Boeing launched a new rhetorical offensive in the KC-X contract battle at Farnborough, reviving old criticisms about its rival's approach to hard envelope protection and non-feedback sidesticks.
Charles Johnson, Boeing vice-president of mobility, charged that the bedrocks of Airbus's cockpit philosophy would place military pilots in danger.
In response, EADS North America, which has proposed an Airbus A330-200 modified into the KC-45 tanker, shot back that the KC-767 NewGen Tanker poses the greater risk to pilot safety.
© Airbus Military
"Boeing is clearly raising these red-herring issues in an attempt to distract from its lack of a tanker and from the considerable risk it is offering the [US] Air Force by proposing a tanker that only exists on paper," EADS NA says.
The new debate aggravated the rhetoric on both sides of the debate, which had previously been mostly characterised by bickering over fuel capacity and commercial aircraft subsidies.
In marketing videos, Boeing had boasted about how the KC-767 is designed to give pilots full control to manoeuvre the aircraft in any situation, such as dodging a missile attack.
But company officials had so far refrained from directly criticising the Airbus hard envelope protection system, which is designed to limit the pilot's ability to manoeuvre the aircraft beyond preset limits.
The KC-767, by contrast, gives the pilot "complete, full access to the aircraft envelope", Johnson says, adding: "The pilot can always override" limits set by the flight controls.
"You want to be able to make [certain manoeuvres] and not always be limited," Johnson says.
EADS NA says that pilots in the A330 multi-role tanker transport - on which the KC-45 is based - are not limited to making any manoeuvre that they would need in combat.
Johnson also criticises the Airbus use of sidesticks that provide no feedback response to pilots. Boeing yokes are back-driven, allowing the pilot to feel a response from the flight controls even in a fly-by-wire aircraft.
"Boeing's condemnations of fly-by-wire technology are puzzling, given its extensive use of the same technology in many of its own military aircraft, and the air force's use of sidestick in some of its most successful aircraft," EADS NA says.