Amateur-built RV12 N666BE accident near Chadron, Nebraska

Probable cause

The pilot’s failure to properly secure the latch to the tip-up canopy before flight, which resulted in the canopy opening on takeoff and a subsequent loss of airplane control while attempting to land the airplane.

NTSB analysis

The pilot stated that, just as the airplane became airborne after takeoff, the tip-up canopy popped open about 3 inches. The pilot grabbed the canopy with his hand and simultaneously lowered the airplane's nose and partially reduced power in an attempt to land on the remaining runway. The airplane nosed over, and the pilot lost grip of the canopy when it "opened to the full vertical position," which caused the airplane's nose to further pitch over. He applied back pressure on the control stick; however, the elevator and rudder did not respond. He was able to level the wings before the airplane landed hard on all three landing gear.

A postaccident examination of the airplane revealed that the canopy latch operated normally except for some slight resistance when locking the latch into the detent position. The pilot stated that the canopy latch was hard to latch and that he most likely did not secure it properly. The airplane's kit manufacturer reported that it had not conducted any testing on the aerodynamic effects of the airplane's canopy opening in flight; therefore, it could not contest the pilot's claims that the canopy opened to the fully open/vertical position. However, the kit manufacturer did report that it has had a "reasonable amount" of field experience with tip-up canopies opening in flight on similar model airplanes in which no loss of control was reported and that, "While the extent that a canopy tends to open will vary with airspeed, it is our experience that a tip-up canopy will open to a point where the aerodynamic equilibrium is reached...at which point the canopy's position will stabilize." However, because the airplane was in the process of landing, it is likely that the canopy position did not have a chance to stabilize before touchdown. This accident was the first reported instance where pitch authority was affected from a canopy opening in flight on any model equipped with a tip-up canopy, and a lack of flight test data precluded a determination of the aerodynamic effects on the airplane's elevator and rudder if the canopy fully opens during landing.

Text from the NTSB. Open the NTSB docket for CEN13LA340 for the full record.