AAIB investigation to Pierre Robin R2100A, G-BICS

44� Crown copyright 2018 All times are UTC AAIB Bulletin: 10/2018 G-BICS EW/G2018/05/06 ACCIDENT Aircraft Type and Registration: Pierre Robin R2100A, G-BICS No & Type of Engines: 1 Lycoming O-235-H2C piston engine Year of Manufacture: 1977 (Serial no: 128) Date & Time (UTC): 6 May 2018 at 1100 hrs Location: Eaton Bray Farm Airfield, Bedfordshire Type of Flight: Private Persons on Board: Crew - 1 Passengers - 1 Injuries: Crew - None Passengers - None Nature of Damage: Substantial Commander’s Licence: Light Aircraft Pilot’s Licence Commander’s Age: 55 years Commander’s Flying Experience: 876 hours (of which 274 were on type) Last 90 days - 7 hours Last 28 days - 4 hours Information Source: Aircraft Accident Report Form submitted by the pilot Synopsis During takeoff, the aircraft did not attain flying speed and collided with a hedge at the far end of the runway. Performance calculations by the AAIB indicated that, although the ground run required was less than the runway length available, the takeoff distance required exceeded the takeoff distance available. History of the flight The pilot reported that he had planned a flight with a passenger from his home base at Eaton Bray Farm Airfield, Bedfordshire to Sandown Airport, Isle of Wight. The pilot decided to use Runway 29, although it would involve a slight tailwind, as it would be away from buildings close to the threshold of the runway. After completing his checks, the pilot commenced the takeoff roll. The aircraft reportedly reached an airspeed of 40 kt approximately 400 m along the runway, but its acceleration did not continue as expected. The aircraft collided with a 2 m (6.6 ft) high hedge at the far end of the runway at an estimated airspeed of 45 kt. (The rotate speed for this aircraft is 49 kt and the best climb angle speed is 62 kt.) Both occupants, who were wearing four-point harnesses, were uninjured and able to vacate the aircraft unaided. The aircraft was substantially damaged, (Figure 1). 45� Crown copyright 2018 All times are UTC aaib bulletin: 10/2018 G-bics ew/G2018/05/06 Figure 1 General view of the aircraft post-accident The pilot commented that the engine was being operated on condition and, although worn, it appeared to be developing its normal engine speed for takeoff of 2,300 rpm on the day. The aircraft’s flight manual states that maximum takeoff engine power is achieved at 2,600 rpm; the minimum engine speed for takeoff is 2,300 rpm. Previous experience gained over 5 years and 250 takeoffs from the strip had led the pilot to become used to the aircraft’s marginal takeoff performance. His normal procedure was to “pull” the aircraft into ground effect and accelerate away. Later inspection by the pilot revealed that the flaps were fully extended, rather than being set for takeoff. The flaps are usually fully extended when the aircraft is parked, as this allows the occupants easier access to the cockpit. During checks prior to takeoff, the flaps are normally retracted to the takeoff position. The pilot suggested that this omission may have been due to the distraction of having a passenger onboard. Weather information The weather conditions were reported as good; the wind was from the south-east at 0 to 2 kt and the temperature was 20 to 22ºC. Weight and Balance information The pilot’s weight and balance calculations indicated that the aircraft was “heavy” but loaded within limits. 46� Crown copyright 2018 All times are UTC aaib bulletin: 10/2018 G-bics ew/G2018/05/06 Airfield information The runway is orientated 29/11 and has a grass surface. Its condition was reported as dry and newly rolled. The farm’s website states the runway length is 600 yards (549 m). The pilot reported that he had measured the strip and found it to be 615 m long. Measurements taken from aerial imagery of the airfield more closely match the length stated on the farm’s website. Adjacent to the Runway 29 threshold and under the approach path are a parking area and hangars, (Figure 2). Figure 2 View of Eaton Bray Farm Airfield indicating runway length Aircraft performance