Wednesday, September 9, 2009
Gobosh 800XP: Flying With Composites
It has been five years since the FAA approved the first LSA. Here’s one of the latest and most innovative entries in the class.
The Gobosh 800XP features a composite design. Its 45-inch-wide cabin comes standard with a dual-screen Dynon glass panel and Garmin’s 495 GPS, SL 40 COM and GTX 327 transponder.
A design from the Kabrt brothers of the Czech Republic, the 800XP represents one of the more aesthetic designs in the industry, partially a function of composites. It’s a faired and swept low-wing single with rakish looks, spiffily spatted wheels and a traditional horizontal stabilator. The earlier 700S proved a quick and capable little airplane, so I was curious what could be different about the 800XP (besides the use of composites).
The major change between the 700 and 800 is control response, in spades. The 700 is a nice-handling airplane with no bad habits that’s pointed directly at the training market, but the 800 is directed more at the sport-flying buyer. Aileron and elevator response is right now, with practically no slop. Pitch and roll reactions are much quicker than on any other LSA I’ve flown. Aileron inputs, always the most dynamic, almost seem aerodynamically assisted by aileron shovels (à la Pitts S2C). In fact, the airplane cries for aerobatic certification.
The two aircraft offer fairly comparable performance. With the longer wing, you might expect the 800XP to fly slower, but the opposite is the case. The 800 climbs at 1,050 fpm, and the 700 at 850 fpm. Gobosh lists the 800’s cruise spec at 119 knots against the 700’s 116 knots.
In fact, both the latter numbers are under perfect conditions with all vents closed, the CG at the aft limit, the moon in the proper phase and all your biorhythms at their peak. In the normal world, you should see a realistic 112 to 115 knots from the 800 under reasonable conditions. Pilots in less of a hurry may throttle back to 65% and drift along at an easy 105 knots.
Endurance is one area where you might not logically expect big numbers, but the 800XP, with its larger fuel tank, boasts very respectable reach. Fuel consumption with the little 912 Rotax is about 3.8 gph. Round up the book burn to 4 gph, and you have an easy six hours of endurance on the 800XP (31⁄2 hours on the 700S). At a block 110 knots, the 800XP offers 730 nm between restroom breaks—Albuquerque to Houston, Chicago to New Orleans, or St. Louis to Philadelphia.
True, you might not want to sit in any little airplane for that long, but at least you could take some consolation that you’d only burn about $100 worth of avgas on such a trip. Remember, too, that the 700S and 800XP are both approved for mogas, reducing the cost by perhaps another 20%.
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