Guy Norris/Redmond
An advanced ground proximity warning system for general aviation applications is under study by AlliedSignal and could be given the go-ahead by the end of the year.
The system would take advantage of packaging features of the Mk VI enhanced ground proximity warning system (EGPWS) now under development for regional air transport aircraft. It also builds on the digital terrain database technology introduced on the Mk V and Mk VII systems. The Mk VIII, as the proposed system would be called, will combine the regional aircraft version with a 75 x 75mm flat panel display being developed in conjunction with recently acquired Grimes Aerospace.
"They are now developing a TCAS [traffic collision avoidance system] display for us, and we're planning to combine the Mk VI with that and use some VLSI [very large scale integration] technology to package it into a single line replaceable unit [LRU]," says GPWS product director Brian Pulk. "One of the major issues is cockpit space and, by introducing a dedicated terrain display unit, we are making it in a radio altitude display replacement". The company describes the single LRU project as "an ambitious development", while Pulk says "-the Mk VIII may not happen. We will decide by the end of the year."
The Mk VI EGPWS is designed to replace existing Mk VI GPWS computers, which now operate on regional turboprops. The system will display terrain on existing colour weather radar plan position indicators, or on a dedicated terrain display. "We've tried to take out the cost," says Pulk, who adds that the catalogue price will be around $24,000 per unit against about $68,000 for a standard Mk V. "We've taken out the interface programmability, so there are just a few basic interface options. We will also take out some of the memory and will be using a regional database instead," he adds. The Mk VI will be available in June 1999, while the Mk VIII, if it goes ahead, could be ready later the same year.
The US Federal Aviation Administration is passing legislation that calls for all production aircraft with six seats and above operating in the USA to be required to have an EGPWS and a display from 2000. By 2003, all aircraft will be required to be retrofitted with an EGPWS and a display.
Source: Flight International
