AOPA PILOT - Mooney M20M Bravo Review

operated speed brakes; a built-in oxygen system; and backup vacuum pump. Those dual batteries are there mainly to offset the weight of the six-jug Lycoming up front, but in concert with the pair of alternators they make for excellent elec- trical redundancy. The backup vacuum pump is also electric. Weeping-wing deice equipment is optional, allowing flight into known icing conditions. Unless you feel that you really need the available electronic flight instrument system (EFIS), these accouterments should suit you just fine. In fact, the only item missing here is some kind of engine monitor-no turbocharged airplane should be without one. Starting with a base price of $364,950, this Bravo's bottom line swells by $53,750 for the advanced avionics in what's called the Classic/Plus group- basic IFR instrumentation and avionics are standard on the Bravo. A second glideslope receiver and nav head, Bose headset, electric prop deicing boots, an upgrade from the Classic/Plus's standard WX950 Stormscope to the WXI000+, and leather seats help boost the final number to $436,700. For this sum, you get a tremendously capable airplane. As a big fan of tur- bocharging, I'm usually the first to defend its cost and complexity. When you have a country to cross, the ability to top weather, move into more favorable winds aloft, and just generally enjoy a smoother, cooler ride pays off big time. For the first leg out of Long Beach, California, the Bravo managed an ini- tial climb rate of 950 fpm by using the recommended cruise-climb parame- ters of 120 knots indicated, 34 inches manifold pressure, and 2,400 rpm. Fuel burn, according to the Shadin, was about 26 gph at full rich, and 23 gph leaned to 1,600 degrees TIT. The Bravo will maintain a strong rate of climb through 18,000 feet, above which the climb rate dips below 500 fpm. Mooney lists the Bravo's maximum rate of climb from sea level-using full power and a high-deck-angle 105 knots indicated- as better than 1,100 fpm. Weight plays a big part in climb performance; leave 250 pounds of stuff at home and you'll pick up 100 fpm at most altitudes. November 63W weighed a smidgen more than 2,400 pounds empty, leaving 968 pounds in the useful load column. Top off the tanks (89 gallons usable) and you could still carry 434 pounds in the cabin. I flew the airplane solo most of the trip, so typical operating weights were around 3,150 pounds, well shy of the maximum takeoff weight of 3,368 pounds and still under the max landing weight of 3,200 pounds. As a result, the speeds and climb rates noted on the journey generally were better than those in the handbook. Leveled off in cruise, the Bravo cuts loose with some impressive numbers. Because the weather was beautiful, I started the trip at 17,500 feet, VFR; tem- perature aloft was some 15 degrees Cel- sius above standard. Leaving climb power set (34 inches/2,400 rpm, also the maximum-cruise setting) and allow- ing the airplane to accelerate leaves lit- tle to do but close the electric cowl flaps and commence the trim dance- Mooney fits the Bravo with rudder trim, so you get to fine-tune in two axes. Even when leaned to peak TIT-usually very close to the 1,750-degree redline-the Bravo will hit the magic 200 KTAS on 17.5 gph; with the red knob pushed in to best-power mixture (1,650 degrees TIT), the M20M goes about four knots faster on 20.6 gph. At FL250, the Bravo will cruise at 215 KTAS on 20.5 gph-no peak TIT allowed above 22,000 feet to keep engine temps in check. Mooney did the right thing in 1989 by fitting the TLS (and hence today's Bravo) with a high-caliber automatic turbo system. The 'Garrett AiResearch TA-04 turbo is managed by sophisti- cated density/differential controllers and breathes through an air-to-air intercooler. The turbo's operation couldn't be more seamless. Even at high ambient temperatures there was always boost for the taking, and there's little need to tweak the throttle knob during a protracted climb. (A far cry from my Mooney 231 days of constant fiddling to maintain a desired amount of boost, thanks to its fixed wastegate and too- small turbo.) Uprated turbine casings and a more durable exhaust system allow for the 1,750-degree TIT limit. In the high-power cruise regime, the Bravo's new oil cooling is readily appar- ent on the engine instruments. Higher oil temperature-by 10 to 15 degrees- is the norm, accompanied by slightly lower cylinder-head temps than before. In addition, changes in power or air- speed take longer to show up on the CHT gauge, the result of the oil's provid- ing a bit of thermal stability to the heads. (That doesn't mean you can just chop power and point the nose at terra firma and not see the CHT needle budge, but the engine seems more tem- perature-stable.) At 17,500 feet the Bravo's cylinder- head temperature remained below 400 degrees only at the best-power mixture. Leaned to peak, it would creep to 410 degrees unless the cowl flaps were cracked open-neither Lycoming nor Mooney specifically allow lean-of-peak operation. 1 tried a few more power set- tings; each successively lower power setting produced, predictably, less speed on less fuel and reduced engine temperatures. These settings including 32 inches/2,400 rpm (198 KTAS, 16.4 gph), 30 inches/2,400 rpm (] 89 KTAS, 14.9 gph), and 27 inches/2,200 rpm (172 KTAS, 13.3 gph). There are no percent- ages of power listed in the power-set- ting tables, but based on the fuel flows, the 30 inches/2,400 rpm looks to be the 75-percent-power combination. While Mooney has worked hard on getting the shakes out of this installation-and has for the most part succeeded-there was a noticeable shudder in the airframe at lower engine speeds, rendering the 2,200 rpm setting less comfortable than the higher prop speeds. At the fuel stop in Amarillo, Texas, 3.9 hours after takeoff, the Bravo took 68 gallons, for a block-to-block average of 17.4 gph and 212 knots for the 825-nm trip. A short hop into Ada, Oklahoma, for an overnight and then a fuel stop at Kentucky's Sturgis Municipal the next day completed the trip into AOPA's AOPA PILOT· 47 . JANUARY 199R Oil capacity Baggage capacity Recommended TBO Propeller MooneyTLS Bravo Base price: $364,950 Price as tested:.