Amateur-built ZODIAC 601 XL N315SV accident near Cumberland, Maryland

Probable cause

An inadvertent release of the canopy, which allowing the canopy to open during flight and led to an inflight loss of airplane control. Contributing to the accident was the lack of any safeguard to prevent the inadvertent opening of the canopy.

NTSB analysis

Shortly after departure, the noncertificated pilot and builder of the experimental amateur-built airplane was flying at 1,000 ft mean sea level on the base leg of the airport traffic pattern when the right side of the cockpit canopy suddenly came loose and popped open. This was immediately followed by the left side of the canopy opening and then the entire canopy opened. The pilot stated this open canopy acted like a “giant air brake” and the airplane entered a descent that he was unable to arrest. The airplane descended into trees bordering the airport property, which resulted in substantial damage to the airframe.

Postaccident examination of the right side canopy frame and latching mechanism found that although the latch did not show any irregularities or anomalous preimpact damage, the mechanism could easily be opened with slight finger pressure and no safeguard was present to keep the latch from opening prematurely. In addition, the several layers of foam weatherstripping installed along the frame of the canopy may have made it difficult for the latch to become properly seated during closure. Based on this information, it is likely that the latching mechanism was not completely secured prior to the flight or that the pilot inadvertently released the mechanism, with resulted in the canopy opening fully while in the airport traffic pattern, and the subsequent inability to sustain further flight.

Text from the NTSB. Open the NTSB docket for ERA21LA247 for the full record.