What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The flight began at approximately 10:05 and started with engine start and ground ops checks associated with the production flight test. Ari springs were noted to be stiff making taxi difficult while holding the stick.
Normal takeoff with evaluation of aileron trim was normal, a low approach was executed with a departure south.
During the climb data gathering, the instructor noticed airspeed was off and called out airspeeds a couple of times, but could not see the forward airspeed indicator. During the stall tests, the crew again noticed a discrepancy in airspeeds between the numbers indicated on fore and aft instruments.
During the stall series of tests, ari spring tension was noted to be high, causing wing low stall recovery to be problematic as rudder inputs would also drop an aileron,
While briefing the high speed tests, the crew noticed that the airspeed markings had discrepancies, but did not think that the calibration would be off. The tests were normal and uneventful, and returned to the airport.
The approach to runways 23 was normal. The instructor noticed that the speeds were low on final but seemed to be reasonable for a 3 point landing. The aircraft was in a good attitude for a 3-point landing but started sinking rapidly over the threshold and the aircraft made a hard 3-point landing and bounced. The PIC executed a go-around at this point. The crew communicated about the landing and discovered that the airspeed indicator discrepancy was a lot worse in slow speed landing conditions than it was at altitude and with higher speeds.
The instructor called out airspeeds throughout the pattern and subsequent approach and they used the lower of the two speeds indicated for safety margin. The PIC landed in a 3-point attitude on the center of the runway and made comments about how bad the ari springs were affecting his control. The aircraft began to drift to the right of the runway, and as PIC made corrections back to the left, the tailwheel became unlocked (or perhaps was unlocked from the previous landing) and the aircraft departed the runway to the left with a ground loop resulting. The right wingtip was damaged. Aircraft was taxied back to the ramp under its own power and subsequent inspection found that the forward airspeed indicator is a T660 model, not the correct one for the 510.
As the FAA filed it
THE FLIGHT BEGAN AT APPROXIMATELY 10:05 AND STARTED WITH ENGINE START AND GROUND OPS CHECKS ASSOCIATED WITH THE PRODUCTION FLIGHT TEST. ARI SPRINGS WERE NOTED TO BE STIFF MAKING TAXI DIFFICULT WHILE HOLDING THE STICK.
NORMAL TAKEOFF WITH EVALUATION OF AILERON TRIM WAS NORMAL, A LOW APPROACH WAS EXECUTED WITH A DEPARTURE SOUTH.
DURING THE CLIMB DATA GATHERING, THE INSTRUCTOR NOTICED AIRSPEED WAS OFF AND CALLED OUT AIRSPEEDS A COUPLE OF TIMES, BUT COULD NOT SEE THE FORWARD AIRSPEED INDICATOR. DURING THE STALL TESTS, THE CREW AGAIN NOTICED A DISCREPANCY IN AIRSPEEDS BETWEEN THE NUMBERS INDICATED ON FORE AND AFT INSTRUMENTS.
DURING THE STALL SERIES OF TESTS, ARI SPRING TENSION WAS NOTED TO BE HIGH, CAUSING WING LOW STALL RECOVERY TO BE PROBLEMATIC AS RUDDER INPUTS WOULD ALSO DROP AN AILERON,
WHILE BRIEFING THE HIGH SPEED TESTS, THE CREW NOTICED THAT THE AIRSPEED MARKINGS HAD DISCREPANCIES, BUT DID NOT THINK THAT THE CALIBRATION WOULD BE OFF. THE TESTS WERE NORMAL AND UNEVENTFUL, AND RETURNED TO THE AIRPORT.
THE APPROACH TO RUNWAYS 23 WAS NORMAL. THE INSTRUCTOR NOTICED THAT THE SPEEDS WERE LOW ON FINAL BUT SEEMED TO BE REASONABLE FOR A 3 POINT LANDING. THE AIRCRAFT WAS IN A GOOD ATTITUDE FOR A 3-POINT LANDING BUT STARTED SINKING RAPIDLY OVER THE THRESHOLD AND THE AIRCRAFT MADE A HARD 3-POINT LANDING AND BOUNCED. THE PIC EXECUTED A GO-AROUND AT THIS POINT. THE CREW COMMUNICATED ABOUT THE LANDING AND DISCOVERED THAT THE AIRSPEED INDICATOR DISCREPANCY WAS A LOT WORSE IN SLOW SPEED LANDING CONDITIONS THAN IT WAS AT ALTITUDE AND WITH HIGHER SPEEDS.
THE INSTRUCTOR CALLED OUT AIRSPEEDS THROUGHOUT THE PATTERN AND SUBSEQUENT APPROACH AND THEY USED THE LOWER OF THE TWO SPEEDS INDICATED FOR SAFETY MARGIN. THE PIC LANDED IN A 3-POINT ATTITUDE ON THE CENTER OF THE RUNWAY AND MADE COMMENTS ABOUT HOW BAD THE ARI SPRINGS WERE AFFECTING HIS CONTROL. THE AIRCRAFT BEGAN TO DRIFT TO THE RIGHT OF THE RUNWAY, AND AS PIC MADE CORRECTIONS BACK TO THE LEFT, THE TAILWHEEL BECAME UNLOCKED (OR PERHAPS WAS UNLOCKED FROM THE PREVIOUS LANDING) AND THE AIRCRAFT DEPARTED THE RUNWAY TO THE LEFT WITH A GROUND LOOP RESULTING. THE RIGHT WINGTIP WAS DAMAGED. AIRCRAFT WAS TAXIED BACK TO THE RAMP UNDER ITS OWN POWER AND SUBSEQUENT INSPECTION FOUND THAT THE FORWARD AIRSPEED INDICATOR IS A T660 MODEL, NOT THE CORRECT ONE FOR THE 510.