zlin plane? poor design?
02-03-2013, 03:43 AM
#1
zlin plane? poor design?
my friend took his Zlin out for maiden yesterday.
http://www.nitroplanes.com/zlzen4656nig.html
it had an evolution .46 nitro engine with an 10 x 6 prop.
prior to flight engine was turning 11,000 rpm.
this plane is a low wing design. we checked cg before flight and it was on recommended 8 cm aft to LE near root.
airplane took off, right on take off, plane rolled left, rolled right, rolled left, rolled right then inverted and became a lawn arrow. flight was less than 10 seconds and it did not get over 10 feet off ground.
i was looking at wing after the flight. it was a single unit and he glued halves together. and it appears wing had upside down dihedral. wings had minor damage. plane is totaled. seems to me like that may have been cause if he glued them in with this upside down dihedral.
http://www.nitroplanes.com/zlzen4656nig.html
it had an evolution .46 nitro engine with an 10 x 6 prop.
prior to flight engine was turning 11,000 rpm.
this plane is a low wing design. we checked cg before flight and it was on recommended 8 cm aft to LE near root.
airplane took off, right on take off, plane rolled left, rolled right, rolled left, rolled right then inverted and became a lawn arrow. flight was less than 10 seconds and it did not get over 10 feet off ground.
i was looking at wing after the flight. it was a single unit and he glued halves together. and it appears wing had upside down dihedral. wings had minor damage. plane is totaled. seems to me like that may have been cause if he glued them in with this upside down dihedral.
02-03-2013, 12:28 PM
#2
Senior Member
My Feedback: (14)
RE: zlin plane? poor design?
My initial reaction to your post is..."This guy did not have enough experience to fly this bird to success! Which may or may not be true, as there is no video, and I wasn't there.
However my gut tells me your friend had his ailerons set backwards!!! Rookie mistake, and usually always kills the bird.
HOWEVER, even if he did build the wing, and install it upside down......there is NO WAY that is the cause of this crash!!! NO WAY!!!
Good luck.......
However my gut tells me your friend had his ailerons set backwards!!! Rookie mistake, and usually always kills the bird.
HOWEVER, even if he did build the wing, and install it upside down......there is NO WAY that is the cause of this crash!!! NO WAY!!!
Good luck.......
02-03-2013, 01:48 PM
#3
RE: zlin plane? poor design?
thanks for comments.
i helped him with the build, but not all of it. he glued wings together, i was not there, but it seems he put it in anhedral.
prior to flight, we did flight check. and ailerons were not reversed.
i also checked incidence and it was +.5 wing relative to stab.
we also did cg check and it was 8 cm aft to LE near root.
02-04-2013, 04:01 AM
#5
RE: zlin plane? poor design?
i know
my fault for not checking it
it was ever so slight
but i noticed it after the crash
i was so perplexed as to why it crashed.
we did check cg, incidence, range check, flight surface movements.
i did not check the wing.
the wing, when i had seen it, was a single unit
i was not aware it came in two parts and that he glued them together.
i got this info from him after the crash.
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02-04-2013, 09:37 AM
#7
My Feedback: (9)
RE: zlin plane? poor design?
Sorry for the crash. Hopefully it can be repaired, but the airframe was very inexpensive according to the link you provided. Many factors could have led up to the problems you described. As someone else mentioned, reversed aileron servo would be a likely culprit. If the plane was set up for 3D and no expo, I could see this sort of thing happening. Its always better to start out on the "gentle" side, and a bit nose heavy if possible. Smaller 40 size planes can be very twitchy if the set up is off much. If your friend was moving up to this plane from a hi-wing trainer, it might have been to much of a jump for him to handle. Good luck with the next flight.
02-05-2013, 03:52 AM
#8
RE: zlin plane? poor design?
thanks for comments. yes he had flied before, he has flown i think 5 planes before, and crashed some as well. But he always got to fly them a good bit. He even had an EF electric extra, the small one. he flew that one several times before he crashed it.
02-05-2013, 03:55 AM
#9
RE: zlin plane? poor design?
Zx32tt: his plane is beyond repair. LOL!!!
the cone was in the packed soil for about 4 inches deep.
Whole fuselage is split in multiple pieces.
He only paid 90 bucks for the plane, so i think it was a cheap plane, in combination with the wing anhedral, then very touchy with ailerons, although we set them in low rates, and i asked him that right before flight: "do you have everything on low rates?"
he said yes
those were last words before that bird had its fatal first and last flight attempt.
02-05-2013, 04:54 AM
#10
Senior Member
My Feedback: (14)
RE: zlin plane? poor design?
STOP BLAMING THE AIRFRAME.........this was Pilot error, pure and simple. It was too much bird for his skill set. It was not set up properly....probably NO expo in the Ailerons.
Buy another bird and move on..........
Buy another bird and move on..........
