Boeing has floated the possibility of using vibrating cockpit seats as an alternative mechanism to visual and aural indicators on the flightdeck.
Its suggestion is contained in a newly published patent document that details a proposal for a module mounted beneath the pilot's seat which, once triggered, would provide a tactile signal to the crew.
While the document mentions various types of alerts requiring immediate pilot action - such as terrain-avoidance or stall-warning alarms - it says there are several other instances during flight where the crew may need to act in a less-urgent manner, to maintain safety.
These include making position reports by voice or datalink or reporting to air traffic control before top-of-descent.
"Certain physiological factors may have an effect on the ability of the flightcrew to remain alert to perform such flight interaction tasks," it says.
It mentions the risks associated with fatigue as well as the requirement for crews to control rest periods during non-critical stages of flight.
"There exists a potential need for a system and method for alerting a flightcrew of the need to perform a task by increasing the level of stimulation that is provided to the flightcrew," it adds, although there is no indication of any immediate plans for application.
The 27 January patent document, whose authors include Boeing chief test pilot Frank Santoni, describes a mechanism comprises two travelling probes capable of vibrating at various amplitudes, frequencies and durations, depending on the nature of the required alert.
This could be pre-programmed to ensure timely intervention at specific points in the flight. But the document also shows that it could be activated, if necessary, by external interaction from air traffic control.
Boeing's document suggests the mechanism may provide overflight prevention capability. The system could also be used to obtain the attention of pilots who are not responding to radio calls.