Air Command 447 flight test problem

Buckingdummy

Member
Joined
Sep 17, 2012
Messages
128
Location
Adel, Or
No I purchased it in working condition. Guy I bought it from built and flew it extensively said he used to take off and land on the beach. Workmanship is really good the only thing I have changed is the carb setting to match my altitude. Sea level to 4800ft is a big change.
 

AirCommandPilot

Just a fledgeling
Joined
Feb 24, 2014
Messages
574
Location
Houston
Aircraft
Air Command Elite #003
Total Flight Time
88
No I purchased it in working condition. Guy I bought it from built and flew it extensively said he used to take off and land on the beach. Workmanship is really good the only thing I have changed is the carb setting to match my altitude. Sea level to 4800ft is a big change.
You need to do a hang test with YOU in the seat. This is VERY important for your safety. You may have to remake the cheek plates to get the proper balance. Every time a single seat gyro is sold or gets a different pilot, this needs to be checked.
 

Doug Riley

Platinum Member
Joined
Jan 11, 2004
Messages
6,323
Bucking: You'll need to specify exactly what the gyro does that makes you uncomfortable.

A lowrider A.C. without the H.S. is pitch-unstable in turns, in that it tends to slow down unless you add forward stick pressure. A stable gyro (or FW plane) needs back stick in turns. The factory HS pretty well corrects this flaw, though, as does the highrider conversion.

This backwards reaction is a byproduct of high prop thrustline (HTL): with uncompensated HTL, the rotor's thrust is what holds the nose up, while the prop is continually trying to push it down. You increase rotor thrust in a turn, so the rotor pulls up extra-hard on the nose, and the gyro tends to pitch up and slow down unless you apply forward stick pressure. Again, though, the H-stab largely fixes this.

Coordinating turns? Well, the original A.C. had a short tail tube and a vertical tail of only about 4.5 sq. ft., contrasted with Bensen's 6 sq. ft. Moreover, the A.C. all-flying tail has less maximum potential lift (the rudder's forces are just sideways lift) per square foot because it's an all-flying surface, while Bensen's is a 2-piece (flapped) surface. Many people erroneously believe an all-flying tail is more powerful for its size, but the reverse is true. Bensen's split-panel, hinged job has more maximum lift per square foot, for the same reason that flaps increase the lift of fixed wings.

A lowrider with a body pod may feel strange in a turn if you slip or skid the turn. The body, being a draggy object well below the aircraft's CG, will try to add or subtract bank angle if the gyro moves at all sideways to the air. In extreme cases, this effect can overpower the pilot's control inputs in the roll axis. Draggy items located below the CG are, in general, de-stabilizing in pitch, roll and yaw.

So those are some specific instabilities that you might encounter. Let's hear what you actually did notice, though.
 
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