What happened
On 26 August 2003, an Avro 146-RJ100, registration G-CFAD, was performing a passenger flight from Glasgow to London City Airport. During the final stages of the ILS approach to Runway 10, which features a characteristic 5.5° glideslope, the aircraft began to descend below the established path.
As the aircraft approached the threshold, the commander attempted to correct the descent by increasing the pitch. However, this maneuver increased drag without a corresponding increase in engine thrust, causing the airspeed to decay. At approximately 100 feet altitude, the thrust levers were moved to idle. This reduction in power, combined with the existing loss of speed, resulted in the aircraft touching down at 107 kt, which was 8 kt below the required approach speed. To arrest the resulting sink rate during the landing flare, the pilot reached a pitch attitude of 7.82 degrees, causing the tail of the aircraft to scrape the runway.
The investigation
The AAIB investigation examined the aircraft's flight data recorder and cockpit voice recorder, alongside physical inspections of the aircraft and the runway. The investigation found that the aircraft's lower rear fuselage and tail bumper strip had sustained significant abrasion and structural damage, including buckled internal frames.
Analysis of the flight data revealed that while the aircraft was stable at 500 feet, it began to deviate below the glideslope at 280 feet. The investigation established that the crew had correctly configured the aircraft for the steep approach, but the loss of airspeed was not adequately managed. The investigation also noted that the co-pilot observed the low airspeed at 100 feet but did not issue a warning, assuming the speed was acceptable for that stage of the approach.
Findings
- The primary cause of the accident was the lack of sufficient thrust during the latter stages of the approach, which allowed the airspeed to decay.
- The loss of speed was further aggravated by the early reduction of thrust during the landing flare.
- The high pitch attitude required to compensate for the sink rate exceeded the manufacturer's limit for avoiding a tail strike.
- The commander's awareness of the airspeed loss was insufficient, a situation compounded by the co-pilot's failure to alert the handling pilot to the speed deviation.
- The inherent challenges of the steep approach at London City Airport contributed to the difficulty in maintaining the correct flight profile.