Definition
Aircraft flight instruments that present information on electronic display screens rather than through individual mechanical gauges. A computer receives data from sensors and renders airspeed, altitude, attitude, heading, and engine information on one or more flat panel displays, typically arranged as a Primary Flight Display (PFD) and a Multi-Function Display (MFD).
Plain English
Instead of a panel full of separate round dials with needles, the cockpit shows everything on computer screens. The screens draw the airspeed, altitude, attitude, and other readings electronically.
Context Anchor
Seen in modern cockpit instrumentation, especially when comparing older round-dial panels with newer screen-based panels.
Derivation
Called 'glass' because the displays are flat glass screens, in contrast to the older 'steam gauge' panel made of many individual mechanical instruments. 'Digital' refers to the underlying electronic processing of sensor data.
Why Pilots Care
They reduce workload by presenting integrated data at a glance and improve situational awareness compared with scattered analog instruments.
Analogy
It is like the difference between several separate wall clocks and one screen that shows the time, date, weather, and alarms together. The information is still there, but it is presented through one electronic display instead of many separate devices.
Intuition Check
Do not read glass as meaning fragile or decorative here. In aviation, glass instruments means electronic screen displays that replace or combine traditional cockpit gauges.
Example Sentence 1
The training aircraft was equipped with digital glass instruments, so the student learned to scan a PFD instead of six separate gauges.
Example Sentence 2
Transition training focused on interpreting the digital (glass) instruments for engine monitoring.