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#11
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UFO HeliThruster and IFR?
On Fri, 28 Sep 2007 11:46:35 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in : The issues that Gyros have with negative G's make them less IFR capable than a similar helicopter or fixed wing aircraft. Is this claim a Mollerism? http://www.cartercopters.com/ I have heard that two-bladed, teetering rotor systems have a reputation for something called "mast bumping" in low-g flight. What is mast bumping, and why is the CarterCopter not susceptible to this problem? Mast bumping is caused in helicopters by a lack of control of the aircraft due to the rotor not producing much lift or negative lift. During a zero-g maneuver, when the rotor is unloaded, it does not create any lift force, so it does not have any force to apply to the helicopter to control it. In this situation, if the pilot moves the cyclic to try and control the aircraft, the rotor will still tilt, but since it is producing no net lift, it will not have a reaction on the rest of the aircraft. If the pilot inputs more control because he does not feel the aircraft responding, he makes the rotor tilt even more, until it hits the mast. The tail rotor can aggravate this problem. Because it is still producing a force, it pushes the aircraft to the side, and if it's not directly on the centerline, causes the aircraft to roll as well. The pilot feeling this movement will try to counter it with the stick, causing the problem outlined above, with the tail rotor pushing the fuselage in the opposite direction of the rotor. In the CarterCopter, because of the dual control system (airplane as well as autogyro), the pilot always has control of the aircraft, as long as he has sufficient airspeed. During a zero-g maneuver, with the rotor unloaded and producing no lift, the elevators and ailerons are still effective. When the pilot moves the stick, the ailerons or elevator will control the fuselage, keeping it in approximately the same relative position compared to the rotor, so mast bumping is not a problem. |
#12
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UFO HeliThruster and IFR?
"Jim Stewart" wrote OTOH, since I've never seen a pilot in a standard certificated fixed-wing aircraft wearing a helmet, I must assume that the helmeted gyrocopter pilots are feeling a greater degree of risk than the fixed-wing pilots. My take is that in the case of an engine failure, the gyro driver has the "autorotate" maneuver as his emergency landing option. The chance of a survivable but hard landing is a real possibility. A helmet would possibly help that hard landing be survivable. On the other hand, a fixed wing emergency landing is likely to be relatively smooth, (no helmet needed) or so hard that a helmet would not likely help much. That's my guess, anyway. -- Jim in NC |
#13
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UFO HeliThruster and IFR?
"Steve R" wrote Don't assume that the gyro is automatically going to be a hard landing and the airplane is automatically going to be a smooth one. It's just not that simple. I take from the tone that you are an autogyro guy. :-) I know and understand how an autogyro handles an engine failure. It is a smooth landing, and slow, _if_ the pilot does everything right, and if sufficient altitude and forward speed exist at the time of the failure. If the pilot misjudges the flare, bump. If the engine craps at a low altitude, and there is not enough time to trade altitude for airspeed and rotor speed, bump. Helmets help bumps. If a fixed wing has good altitude and speed, he has a chance to get a smooth landing, if there is suitable room for a landing. No need for helmet, perhaps. Not enough room, probably, a helmet won't help. If there is not sufficient altitude and airspeed, and there could be a stall-spin, also, there will probably be little left that a helmet could help. If anything, I'm coming down on the side of a gyro accident being (possibly) more survivable, and a helmet would definitely help, when it comes right down to the last seconds. Lastly, I know these are all probably's. No solid rule holds for everything in life. It just my gut feeling that a helmet is likely to do you more good in an autogyro than a fixed wing. Not in an enclosed cockpit fixed wing? Probably going to want a helmet, for one of those, too. That also reminds me of another reason so many autogyro drivers wear helmets. The majority of autogyros probably are open cockpit, too. -- Jim in NC |
#14
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UFO HeliThruster and IFR?
"Jim Carter" wrote in message ... I think it was built by Aerospace Industries if I remember right, and it carried an N-number registration. I'm pretty sure it would cruise above 100 mph because it had a pretty small rotor diameter. Probably this: http://www.geocities.com/CapeCanaver.../5249/a18a.htm Vaughn |
#15
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UFO HeliThruster and IFR?
