CASE POL 3 - Tires for Refueling Vehicles/ FOD Hazard, R. Thomas
Problem: Stones being picked up in the tire treads of aircraft refueler
trucks and dropped on the aircraft parking apron, creating a F.O.D. (Foreign
Object Debris) hazard.
Symptom: Engine damage to aircraft and G.S.E. (Ground Support Equipment)
turbine engines due to F.O.D. pickup by air intake.
Collection of Facts: Due to the location of many Navy refueler fill stands,
and the roads traveled by refuelers, stones are picked up in the truck tire
treads. When anti-F.O.D. tires are used, tread life is short, and there is
still some stone pickup which must be removed.
Solution: Field tests have been initiated and completed at NATC Patuxent
River using "racing slick" type recap tires on refuelers. They carry no
F.O.D. and results show about l/3 more tire life than threaded tires.
Traction has proven to be excellent in all types of weather-rain, ice and
snow. Stations and contract refuelers now have the option to go to "slick"
tires and feed-back from the field is showing similar good results.
Commercially, Dulles Airport is now using "slick" tires on their "people
movers" to transfer passengers from the terminal to the aircraft out on the
CASE POL 4 - Failure of Filter/ Separators, R. Thomas
Problem: Failure of filter/separators (F/S) to coalesce water at aviation
refueler fill stands.
Symptom: Premature shut-down of fuel flow by fuel contamination monitors
during water overload.
Collection of Facts: During recent fuel facility surveys at Navy and Marine
air stations, it was noted that when stations converted from top loading to
bottom loading fill stands, lubricated swivels and valves were reused. Due to
their age, some had leaks and a way to stop the leak was to pump grease into
the fitting. Unfortunately, some grease works its way into the fuel and in
effect "wets" the coalescencers and prevents the "beading" or "coalescing" of
water droplets. With a faulty or slow acting slug, valve water can then pass
through the F/S and cause premature shutdown of fuel monitors at the fill
stand or on the refueler trucks.
Solution: Replace all lubricated valves and swivels at aviation refueler fill
stands with non-lubricated type. (As required by NAVFAC DM-22).