Date: 201410
Local time of day: 0001-0600
Location: IAH.Airport, TX
Aircraft: A300
Operator: Air Carrier
Mission: Cargo / Freight / Delivery
Reporter organization: Air Carrier
Reporter function: Technician
Human factors: Situational Awareness
Anomaly: Ground Event / Encounter Other / Unknown
Detector: Person Maintenance
When detected: Aircraft In Service At Gate; Taxi
Result: General None Reported / Taken
Contributing factors: Airport; Human Factors
Primary problem: Ambiguous

Narrative: I have a safety concern regarding the current aircraft positioning on the ramp. The new (redrawn) ramp taxi and parking lines have three of the aircraft parking where the landing gear brakes are in very close proximity ( within 2 to 8 ft.) to our fueling hydrants (fuel pits). These same aircraft will have the right side engines go over these fuel pits or come in very close proximity while they taxi into parking position. The fuel pits we have on our ramp have a 2 X 3 foot pit below the fuel coupling that holds all spilled residual fuel that is leaked from the coupling during fueling and or during connecting and disconnecting the fuel transfer vehicle. These pits can contain more than a foot of fuel at any given time and get sumped out once or twice a week.  On average when I looked at several of these pits over the last few weeks they had well over a foot of fuel each time I looked at them and have been told on occasion they can be full (up over 2.5 feet). The lids on these pits are not vapor proof; so fuel vapors can be present above these pits. The five major concerns I have with these fuel pits being so close to the landing gear and engines during taxi and parking are as follows:      1) If there were a hot brake or brake fire during taxi or parking the vapor in the fuel pit could ignite under certain conditions.      2) Having a running engine go over the top of a fuel pit with fuel vapors present could ignite under certain conditions.       3) During a quick turn the brakes may not have had sufficient cooling time. Fueling may begin within 15 minutes of aircraft arrival; If there were a fueling accident (fuel spill; coupling failure; hose failure) that caused fuel to be sprayed on a hot brake the fuel mist or spilled fuel may auto ignite      4) A tailpipe fire during startup of a right side engine could cause a fire in the fuel pit that is directly behind it or in close proximity behind the tail pipe.    5) During a quick turn the A300 brake fans may be turned on to assist in cooling the brakes (These brake fans are electric motor driven). Having them turned on while the fuel pit is being used (active fueling) and in such close proximity to fuel vapors could cause the vapors to ignite.   Our fueling manual references the NFPA code 407 as a reference.  Annex A of NFPA 407 section A.1.2 paragraph B it says the auto ignition temperatures of turbine fuels are such that residual heat of turbine engines after shutdown or residual heat of turbine aircraft brakes following hard use can ignite such fuels if they are spilled or sprayed before they have cooled below the auto ignition temperatures of the fuels. Annex B of NFPA 407 paragraph B.2.1 (Flashpoint) says that when Jet A is heated above its ignition point (or exists in the form of a mist); the mixture can be ignited. This condition can develop where temperature are 38 deg C (100 deg F) or higher. Annex B of NFPA 407 paragraph B.2.4 (auto ignition temperature) says jet A turbine fuel has an auto ignition temperature of 246 deg. C (475 deg F ). Temperatures in this range can exist for a considerable period in turbine engines after shut down or on brake surfaces following a hard use. We have three Aircraft; [two engine aircraft] that when parked on their current spots have a fuel pit that is within 2 to 8 feet of the right side landing gear brakes depending on where each aircraft is stopped. [On one aircraft] the right side engine goes directly over the top of its fuel pit while taxiing into position. The other two both have right side engines that; while taxing into position come in close proximity to the fuel pits.




Synopsis: Air carrier Mechanic believes that the location of fuel pits in relation to hot engines and brakes; when the aircraft is parked; is dangerous and a potential fire hazard.