Description

On 15 June 2006 a Boeing 737-300 being operated by Belgian Airline TNT on a public transport scheduled service cargo flight from Liège to London Stansted had diverted to Nottingham East Midlands because of deteriorating weather at the intended destination. A Cat 3A ILS approach in daylight and Instrument Meteorological Conditions (IMC) at East Midlands was interrupted when the aircraft was at about 500 feet aal by ATC passing on a Company Message that the flight was to divert to Liverpool instead. The aircraft commander elected to respond to this message and in doing so inadvertently mis managed the aircraft, still in IMC and lost situational awareness. After an EGPWS ‘Pull Up’ Warning and sight of grass ahead through the fog which prevailed, the aircraft touched down with a high rate of descent on the grass 90 metres to one side of the runway paved surface whilst a go round was being initiated. The RH MLG assembly broke off before the aircraft left the ground again and it was then flown to nearby Birmingham for a successful emergency landing.

Investigation

An Investigation into this Accident was carried out by the UK AAIB. It was found that the aircraft ILS approach to Runway 27 at East Midlands had been a CAT IIIA approach because of the poor conditions. This CAT IIIA approach, with the aircraft commander as PF, was the first he had flown in actual Cat lll conditions since his promotion from co‑pilot some four months earlier and was uneventful until approaching 500 feet aal. At this point, ATC transmitted the ‘Company Message’ to the effect that the Operator wanted the aircraft to go to Liverpool rather than East Midlands and advised that, at the discretion of the crew, they could go-around.

It was considered that “the commander’s attempt to respond to, and clarify the contents of, the call from ATC, late in the approach, was an inappropriate action for the Pilot Flying”. In his attempt to clarify the ATC message, the commander inadvertently disconnected the autopilots and his attempt to re-instate them whilst talking to ATC was considered to have been an inappropriate action not in accordance with the company CAT III SOPs. In fact, the attempt to reinstate both autopilots was only partially successful, with only one being restored and this only in pitch and roll. The aircraft commander did not initiate a go-around until the EGPWS sounded a hard warning of “SINK RATE PULL UP” at a radio altimeter height of between 87 feet and 59 feet and he saw the green colour of the grass ahead. This go-around was initiated too late to prevent the aircraft striking the ground and it made contact in the sterile grassed area to the left of Runway 27, abeam the threshold. During the ground contact, the right main landing gear detached from the wing, causing damage to the right flaps and the loss of one of the hydraulic systems. On striking the ground, there was a short period of confusion on the flight deck, after which the commander resumed control and the aircraft was climbed away. The flight crew had no knowledge of where the aircraft had struck the ground.

The aircraft was flown to Birmingham Airport with the nose and left landing gear remaining down and with the trailing edge flaps stuck at 32° and 40° left and right respectively which produced a tendency to roll left. The Runway 15 ILS GS transmitter at Birmingham remained switched off following earlier maintenance and the aircraft commander decided to accept a longer route in order to be able to carry out a full ILS approach for Runway 33. The longer route to Runway 33 allowed an opportunity for the police helicopter to inspect the aircraft but in order for this to be done, the damaged aircraft flew over the city of Birmingham. The inspection by the police was helpful to the flight crew and a successful partial gear up emergency landing was then made at Birmingham.

The emergency landing at Birmingham International Airport on 15 June 2006 - the video was shot by from a Police helicopter:

The Investigation considered that “For a short period during the approach into EMA, the commander lost situational awareness, following inadvertent disconnection of the autopilots, and allowed the aircraft to descend to an uncontrolled contact with the ground. The analysis of the ground marks to the left of Runway 27 threshold, in conjunction with the damage to the right wing tip, indicated that the aircraft had been close to entering an uncontrollable situation as it slid over the ground, from which it would almost certainly not have recovered. The detached right main landing gear had struck the right inner flaps, the rear fuselage - narrowly missing the horizontal stabiliser - and the aircraft passed very close to the surface movement radar head. It is therefore apparent that a catastrophic accident was narrowly avoided.”

It was noted that during the course of the Investigation, an amendment to the UK Manual of Air Traffic Services Part I was published to advise controllers to ensure that any transmission of a Company Message will not compromise safety and will not cause a distraction to pilots at a critical period of flight. The AAIB comment was that “any approach in weather conditions which require an automatic landing should be considered a critical period of flight.”

Causal and Contributory Factors

The Investigation found that the following were Causal Factors:

• ATC inappropriately transmitted a company R/T message when the aircraft was at a late stage of a CAT III automatic approach.
• The commander inadvertently disconnected the autopilots whilst attempting to respond to the R/T message.
• The crew did not make a decision to go-around when it was required under SOPs after the disconnection of both autopilots below 500 ft during a CAT III approach.
• The commander lost situational awareness in the latter stages of the approach, following his inadvertent disconnection of the autopilots.
• The co-pilot did not call ‘go-around’ until after the aircraft had contacted the ground.

It also found that the following were Contributory Factors:

• The weather forecast gave no indication that mist and fog might occur.
• The commander re-engaged one of the autopilots during a CAT III approach, following the inadvertent disconnection of both autopilots at 400 ft aal.
• The training of the co-pilot was ineffective in respect of his understanding that he could call for a go-around during an approach

One Safety Recommendation as made as a result of the Investigation:

• that the Kingdom of Belgium Civil Aviation Authority require TNT Airlines in Belgium to carry out a review of their standard operating procedures to ensure that it is clear to all pilots when go-around action is required. [2008-010]

The Final Report of the Investigation was published in 2008 and may be seen in full at SKYbrary bookshelf:Aircraft Accident Report No: 5/2008 (EW/C2006/06/04)

Further Reading

• Runway Excursion
• Rejected Landings
• Go-around from Low Airspeed/Low Thrust
• Low Visibility Procedures (LVP)
• Precision Approach
• Situational Awareness
• Pilot judgment and expertise (OGHFA BN)
• Runway Overrun After Unstabilised Approach (OGHFA SE)