Landing Gear Retraction During Landing Leads to Aircraft Damage

Casualties unknown • Aerodrom „Vojka“, opština Stara Pazova, RS

A Piper PA-34-200T experienced an electrical failure and subsequent landing gear collapse during an approach at Vojka Aerodrome.

What happened

On July 31, 2021, at approximately 08:30 LT, a Piper PA-34-200T, registration LZ-TLU, departed from Vojka Aerodrome, Serbia, for a technical flight to Belgrade, with a planned continuation to Podgorica, Montenegro. Shortly after takeoff, the pilot reported the failure of the first GNS 430 radio transmitter, followed minutes later by the failure of the second GNS 430 unit. The pilot contacted Belgrade control via mobile phone to declare the communications failure and requested a return to the departure airfield.

During the return approach to Vojka, the aircraft suffered a total electrical failure, causing all cockpit instruments to go dark. Following standard checklists, the pilot extended the flaps and landing gear. Due to the lack of electrical indications, the pilot performed a visual inspection and confirmed the nose gear was extended. However, upon touchdown, the landing gear retracted. This caused the propellers of both engines to strike the ground, resulting in the aircraft sliding on its fuselage until it came to a halt.

The investigation

The CINS investigation focused on the sequence of electrical failures and the mechanical state of the landing gear. Investigators examined the aircraft battery, alternators, and the landing gear hydraulic and kinematic systems. Testing revealed that the aircraft battery had been depleted to 4 volts, likely due to being left in a discharged state for several days following the accident, which caused internal cell damage.

Regarding the electrical system, investigators tested both alternators using an external power unit and an electric motor to simulate engine operation. The tests confirmed that both the left and right alternators and their associated electrical installations were fully functional. The landing gear system was also inspected; despite finding soil and grass debris in the nose gear door mechanism, the hydraulic pump, hydraulic system, and the gear retraction/extension mechanism were found to be in proper working order and capable of functioning correctly.

Probable cause

The **failure of the pilot to engage the alternators** led to the depletion of the aircraft battery and subsequent total electrical failure. This was compounded by the pilot's failure to follow established emergency procedures for handling such failures.

Frequently asked questions

What happened in the 2021-07-31 Piper PA-34-200T accident near Aerodrom „Vojka“, opština Stara Pazova, RS?

A Piper PA-34-200T experienced an electrical failure and subsequent landing gear collapse during an approach at Vojka Aerodrome.

What aircraft was involved and where did it happen?

The accident on 2021-07-31 involved a Piper PA-34-200T, registration LZ-TLU, at Aerodrom „Vojka“, opština Stara Pazova, RS.

What was the probable cause of the accident?

The **failure of the pilot to engage the alternators** led to the depletion of the aircraft battery and subsequent total electrical failure. This was compounded by the pilot's failure to follow established emergency procedures for handling such failures.

Loading the flight search…