Incident
On 29 April 1998 at 0630 hours UTC, a Boeing 767-31K, registration G-DAJC, operated a positioning flight from Manchester to Birmingham International Airport. The aircraft landed on Runway 15 at 0700 hours and was cleared to taxi to Stand 56. As the aircraft approached the stand, the Safegate Docking Guidance System (DGS) displayed flashing lower green lights and a 'STOP SHORT' message on the upper display. The captain taxied slowly along the centerline, observing two ground crew members and an engineer. A bump was felt, and the aircraft was brought to a halt. The port engine nacelle became wedged under the airbridge, and minor damage occurred to the left engine cowling and left leading edge slats. There were no injuries to the 11 crew and 2 passengers.
Background
Stand 56 was equipped with a Safegate DGS and a fixed nose loader airbridge. A Movement Area Safety Unit (MASU) Instruction, dated 24 August 1997, governed use of the stand by Boeing 767-300 aircraft. On 19 February 1998, Airfield Management instructed handling agents that they were responsible for marshalling and setting the DGS. The day before the incident, Apron Control allocated the stand to the handling agents. At 0755 hours on the day of the occurrence, Apron Control reminded the handling agent that a marshaller was required and that the aircraft must stop short and be towed forward. However, no marshaller was present when the aircraft arrived. The airbridge operator had previously selected 'STOP SHORT' on the DGS panel. As the aircraft moved along the stand centerline, the ground engineer waved his arms to signal the aircraft to stop. The aircraft overran the paint mark indicating the nosewheel position for a Boeing 767-300 by 3.3 meters. Neither the airbridge operator nor the engineer used the DGS emergency stop buttons.
Docking Procedures
Information on Safegate DGS procedures was available to flight crew via Jeppesen publications and to ground staff via an Airport Operational Instruction (AOI). The Aeronautical Information Publication (AIP) and Civil Aviation Publication (CAP) 637 also described DGS types. The Jeppesen documentation described the green lights and messages but did not include the 'STOP SHORT' message. In contrast, CAP 637 and the AOI stated that the 'STOP SHORT' signal appears on the top panel if an object is left on sensors or if the aircraft stops short of the current stopping point.
Aftermath
Stand 56 had been used 32 times for Boeing 767-300 aircraft in the previous two years without incident. Following the incident, engineering staff inspected the airbridge and declared it fit for use. The DGS was taken out of service because three induction loops were inoperative, but this did not affect the 'STOP SHORT' indication. The two emergency stop buttons were found serviceable. The CAA proposed to amend CAP 637 to include a description of the 'STOP SHORT' function as a manual operation for use when ground staff wish the aircraft to stop short of the normal stop position.