Thursday, March 1, 2007
Liberty XL2: Trainer With A Difference
Cross-country comfort and performance enter the two-seat, flight-training class
Two-seat general aviation airplanes have had a checkered career at best. For every Cessna 150/152 or Citabria that’s had a model run of 30 years, there have been a half-dozen other types that only lasted for three or five.
From the pilot’s perspective, FADEC is totally transparent. Once you start the engine, you merely push forward to go and pull back to stop. FADEC does the rest.
Engine health reads out through a Vision Microsystems VM1000 that serves as an EICAS—airline speak for Engine Instrument Crew Alerting System. The system reads power in percentages, and it automatically warns the pilots if any parameter approaches tolerance limits.
Climb into the cabin through the twin gull-wing doors, and you’ll find a space that’s surprisingly roomy for what we’ve come to expect from a two-place machine. Old-generation two-seaters, such as the Skipper, 152 and Tomahawk, made do with internal cross sections of 40 inches or less. In stark contrast, the Liberty offers a comparatively huge cabin that measures 48 inches at the elbows. Cabin height also is a generous 46 inches. Liberty claims the cabin can accommodate a pilot and passenger as tall as six feet, six inches. The idea was to offer more than just barely enough room. This is, after all, supposed to be a “sport touring” airplane rather than strictly a trainer, so you should be able to sit in it for longer than an hour without feeling claustrophobic.
Control and panel layout is reasonably conventional—a stick for roll and pitch and the usual pedals for yaw control. One interesting variation for ground control is finger brakes. The nosewheel is full-castering, but rather than mounting toe brakes for differential braking, the Liberty utilizes two small levers on the center console that work exactly like toe brakes except with the first two fingers of the pilots’ inboard hand. There’s nothing especially difficult about the system, but you can’t help wondering what was wrong with the more conventional toe brakes. The throttle is center-mounted, so it’s not a major trick to have your outboard hand on the stick and control both brakes and power with the inboard hand. Still…
With FADEC on the job, engine starts are nearly guaranteed the first time every time. Taxi is similarly simple, and the airplane is ready to fly nearly as soon as you are. Push power full forward for takeoff, and acceleration is better than you might have expected. That’s partially a simple function of power loading. The XL2 sports 125 hp to lift only about 1,650 pounds; the Skipper, 152 and Tomahawk all employed 115 hp or less to do roughly the same job.
Accordingly, the XL2 records the shortest takeoff distance in the class, 750 feet. Climb typically settles in at about 700 fpm, and the little wing keeps on keeping on to a service ceiling of 14,000 feet.
On the way uphill, you can’t help but notice the XL2’s excellent visibility. The windshield is wide and tall, and side windows in the clamshell doors wrap well back past the pilot and copilot shoulders, opening up the view to the top and through at least the front 240 degrees. It’s not quite as open as a bubble canopy, but that’s probably just as well. The overhead and side post structure provides shade that’s sometimes missing with a sliding hatch.
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