Background
On 29 March 2005, at 1819 UTC, an Avro 146-RJ100 (registration G-CFAH) operated by a public transport airline was conducting a passenger flight from Geneva to London City Airport. The crew consisted of five members and there were 104 passengers on board. No injuries were reported, and the only damage was to the tail protection strip.
History of the Flight
The crew had rested for over 14 hours before reporting for duty. The aircraft departed Geneva at 1650 hrs, and this was the third sector of the day for the crew, with this being their second landing at London City Airport. The crew had briefed for a monitored ILS approach to Runway 10, with the first officer (FO) as pilot flying. The operator's procedures required that landings at London City be flown by the aircraft commander, who would take control when sufficient visual references were acquired.
The aircraft was vectored by ATC onto an intercept heading for the ILS localiser. The autopilot and autothrottle were engaged, with landing gear down and flaps set to 33°. As the aircraft intercepted the 5.5° glideslope, the airbrake was selected. At 500 ft radio altitude (RA), the approach was confirmed stable. At 400 ft RA, the commander sighted the runway lights through rain, took control, and disconnected the autopilot and autothrottle.
The speed remained at 127 kt until 200 ft RA, when the FO noted an increasing trend. The commander reduced thrust by about 1% N1, in addition to the automatic 2% reduction from the FADEC upon autothrottle disconnection. Two to three seconds after the 100 ft RA call, the commander reduced thrust further to achieve a touchdown speed of 115 kt. The FO observed a momentary drop to 120 kt IAS, then acceleration through 122 kt. At about 60-70 ft RA, the commander noted a high rate of descent and began the flare at 40-50 ft RA. The FO saw 117 kt IAS during the flare with a higher than normal descent rate and sensed a ground-rush. The touchdown was heavy, but the aircraft stopped within the available runway length. ATC suspected a tail scrape and initiated a runway inspection, which revealed contact with the tail protection strip. The flight crew were unaware of the damage.
Weather Conditions
The synoptic situation at 1800 hrs showed low pressure and associated frontal systems moving east along the English Channel. The area experienced light rain with surface visibility of 2,000 m, an overcast cloudbase at 400 ft, and QNH 1011 hPa. The TAF for London City Airport between 1600 and 2200 hrs forecast surface wind 070°/10 kt, visibility 2,000 m in mist, overcast at 500 ft temporarily lowering to 400 ft, with temporary rain. The METAR at 1820 reported surface wind 060°/09 kt, visibility 2,000 m in light rain, overcast at 400 ft, temperature 7°C, dewpoint 7°C, pressure 1011 hPa.
London City Airport
London City Airport has a single concrete runway, 28/10, 1,508 m long and 30 m wide. The Landing Distance Available for Runway 10 is 1,319 m, with a threshold elevation of 16 ft. The touchdown zone end is marked by pairs of white high-intensity lights 360 m from the threshold. PAPIs are set to a 5.5° approach angle, matching the ILS glideslope.
Flight Recorders
The aircraft was equipped with a solid-state flight data recorder (FDR) and cockpit voice recorder (CVR). Data from the incident approach were compared with a normal landing earlier that day by the same crew in the same aircraft. The final descent started from 2,000 ft RA, two minutes before touchdown, with flaps at 33°, gear down, and airbrake deployed. Speed varied between Vref and Vref+5 kt CAS. For the incident approach, data from 18 seconds before touchdown showed the aircraft on glideslope at 320 ft RA, 127 kt CAS, descending at about 1,200 ft/min with 58% N1. The autothrottle remained engaged until 300 ft RA, 17 seconds before touchdown.
Manufacturer and Operator Guidance
The aircraft manufacturer issued a Flight Operations Bulletin in June 1989 covering tail strike risk, applicable to the RJ100 variant. It stated that a tail strike on landing could only occur with a late flare from a high sink rate, resulting in a heavy landing, with a pitch incidence of about 8° and descent rate exceeding 10 ft/sec on the -300 variant. The operator's Flight Operations Manual, Part B, provided guidance on steep approach and landing. It noted that speed control is crucial, and a high-speed approach must be avoided. The most common cause of a tail strike on landing was a fast approach leading to prolonged flare and increased ground closure rate. The manual advised that attempting to reduce descent by additional flaring would not reduce the rate of descent and could cause a tail strike.