Serious simulators: X-plane and 747-400 precision simulator

Flight Journal, Oct 1999 by Lert, Peter

That being said, for many pilots, the actual flying of the -400 isn't particularly difficult; it's getting used to controlling, interpreting and administering all the automatic systems that presents a challenge. One system in particular-the flight-management system (FMS)-is the heart of the airplane's operation, and it's one of the crew's main methods of interfacing with all the automation. Though a few products have approximated the -400's handling and performance fairly well, only PSI delves into the massive airplane's systems. According to software developer Aerowinx, more than 96 percent of the -400's systems, controls and displays are faithfully duplicated in PS1, including a fully implemented FMS.

With this emphasis on systems operation and management, one might expect both flying qualities and visuals to be neglected. Not so!-at least in terms of flying qualities and internal visuals. Since the system has to deal with only one particular aircraft, the flying-qualities model can be optimized for it, allowing a somewhat simpler software "engine" than X-plane's to provide an entirely adequate replication of handling and performance. "Outside-in" views of the aircraft are absent, while the only "inside-out" view is a small section of the windshield that provides fairly basic graphics (though they're still adequate for runway lineup on landing, etc.). Weather can be programmed in considerable detail for takeoff, several separate cruise segments and for landing, but its effects are evident primarily in aircraft performance and handling rather than the view out the little windshield.

On the other hand, the inside view is excellent, particularly when you consider that it's optimized for basic VGA. The basic display covers the left twothirds of the -400's panel, including the captain's "all glass" primary flight display (PFD) and navigation display (ND), the engine instrument and crew-alerting system (EICAS) that's in the center of the panel and the large synoptic display that's actually installed at the front of the center pedestal. A few other vital center-pedestal controls and indicators as well as the function keys and display screen for the captain's side FMS are also displayed below the PFD. In its cockpit, the real airplane has only three round "steam gauges": the standby artificial horizon, direction indicator and combined airspeed indicator and altimeter; these aren't included in PS1.

Particularly clever is the way Hardy Heinlin manages to provide access to both the big mode control panel (MCP) that runs across the glare shield in the real airplane and those functions in the ceiling panel necessary to control airplane systems. A portion of the MCP appears above the main instrument panel; placing the mouse pointer in that area and moving it from side to side allows other parts of the MCP to appear, while all controls can be manipulated by mouse clicks. Similarly, clicking the mouse in the center of the ND changes that section of the screen to a window showing part of the overhead panel; moving the mouse then allows you to select the relevant part of the overhead that you need, while clicking the mouse anywhere else on the screen restores the ND. Any control in the cockpit can be operated either by direct mouse input or from the computer keyboard; a yellow square on the display shows which control is the current candidate, while the cursor keys move the square about as necessary.