Boeing is close to agreeing to airline requests that it replace electro-mechanical standby instruments on the 737-600/ 700/800 flightdeck, with a single, solid-state, liquid-crystal-display (LCD) unit.
A final decision is expected when the manufacturer can ascertain whether enough of the units can be supplied to meet planned next-generation 737 production rates. The standby instruments show aircraft attitude, speed and altitude information.
The change was agreed in principle at a customer meeting in December, and comes so late in the programme that some early-production aircraft will have to be delivered with the electro-mechanical devices. Boeing is expected to invite bids from avionics suppliers by the end of the first quarter. Companies thought likely to tender include BFGoodrich, Meggitt Avionics and Sextant Avionique.
Several key customers have been pressing for the change because they believe solid-state devices offer significantly higher reliability levels. SAS, the 737-600 launch customer, says that it wants the change partly for safety reasons, because pilots are used to reading electronic flight-instrument displays, but would have to revert to electro-mechanical instruments in an emergency.
"SAS has been pushing hard for this change to take place," says Lars Lindberg, SAStechnical pilot, flight standards and development. "The pilots are used to one display format."
Boeing has been "very responsive to our request", Lindberg adds. "We hope they will be able to meet the [aircraft delivery] schedule - if they can't we will have to work out some sort of retrofit."
Boeing 737 chief project engineer, Pete Rumsey, says: "We have looked at the various LCD displays, and they do meet our standards for readability. We have also talked to the manufacturers about making some changes if we decide to go ahead with the programme."
Source: Flight International
