Abstract: A timer usable in navigating and piloting an aircraft, the timer having a plurality of application modes for management of time and numeric data, including an approach mode, a fuel mode, a chronograph mode and a clock mode. Each application mode can drive independent but simultaneous time count sequences for use in flight management and navigation such as counting down approach times, fuel-tank switching intervals and other time sensitive events, as well as providing military time, standard time and UTC time.

Abstract: A menu-driven, hand-held navigation and flight performance computer having a keyboard, display, and CPU. The display includes a menu region for displaying the names of navigation and flight performance functions, one or more parameter name regions and a data region. The keyboard includes a first cursor key for selecting among the navigation and flight performance functions on the menu portion of the display. The keyboard additionally includes a key for triggering the start of a specific function selected by the cursor key, a plurality of arithmetic operator keys, a plurality of number keys, and a conversion key for converting data from one unit of measure to another. A timer is included for upcounting and downcounting and for triggering the automatic shut-off of the computer after a specific period of time expires since the last keyboard entry. The CPU retains outputs of select programs to be used as default inputs to select subsequently executed programs.