On Sep 23, 8:51*am, Jeff Findley wrote:
In article
tatelephone,
says...



On 9/22/2010 12:18 PM, Jeff Findley wrote:

That vertical landing on a mobile landing platform by those tail sitters
was abandoned in the 1950's for a reason. *The transition from
horizontal to vertical flight was tricky, and the actual "landing" onto
those platforms was even trickier.

The Convair Pogo could be landed on any flat surface, but its one
vertical landing left its test pilot so spooked by the process that he
felt he was lucky to be alive, and they never tried it again.
When the French tried in in their straight-out-of-"Thunderbirds" SNECMA
Coléoptère, the result was the aircraft going out of control and the
pilot ejecting.

True. *Any way it was tried, the "tail sitter" mode of landing was just
too dangerous to proceed to an operational vehicle.

Today, vertical landing with the aircraft in the horizontal position is
preferred (e.g. Harrier, V-22 Osprey, and pretty much every operational
helicopter). *This eliminates the 90 degree rotation required by a tail
sitter which eliminates the requirement for the pilot to guide the craft
down with his back to the ground and his eyes pointed up at the sky.

Jeff
--
The only decision you'll have to make is
Who goes in after the snake in the morning?

Still, the tail sitter is rather simple to carry out as a method to
recover through automatic means an ET sized booster with minimal added
mass and minimal complexity.

If you'd fly a model aircraft to a vertical landing transitioning from
horizontal flight, you'd see how simple it is.

Restarting an aerospike engine to carry out a landing similar to that
of the DC-X provides a simple light weight approach to booster
recovery.