$436,700 140 KlAS 106 KIAS 174 KIAS 195 K!AS 67 KIAS 59 KIAS Limiting and Recommended Airspeeds Vx (best angle of climb) 85 KIAS Vy (best rate of climb) 105 K!AS VA(design maneuvering) 127 K!AS VI'E (max flap extended) 110 K!AS VLE(max gear extended) 165 KIAS VLO (max gear operaIing) Extend Retract VNO(max structural cruising) VNE (never exceed) VSI (stall, clean) Vso (stall, in landing configuration) All specifications are based on manufactllrer's enl- wlatiolls. All performance figures are based on stalldard day, stalldard atmosphere, sea level, gross weight cOllditiolls ulliess ot/zerwise noted. Max level speed 214 kt Cruise speed/endurance w/45-min rsv, std fuel (fuel consumption) @ 89% power, best power mixture 25,000 ft 214 KTAS/3.7 hr (123 pph/20.5 gph) 10,000 ft 188 KTAS/3.7 hr (122 pph/20A gph) @ 60% power, best economy 25,000 ft 187 KTAS/4.8 hr (80 pphll3.3 gph) 10,000 ft 168 KTAS/5.3 hr (77 pph/12.8 gph) Max operating altitude 25,000 ft Landing distance over 50-ft obstacle 2,500 ft Landing distance, ground roll 1,200 ft E-mail the author at marc.cook@ aopa.org the 231/252 and Encore; and, yes, the Bravo's full-fuel payload is no better than those of the smaller airplanes. But the performance is there for the taking. At comparable percentages of power, the Bravo and the Encore remain sepa- rated by about 15 knots. The Bravo's extra power makes for better high-alti- tude climb and slightly improves run- way performance. Current owners of wet-head TLSs and potential customers for the Bravo might be asking the same question: Does the oil-cooling scheme make the turbo Lycoming worthy of its 2,000-hour TBO? Too early to tell, but the initial indica- tions are promising. The question remaining to be answered is this: Now that the exhaust valve guides are cooler, what is the next-weakest link in the chain? Bravo (and wet-head TLS) owners then face a dilemma square-on: Do you throttle back a bit-to, say, 75 percent of maximum for cruise-and sacrifice about 10 knots for the possibility of greater engine longevity? Or, do you run at maximum cruise-because, as one TLS owner told me, "I didn't buy the air- plane to go slow"-and hope the addi- tional oil cooling does the trick? 0 for more informatioll, COiltact Mooney Aircraft Cor- poration, Louis Schreiner Airport, Kerrville, Texas 78029; telepholle 800/456-3033 or 830/896-8181; fax 830/896-7333; Web (www.moolley.com) .• Specifications Textron -Lycoming TlO-540-A 1FB, 270 hp @ 2,575 rpm 2,000 hr Hartzell, three-blade. constant-speed, 75-in dia 26 ft 6 in 8 ft4 in 36 ft 1 in 174.8 sq ft 19.26Ib/ sq ft 11.85Ib/hp 4 10 ft 6 in 43in 44in 2AOIlb 3,3681b 967lb 433lb 3,2001b 95 gal (89 gal usable) 570 Ib (532 lb usable) 10 qt 120 lb, 20.9 cu ft Length Height Wingspan Wing area Wing loading Power loading Seats Cabin length Cabin width Cabin height Empty weight, as tested Maximum gross weight Useful load, as tested Payload w/full fuel, as tested Max landing weight Fuel capacity, std Powerplant Performance Takeoff distance, ground roll 1,000 ft Takeoff distance over 50-ft obstacle 2,200 ft Max demonstrated crosswind component 13 kt Rate of climb, sea level 1,010 fpm Max level speed, sea level 168 kt able nonpressurized long-distance trav- eler I've enjoyed. Better, in many ways, than the fondly remembered Mooney 231 that was my ride for three years. Inevitably, the Mooney faithful com- pare the Bravo to the more traditional M20s, particularly the vaunted 252- now returned as the Encore. Yes, the Bravo's Lycoming is thirstier and rougher than the smaller Continental in Frederick, Maryland, headquarters. All told, the Bravo posted a total flying time of 10.7 hours, for an average of 194 knots over the ground. Most of the quicker airplanes can tackle a two-day continent crossing without torturing their occupants, but the Bravo's speed, altitude capability, sophisticated and smooth autopilot, and weather-avoidance gear add up to a conveyance that makes such long-dis- tance travel not just endurable, but enjoyable. This point was brought into focus on my return trip. Meetings had delayed my departure from Frederick and-coupled with obligations for the airplane-called for a one-day, into-the- wind westward thrash. Launching into pale, predawn light, I pointed the Bravo in the general direc- tion of California and, 4.7 hours later, touched down in Butler, Missouri, for fuel. With the Lycoming cranking along at the more moderate 30 inches/2,400 rpm setting-in an effort to extend the Bravo's range a bit-the Shadin typically showed a consumption rate of 15 gph at 16,500 feet. Later in the trip, to maintain visual surveillance on thunderstorms and to avoid the usual turbulence of the desert southwest, I climbed the airplane to FL200 and then to FL220. Even at this comparatively modest power setting, the Bravo trued 192 knots. By midafter- noon-with a second stop in Albu- querque for fuel-I was back in Long Beach, a bit tired of sitting in one place and raspy-voiced from being on oxygen during most of the trip, but certainly not ready to crawl into bed for a week. In fact, the Bravo was easily the most comfort- AOPA PILOT' 48· JANUARY 1998