc.com/instructors/cg.htm
Also, these planes need to be flown faster than it may have been flown, I dunno, but usually balance point differences, will NOT cause tip stalls, but loss of airspeed can.
Have you you ever heard of a thing called, downwind stalling, it happens when the aircraft is flown down wind, then banked, & elevator is applied, but no additional throttle is used to keep the airspeed up, & because the plane is flying too slowly through a sideways moving airstream, in relation to the plane, most of it's airspeed has been lost, because it has slowed too much, this could be your problem, tip stalls occur when the wing tip stalls, easy as that, the only way to stop it, is to keep the wing flying, in other words, keep the speed up.
