Microsoft Flight Simulator '98 Codes -

Slew mode:
Press Y in flight or before take-off. Then, press [F4] to increase altitude, [F3] to decrease altitude, [F2] to move forward, and [F1] to stop. The cursor keys may also be used to move the aircraft. Press Y to resume normal flight.

Fly faster:
Type bgry. The screen will freeze and red writing will appear. Press [Cursor Up] to fly quickly forward or [Cursor Down] to move quickly backwards.