flying hours / logged flight hours

logged flight hours / flying hours

engine logged hours

helicopter logged hours

airframe flying hours

assigned life (of an aircraft in flying hours)

mean time between repairs (flying hours)

time to first overhaul (flying hours)

total airframe flying hours

accident-free flying / mishap-free flying

mishap-free flying / accident-free flying

low flying aircraft / low-flying aircraft

maintenance by flight hours

operational flight/ flying

hours flown in combat

cryptanalyst hours

sack duty (hours, time)

in the hours of daylight

Watt hours (Wh) rating

man hours of duty

flight restriction zone / flight restricted zone (FRZ)

anti-low-flying aircraft missile

flying boat

flying bomb

flying control officer

flying properties

flying squadron

flying wing

non-flying squadron

unidentified flying object (UFO)

with flying colors

nap-of-the-earth (NOE) (ground-hugging / terrain masking / flying under the radar / hedgehopping)

achieve coordination in flying