What happened
On April 14, 2004, a PIPER 28R-180, registration EC-BNY, was conducting a visual instructional flight between Málaga and Seville. The crew, consisting of an instructor and two students, was preparing for landing at Seville when they noticed that the nose gear indicator light remained unlit, despite the main gear lights being active.
After notifying air traffic control, the crew attempted to extend the nose gear using both standard and emergency procedures. These attempts were unsuccessful. After consulting with another aircraft in flight and considering fuel availability, the crew decided to divert back to Málaga. The aircraft landed at approximately 11:55 h using only the main landing gear. While the airport fire services were on standby, no fire was necessary. The landing caused damage to the engine cowling, the exhaust manifold, and the propeller tips, which made contact with the runway surface. There were 0 fatalities and the crew remained uninjured.
The investigation
Following the recovery of the aircraft, investigators examined the nose gear assembly. They discovered that a cable used to regulate the engine's alternator air intake was caught in the nose wheel hub. Once this cable was released, the nose gear extended fully and functioned normally.
Further inspection revealed that the cable had lost one of its securing zip ties, which was intended to keep the cable away from the moving components of the nose gear assembly. The investigation noted that the inspection of such zip ties is typically performed on an "on condition" basis.
Findings
- The nose gear failed to extend because the alternator air intake cable became entangled in the nose wheel mechanism during the gear deployment sequence.
- The cable had become loose due to the loss of a securing tie that should have prevented interference with moving parts.
- It is probable that the condition of the securing tie was not properly verified during recent maintenance activities.