Master of Mobility

You’re a mover and a shaker. You’re going places, but munching pretzels in seat 27F isn’t flying. That’s being flown. If, however, you have the piloting qualifications to be master of your own mobility, the TBM 900 may be just what you’re looking for. Daher-Socata touts its TBM 900 as the world’s fastest certified single-engine turboprop. My brief exposure to this French speedster demonstrated an easy-to-master airplane with impressive performance for a pilot-on-the-go.

A few successful airplane designs are revolutionary, but most of the best are evolutionary; incrementally refining a sound fundamental concept. The TBM series of turboprops happens to be both. Introduced in 1990, skeptics cast an incredulous eye at the possibility that grown-ups might elect to climb into the Flight Levels behind a single engine. The original TBM 700 proved the concept admirably and the design matured through various iterations. The TBM 850 arrived in 2006, named after its heftier 850 shaft horsepower engine, later incorporating the Garmin G1000 avionics system.

In 2010, Daher-Socata began studying ways to once again squeeze more capability from the TBM design. Called the “Century Project,” it employed the latest techniques in computational fluid dynamics, and was a closely guarded secret within the company until the fully-certified TBM 900 was unveiled in March 2014 at the company’s headquarters in Tarbes, France. The improvements that became the TBM 900 were done by aerodynamic refinement rather than by force-feeding the aircraft more brute horsepower. Enhancements included the addition of winglets, a comprehensive redesign of the engine cowling, air inlet and induction air plenum, changes to the inner landing gear doors, modification to the exhaust stacks, and the addition of a new five-bladed propeller. 

The pre-flight inspection, with Daher-Socata demonstration pilot Ken Dono, showed an airplane that is well-built and conventional, appearing powerful and attractive on the Ottawa ramp. Although the big, swept five-bladed Hartzell propeller was selected for efficiency, it also happens to be gorgeous. Forward and aft luggage compartments are easily accessible from a standing position beside the aircraft, and provide wide loading options. Big slotted Fowler flaps take up most of the wings’ trailing edges; a strong hint that the design is optimized for speed. The small ailerons are supplemented by roll spoilers.

The panel layout had the single pilot in mind, with everything falling neatly to hand from the left seat. A welcome innovation in the TBM 900 cockpit was the single-lever power control. Easier to use than to describe, it looks like a fancy automotive stick-shift, and neatly fulfils the function of a power lever, propeller governor lever and engine condition lever, greatly simplifying engine operation.

Engine starting involved engaging the starter and subsequently moving the power lever forward to the Low Idle position. That’s it. At 52 per cent Ng, the starter disengaged automatically. Ground checks are done at High Idle, following which the power lever was moved left into the Taxi range to unfeather the propeller and start moving. Dono also pointed out the fuel selector knob at the base of the centre console. An automatic tank selector feature switches tanks every 10 minutes in flight to ensure even fuel feed. Nice. One less thing for a pilot to screw up. 

Takeoff was straightforward, pardon the pun. We set the power to 40 per cent, checked the T’s and P’s, and then rolled as I brought the power up to 90 per cent. Dynamic pressure added the last margin of power as the airspeed increased. The throttle was a bit sensitive, and typical of a PT6 engine, prone to a bit of lag, creating a slight fussiness to precise engine management. The requirement for a touch of right rudder against torque was the only hint that we weren’t flying a light jet. 

The Achilles heel of the previous TBM models was a torque limiter that restricted the aircraft to 700 shaft horsepower for takeoff. The TBM 900’s aerodynamic improvements obviated that limitation, allowing all 850 shaft horsepower to be used. The Flight Manual specifies a takeoff distance of 2,555 feet to clear a 50-foot obstacle, at maximum takeoff weight at sea level, standard conditions. 

PHOTOS IN FORMATION 

Our plan involved an airborne join-up with a Cessna camera plane for some air-to-air photography. Blasting off straight into formation is absolutely the best way to learn the quirks of a new airplane. As we settled into echelon behind the Cessna’s right wing, I recalled Dono’s comment that the vast majority of TBM 900s are owner-flown. To my mind, this raises the bar where handling qualities are concerned. Aircraft operated by a paid crew are expected to be utilitarian, but aircraft flown by the guy who writes the cheque must also aspire to be delightful. 

This was a good test. Formation flying demands precision, and the TBM 900 made it easy. The flight controls were crisp, tight and responsive. The controls were slightly heavy for the delicate balancing act of formation flying, but are well suited to its mission as a cruising aircraft. Flying the TBM 900 in formation was fun!

Upon completion of the formation photography, we picked up an IFR clearance. Air traffic control assigned us a climb to 28,000 feet (FL280) toward Val-d’Or, Que. The autopilot maintained the best rate of climb speed (124 knots indicated airspeed) as I set climb power. An index on the torque meter denoted the prescribed climb power, but once again the throttle was slightly sensitive and required intermittent pokes to sustain the power setting as we climbed. Climb performance was impressive, however, averaging 2,000 feet per minute to 20,000 feet in conditions that averaged 14C warmer than standard (ISA+14C). The Flight Manual claims 18 minutes 45 seconds to climb to its certified ceiling of 31,000 feet (FL310) at maximum takeoff weight under standard conditions. 

