The PFL (Russian: Противогаз Лётный Фильтрующий - "Filtering flight mask") is a Soviet aviation mask, based on the PPM-88, intended for use by the crews of transport aircraft and helicopters. The mask has largely been replaced in Russia, but still sees some use in air force reserves.
The PFL has a thick perspex panorama lens, held in place by a plastic clamp around the outside, and a spring just behind it.
The mask has a five-point rubber head harness, fixed in place, except for the lowest two straps, which adjust similarly to those on a PMK-series mask
The mask has a 40mm GOST inlet, but it can't accept filters normally because the exhale valve protrudes too much (although it can be partly dismantled to allow this). The exhale valve assembly itself is identical to those found on PMK series masks.
The oral-nasal cup is lined with a soft felt-like material, as is the back of the head harness, making this one of the most comfortable Soviet masks.
The mask has an integrated microphone, which is connected to a small amplifier circuit (UK-9) with a two-pronged plug at its end.
The PFL is issued in a bag very similar to that of the PMK-1, comes with six lens inserts, individually sealed in plastic bags inside a tin, and a small cloth for cleaning the lens.
The mask is issued with a two-part hose, joined with a tight bayonet fitting, allowing the mask to be connected to an air source on a plane. The hose has clips to connect it to the pilot's protective suit, and the mask is issued with canvas covers for the hose.
The KPL-3 is the filter issued with the PFL. Unusually for a Soviet filter, it doesn't have a conventional 40mm connector, and is shaped to be put in a pocket on the pilot's suit.