Plane & Pilot
Tuesday, February 11, 2014

A Retro Comeback LSA


Thierry Zibi’s new S-LSA embraces pseudo-military design


The designer has gone a step further in customizing his unusual LSA. If you're into a more au naturel look, Zibi has fitted the airplane with a removable canopy. Everything above the waist except the windshield comes off in a few minutes, a standard feature on all SAM LSAs.

Flaps are electrically continuous, 35 degrees worth, with a nifty indicator on the right subpanel. Four steam gauges provide backup to the Dynon; VSI, altimeter, ASI and turn and bank, right to left. Fuel selector is on the right floorboard to advise of up to 11 gallons a side, but Zibi wisely sticks the tanks every time he flies so he'll know exactly how much 100LL is on board. The airplane burns 4.5 gallons an hour at 75% power, and you can plan trips of four hours with a reasonable reserve.

Today, we're out to explore the SAM's flight envelope, nothing exotic, just steep turns, stalls power on and off and some landings at nearby Parker Airport, a few miles west of Fort Worth. My first takeoff in the SAM is perhaps strangely reminiscent of a much larger, more powerful airplane.

Designer Zibi configured the fuselage with a two-degree negative angle of attack, so it's necessary to perform a positive rotation rather than wait for the wing to gain lift and rotate by itself. Leave the stick forward on the ground above about 50 knots, and the wing will actually begin to create a downforce.

This is a characteristic of several twins, most notably, the Aerostar. Fail to rotate the wing to a slight-up angle, and the Aerostar will happily drive right off the end of the runway.

In my case, I started the joystick aft at about 50 knots, and the SAM promptly hopped off the runway and began a leisurely climb. Zibi's test specs suggest ascent slightly better than 800 fpm, but that wasn't in the cards on the day of my flights, partially because the SAM was using a borrowed wooden prop in place of the normal, all-composite Sensenich, and the spinner was missing, as well. I'd bet further flight tests will reveal that takeoff flaps, perhaps 10 degrees, provide good climb without rotating the nose quite so high and blocking the view forward.

We were vectored to the west out of the Meacham control zone to keep us away from inbound AOPA Summit traffic. We chose a small uncontrolled strip 20 miles west of Fort Worth for our landings.

On the way out, I elected to try some stalls and miscellaneous maneuvers. Zibi assured me the test pilot he hired to do the shakedown flights tried everything he could think of to induce a spin and couldn't get into anything more exotic than a hobby-horse-bucking side slip, similar to a Cherokee's reaction at the bottom of the envelope. I tried stalls, power on and off with no flaps and full flaps, and my maneuvers tended to corroborate the test pilot's conclusions. No matter what I did, I couldn't get the SAM mad at me.



Labels: LSAs

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