Almost half of the worldwide fleet of Airbus Helicopters EC135s have been checked for a problem with their fuel sensors, following the issuance of a EASA airworthiness directive mandating the examinations on 19 December 2013.
The Marseille-headquartered airframer released the latest figures from the checks on 13 January. They show that 467 aircraft have been tested – or 44% of the global fleet.
Airbus Helicopters says of the 934 sensors examined 16 required cleaning before refitting, three failed and were replaced, 866 passed and tests are still ongoing on the remaining 49 units.
Based on these figures, the component is showing a problem in around 2% of cases.
Each of the light-twins is equipped with two sensors – one in each engine feed fuel tank – that provide an early indication that fuel levels are dwindling. If a malfunction occurs, Airbus Helicopters warns that the pilot could overestimate the amount of fuel on board, only receiving the critical low-fuel warning that appears when there are 8-10min of flight-time remaining.
The company's move came on the back of the December temporary grounding by UK operator Bond Air Services of its fleet of 22 EC135s, after discovering fuel warning malfunctions on several aircraft. Subsequent checks by the operator and Airbus Helicopters revealed that the probes could generate an "erroneously high signal" if contaminated with water or sediment in the fuel.
Source: FlightGlobal.com
