Abstract: A sealing system is provided for a prefabricated pit for servicing an aircraft that is formed with an open bottom and an inner cylindrical wall for surrounding a riser pipe therewithin. An annular rubber boot having annular inner and outer marginal edges is located at the bottom of the pit. The inner peripheral margin of the boot is secured to the riser pipe by a conventional metal band clamp to establish a liquid tight seal therewith, and the outer peripheral margin of the boot is compressed radially outwardly against the cylindrical wall surface by means of an outer clamp.

Abstract: A subsurface pit for servicing aircraft on the ground and having walls with an opening into which a refueling conduit extends is provided with both a ground moisture seal and a pressure seal located about the moisture seal. Together the ground moisture seal and the pressure seal define a fluid tight cavity therebetween which is pressurized with air to approximately three pounds per square inch above atmospheric pressure. A pressure gauge is coupled to the pressure seal by means of a disconnectable fitting to allow pressure within the cavity between the seals to be externally monitored.

Abstract: An access lid for a subsurface aircraft servicing pit is provided with a latch located below a surface across which aircraft roll. The fastening mechanism of the improved subsurface chamber is engaged by the force of gravity when the access lid is closed and when a latch operating element is released. The latch operating element is located in a hand grip cavity, accessible from above and defined beneath the top surface of the lid. Actuation of the operating element overcomes the force of gravity and disengages the latch mechanism. Release of the operating element allows the force of gravity to urge the latch mechanism into an engaged position which prevents the access lid from being opened.