Concorde Climb / Descent

[Speedbird252]

Greetings PPRuNers,

Im desperately trying to convince myself this isnt a dumb question, but what the hell.

What is it that Concorde has / does to climb and descend? Im trying to establish how you can accurately control the ROC / ROD without the traditional elevator, especially at the relatively high AOA that the aircraft requires during say, the landing phase.

Most elevatorless (made that up) aircraft such as the TU144 and smaller Jets such as the Eurofighter and Grippen have canards at the sharp end, so im at a loss for a straightforward explanation.

Thanks all and be gentle with me.....

Speedy

[NW1]

252,

Control column inputs are fed through a fly-by-wire system and various resolver and mixer boxes through to the 6 elevons to control pitch by a symmetrical delfection and roll by an asymmetrical deflection. If all 6 elevons go down together, the result is a pitch down because the elevons are aft of the centre of gravity, and the resultant couple (torque) acts (roughly - for the pedants) about the CofG. The machine is stable without a tail- or a fore- plane because of the nature of slender-delta aerodynamics (a much deeper subject - try Kermode's "Mechanics of Flight"). That's how I understand it all anyway.....

In practice, if you push the nose goes down and if you pull it goes up. The faster you go the better your rate of climb (about 4000fpm at 400kts and max weight), so sometimes you need to push to lower the nose, speed up and climb faster - geddit?!:D

Pitch and roll control is very immediate and precise compared to other airliners of similar mass - partly due to a much smaller effective wingspan, bigger more powerful flying control surfaces to handle supersonic airflow and the first commercial application of autostabilised fly-by-wire. Also with fully mechanical cable back-up. Sadly they don't make them like that anymore.