Sunday, August 1, 2004
Socata Trinidad GT
A beautiful little French retractable with a certain je ne sais quoi
| By any measure, the sky around us is an aviation mecca. For one week each spring, the weeklong Sun ’n Fun Fly-In brings thousands of flying machines and several hundred thousand people to warm, comfortable central Florida.|
If there is any significant wind-blowing, the doors can blow down unexpectedly, or the hinges may be warped by a gust of wind. On the plus side, the fiberglass frame doors are almost pure-clear Plexiglas from the pilot’s and copilot’s elbows almost to the tops of their heads. This makes visibility to the sides and up quite exceptional.
A cursory examination of the Trinidad’s wing might suggest the airfoil is a standard Hershey-bar design. Hardly. Although there is nothing terribly unusual about the wing, it was computer-designed specifically for the Trinidad. Goals were predictability and safety, and Aerospatiale achieved those goals in spades.
For the aerodynamicists among you, the small, rectangular, 128-square-foot wing is a constant-chord, RA16-3C3 airfoil with 6.5 degrees of dihedral, conventional in shape and Cherokee-like in configuration, but it provides the Trinidad with a comparatively high 24.1 pounds per square feet of wing loading. High wing-loading lends itself to a smoother ride in turbulence. It’s hard to imagine a more docile high-performance retractable airfoil. In combination with 250 hp out front, the wing generates sea-level climb in excess of 1,000 fpm.
The TB-20’s empennage also is a little different, featuring totally separate horizontal and vertical tail surfaces with the lower, all-flying stabilator mounted well aft of the vertical. The rudder is reasonably effective, but hardly necessary for coordination of most normal maneuvers.
In addition to their obvious visual appeal, the TB-series airplanes benefit from high-tech applications of aerospace construction techniques and equipment that make the airplane simpler rather than more complex. The Caribbean singles are built at Socata’s ultramodern Tarbes, France, facility. Parts are manufactured on the same numerical control machines used to subcontract components for Airbus airliners, Falcon business jets and Eurocopters. With the help of its advanced design and automated manufacturing equipment, Socata realizes economies not possible for other builders. The company puts together the fixed-gear Tobago’s 800 parts in only about 600 labor hours. The more complex, retractable Trinidad is slightly more labor-intensive, but still far less time-consuming than other, comparable airplanes.
Power for the Socata Trinidad GT is provided by a 540-cubic-inch Lycoming engine, specifically, the IO-540-C4D5D, derated to 250 hp. This is essentially the same engine that was used so successfully in pairs on the old Piper Aztec, so it’s a well-proven powerplant, under-worked and rated for 2,000 hours between overhauls. It’s interesting that Lycoming uses the same block to produce up to 350 hp for applications such as the Piper Navajo Chieftain.
Max takeoff weight is listed at 3,080 pounds (1,400 kg in European-speak), and a typical empty weight runs about 1,900 pounds. The test airplane had the optional air conditioning, which probably boosted empty weight by at least 50 pounds and price by an additional $18,000. In other words, there is a payload-per-price penalty for the privilege of a cool cabin on the ground.
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