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.
The very first of the luxury single-engine propjets was EADS Socata's TBM 700, introduced in 1991. Though the French aircraft would be followed by the Pilatus PC-12 and the more recent Piper Meridian, Czech Ae 270 Ibis and Extra 500, Socata's single-engine entry has remained the preeminent turbine single among corporate airplanes.
The follow-on to the TBM 700 is the TBM 850, introduced two years ago. As the model designation implies, the most significant improvement was an increase in the flat rating from 700 to 850 shp. The extra power is accessible in cruise and translates directly to a 15- to 20-knot speed improvement at altitude, especially in hot and high conditions.
The state-of-the-art Garmin G1000/ GFC 700 flight deck consists of two 10.4-inch PFDs and one 15-inch MFD. |
To call the new airplane's reception spectacular is an understatement. EADS Socata has sold 150 of the type in just over two years, most of them here in the States. Now, in an attempt to make its best seller even more popular, Socata has taken another step in adapting its single-engine turboprop to the coming age of VLJs.
In keeping with the industry's trend toward flat-panel-display avionics, the company has fitted the new TBM 850 with Garmin's G1000/GFC 700 flight deck. In the case of the newest TBM, the Garmin system consists of one 15-inch MFD in the center panel and twin 10.4-inch PFDs. All engine information is seamlessly displayed on the large MFD, including output from two of practically everything: dual airborne heading-attitude reference systems (AHARS), digital audio controllers, air data computers, magnetometers and NAV/COM/GPS units. Additionally, the Garmin system incorporates weather radar, the GFC 700 automatic flight control system, terrain avoidance, TCAS and a Chart View feature. In short, the TBM 850 has virtually every capability normally consigned to airliners.
Yes, before you ask, if you haven't flown flat-panel before, it will take some time to get your brain up to speed on the avionics, but it's far simpler if you're basically familiar with Garmin's 430/530 system. Most operating functions work roughly the same. If you've flown flat-panel before, you'll quickly become comfortable with the TBM 850's G1000 setup. If you haven't, there will be a transition period, but the system is fairly intuitive, and Socata will train new buyers to proficiency. (One fringe benefit of the G1000 system is that pilots who fly a variety of airplanes may be more comfortable transitioning from one type to another.)
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.
Many 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.
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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