Pilot Journal
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

vljSingle-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.
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Socata VLJ
Socata VLJ
Socata VLJ
Pages on the MFD include electrical system data (top) and weather radar (middle). A remote data-entry keypad is accessible on the center console (bottom).
Training for the TBM 850 is through SimCom (www.simulator.com); the Orlando, Fla.–based instruction center teaches not only the G1000, but also every aspect of operating the TBM 850 in a dedicated motion-based simulator. Instructor Jerry Chipman says the standard transition course requires seven full days of training, with the final day spent in the customer’s airplane.

“It’s about 56 hours of training, with most of the simulator work accomplished in a fixed-base simulator or a desktop training device,” explains Chipman. “We train the customer in aircraft systems, operating procedures and also in the Garmin G1000 flat-panel display. That’s generally enough to bring pilots to proficiency in the airplane.”

Another improvement on the new-generation TBM 850 was delightfully unexpected. It’s a fact that most airplanes, from Cubs to Boeings, gain weight as they age, not unlike the vast majority of people. Research popular aircraft models from the last 50 years, and you’ll often find that a given model with the same engine and features somehow manages to fatten up with successive iterations. Manufacturers sometimes deal with the problem by increasing the gross weight, but Socata decided to take more decisive action. Accordingly, the company launched a major streamlining program to find and eliminate any unnecessary weight from its aircraft.

When they were done, the TBM 850 had lost 130 pounds of empty weight. Because gross weight didn’t change, the reduced weight translated directly into additional useful load, and Socata elected to turn some of the increase into fuel. In this case, the company added 11 gallons of usable fuel, leaving the other 64 pounds for extra cabin payload. At max economy power settings, the additional 11 gallons could translate to as much as an extra 100 nm of range, the most common requirement of corporate aircraft.

The airplane I flew sported a 4,560-pound empty weight against a 7,394-pound gross weight. As with most turbine aircraft, you can rarely carry full tanks and full seats, but the TBM 850 approaches that ideal. After subtracting 1,910 pounds of fuel, you’re left with about 920 actual paying pounds for people and cargo. The airplane’s payload is only 100 pounds shy of six, full-size folks.

Socata VLJMany people insist on traveling in what can only be called the lap of luxury. The TBM’s interior has always been about as plush and comfortable as is possible to build into an airplane. No word on whether the interior was styled after a Rolls-Royce or Bentley, but there’s certainly no question that it’s a comfortable place for travelers.

Launch the TBM 850, and you’ll definitely feel launched. Turning loose the full 700 shp, with only 7,400 pounds to lift, results in a power loading of just over 10 pounds per hp, and power loading is a major defining factor in takeoff and climb performance. Initial climb will touch 2,000 fpm if you need it to, but the important number is how long the airplane requires to reach cruise altitude.

In this case, the TBM 850 can high-jump to 26,000 feet from sea level in about 15 minutes, and the service ceiling of 31,000 feet comes up in only 20 minutes. Another benefit of strong climb is the airplane’s adaptability to high-altitude airports. Leadville, Colo., (elevation 9,927 feet) in the summer need not be of any major concern, and you certainly don’t have to worry about more normal departures from Albuquerque, Denver, Cheyenne, Telluride or other airports where the elevation is below 8,000 feet, even on the hottest days of summer.


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