fuel level indicator

instantaneous vertical speed indicator / instantaneous vertical-speed indicator (IVSI)

engine oil level indicator

fuel pressure indicator

fuel remaining indicator

fuel quantity indicator

depot maintenance (beyond O and I level activities, performed in an industrial-type facility) / D-level maintenance

surveyor's level (surveying level, tbc)

fuel level switch

Proton Exchange Membrane Fuel Cell (PEM fuel cell, PEMFC)

air-flow indicator

artificial horizon (gyro horizon/ attitude indicator)

desiccant indicator

gyro course indicator

indicator console

indicator lamp

indicator light

indicator system

performance indicator

radiac computer-indicator

range height indicator (RHI) scope

target indicator

telltale indicator

turbine inlet temperature indicator

vertical gyro indicator

vertical scale indicator

counter indicator

gyroscope course indicator scale

zone-beat indicator

fire extinguishing system indicator disc

slave indicator

indicator sight glass window

indicator elevating mechanism