Thursday, May 29, 2008
VLJ With One Prop
Socata’s TBM 850 offers performance only slightly below that of some VLJs—at 30% less operating cost
|Single-engine turboprops are becoming the rage these days, if you can call a half-dozen models a “rage.” The Malibu JetProp’s mod transforms standard Piper Malibus and Mirages into fire-breathing turbines, and the single-turbine Epic LT will be available as both a homebuilt and a production airplane with a PT6A rated for 1,200 shp.|
One big question concerns cruise performance, and check pilot Jacques Raissiguier, who ferries the airplanes across the Atlantic on a regular basis, showed me logs of recent deliveries that suggested true airspeeds at cruise of 311 to 315 knots, depending, as usual, on temperature.
Comparing 310 knots to a typical 330- to 340-knot VLJ might seem to give away too much, but in the real world, it gives away practically nothing. Do the math and the difference is insignificant. On a 650 nm business trip, you’d arrive only about 10 minutes behind the jet and save about 30% to 40% of the jet’s fuel burn.
|Passengers in the TBM 850 travel in a luxurious cabin rivaling the interior of any Rolls-Royce or Bentley. The amenities include passenger- adjustable cabin temps and fan speeds.|
Of course, if the mission demands longer legs, you might leave virtually all the short-range VLJs behind with the TBM 850’s excellent range capability. With 291 gallons available and a burn of 60 gph, you have an easy four hours of endurance plus reserve at max cruise. Even at only 300 knots with four folks aboard, that’s 1,200 nm, a number hardly any VLJs will match (remember, that’s at max cruise). In optimum ISA conditions, plan on 1,400 nm at max cruise or nearly 1,600 nm at economy setting.
Raissiguier says range is one comfortable aspect of his job delivering TBM 850s westbound across the northern pond, where the wind is nearly always in your face. “Even if you’re faced with a 50- to 75-knot headwind,” says the TBM pilot, “you have plenty of endurance for the 650 to 700 nm legs between Scotland, Iceland, Greenland and Canada. Range just isn’t much of a concern in this airplane.”
When it’s time to descend, turboprops have an advantage over jets—the big lever on the left does it all. Jets often employ speed brakes to help them descend, but the TBM 850’s huge, paddle-blade prop serves as an excellent speed brake, allowing the airplane to drop out of the sky at 2,000 fpm without pushing IAS past the barber pole.
Patterns work well at any speed between 120 and 90 knots, and the TBM 850’s runway requirements are minimal. The aircraft can use any unobstructed runway of 2,500 feet or more without reverse. If you do throw in a little reverse thrust, you can get down and stopped in much less space than is required to get back off.
Socata sees the market for the new TBM 850 as a head-to-head battle with the lower-order VLJs, specifically the Diamond D-JET, the upcoming PiperJet, “the-jet” from Cirrus and the possible entry of the Eclipse ECJ. Perhaps ironically, the TBM 850 is more expensive than any of the above, though it probably offers a larger cabin, equal or better climb and better operating specifics.
The airplane I flew for this article was a ferry-time-only 2008 model that listed at $2.98 million. With that price tag, it’s more costly than any of the proposed true VLJs, and even a few dollars more than a Cessna Citation Mustang.
No one can guess the reception of the VLJs when there’s more than one of them on the market, but the TBM is here and has been for nearly two decades. It offers nearly the same speed, better range and much of the same performance for a significantly lower hourly operating cost. Even for those who don’t need to ask how much, that says a lot.
To learn more about EADS Socata, log on to www.socata.eads.net
.SPECS: EADS Socata TBM 850
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