Turbine Pilot

Enhancements mark the newest TBM 700s

To the untrained eye, the EADS Socata TBM 700 has remained a static design since its introduction in 1989. The truth is that several changes, major and minor, were made with the 1999 model year — enough changes to prompt a new type designator (TBM 700B). All significantly enhance the appeal of this 300-knot six-seater that many feel reigns as king of the single-engine turboprops.

Truth be told, this turboprop, because of its modern systems designs and single engine, behaves more like a high-performance piston single — think Beechcraft Bonanza — than most turboprops. The big difference to those stepping up, of course, is speed. This hot rod goes almost twice as fast and flies three times as high as your average single-engine piston.

Model 700Bs began with serial number 126, and these airplanes' most distinctive signatures are their large aft doors. At 3 feet, 6.5 inches wide, the new doors are almost twice as wide as those on earlier TBM 700s, and they come with other welcome enhancements. There's a solid aluminum airstair assist railing (no more woven cable), a snubber piston and a rubber bumper to prevent the drop-down stair assembly from banging against its stops, and a motorized door-closing mechanism. The latter is necessary because the door hinges at the top. When the door is fully open its grab handle is out of reach for most people, so the handy fuselage-mounted button is necessary to start the door downward. A similar button is inside the cabin.

New TBM 700s also have a pilot door available as a $45,000 option. This smallish door next to the pilot's seat comes with a set of narrow fold-down stairs. With practice, you get the hang of exiting through this door and scooting off the leading edge and down the ladder.

Why these door changes? No doubt the Pilatus PC-12, with its cavernous cabin and humongous aft door (which also uses an electric motor for closing), created competitive pressure. The PC-12's big door allows large, bulky objects to be more easily loaded, and a bigger door made sense since more TBM 700s are seeing service as modest cargo haulers. (LabCorp, a pharmaceutical firm, recently bought six TBM 700s to shuttle medical supplies.) Also, passengers appreciate having more entry room, and it's easier to load the aft baggage area with the large door. Just fold down the aftmost seat and load your bags directly from the ramp. With earlier models you had to schlep the bags into the cabin, then fold down the backseats to load the baggage area.

The pilot door addresses two main issues. One is that many pilots insist on closing the cabin door themselves. Do this from inside the airplane and you're in for some clumsy and potentially embarrassing maneuvering near seated passengers. The pilot door lets you finish your preflight in the cockpit and then exit, close the aft door from outside, and get back in the saddle — without having to squirm past passengers. In cargo operations, the pilot door lets you fill the cabin to the brim. Having your own door nearby means not sacrificing cabin volume to an aisle.

There are other less obvious but equally significant airframe improvements that come as standard features with the B models:

• Certification for flight up to 31,000 feet (up 1,000 feet from the A model), thanks in large part to a new bottled oxygen system (A models use a chemical oxygen system), drop-down cabin masks, quick-donning crew masks, and crew smoke goggles with purging capability.
• Electric windshield anti-ice on the right windshield. Older models only had windshield heat on the pilot's side.
• Precise Flight pulse lights.
• Oil pressure relief lines are now routed to the exhaust system for complete burning of oil; A models have a relief vent on the belly, where the oxygen system intake could become fouled by oil residue.

B models also have a pretty impressive complement of upgraded avionics. The standard suite includes the Honeywell IHAS 8000 with its KMD 850 multifunction display. The IHAS (integrated hazard avoidance system) shows terrain, traffic, and uplinked weather information on the multifunction display, as well as imagery from the airplane's own color weather radar, a Honeywell Bendix/King vertical-profiling RDR 2000. Dual transponders, dual encoders, and a radar altimeter are also standard, as are the Honeywell 40 EFIS and the glareshield-mounted Honeywell KFC 325 digital flight control system.

Goodrich's Skywatch and WX-1000+ Stormscope are also standard. Skywatch traffic advisories can be displayed on the KMD 850 or the dedicated Stormscope display screen. As for terrain warnings, TBM 700Bs have true EGPWS (enhanced ground proximity warning system) functions, thanks to the IHAS' KGP 560 EGPWS receiver and a radio altimeter, which adds a necessary element of terrain-clearance information to the terrain-elevation data in the ship's GPS moving-map memory.

Don't want the Honeywell IHAS or KMD 850? Then order the optional dual-Garmin GNS 530 setup. The Skywatch and Stormscope data can be routed to display on these units.

Electronic engine trend monitoring is provided via the Shadin ETM-700, another standard item. The Shadin is a fuel totalizer that also automatically records all starts, shutdowns, ITTs (inter-turbine temperatures), fuel flows, compressor speeds, propeller rpm, and a wide range of other variables. By downloading and graphing this data, owners can better monitor their engines' health — and extend their maintenance intervals and service lives. With the Shadin, B models need not adhere to fixed hot-section or overhaul intervals. They can be serviced on-condition, which is another way of saying "as indicated." As long as the Shadin reports A-OK, then you can fly past the usual 1,500-hour hot-section inspection or 3,000-hour time between overhaul assigned to the TBM's Pratt & Whitney PT-6A-64 engine.

Flying a new TBM 700 is pretty much like flying an older model. Hit the master, fuel pump, and start switches, wait for the engine to spool up, then move the condition lever (the red lever at the right of the center pedestal) forward to admit fuel to the combustion chamber. The engine lights off, you fire up the avionics, set the flaps and rudder trim for takeoff, make your pretakeoff checks, and you're ready to go. Rotate at 85 kt, climb away at 140 kt, settle into a 2,000-fpm climb, and within 25 minutes or so you're at Flight Level 310 doing about 300 kt true. The day I flew N700BY, TBM demonstration pilot Tom Cunningham and I cruised at FL280 and saw a true airspeed of 290 kt — on a 53.6-gph fuel burn.

For an emergency descent to 10,000 feet — something you'd have to do in case the pressurization system failed, there was a bleed-air overheat, or an unlatched door — I slammed the power lever back to flight idle, then dumped the nose until we reached the V _MO of 266 kt. The vertical speed indicator pegged, the horizon left the windshield, and we seemed aimed straight at the terminator (the ground). After two minutes, 15 seconds we were level at 10,000 feet.

As for pattern work, it continues to amaze me how an airplane with the size and speed of a TBM 700 can be landed essentially like any piston-powered, high-end complex single. (This probably explains a large part of the airplane's success.) Fly downwind at 100 kt (use 55-percent torque as a ballpark power setting), slow to 90 on final (25-percent torque), then let airspeed bleed off to 85 as you cross the fence. Once on the ground you can go into reverse thrust to minimize landing distance and spare your brakes. The only unusual things about flying the TBM are the yoke-mounted rudder trim and the pitch-down with flap extension. But after a few sessions at the Orlando SimCom training center (which provides pilot training as part of the purchase price) you adapt to these idiosyncrasies.

EADS (the European Aeronautic Defense and Space Company) Socata has come a long way in the development of the TBM 700, but it's not done. By the end of the year, Socata says a third iteration — the TBM 700C — will be on the market. This will be an increased-takeoff-weight (7,388 pounds) version that will give operators approximately 800 pounds more useful load than is currently available. Four-point harnesses will be at the pilot stations, passengers will have three-point harnesses anchored to the seats, and the interior cabinets will be bigger, a Socata official said. With the ability to carry three more passengers in increasing levels of comfort and safety, the C model should continue to expand the TBM 700's special niche as a plush hot rod.

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