Incident Overview
On 5 November 1999 at 1110 hours UTC, a Boeing 737-4Y0 aircraft, registered G-OBMF, was involved in a ground incident at London Heathrow Airport. The aircraft was parked on Stand B2, which is situated at the end of a cul-de-sac. The pushback procedure required the aircraft to be turned through 90 degrees in one direction, followed by a 180-degree turn in the opposite direction before being released for movement under its own power.
Sequence of Events
The initial pushback appeared normal to the flight crew. However, towards the end of the 180-degree turn, a series of 'thumps' were heard before the aircraft came to rest. Radio communication with the ground handlers revealed that the tug had struck the underside of the aircraft. Subsequently, a replacement tug driver was called, who towed the aircraft back onto the stand.
Investigation Findings
An investigation was conducted by the Ramp Safety and Training Manager. The conclusion was that the tug driver had attempted to turn too tightly. The driver had been cleared for solo towing operations since September 1999. Following this incident, the driver received retraining, after which he underwent a practical test and was subsequently cleared to resume towing duties.
Damage and Injuries
The incident resulted in damage to the aircraft's radome. There were no injuries to any of the 9 crew members or 117 passengers on board. The Commander held an Airline Transport Pilot's Licence and was 37 years old, with a total flying experience of 4,141 hours, of which 3,236 were on type. In the last 90 days, he had flown 123 hours, including 42 hours in the last 28 days.
Conclusion
The investigation determined the cause of the incident to be the tug driver attempting to turn too tightly during the pushback maneuver.