Citation Descent Profiles

[nomorecatering]

I found a copy online of th Citation Bravo flight planning guide. In it, it lists 2 descent profiles. High and low speed.

For planning purposes, getting the max range, which one is used.

Interestingly, the fuel flow on the descent works out pretty much the same as the long range cruise fuel flow per hr. is that due to them not using idle power for the decent as the large jets do, think its for door seal inflation?

Do te newer CJ series use idle power for descents?

[dbee]

3 miles per thousand is a good starting point for ANY jet!! dbee:ok:

[what next]

Hello!

...is that due to them not using idle power for the decent as the large jets do, think its for door seal inflation?

Certainly not, as the Bravo can easily maintain pressurisation (including the door seal!) at idle power. But unless you descend very steeply, it will slow down considerably on idle power. And because flying minutes are very expensive in our part of the world, we tend to optimise our profiles for flight time. A well planned continuous descent works quite well, giving you red-line speed all the way down at 1500 to 2000 ft/min descent rate and something like 60% power (N1) with a little over 400lb/min fuel burn for each engine. If weather and ATC permits of course.

Regards,
max

[Tmbstory]

what next:

I do not know about the Bravo but some eariler business jets at high altitude used to lack sufficient bleed air to stop the cabin altitude from climbing with throttles at flight idle.

At low level, no problem. It is good procedure to keep aware of how your cabin altitude is behaving

Tmb

[supermoix]

Hello, I use the normal 2,000 fpm, which at TOD will give you about 3.2 degrees descent angle. It is efficient fuel wise and comfortable for the passengers. 3,000 fpm is to steep.

You will not use idle power in the descent in a bravo because it is no a sleek airplane, you need power to keep your speed at near VMO in a normal descent, if not, the airplane slows down too much (straight subsonic wing).

The two seals in the citation bravo doors will keep the airplane pressurized in any descent regime without any problems, the auto press controller works marvels, even at descents of 4,000-5,000 fpm.