Reaching our cruising altitude, I set maximum cruise power as depicted on the engine display, and watched with interest to see how fast the TBM 900 would go. The answer: an impressive 324 knots true airspeed, burning 62 gallons per hour at an engine torque of 96 per cent, under ISA+10C conditions. For jet pilots, that fuel flow is about 420 pounds per hour. Read ‘em and weep! With its heavily derated PT6A-66D engine and optimized induction system, the TBM 900 maintains rated power to FL280 under ISA conditions, where it achieves its maximum cruise speed of 330 knots true airspeed. Daher-Socata claims a range of 1,440 nautical miles at maximum cruising speed, under ISA conditions with a 45 minute reserve. Even longer range is achievable by slowing to the 252 KTAS maximum range airspeed. 

Long range is nice, but the flip-side of the coin is payload, and range-payload flexibility denotes a useful airplane. Our test aircraft was typically equipped, weighing 4,750 pounds empty. Adding two crew, 30 pounds of cargo and full tanks (292 U.S. gallons usable, 1,950 pounds), our gross weight at takeoff was 7,080 pounds. The maximum takeoff weight is 7,394 pounds, so with full tanks we could have added 314 pounds of additional cargo. In practice, we could have carried three 185-pound humans, each with about 40 pounds of baggage, and perhaps a bit more if one makes allowance for the higher maximum ramp weight of 7,430 pounds. In exchange for range, the maximum zero fuel weight of 6,032 pounds would have allowed a maximum payload of 1,282 pounds, which equates to filling the six seats and adding 172 pounds of luggage. The maximum payload case would still allow for 1,362 pounds of fuel. For most private owner-operators, that’s a useful range-payload envelope indeed. 

After we reversed course for Ottawa, I sat back to take stock of the TBM 900’s Garmin G-1000-equipped cockpit. The system is easily accessible, well integrated and fully exploits the capabilities of the G1000, incorporating a wealth of features: synthetic vision, SafeTaxi charts and georeferenced approach plates, weather data via radar, Stormscope and XM Radio-based NexRad receiver, Terrain Awareness Warning System (TAWS), Traffic Information System (TIS) and Iridium satellite-based telephone in the cockpit and cabin. 

Like it or not, Garmin’s G1000 is nearly ubiquitous these days, making it an ideal choice for the TBM 900. Pilots moving up from any number of aircraft types will often find the G1000 already in their skill set, simplifying the transition and making the TBM 900 seem familiar. Since its systems and procedures are simple, and the avionics are likely familiar, what is the challenge for pilots transitioning to the TBM 900? To be honest, not much. The only novelty is that the TBM 900 covers more sky much faster than their former piston-popper, so pilots need to learn to think ahead of the airplane.

The best thing that I can think to say about the general handling of the TBM was that it was eminently conventional. It has a solid predictable feel, like a much bigger airplane, but no surprises or particular challenges are lurking for any pilot with sound fundamental skills. It is a very speed stable aircraft, necessitating use of trim, both for speed changes or power changes. There is a mild pitch trim change with flap or landing gear.

I let the autopilot fly the GPS approach to Runway 25 in Ottawa. The generous speed limit of 180 knots for the landing gear and takeoff flap provided flexibility in speed management. The marriage of the TBM 900 with the G1000 autopilot is a happy one, with smooth intercepts and solid tracking. Passing the final approach fix, the highway-in-the-sky synthetic vision symbology provided a view of the runway directly under the velocity vector. The lateral offset of the runway on the display gave evidence of a slight crosswind before we broke out of the simulated cloud. How’s that for situational awareness? 

Garmin’s airspeed tape was a bit lively, but the TBM 900 presented no difficulty in holding the prescribed approach speed of 85 knots indicated airspeed, aiming for a 78-knot touchdown speed. Power off in the flare, it was predictable in pitch and capable of some float. I planted the rubber, gently squeezed the brakes and applied a bit of reverse thrust. We made the first turn off. 

If your airplane choice vacillates between a TBM 900 or a light jet, and you are inclined to think that cruising at “only” 325 knots is a hardship, then consider the field performance trade-offs. According to the Flight Manual, the TBM can land over a 50-foot obstacle in 2,430 feet, under sea level standard conditions, which opens up a wide range of destinations. 

For many operators, “bang for buck” equates to “miles per dollar,” and with its single turboprop engine to feed, the TBM 900 compares favourably to the light jets. The original revolutionary single-engine turboprop concept that begat the TBM series has undergone an evolution of refinement into a very well-mannered aircraft with impressive performance.