A Britten-Norman BN-2A-27 Islander was on an international scheduled passenger flight between the airports of Antigua-V.C. Bird International Airport (ANU/TAPA), (Antigua and Barbuda) and Montserrat-John A. Osborne Airport (MNI/TRPG) (Montserrat).
One pilot and seven passengers were onboard the aircraft for the short flight (~60 kilometres or 38 miles).
The aircraft in its final position (© AAIB)
The flight was uneventful and a normal approach was flown. The aircraft touched down at runway 10 (596 x 28 metres, with a landing distance available of 540 meters and a 200 feet vertical drop at the end of the runway). As the pilot applied the brakes he noticed there was no resistance (as normal) from the right brake, as the pilot pumped the brakes in an attempt to decelerate the aircraft directional control was maintained with the rudder. There was no noticeable effect on the right brake pedal as a result of pumping the brakes. To avoid running off the end of the runway the pilot applied the left brake, resulting in the aircraft vacating the runway onto the grass, just past the runway exit. 20 metres from the runway edge the aircraft struck an embankment at a speed of approximately 10 knots resulting in substantial damage. The following damage was reported;
Nose section structural damage
The nose landing gear collapsed
Left-wing tip leading edge suffered impact damage
There were no injuries to the occupants of the aircraft.
During the previous flight, the pilot had reported issues with the right brake-hand system. An O-ring on the right outer brake was found defective and replaced, subsequently, the master cylinder reservoir was refilled and the system was bled with the aid of the pilot.
The accident aircraft in better days (© Unknown Source; https://nl.flightsim.to/)
An investigation was launched by the Air Accidents Investigation Branch (AAIB), in their report they concluded that the probable cause for the loss of right braking was trapped air in the right brake hydraulic lines. This air may have been present prior to the O-ring seal removal but was more likely to have been introduced during the seal removal and replacement. The investigation also revealed the existence of several different brake bleeding procedures. The aircraft manufacturer had three different brake
bleeding procedures, namely the Islander AMM procedure, the Trislander AMM procedure and their own production procedure. Several safety actions were taken by different parties involved, also a safety recommendation was made by the AAIB. Details on the safety actions and recommendations can be found in the AAIB Bulletin (which served as the source for this blog) by clicking on the .pdf file below.
The aircraft was repaired and returned to service, on the 23rd of September 2020 the aircraft was involved in another landing accident. This accident was featured in an earlier blog on this site. Click here to get access to that blog.