bird strike?

blw2

Newbie
Joined
Dec 15, 2013
Messages
36
Location
Jacksonville, FL
Aircraft
C120, C140, C150, C152, C172, C172RG, C182, C182RG, C177RG, 7ACBM, M20, PA-23, PA-28, B777 sim clD
Total Flight Time
300
random thought came to mind...
how durable are these blades against a typical bird strike?
does that happen very often?
 

WaspAir

Supreme Allied Gyro CFI
Joined
Oct 21, 2006
Messages
4,485
Location
Colorado front range
Aircraft
Bell 47G-3B-1 / A&S 18A / Phoebus C, etc.
Total Flight Time
stopped caring at 1000
I have had bird strikes on a Cessna, a glider (attacked from above by a hawk), an Alfa Romeo, and even a Norton motorcycle, but never on a rotorcraft. Guess they're too slow, loud, and ugly, giving enough warning for the birds to stay away.
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,879
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2200+ in rotorcraft
Depends on the bird.

I am not aware of any gyroplane crashes caused by a rotor bird strike.

I have a dent in my fuel tank from hitting a seagull.

In my experience most birds won’t get too close below seventy knots.
 

SportCopter

Active Member
Joined
May 13, 2014
Messages
134
Location
Scappoose
Aircraft
Vortex M912, SportCopterII, Vortex 582
A Vortex M912 owner reported a hawk strike, which was posted about here:

I was flying over the trees to come in for a landing in a rough field and on approach I saw a hawk fly out of a tree. I thought he was going to go left, but he flew up and then I heard him hit the rotors and felt a slight bump at the same time. The hawk was completely severed and the Vortex never missed a beat. I proceeded to land and upon inspection found a couple small dents underneath the rotors (maybe from the talons). After having lunch with my mom I then flew it 30 miles back home and did not have any stick shake. I just flew it again yesterday and still no shake. I am still confident in the rotors to fly. I cannot believe how tough Sport Rotors are!!!! This was no small hawk (as you can see in the picture).

hawk IMG_7019.JPG
hawk IMG_7023.JPG

Below is from another incident, in which a newbie pilot unknowingly had a prop strike on the takeoff roll, circled the pattern,
and landed without knowing one of his blades had been damaged from the trailing edge two-thirds in. Overbuilt strength pays off!

Sport Rotor surviving prop strike.png
 

Doug Riley

Platinum Member
Joined
Jan 11, 2004
Messages
6,347
Good bonded-metal blades seem generally to survive the (rare) bird strike. A gyro is slow enough for birds to get out of the way, and most will if they can. Some predator birds are so belligerent that they will turn and threaten to fight. A friend, flying his hang glider, had one flip in the air and show its claws when he got near. It eventually was sensible enough to fold its wings and dive away, though. Intellect won over testosterone, I guess.

Bensen ran some tests on his metal blades in the early 70's, catapulting dead birds into a Bensen rotor being turned by a prerotator of 8 hp or so. Songbird-size critters just left a smear. An 8-10 lb. turkey caused some minor buckling of the blade skin, but nothing that would cause a crash.

Bensen's blades were quite different from most blades sold today; they were very light, meaning that loss of RPM in a bird collision would be more of a worry with them than with heavier modern blades. Bensen's upper skins were small plates riveted in place, not a single long strip as in today's blades. This would localize any damage, but the rivets required holes, which create weak spots. Bensen's lower skins were thick, lap-jointed strips.

I would not care to have a bird strike while flying unshielded wooden blades. I believe that the original Bell-47 helo blades, while wood, had U-shaped steel skins over their leading edges -- probably an adequate turkey-slicer.
 
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