Performance of P337 with GAMI and intercoolers

Vref · #1 11-26-21, 04:24 PM

Dear All,
I am currently a Beech driver and flying a V35 Bonanza equipped with TKS tip tanks in Europe now almost 8 years I have that aircraft It has served me well and I love flying the Beech. My mission is 600Nm West East bound over central Europe with some terrain up to 7000Ft for 40 Minutes. destination aerodrome is VFR with about 2000Ft concrete with grass extensions so no worries. I have done this many times but the older I get the more I long for more redundancy in systems..Mostly I flew alone or a another Pilot however want to take my kids along and this changes a bit on how I look at this mission. From April till end of September I always have to deal with TCUs in that area and having a turbo would solve a big part of that problem also to be able to climb out potential icing. I can cruise my Bo at 11000 around 12 Gallons doing 160Kts TAS. Doing this mission with a P337 equipped with 123 Gallons total seems doable? I read 25GPH which seems quite a lot...I never saw TAS numbers for 50% power. I am looking at the same bird as alainb wanted to buy, however what I understood he didn't go for it...What can I realistically expect in TAS when running this bird on 50% at 17000. Radar, Boots, intercooler, GAMIs..Fuel is expensive in Europe...Thanks for your input

mshac · #2 11-26-21, 04:39 PM

The POH gives numbers for 16k and 18k, here are the 18K numbers:

2400 RPM, 51% BHP, 25" Manifold Pressure, Standard day, yields 174 KTAS at a fuel burn of 117 PPH, or 19.5 gallons per hour.

174 KTAS/160 KTAS = 1.0875

19.5 GPH / 1.0875 = 17.93 GPH Equivalent Fuel Burn. In other words, at 50%, it would cost you about 5 GPH for the redundancy and extra capability of the Skymaster vs. The Bonanza. Plus you'll arrive a little sooner.

If you're in a hurry:

2500 RPM, 76% BHP, 33" Manifold Pressure, Standard Day, yields 202 KTAS at a fuel burn of 160 PPH, or 26.66 GPH.

202 KTAS/ 160 KTAS = 1.2625

26.66 GPH / 1.2625 = 21.12 Equivalent Fuel Burn

BTW, my previous aircraft was a V-tail Bonanza as well. The only time I miss it is when I fly solo, but most of my trips are with all seats full in the Skymaster. The comfort level for me and my passengers, especially in the back seat, is an order of magnitude superior to the Bonanza.

I attached the POH page for your consideration.

Vref · #3 11-26-21, 05:01 PM

Thanks much appreciated. Its not so much the speed I am interested in. I love flying even 4Hrs. When above the clouds listening to music in Zen state. I guess I am one of the few in Europe doing this actually :-). This particular P337 seems a lot of value for my specific mission me with two or three kids. It has the monochrome Bendix radar which maybe be compatible with the avidyne mfd...

Quote:

Originally Posted by mshac

The POH gives numbers for 16k and 18k, here are the 18K numbers:

2400 RPM, 51% BHP, Standard day, yields 174 KTAS at a fuel burn of 117 lbs, or 19.5 gallons per hour.

174 KTAS/160 KTAS = 1.0875

19.5 GPH / 1.0875 = 17.93 GPH Equivalent Fuel Burn. In other words, it would cost you about 5 GPH for the redundancy and extra capability of the Skymaster vs. The Bonanza.

BTW, my previous aircraft was a V-tail Bonanza as well. The only time I miss it is when I fly solo, but most of my trips are with all seats full in the Skymaster.