On Sep 23, 9:00*am, Jeff Findley wrote:
In article fd456a18-e444-4b5c-b8dc-cafde4fe0203
@u4g2000prn.googlegroups.com, says...





On Sep 22, 8:04*pm, Pat Flannery wrote:
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.

Pat

The tail sitting system is well defined

No it's not. *It was abandoned as an R&D program before the serious
problems were worked out of the system.

and modern avionics and
computing obviates any concern over the legends you repeat here
without any analysis. *

This remains unproven in flight hardware.

VTOL aircraft like the Harrier had similar
teething difficulties which were addressed by improved avionics and
computer control.

Not true. *The tail sitters were much more difficult to fly than the
early Harrier,

Not true

http://www.youtube.com/watch?v=6-wc6-yspYw
http://www.youtube.com/watch?v=9t731Y2tSqQ
http://www.youtube.com/watch?v=Nh9dhBJY010
http://www.youtube.com/watch?v=XJ1D_eiHafY
http://www.youtube.com/watch?v=Ja9kFc1BdT8

Get a POGO model and try it for yourself! lol.

Without wings - the DCX took off and landed vertically

http://www.youtube.com/watch?v=wv9n9Casp1o

So did the JAXA RVT

http://www.youtube.com/watch?v=-irOfrXy4N4

What I propose, is rather simple.

(1) parallel staging of an existing airframe;
(2) equipped with thermal protection for ballistic re-entry
(3) equipped with lift systems to act as glider
(4) recovery of the glider down-range
(5) release of the glider near the launch center
(6) transition to vertical flight
(7) vertical landing

The procedure and technology is simple and provides a system of
minimal weight, complexity and innovation to deliver a maximum of
performance.

due partly to the fact that the pilot was trying to land
with his back to the ground and eyes pointed up at the sky.

This isn't an issue in an unpiloted craft.

*At least in
a Harrier, the hand-eye coordination was more natural because the pilot
could easily see and feel what he was doing.

This is not an issue for an unpiloted vehicle.

The Hawker P-1127 had significant difficulties and design problems
from the early stages in the 1950s. These difficulties led to Convair
proposing a simpler easier to build alternative with far fewer
problems.

Plus, if the pilot got into real trouble, ejecting from a tail sitter
was more challenging than ejecting from a Harrier, again due to the
orientation of the pilot's seat during the tail sitting landing. *

This is not an issue for an unpiloted vehicle.

Even
with its early teething problems, the Harriers were safer for the pilots
than tail sitters would have been.

In the 1950s the tail sitters were obviously less complex and
dangerous than redirecting jet exhaust

http://www.youtube.com/watch?v=f8W2SI4c93s

The P-1127 crashed in 1963 at the Paris Air Show and the P-1154 was
canceled when it became clear that its performance would never be what
it was promised to be.

*Thankfully, the tail sitters were
abandoned well before the stage where "teething problems" would likely
have killed several pilots.

No tail sitters have crashed. Many Harriers have.

http://www.youtube.com/watch?v=1USNC3Ozw18
http://www.youtube.com/watch?v=HB5CXlEALJ0
http://www.youtube.com/watch?v=VGE7AYe7DtY

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