199212-1992 Beech Bonanza A36 Turbine

tions. Pulling the power lever back to Flight Idle is like deploying a small drag chute from the tailcone. When the airspeed bleeds off to below 154 knots, I extend the gear, then push the nose over-way 88 • DECEMBER 1992 over-to maintain 140 knots. Check that VSI again, Joe: We are heading earthward at 3,000 fpm. Back at the airport, we make a nor- mal full-flap approach. Speeds and procedure are the same as in an avgas A36, the only difference being the sen- sitivity of the power. On short final, I decide to execute a missed approach and cob the power-gingerly. Despite nose-up trim and all that power, the abort is routine. The next circuit is to a full and forceful stop. When the mains touch, I pull the power lever up and back past Flight Idle and Ground Idle and into Reverse. The· propeller blades rotate to a negative pitch, and the engine spools up with a whoosh, directing thrust for- ward. It's very effective stopping power-ABS without the brakes. In little more than the length of a football field, better than 1.5 tons of Bonanza is brought to a halt. Stretching the turbine Bonanza to its limits is not the stuff of everyday flying, but it serves to demonstrate that the airplane is easy to manage even under extreme conditions. It's also instructive to sample the kind of performance you can call on if and when it's needed. Until getting to know the Allison- powered Bonanza, you might consider it an expensive indulgence, good for astounding friends and spectators with zoom climbs, kamikaze descents, and arresting-hook landings but of no real practical use. After all, the A36 is not pressurized, which means you have to breathe oxygen to take full advantage of the engine's ability to deliver high true airspeeds. If not, if instead you choose to fly low and breathe free, you'll have to do so at partial power. The turbine engine imposes an air- speed restriction on the A36. The red- line on the airspeed indicator is reduced from 205 knots on the stock airframe to 167 knots. In other words, the yellow caution range is gone. Top of the green is as fast as the turbine Bonanza can legally fly. The airspeed restriction is not unique to the A36. All piston-to-tur- bine conversions are subject to the "top of the green becomes red" rule. That's because airspeed indicators in turbine-powered aircraft do not have yellow arcs. So why not extend the green arc to the existing redline instead of reducing the redline? The reason is the power of the Alli- son compared to the piston engine it replaces. At lower altitudes and full power, the turbine Bonanza could fly perilously close to and perhaps even beyond the stock A36's 205-knot VNE. That's a long way from the 141-knot maneuvering speed. The Federal Avia- tion Administration takes the conserv- ative approach with turbine conver- sions by reducing never-exceed speed. It makes sense. Given the lack of pressurization and the airspeed restriction, how practical can it be to spend lots of money hang- ing a turbine engine on a perfectly , good Continental-powered A36? And it is lots of money-$381 ,000 for the conversion minus about $30,000 cred- it for the piston engine if it's new, less AOPA PilOT· 89 if there's time on it. But spend a day bisecting the continent with Boyd in 600TT, and you'll come to appreciate the transportation benefits of a kerosene-burning Bonanza. We departed North Las Vegas Air Terminal early in the morning and, fol- lowing a brief ATC-mandated wait at 11,000 feet, were cleared to 17,000, an optimum altitude for the Allison. The Bonanza averaged about 1,000 fpm in the climb, and the optional Aero- Trim electric rudder trim saved my right leg from fatigue on the way up. Ambient temperature has a big effect on a turbine engine's ability to make power. It was warm over the Rockies at 17,000, so the Allison was only putting out about 69-percent power-about 290 shp-at 24 gallons per hour. That's the same power and fuel flow you'll get from a piston-engine A36 early in a climb. But there we were, looking down at snow-brushed mountain peaks, indi- cating 160 knots for a true airspeed of about 214 knots. We landed in Amarillo 3 hours 11 minutes and 79 gallons after taking off from North Las Vegas. The tanks were full when we departed, so we shut down with 30 minutes of cruise fuel remaining on top of an hour's reserve. After lunching in the cozy airport cafe, Boyd gave me a tour of the Tradewind facility. Several A36s were undergoing conversion, including a couple of brand-new Bonanzas. The ability to match a new airframe with the Allison engine is a big selling point. Boyd is talking to representa- tives from two foreign countries about the purchase and conversion of 55 new Bonanzas. One country would use the airplanes as military trans- ports, the other for training pilots for the national airline. Boyd's wife, Dorothy, joined us for the flight to Chicago. Back again at 17,000 feet, with the day drawing to a close, Joe snoozed while Dorothy, breathing from her own bottle of oxy- gen, busied herself with work at the foldout table in the club cabin. Thanks to a little push, we were scooting over the heartland at better than 250 knots. The weather deteriorated as we advanced northward. For the first time since leaving Vegas, we encountered clouds. I flipped the switch activating the anti-ice system, which includes engine ignition and electrically heated engine inlet lip, stator vanes, pitot tube, and propeller blades. The cowl flap, which controls airflow through the oil cooler, must be opened when anti-ice is turned on. We climbed to try to top the weath- er, first to 19,000 and then 21,000. The airplane still was climbing at about 800 fpm when we reached Flight Level 210 and clear air. With anti-ice off, the airspeed settled on 147 KIAS, 210 knots true, at 21.5 gph. Before landing at DuPage, I wanted to sample cruise flight at a non-oxygen altitude, so we descended. As expect- ed, I had to pull off some power to avoid exceeding VMO in level cruise at 9,000. True airspeed worked out to 193 knots at just under 26 gph. The conclusion of the flight couldn't have been more of a contrast to the serenity of the day: a night, low- IFR approach to DuPage in some very turbulent air. The Allison's power and response allowed for precise speed control in the difficult conditions, and using Reverse after touchdown eased concern about the potential for hydroplaning on the wet runway. The trip was over. I had eaten eggs for breakfast in Vegas, chicken-fried steak for lunch in Texas, and airport pizza for dinner in Chicago. In 6 hours 41 minutes of flying, we had covered more than 1,600 nautical miles and used 165 gallons of gas. That's an aver- age of about 240 knots and 24.5 gph. The same trip in a Continental-pow- ered Bonanza would have taken 8 hours and 128 gallons, but that's assuming the winds down low would have been equally as helpful, and that's rarely the case. If you're reaching for a calculator to figure out how much more it costs in fuel to fly the turbine Bonanza, you're probably not going to be com- fortable spending more than a third of a million bucks on getting the turbine engine in the first place. Those who can sign the check without flinching will be buying a very special airplane. It's a Bonanza, only better. I caught a bus to Chicago-O'Hare for a commercial flight back to Wash- ington, D.C. The drive to the airport took an hour, then I and my fellow passengers cooled our heels in the ter- minal for several hours while the flight crew waited for a first officer to show up. I finally arrived in Washington in the wee hours of the morning, facing another hour's cab ride before crawl- ing into bed. If only I could have caught the Tradewind .... D