Huey rotor blade weathering question

Welcom back Mel

As Mel stated if the door was pinned back then it should not have come off. A possible reason is the rollers had worn through the guides on the fuselage, and worn rollers and guides could allow the door to fall off.

Ed

I don't remember the exact cause of the door leaving the airframe, It might have been in the closed position and not latched and vibrated back, but it did go aft and up when it came off.  Never recovered the door.  Most test flights were with minimum crew of two, three at most.  If it was open and pinned properly it should have never come off. 

 

did someone get introuble for not pinning the door? heheheh....Lucky no tail rotor strike huh?

how did door go up instead of down and back?...jeez

I can tell you that a Huey M/R blade striking a small branch about the size of your thumb sounds just like a AK-47! Both got your "pucker" factor up there!   Catching branches and brush with the tip happened occasionally and first chance you got you shut down and checked it out.  We had a cargo door off a Charile model come off during test flight and put a "V" shaped hole in the main blade about half way down about 6" tear both legs.  The pilot keep his "cool" and did a shallow slow approach to the first clearing.  They "hooked" the bird back to Chu Lai and changed the blade.   

The old man was flying an -H model out of Grafenveheor (hell I have forgotten how to spell it now!) in '87 and snagged a limb, with no APPARENT damage that could be seen( other than the limb which was thrown in the back of the ship ). Kept on flying but who knows what real damage was done to the blade and its underlying core. 

A problem I often see on models of Cobras is with the same simulated wear pattern,showing worn silver to the same extent (about 30% chord) of that composite blade.  Composite blades have the steel wear strip, often near the tip only, but the rest of the blade will not show that particular wear pattern since they are not metal skinned, but a composition material.  They DO show wear but when they do it will be an abrasion of the outermost protective epoxy coating. Working offshore and forest fire (PHI and Rogers helos) I did not see the same extent of wear to our blades as I saw in the military, despite the salt/soot/sand operating environment (this  was the Bell 206 family, Huey family, 222, Astar/twinstar, etc) so it may come down to the blade itself and how often it gets dressed with fresh paint.  The fire contract called for high visibility stripes and I have painted several sets of them to keep current with the contract.

 

David 

Chief Snake is right, damage of that kind would require grounding of the a/c and removal and replacement of damaged blades. Otherwise blades could fail in flight and you find yourself a smoking crater in the ground.

Acceptable damage doesn't exist. Small depressions in the metal skin under a certain depth and less than a certain diameter are to be watched for increasing stress. Blade strikes of tree branches do one of two things: nothing that is seen or damage resulting in removal. The stories one may hear of intentional blade strikes to tree limbs are the result of life and death situations. Routine limb strikes would be an excellant way to find oneself grounded from flying.

 

Chief Snake 

Correct me if I'm wrong:

Slicks would tend to have an additional type of Main rotor weathering I'm thinking about adding....when hitting small branches of trees the leading edge may recieve small dents?

and the underside of the blades past the leading edge was made of honeycombed material so it would get tears in it from branches..exposing silver edged metal?

dents and tears would mean replacement time? or is there a small amount of exceptable damage for  war time?

 

 

Thanks guys. This answers my question perfectly.

Cheers,   Rich

Here is a photo showing the bottom of the rotor, top would wear about equally, note tail rotor would also wear in a similar fashion(props on airplanes wear the same). Paint doesn't "peel" but has the look of having sandpaper used to remove paint, since the air it moves through is filled with sand, dust and other fine particiles.

 my guess is that it would be expressed on the underside of the blade as well,since the blade is shaped like an airfoil(lifting wing)finding an aircraft and looking at the leading edge should give ya a good idea of how air moves thus piant peel.If i recall correctly air moves faster over the top and slower underneath thus faster air more friction more paint wear.good luck and happy modelling.