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fuel controls are similar to modern King Airs. The throw-over yoke, trim wheels, and piano-key switches are pure vintage V-tail Bonanza.
The only thing that feels foreign is the non-standard arrangement of the power quadrant. Beech put the throttles in the center and prop controls to the left, opposite of Piper and Cessna piston twins. However, with geared engines to manage, the arrange- ment is quite handy. Big power adjustments are made with the prop controls first, then throttles, to ensure the engines remain “loaded.” It is important to keep the engines turning the props, not vice-versa (which can cause mechanical “backlash” and damage to the 77:120-ratio gearboxes). Ground-idle RPMs of 1,200+ are recommended for the same reason. Engine starts were straight- forward, and taxiing the big twin was easy. The steering system uses direct linkage to the nosewheel, and any need for differential power is limited to the tightest of turns only.
Author Matt McDaniel in the left seat, and owner Brett Zefting in the right
Normal takeoffs are accomplished using flaps up and full power, achieved at 3,400 engine RPM. Noise is far less than you might imagine, thanks to prop RPM being 36% slower. The TwinBo’s big wing will want to fly slightly before the 90 mph Vmc (minimum control speed or the lower redline).
So, immediately after liftoff, climb should be shallowed to allow speed to quickly build above Vmc and toward the 110 mph Vyse (best rate of climb single engine speed or blue line). This will allow sufficient control and the best climb performance should one engine decide to go silent. For even
shorter takeoff distances, half-flaps are used and retracted once speed is safe and obstacles cleared.
The first power reduction is a big one. Pull the prop controls to reduce engines below the 3,100 RPM caution range, keeping the engines loaded. Manifold pressure can then be reduced accord- ingly. The big girl climbs out easily, far lighter on the controls than her size would imply. Pilot work- load is very low compared to most piston twins. The T-Bone’s pressure carburetors are altitude- compensating, meaning mixtures don’t require adjustments during climb. The big cowlings lack cowl flaps to fiddle with, and there is no pressur- ization to monitor.
Twin engine maneuvers are a pleasure to fly. The airplane goes exactly where you point it. It displays no bad characteristics in steep turns or slow flight, and control harmony is excellent. The manual trim wheels are centrally located below the power quadrant, but I would not call them conve- nient. Beechcraft’s big throw-over yoke mechanism is in the way of anything below or behind it, which the trim wheels are. A bit of working around it is required, but it’s manageable. Single engine handling proved docile, all the way down to Vmc. Granted, with just Zefting and myself aboard, we were well below maximum gross weight and well forward of the aft C.G. limit. Thus, even with the
March 2024 / TWIN & TURBINE • 21
PHOTO COURTESY OF DWIGHT BARTON.