The aircraft flight manual provides performance information when using a dry, hard runway, full throttle and flaps set to the takeoff position. Data to account for various weights, headwind speeds and elevations is included. It also notes that the distance needs to be increased by 8% for every 10ºC increase in temperature above standard at the altitude concerned and by a further 8% when using a dry grass runway. No factor was stated for a tailwind, but CAA Safety Sense Leaflet 7c, ‘Aircraft Performance’, recommends adding 20% for a tailwind component of 10% of the lift off speed. The leaflet also recommends that at least 150% of the tailwind component of the reported wind be used. As this aircraft’s lift off speed is 49 kt, for every 5 kt of tailwind an extra 20% should be added to the takeoff distance required. For the accident flight, and using the appropriate additional factors, the takeoff distance required to clear 50 ft was calculated to be 2,112 ft, or 644 m. The CAA also strongly recommends that an additional safety factor of 1.33 be used to account for a number of factors including: aeroplane/engine wear and tear and less than favourable conditions or technique. Using this additional safety factor, the takeoff distance required to reach 50 ft was 856 m (Figure 3 and Table 1). 47� Crown copyright 2018 All times are UTC AAIB Bulletin: 10/2018 G-BICS EW/G2018/05/06 Figure 3 Extract from aircraft flight manual Parameter Reported value Factor Distance required Takeoff weight 758 kg from flight manual (sea level assumed) 1,654 ft Temperature 22ºC plus 8% per 10ºC above standard - 7ºC above standard = plus 5.6% (x 1.056) 1,747 ft Surface Dry grass plus 8% (x 1.08) 1,886 ft Headwind / Tailwind 2 kt Tailwind (lift off speed 49 kt) CAA Safety Sense 7c, use 150% of reported tailwind, add 20% for tailwind of 10% lift off speed - 3 kt tailwind = plus 12% (x 1.12) 2,112 ft or 644 m Plus safety factor for takeoff distance required plus 33% (x 1.33) 2,809 ft or 856 m Table 1 Summary of takeoff performance calculation Information is also provided in the flight manual to calculate the ground run required. Using the same parameters and additional factors, a ground run of 470 m was calculated. 48� Crown copyright 2018 All times are UTC AAIB Bulletin: 10/2018 G-BICS EW/G2018/05/06 Other information The CAA Safety Sense Leaflet 7c, ‘Aeroplane Performance’ 1 , includes useful information to assist a pilot in assessing if the proposed flight can be safely made. It discusses where to find and how to use performance data, performance planning and general points that may affect aircraft performance. It also includes a useful and easy to use summary of these factors and how they affect performance (Figure 4). The leaflet also discusses the importance of having a decision point so that a pilot can safely abandon a takeoff if the aircraft performance is not as expected. Similar information can also be found in UK Aeronautical Information Circular (AIC) 127 /2006 (Pink 110) ‘Take Off, Climb and Landing Performance of Light Aeroplanes’ 2 and in the CAA’s ‘Skyway Code’ 3 . This leaflet also notes that the performance figures used in the flight manual are those achieved by the manufacturer using a new aeroplane and engine in ideal conditions flown by a highly experienced pilot (Figure 4). Effect of flap on takeoff performance An appropriate flap setting can be used to optimise an aircraft’s takeoff performance, but only flap settings that are specified in the aircraft flight manual should be used. For some aircraft, a greater flap setting can be specified for ‘short’ or ‘soft’ field takeoffs to minimise the ground roll. The increased lift from the increased flap setting allows the aircraft to become airborne at a lower speed, but the increased drag once airborne can degrade climb performance and therefore obstacle cl

Accidents Database

AAIB investigation to Pierre Robin R2100A, G-BICS

Report Overview

Summary:

Download report:

Download glossary of abbreviations:

Official Documents

Document Content Preview

Pierre Robin R2100A, G-BICS 10-18

Change History

Related Entities