Operating cost of the B60T + The price of the duke + Turbine = close to the GDP of a small country :(Any idea if Realair can model turbines with vegetable oil or vodka ?Benjamin

Turbine fuel is a, heck of a lot cheaper than vodka! Heck if it burns then a turbine will run it. You can even run avgas in a pt6 (with certain restrictions).As for the pressuixation , I am still at a loss why the cabin can not maintain less than 10,000 feet when at 24,000 feet.

Turbine fuel is a, heck of a lot cheaper than vodka! Heck if it burns then a turbine will run it. You can even run avgas in a pt6 (with certain restrictions).As for the pressuixation , I am still at a loss why the cabin can not maintain less than 10,000 feet when at 24,000 feet.

Jack; Assuming standard temperature and pressure and a standard lapse rate from sea level, the absolute atmospheric pressure at 10,000 ft is 10.1 PSI. The pressure hull on the B60 is limited to 4.5 PSI differential pressure--defined as the difference between the air pressure inside the cabin and the outside air pressure. At STP, the absolute atmospheric pressure at 25,000 ft is 5.46 PSI, so to maintain 10,000 feet in the cabin with the aircraft at 25,000 ft means you'd have to maintain a differential pressure of 10.1 - 5.46 = 4.64 PSID, which exceeds the max of 4.5 PSI. Other aircraft can do better because their pressure hull is stronger (and also considerably heavier). The Gulfstream V, for example, can maintain over 10 PSID in the cabin, which allows the cabin to remain comfortably at 6,000 ft even with the jet flying up in the high 40s. RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Ah i was under the impression the duke had a better diff than that. Like I mentioned, the be10 i used to fly had a diff of 4.6 and we could hold fl250 without the cabin alt light illuminating.

Jack; Assuming standard temperature and pressure and a standard lapse rate from sea level, the absolute atmospheric pressure at 10,000 ft is 10.1 PSI. The pressure hull on the B60 is limited to 4.5 PSI differential pressure--defined as the difference between the air pressure inside the cabin and the outside air pressure. At STP, the absolute atmospheric pressure at 25,000 ft is 5.46 PSI, so to maintain 10,000 feet in the cabin with the aircraft at 25,000 ft means you'd have to maintain a differential pressure of 10.1 - 5.46 = 4.64 PSID, which exceeds the max of 4.5 PSI. Other aircraft can do better because their pressure hull is stronger (and also considerably heavier). The Gulfstream V, for example, can maintain over 10 PSID in the cabin, which allows the cabin to remain comfortably at 6,000 ft even with the jet flying up in the high 40s. RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Thanks for the specs on the pressurization differential Bob. Yes, Jim Lewis presented on the new Gulfstream G650 at our club late last year and when he mentioned the pressurization of 10.7 I was amazed. Cabin altitude of less than 5,000 feet at the service ceiling of 51,000 feet... unprecedented! I'm looking forward to the Royal Turbine getting the STC for 5.5 because at present state you have to don masks to fly at 28,000 feet.

I am on an ATW hoplist I created for the flight group I'm associated with. Only on hop 4 of 100, but the Turbine Duke is the vehicle for the adventure, and it was a challenge attempting to create a set of hops worthy of the turbine conversion but we did it, and it has allowed me to grow very close the duke.She is a brilliant airplane to fly. Thanks again RealAir for your hard work. I hope the profits you saw over your two Duke aircraft will allow you to keep stepping up your game and developing for FSX. Now, back to my flight.