Difference between service ceiling and max allowable altitude?

[D_G]

The caravan POH shows 22,800 service ceiling, and 25,000 max allowable altitude.

Thanks.

 

[minitour]

Doesn't service cieling have something to do with a Vx or Vy climb or like 100fpm???

Someone help me out here...Give-a-brotha-a-hand!

-mini

 

[generaltso]

I thought service ceiling was a 50fpm climb.

 

[Singlecoil]

Isn't it service ceiling for a twin is 100fpm climb, and for a single 50 fpm climb?

 

[EagleRJ]

Service ceiling is where climb rate decreases to 50 fpm under standard conditions.

Max allowable altitude is regulatory, since the Caravan doesn't have drop-down oxygen masks. You probably wouldn't be able to climb that high anyway, but if you were able to, you couldn't go above FL250.

 

[DAS at 10/250]

EagleRJ, good comment on the 208.

So why does the PA31 have a 24,000 max allowable (24,000 not FL240) altitude?

 

[VNugget]

Can you guys point me to where you got the 50 fpm figure? It's 100 everyone I've seen. Doesn't seem to be defined in the FARs or AIM, though.

 

[Lead Sled]

Don't forget that the service ceiling is also based on a max gross weight takeoff. As fuel is burned off, the aircraft is able to climb higher - above the max gross weight service ceiling. At that point, the maximum allowable altitude becomes limiting. Case in point, take the Gulfstream G100 as an example, at a max gross weight takeoff, the airplane is capable of climbing to approxiamately FL410. As the flight continues and fuel is consumed, the airplane can "step climb" up to FL450 - its certified ceiling and maximum operating altitude.

'Sled

 

[uwochris]

My understanding is:

Service Ceiling (for a twin): the density altitude where you achieve a 100 FPM climb rate with both engines operating.

Single Engine Service Ceiling (one engine inop and feathered): the density altitude where you achieve a 50 FPM climb rate.

Absolute Ceiling: the density altitude where the rate of climb is 0. Vx=Vy here (zero angle of climb and zero rate of climb).

I got this stuff from the Jepp Multi Engine Manual.

 

[cands]

you need a high altitude endorsement to fly an aircraft that has a service ceiling or max operating altitude, whichever is lower, above 25,000 msl. in The caravan you don't need one.

 

[mattpilot]

uhm.... single engine aircraft service ceiling is also defined by the 100ft mark .... i've never heard of the 50ft one ..

 

[zeroline]

This is absolutely correct.

Service Ceiling (for a twin): the density altitude where you achieve a 100 FPM climb rate with both engines operating.

Single Engine Service Ceiling (one engine inop and feathered): the density altitude where you achieve a 50 FPM climb rate.

Absolute Ceiling: the density altitude where the rate of climb is 0. Vx=Vy here (zero angle of climb and zero rate of climb).

I got this stuff from the Jepp Multi Engine Manual.

Right out of the Manual

 

[puddlejumper]

you need a high altitude endorsement to fly an aircraft that has a service ceiling or max operating altitude, whichever is lower, above 25,000 msl. in The caravan you don't need one.

I'm pretty sure that only applies to pressurized aircraft. I may be wrong and I'm too lazy to get the FAR/AIM out. The Caravan is definitely not pressurized.

-pj

 

[Snoopy58]

Ceilings are dependent on today's conditions, so things like gross weight at the moment and temp deviation can have significant effects. On a hot day with a heavy aircraft, your service ceiling will be lower than usual; on a cold day with a light jet, it may be entirely possible to exceed (from a standpoint of performance) the aircraft's max allowable altitude. For some airplanes, the effect of weight & temperature may be small enough that the manufacturer can publish one number as "the" service ceiling (or, they publish it at ISA standard & max t/o weight), but the reality is that performance will vary with the conditions. A certified maximum altitude, however, is fixed, and is independent of performance... on a given day, you may not be able to come close to that max altitude, but on a different day you may be able to reach it quite easily, with the aircraft only too happy to go sailing on above it into illegal territory.

 

[mattpilot]

I'm pretty sure that only applies to pressurized aircraft. I may be wrong and I'm too lazy to get the FAR/AIM out. The Caravan is definitely not pressurized.

-pj

so what about the piper meridian? Its a SE turboprop - i think it goes up to max FL250 and it can be pressurized.

Would one need an endorsement for that?

 

[puddlejumper]

so what about the piper meridian? Its a SE turboprop - i think it goes up to max FL250 and it can be pressurized.

Would one need an endorsement for that?

Yes, definitely. PA46T is certified for at least FL290. It is pressurized. It requires a High Altitude endorsement to act as PIC. Not necessary to log PIC, but that's a whole other discussion.

BTW, many aircraft are limited by cabin altitude/max differential pressurization. The Cheyenne II was limited to FL290 cuz at 5.5 psid, the cabin was at 10,000'. It would climb well above FL290 at lower weights. I think the IIXL was good for FL310.

-pj