ERA10LA004 · Piper PA-32R-300

The pilot reported a complete loss of electrical power and that he was unable to lower the landing gear as a result. Several attempts to lower the landing gear using the emergency procedures published in the Pilot’s Operating Handbook were also unsuccessful. A mechanic and the pilot reviewed the procedure by cellular telephone as the airplane circled over the airport, but the landing gear would not deploy. After an estimated 90 minutes of maneuvering and troubleshooting, the pilot announced that he would land the airplane with the gear up. According to the mechanic, the airplane was at low altitude over the approach end of the runway when the pilot “chopped the power.” He said, “He chopped the power too high, and didn’t have enough ‘flare speed’ and hit the runway pretty hard.” Examination of the airplane at the scene revealed substantial damage to the firewall, fuselage, and empennage structures. Detailed examination of the airplane by the mechanic and Federal Aviation Administration inspectors revealed that the air conditioning compressor had seized, the compressor belt had broken, which then fouled the alternator belt. Once the alternator belt broke, the battery power was exhausted, and the airplane experienced a complete electrical failure. Examination of the landing gear revealed that with electrical power applied, the landing gear would operate as designed. With electrical power removed, the “emergency down valve” which allowed the gear to free-fall into position, would not release the hydraulic pressure to allow the gear to lower. Instead, the pressure was released by opening a hydraulic line, and the gear then lowered as designed. The emergency down valve was found with blockage. The aircraft manufacturer calls for the landing gear system to be tested each 100 flight hours. The last inspection was performed 10.5 months and 20 flight hours before the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset