Actually, it was the rigid rotor system that allowed aerobatics and inverted flight in helicopters such as the Cheyenne (now defunct after years of testing) and a couple other rigid rotor system helos. The fully articulated rotor system as in the OH6A (Hughes 500C) precluded actual inverted flight, to include rolls and loops, but the LOH was capable of some pretty amazing flight maneuvers. I know, I flew them in Viet Nam and have several hundred hours in the OH6A. Other, semi-rigid rotor systems like the UH-1 and Bell 206 Jet Ranger are not capable of such flight. The high inertia systems won't stand those forces and will self-destruct. The articulated rotor system is a low-inertia system and is capable of more severe maneuvers, but still wasn't designed for acrobatic flight. At some point, the rotor disc would simply unload and the blades would fold up and the whole aircraft would fall to the ground with disastrous results guaranteed to absolutely ruin your day.GaryG said:That is cool. Also this is the advance in rotor technology from the 60's and 70's era to now. Back then most copters had rigid rotor heads which precluded this kind of manuvering, exception that I know about was the LOH produced by Huges Aircraft (think it was the 300H in civilan terms)....then an 'articulated rotor head' was developed that allows the acrobatics. What the pilot has to watch is not over torquing the rotor blades. Had to fix several Hueys in Viet Nam because to much torque was applied and the rotors themselves were ripped off.
I hear you re: the OH6A. what a hotrod. That ship was capable of some pretty amazing things. I went down in the jungle in Viet Nam after a tail rotor failure, and the only thing that prevented my serious injury or death was the A-frame construction of the OH6's airframe. Very strong. I have nothing but respect for that helicopter. When I retired from law enforcement (the first time) I also quit flying, and my wife requested, since everything I do is dangerous, that I at least keep my feet on the ground. I have, and I do miss flying, but riding my motorcycle is a pretty close experience.dicepilot said:The underslung rotor system of the UH-1 during low G manuevers led to mast bumping. Rumor has it that with 3 bumps, the rotor head snaps the mast and separated from the airframe. You won't see a Huey do those manuevers more than once.
The rigid rotor system is what is on this helicopter. If I'm not mistaken, it looks like a military variant of a BO-105 (Messerschimdt-Bolkow) sp? The BO-105's and the BK-117, popular with EMS, was a rough ride for the med crews and frequently caused airsickness. An excellent system for military applications.
I flew mostly Bell products. UH-1, OH-58, BH-206 LongRangers, and the 430. The most nimble helicopter I have flown is the Hughes OH-6. What a sports car, zipping along a river bed in Korea!! Ripping the Wing in the curves is the closest I can get to that exhiliration now.
