Cessna Aircraft expects to finish American Society of Testing and Materials (ASTM) compliance testing of the latest iteration of its 162 SkyCatcher light sport aircraft (LSA) "soon" despite a month-long furlough of its production workers from 19 June to 19 July.
ASTM self-certification takes the place of formal US Federal Aviation Administration certification for LSA aircraft.
Pilots and engineers are flight testing the two-seat single each day at Cessna's Mid-Continent Airport facility in Wichita to prove out design modifications developed to improve the aircraft's spin recovery after two accidents that destroyed the first two prototypes.
Cessna has more than 1,000 orders for the 162 SkyCatcher light sport aircraft
Earlier this year, Cessna increased the size of the aircraft's vertical tail, decreased its sweep and removed the dorsal fin as a remedy for power-on spin recovery issues revealed during testing in September.
A second prototype, with the updated tail, crashed in March during power-on stalls.
Although there was speculation that the spin tests that led to the crashes were outside the bounds of ASTM rules, the standards state that a manufacturer must demonstrate that its aircraft cannot obtain an uncontrollable spin regardless of the mode of entry, says Adam Morrison, part-owner of light aircraft consulting firm Streamline Designs.
"Cessna's testing was certainly not out of scope of the ASTM standards," says Morrison, who is also chairman of the ASTM committee that oversees fixed-wing standards.
For the test that led to the second SkyCatcher accident, Cessna's own testing protocol required the pilot to pull the recovery parachute after a certain number of spins regardless of whether the aircraft would have recovered on its own.
A third prototype, with what Cessna says is a larger vertical stabiliser and single strake on the bottom aft portion of the fuselage, is now in the testing programme and is likely to finish its ASTM compliance review this summer - nearly a year later than originally expected.
The company has more than 1,000 orders for the LSA, priced at $111,500 before options.
Cessna has given priority to the aircraft despite tough conditions.
In April, the company announced it would lay off 1,600 staff and implement the furlough to match production with decreased demand.
In addition to the SkyCatcher work, teams also continued with the certification programme for the CJ4, Cessna's $8.4 million six-seat light jet, during the furlough.