The US Federal Aviation Administration has warned operators of aircraft with Chelton Flight Systems' FlightLogic EFIS avionics that the equipment can provide misleading guidance under certain circumstances. The FlightLogic system is being installed in a large number of aircraft operating in Alaska under Phase 2 of the FAA's Capstone programme.
Boise, Idaho-based Chelton has issued service bulletins outlining how to recognise when misleading guidance is being displayed, and is working on a software update to eliminate the problem.
The problem concerns the way the system provides guidance for altitude legs that begin at a certain altitude/location and climb in a specified direction until reaching a specified altitude. The software assumes a climb rate of 300ft/nm (50m/km). This is safe under most circumstances, says Chelton, but some departure procedures require a higher climb rate. In such cases the system will provide misleading guidance into non-protected areas.
There are similar safety concerns with some missed app- roach procedures, says the FAA.
Source: Flight International
