Helicopter aerobatics

[AquaShrimp]

After a little research, I got the scoop on what helicopters can do.

Guys, I'm an old US Army aviator that flew UH-60's. I also AQC'd and have hundreds of hours logged UH-1's, AH-1's and OH-58's (A's and C's). Yes the Hawk can loop and roll (I've seen it), it's common knowledge in the rotary wing community. The first loops and rolls were performed by Sikorsky test pilots back in the 70's and it's a maneuver that's been illegally performed by numerous army pilots since the Hawk entered service back in 79. If a helicopter has a rigid, articulated rotor head it can most likely perform a loop, and a roll. Even helicopters with a semi rigid underslung rotor such as that found on UH-1's and AH-1's have been looped. It's an energy maneuver that can be accomplished as long as their's sufficient altitude at the beginning of the maneuver and positive G is maintained throughout. The rotor system is huge gyroscope, if you unload it (negative G) it will not follow the aircraft through the maneuver properly and most likely contact the tail boom for a spectacular if not somewhat short lived termination of flight.

CH-47's can not loop. NO manned helicopter in the world today is capable of sustained inverted flight, it's impossible. Turbine powered aircraft (like the Lynx) have a governor that adjusts fuel flow to the engine(s) based on the amount of pitch being pulled and rotor RPM, it works more or less like an automatic transmission but it only controls fuel (power) to the engine. Secondly, the rotor blades are not configured to produce lift in the inverted position either by design or rigging. Sustained inverted flight would mean the aircraft could fly without loss of altitude inverted. Trust me, when your inverted in a helicopter you lose all kinds of altitude... really fast.

Even though many of the aircraft the army flies are more than capable of these maneuvers, they are not often seen for a number of good reasons. The first reason is that ALL army aircraft dash 10's (operators manual's) define the bank and pitch limitations as +/- 30 degree's pitch, +/- 60 degree's bank. You NEVER operate an aircraft beyond published limitations without serious repercussions that would most likely end your career. It's not coincidental that the these maneuvers are performed on the sly so to speak, rather than in public where your tail number can be grabbed by a camera. By coincidence, Army flight regs (AR 95-1) prohibit aerobatic maneuvers which are defined by the Army and the FAA (they have rules against aerobatics as well) as +/- 30 degree's pitch, +/- 60 degree's bank. Hmmmm, do you think the limitations in the -10 are coincidentally the same for every aircraft AND Army/FAA regs? Second reason, it's not practical and it's fairly dangerous for inexperienced pilots.

Inverted UH-60

CH-53 looping and rolling

Inverted helo