Carter Copter Crashes

[asra]

Hi Guys,I read the Carter copter crashed on Friday in Texas with Larry Neal andBrad King on board, both walked away from the debris after claiming they had broken the Mu-1 barrier.This is one expensive gyro crash.Image Insert: 5.46

[asra]

Whats the MU 1 barrier?M Barker

[Tim]

In their case Murray it wasn't very high because they slowed the rotor as the wings took more lift. Something like 145kts I think, making negative airflow over the whole retreating blade.Tim McClure

[asra]

Good grief Murray I thought you'd know all about that! No it's nothing to do with cats either.My understanding is that it is a major barrier for rotorcraft as it involves the retreating blade air speed being exceeded by the aircraft's air speed, a situation which would make the retreating blade unstable. Apparently Carter gets around this with those depleted uranium tip weights, belive me they are heavy - 1.5 times the density of lead! Col and I had a feel of them at Oshkosh a few years ago.John EvansThink logically and do things well, think laterally and do things better.

[NiqueNaque]

John.I wondered why you glowed in the dark..Cheers,Nick.

[asra]

Murray,Mu is the ratio of rotor speed to aircraft speed. MU = 1 is when the retreating blade on an helicopter or gyro effectively stays still in space since the overall speed of the aircaft equals the speed of the retreating blade. Its been suggested by Carter Copters that they accidently experienced a brief period (some 1.5 seconds) of greater than Mu = 1 of the morning on the flight that they had a mechanism failure, which is suggested as the reason for the rapid descent leading to the heavy landing. Equipment that recorded this event is currently being examined by the US military for confirmation. Carter Copters are awaiting the decision.Ted

[Scott Hogan]

Hi John,Americans seem to have a loving relationship with, as well as an abundant supply of, Depleted Uranium.'Seems like their love is being spread around the world wherever they go.Iraq, Afghanistan etc.Hoges

[asra]

Sorry to dissapoint you all but I had no idea what MU was,I thought it might be the sound a Cow with a bad stutter makes.M Barker

[Greg Mitchell]

G'Day Gents,Yes, Mu1 approximately 173 miles per hr with retreating blade doing zero air speed. This was one of the major targets set for the CC. Shortly after this flight, Larry and Brad were at 3000 feet normal flight, when they felt a clunk (suspected pre-rotator engagement) putting the CC into a left hand nose down spiral decent. Larry had full right stick and pedals with no relief, managed to land CC I believe with about 75 miles per hr forward airspeed in some mesqite trees (not sure might be small pine or something). The CC continued on for 40 yards, ended up on it's left hand side, necessitating the kicking out of the windscreen to evacuate the wreck. Fortunately Brad and Larry were uninjured. CC totalled.Same day after speaking with Larry by phone to ensure he was OK, I went out to Cranbourne to go flying. This was a deviation to a flying plan I had set myself for the Opperation Managers visit to Tasmanian. I did not get off the ground, well not very high...see accident thread for details.Mitch.www.thebutterflyllc.com

[NiqueNaque]

This is an extract from the Carter Copter Site:"# By flying stably at mu-1, the CarterCopter has demonstrated what some critics have said was impossible, showing that the slowed rotor concept is valid and achievable, and has pioneered the the way for future aircraft to take advantage of this technology. # During a subsequent flight, the pilots executed a forced landing in a nearby field. The pilots walked away from the landing unharmed, but the aircraft sustained significant damage. The exact cause of the failure is still being investigated, but is not in any way related to the high mu ratio on the previous flight."Nick.