Some notes on cabin pressure differentials... can show where these planes comfortably fly, regardless of marketing department speed specs...

3.35 - Cessna p210N
4.2 - Cessna 340A
5.0 (5.3 max) - Cessna 421C / conquest I (425)
6.3 - conquest II (441)
5.8 - Pilatus pc12
6.2 - tbm 700/800/900
5.6 - m600
6.0-6.1 - Mu-2
9.0 - Piaggio avanti
5.0 - king air 90
4.7 - king air 100
6.5 - king air 200/300
5.5 - Cheyenne I/II
6.3 - Cheyenne III
7.6 Cheyenne 400

Merlin 7.1

This is an under appreciated stat. I find that the higher the diff, the less fatiguing the ride.

Took off from Denver in Piaggio last week and ended up at FL390. Cabin climbed 400'. That was pretty nice.

It’d be nice to add a column for maximum pressure altitude while maintaining an 8000’ cabin at maximum pressure diff. Gives an idea of where you can cruise various platforms for those of us who don’t do that math every day.

Early A2PC TC Mu2 are 5psi
Later A10SW TC Mu2 are 6psi


Tj

Aerostar is 4.25 but can be upgraded to 5.5.

Ordered & Expanded

3.1 - King Air 90
3.35 - Cessna P210N, Cessa P337
4.2 - Cessna 340, 414
4.2 - Commander 680
4.25 - Aerostar
4.6 - Duke
4.6 - King Air A90, B90, C90, E90
4.7 - king air 100
5.0 - Cessna 421 / conquest I (425)
5.0 - early MU-2s
5.0 - King Air C90-1, F90
5.2 - Commander 690
5.5 - Upgraded Aerostar
5.5 - Cheyenne I/II
5.5 - Malibu
5.6 - Piper M600
5.8 - Pilatus PC-12
6.0 - Middle series MU-2s
6.1 - MU-2 Solitaire, Marquise
6.2 - TBM 700/800/900
6.3 - Conquest II (441)
6.3 - Cheyenne III
6.5 - King Air 200/300
6.7 - Commander 695
7.0 - Merlin
7.6 - Cheyenne 400
9.0 - Piaggio Avanti
12.0 - SJ30 (not a turboprop, but worth mentioning)

Maximum altitude for a 10,000 ft cabin (approximately). 8,500 requires 0.6 psi more.

1.0 psi - 12,700
2.0 psi - 15,600
3.0 psi - 18,800
4.0 psi - 22,300
5.0 psi - 26,500
6.0 psi - 31,500
7.0 psi - 37,300
8.0 psi - 45,000
9.0 psi - Avanti cabin at FL410 service ceiling is 6,600 ft.
12.0 psi - SJ30 cabin at FL490 service ceiling is 1,800 ft.

Edited many times to include comments from below

Thank you, thank you, thank you, awesome... !!!

Duke 4.6

FYI, the earlier King Air 90s only had 4.6psi. I'm not sure if that has changed in late C90s, but I know C and E 90s from the 80s and earlier were only 4.6. The F90 is 5.0.

Robert

My Meridian is 5.5. I did not know the M600 was 5.6. I assumed same pressure vessel.

Marketing aside, I have never seen 5.6 in our M600. I get 5.5 PSI at FL300 (cabin altitude is 10,650 plus or minus). You get the 10K cabin altitude yellow caution CAS message in the 28,500-600 zone ... Not that it matters a whole lot between the two but I would be very curious if anyone else with a Meridian or M600 sees above 5.4-5.5 at altitude.

I find that altitude to be comfortable for long periods of time but it would be nice to see higher PSI too. I will often fly at 260-270 for Angel Flight passengers to keep them more comfortable, for example.

So us non pressurized people can relate. What is the diff on a 737?

737-800
7.45 below FL280
7.8 FL280-FL370
8.35 above FL370

Russell

A side note but worth mentioning. Higher diff means heavier, more expensive components. The cabin windows on a 441 (6.3 psi) are at lease twice as thick as the 425 (5.0).