RCU Forums - 100% Eagle

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Quote:

Originally posted by Ben Lanterman
...
The height problem is not there in any form when in an airplane of any kind that has a full fuselage around the bottom. Maybe it is my butt that has the height problem! Strange.

.
Way back when, the prototype Tristar had most of the hardware a production airplane would use, except on the galley door. Instead of a prism window that permitted someone inside the galley to check clearance before opening the door on the ground, it had a standard window.
I discovered that by crawling up on the door, I could look and photograph straight down.. all the time hoping the door was really a plug-type, which had to come in before it could open! :D
(not that opening a door in a pressurized airplane is possible.)

Quote:

Originally Posted by Ben Lanterman (Post 650503)

Remember a few years ago when Paul MacCready built a flying model of a pterosaur configuration. He used electric motors and seemed to solve the problems inheret with the configuration. There was also the use of some elastic bands to help smooth the flapping and aid in some energy recovery in each cycle. I believe he used the toothy part (did they have beaks?) and the head for directional control. I am not too sure the model could agressively climb from the ground. It was bungy/dolly launched and it did make enough flights of extended length to show the configuration that they had was workable.

I know this is an ancient post, but I can't resist responding. Paul's 'replica' could be taken as a half scale model of the large morph of the azdharchid Quetzalcoatlus, or a full scale of the small morph (I am currently working on a 1/3 scale replica of the small morph). Paul had to take several liberties with the configuration in order to compensate for being told in error that it flew with legs retracted. For example, he had to break the neck and bend it into an impossible configuration in order to move the head further aft. The animal could not do that. The head was not used for steering - Paul configured it to minimise yaw forces, not to generate them. BTW, Quetz did not have teeth.

His model would not quite maintain level flight in no-lift conditions. If he had used paired AstroFlight 40s instead of the single 60s to power the flapping, it would have been capable of climbing.

I cannot post images because I haven't posted enough for it to be allowed.

BTW, tip slots are correlated with aspect ratio. Birds with A.R. less than 12 have them. Greater than 12 don't.
They are kept closed at cruise and high speed (low lift coefficients). They are opened at low speed and increase the effective aspect ratio.