"Vaughn Simon" wrote in message ... http://www.geocities.com/CapeCanaver.../5249/a18a.htm Another certified autogyro, the McCulloch J-2: http://dayton.hq.nasa.gov/IMAGES/SMA...000-001904.jpg Vaughn |
#16
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UFO HeliThruster and IFR?
I have heard that two-bladed, teetering rotor systems have a
reputation for something called "mast bumping" in low-g flight. What is mast bumping, and why is the CarterCopter not susceptible to this problem? It really isn't "mast bumping." It is "mast bump." It only happens once, destroys the helicopter and you with it. Karl Helicopter mode |
#17
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UFO HeliThruster and IFR?
Vaughn,
everyone and their brother must have hit that geocities URL because it is now "down" due to exceeding its bandwidth. -- Jim Carter Rogers, Arkansas "Vaughn Simon" wrote in message ... "Jim Carter" wrote in message ... I think it was built by Aerospace Industries if I remember right, and it carried an N-number registration. I'm pretty sure it would cruise above 100 mph because it had a pretty small rotor diameter. Probably this: http://www.geocities.com/CapeCanaver.../5249/a18a.htm Vaughn |
#18
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UFO HeliThruster and IFR?
"Jim Carter" wrote in message et... Vaughn, everyone and their brother must have hit that geocities URL because it is now "down" due to exceeding its bandwidth. I just got it OK, but that probably locked it out for a while. Anyhow, just Google "Air & Space 18A" and there are probably other sites out there. In fact, here is a good picture of one in flight: http://www.thejumpingfrog.com/si/1208795.html Vaughn |
#19
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UFO HeliThruster and IFR?
On Sat, 29 Sep 2007 02:09:00 GMT, "Vaughn Simon"
wrote in : "Vaughn Simon" wrote in message ... http://www.geocities.com/CapeCanaver.../5249/a18a.htm Another certified autogyro, the McCulloch J-2: http://dayton.hq.nasa.gov/IMAGES/SMA...000-001904.jpg Vaughn And, of course, there is this early autogiro: http://www.aviation-history.com/airm...t-Autogiro.htm Pitcairn PCA-2 Autogiro Amelia Earhart’s second Autogiro crash is known from a single source, a letter39 to author Susan Butler from Helen Collins MacElwee, sister of Amelia’s New York, Philadelphia and Washington Airway Corporation (NYPWA) colleague Paul Collins. Paul Collins and his sister Helen witnessed the second accident. After a "rather erratic" Autogiro flight she made after taking off from the airfield in Camden, New Jersey, she "finally landed on a fence. Amelia stepped out frustrated and furious, and announced, "I’ll never get in one of those machines again. I couldn’t handle it at all." Earhart’s third accident in an Autogiro occurred during her subsequent Beech-Nut tour while at the Michigan State Fair in Detroit, Michigan on September 12, 1931. Attempting a slow landing in front of the grandstand, she failed to level off in time and dropped twenty feet to the ground. She wrote her mother: "My giro spill was a freak accident. The landing gear gave way from a defect and I ground-looped only. The rotors were smashed as usual with giros, but there wasn’t even a jar." Photographs of ten gyrocopters he http://www.gyrosaway.com/MoreAbout.htm The Magni Gyro M-16 is in current production in Italy, and available for purchase in the US: http://www.magnigyro.com/ Photographs: http://www.airliners.net/search/phot...nct_entry=true |
#20
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UFO HeliThruster and IFR?
"Vaughn Simon" wrote in message ... "Jim Carter" wrote in message ... I think it was built by Aerospace Industries if I remember right, and it carried an N-number registration. I'm pretty sure it would cruise above 100 mph because it had a pretty small rotor diameter. Probably this: http://www.geocities.com/CapeCanaver.../5249/a18a.htm I saw one of these at the Hill Top Fly-In. Prettty neat. I think it sold while it was there. |
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