““[Bill Gates] has been historically one of my best supporters…One of my favorite e-mails he ever sent me…I proposed this crazy project. And he sent back this two-line response: ‘This has got to be the craziest thing you’ve ever suggested. Please proceed.’” ”
Daher-Socata's TBM 700
This is the story of a great single-engine turboprop built in France that in part was born in Kerrville, Texas. As you might expect from the lineage, it is sleek, fast and rugged.
Work on what became the TBM 700 started in 1973 after Mooney Aircraft Co.-a Texas manufacturer of cramped but fast single-engine piston airplanes-hired aircraft designer Roy LoPresti as vice president of engineering. The company asked LoPresti, whose nickname was "The Speed Merchant," to come up with another single-engine piston airplane. Dubbed the 301, it was to be pressurized, seat six and have a 266-knot top speed.
Before the 301 could make it to market, however, a consortium of investors from France purchased Mooney and dropped the project. Instead, the consortium formed a joint venture with Socata, then a subsidiary of Aerospatiale, based in Tarbes, France, to develop a 300-knot single-engine turboprop.
The TBM 700-which incorporated some design cues from the canceled 301-first flew in 1988 and was certified in 1990, when Mooney withdrew from the venture. The end product was a six-seat, 295-knot pressurized aircraft that was mostly metal but used some composites on the control surfaces. Mooney lives on in the model as the "M" in TBM. (The "TB" stands for Tarbes.)
Thanks to the low TBM production rate- some 530 units over the last 20 years-the model has enjoyed relatively consistent demand and solid resale values. These airplanes are essentially made to order. Last year, the manufacturer (which became Daher-Socata in 2008) produced 36 of the latest TBM, the Model 850.
The airplanes are flown largely by owner-pilots, who are brand loyal. This point was driven home to me rather forcefully last summer while I was dining with several of them at the annual Experimental Aircraft Association convention in Oshkosh, Wis. As the conversation moved around the table, each owner bested the previous speaker with a tale of his particular TBM's prowess in terms of range, speed, economy or enjoyment. As they say in Texas, "It ain't braggin' if it's true." Clearly, TBM owners seem to be a happy lot and there are good reasons for this.
The TBM zips along in the relatively less congested airspace between 20,000 and 30,000 feet, where the odds increase for more direct routing and, conversely, for running into rotten weather. Moreover, it will burn only about half as much fuel as a very light jet or twin turboprop and it climbs like a rocket. Plus, it's a great short-runway performer. At maximum takeoff weight, the 700B will lift off from sea level in 2,133 feet. "The B is fun to fly," said John Elford, a well-known TBM instructor pilot who has 11,000 hours in the aircraft. "It flies like a little fighter and is fast and very comfortable."
To the naked eye, the basic TBM airframe seems unchanged from the original. Over the years, Socata has modestly improved the design, with better environmental controls; vapor-cycle air conditioning; avionics upgrades; a small beverage cabinet; a wider main cabin entry door well-suited for loading outsized cargo; and an optional separate forward pilot's door. The new 850 has a more powerful engine, which boosts top speed to 320 knots, and glass-panel avionics.
The 700B made its debut in 1999 (Serial Number 126) and Socata built 100 of them during the model's three-year production run. It was the first TBM to feature the oversized rear door, separate pilot door, more plush executive interior and factory air conditioning. The pilot door and large aft door added more than 140 pounds compared with the original A model. This cut maximum payload with full fuel to just 353 pounds, a reduction of more than 100 pounds from the A model and more than 500 pounds less than heavier follow-on TBM models such as the C2 and 850. Those models have beefier airframes and landing-gear attach points.
Last year Daher-Socata announced that a Garmin G1000 integrated glass-panel-avionics retrofit package would be available for all TBMs in 2010. While the retrofit costs about $300,000, it weighs substantially less than the original avionics and increases the 700B's full-fuel payload by approximately 112 pounds. However, full fuel delivers a range of 1,467 nautical miles and most TBM flights average just 400 to 600 nautical miles, so the B's full fuel (290 gallons) payload number is usually a nonissue. A 700B will burn about 50 to 55 gallons per hour.
Aside from the Piper Malibu, the TBM is the least spacious six-seat turbine cabin in the sky. The cabin cross section is just under four feet wide. Passengers sit in facing club-four seats and there is room for two pilots (although the airplane is certified for single-pilot use and most operators fly it that way). The passenger seats have 18-inch-wide bottoms and 22-inch-high backs. That leaves a narrow 11-inch-wide aisle. A single club table deploys from the right-hand sidewall. The cabin is quiet for a turboprop, but still noisier than a jet. The aft-located main door measures 3.5 feet high and 3.9 feet wide and swings up and out of the way on a pair of gas-charged springs.
Most baggage is stored behind the rear-most row of seats in a cargo net. A small baggage compartment with an external door in the rear fuselage will hold 77 pounds and is big enough for a pilot's overnight bag or a tool kit. An even smaller forward storage compartment, also with an external door, typically holds the tow bar and the engine inlet and exhaust stack covers.
If you require a bathroom, you need to ask the pilot to land. Aside from the G1000 avionics upgrade, owners may wish to consider new paint and interior for around $60,000, according to Terry Winson of New Avex, a TBM dealer in Camarillo, Calif. An engine overhaul of a B's 700-shaft-horsepower Pratt & Whitney PT6A-64 engine-due every 3,500 hours-runs about $220,000.
Elford cautioned that prospective purchasers of 700Bs should schedule a thorough pre-buy inspection and be on the outlook for evidence of engine exceedances and cracked landing-gear supports. Exceedances occur when an engine is operated beyond recommended parameters, generally during startup, while "hard" landings can crack the gear supports. The former necessitates an expensive and detailed engine inspection while the latter mandates a repair.
That said, TBMs enjoy a deserved reputation for ruggedness and their rakish appearance oozes speed, even when they're parked on the ramp. "The B is reliable and has big safety margins," said Winson. However, pilots transitioning into a TBM from a smaller airplane still need type-specific and recurrent training. The TBM's speed is something to admire-and respect.