In Aviation, the operation of an aircraft with all or many of it's extendable surfaces in their extended state, such as Flaps
extended, Landing Gear
out etc. This increases drag on the aircraft and can be used to slow the aircraft. When used during a standard landing will reqire a higher thrust setting than Flying Clean
to maintain the same descent and speed profile, increasing noise and fuel burn.
1:By the time we intercepted the glide slope
the captain had all the hangy bits out, Flying Dirty to get the speed down for landing.
Flying a Clean approach is better than Flying Dirty for Noise Abatement
reasons, for that reason it is best to delay extention of the landing gear
till late on finals to reduce noise.