Event Description
The pilot reported that while in cruise flight, a loud noise was heard, followed by air entering the cockpit. The pilot initially reduced power, unsure of the problem. After visually inspecting the aircraft and finding no apparent issues, power was added. However, the pilot was unable to maintain altitude and noticed directional control problems. During the forced landing, the aircraft nosed over onto its back.
Investigation Findings
The investigation determined that the fabric at the top of the outer windscreen had separated, creating a large scoop area. Additionally, Airworthiness Directive 74-17-04, which required the installation of Piper Service Kit # 754-404, had not been complied with.