Boeing has reported the Federal Aviation Administration (FAA) has approved a temporary exemption from safety requirements to clear delivery of the Boeing KC-46A tanker in October, the company said.
Boeing´s engineers discovered earlier this year that an unresolved software flaw in the KC-46A creates the lack of an independent system to monitor fuel flow, as required by the FAA´s safety regulations.
If a single processor fails while the KC-46A is receiving fuel from another tanker, an overpressure event in the centre fuel tank may go undetected, according to Boeing´s nearly four-month old request for a temporary exemption.
On 2 August, the FAA approved Boeing´s exemption from the safety requirement, allowing the aircraft to be used on operational flights as scheduled after October.
The FAA´s approval requires the USAF to operate the KC-46A in domestic airspace with another crew member in the cockpit to physically monitor the pressure in the centre fuel tank during an in-flight refueling.
The exemption expires on 30 June, but Boeing plans to release a new software update that fixes the problem by then, the FAA says.
In late June, Boeing announced that the USAF has agreed to accept the first KC-46A tanker more than a year late in October. Boeing has reported more than USD 3.0 billion in financial charges related to the programme since winning the development contract in 2011.