power question
 

I feel kind of dumb asking this, riding in the back of airliners I notice a large power reduction once in cruise. Is there an abundance of thrust available in the modern airliner?

I do not fly a jet but in the plane I fly even we have a good sized reduction in power in cruise from say 90% tourque to around 75% to prevent overspeeding.

From jumpseating in mostly boeings it is the same thing, if a good sized reduction is not made at the lower altitudes (no higher than 230 EWR-BOS) then the plane will exceed VMO it seems. I cant speak for FL250 or above because I have not jumpeated above that alt.

The air is very thin at cruise altitude, so there is very little drag...the engines on most airliners could easy push them near or beyond Mach 1.0 in cruise, but the airframes are not designed for the aerodynamic effects which occur during the transition to supersonic (it's also illegal in the US).

Airliner engines are designed to allow the airplane to climb at a certain rate on one engine at MGTOW at a specified density altitude. Since both engines are normally functional, there is plenty of excess power.

Does the Citation not have this excess thrust? (OP's profile says he flies a C550/560)

It should, light piston AMEL are exempt from the requirement to climb on one engine, but turbojets should all be able to. Actually IIRC one of the VLJ's had to get a waiver since it cannot meet the engine-out climb requirement.

Did the Concorde fly below Mach 1.0 when it was over the US so it would not violate the regs?

It depends on the age and model. The older ones are anemic while newer ones climb like a banshee. The CJ2+ that I fly now has great performance to get up into the 40s quickly.

PH

Yes. That law was one of the reasons the concorde was not a financial success...could not be used in the US. It did in fact have to slow down before entering US airspace. Also it only flew from europe to NY and DC...it would have had to break the speed limit to go further west.

That law is based on noise abatement. Several companies are doing serious research on sonic boom suppression, with the intent to design a supersonic biz-jet. The assumption is that the FAA will change the rule as long as sonic-booms don't reach the ground.

Actually the Concorde flew for almost 18 months to Texas. It was an agreement with Braniff. The speed was limited to .95 from DC though. Rumor has it that the last flight back to DC broke Mach 1 with the "blessing" of the FAA rep on board ..... again it was a rumor.

There's no technical reason that it could not fly that slow, it's an economic problem...it cost ten times as much as subsonic airliners, so it didn't make sense to fly subsonic routes at speeds only slightly higher than much cheaper airliners.