Fuel Installation


Fuel tanks

  • Two tanks

Tank 1  (Main Tank)   6,724 litres

Tank 2  (Reserve Tank)  2,293 litres



  • Two Pumps – Either tank can feed either pump

Tank 1 – Main Tanktank1a

Tank 2 – Reserve Tanktank2a

Tank and Pump schematic


Switching Tanks

Normal operation – Tank 1 feeding Pump 1

Symptoms of low fuel level in the tank

  • Fuel flow rate reduces
  • Pump labouring and fuel flow ‘surges’

Change from Tank 1 to Tank 2

  • Replace fuel nozzle in the pump
  • Lift man lid on tank 1
  • Move yellow lever so it is positioned at 90 degrees to the pipe which will close tank 1 outlet valve
  • Lift man lid on tank 2
  • Turn red wheel anti-clockwise (several turns) to open tank 2 outlet valve
  • Replace both man lids – mind your fingers !
  • Remove fuel nozzle and continue refuelling


Tank 1 – Outlet Valve (Open)


Tank 2 – Outlet Valve (Closed)


Switching Pumps

  • If the pump in use (normally No.1) fails during refuelling
  • Replace the fuel nozzle in pump No.1
  • Operate the round green gate valve on the Dunstable side of the filter vessel by turning clockwise – this shuts the valve on the No.1 pump delivery line
  • Operate the round green gate valve on the Pig Farm side of the filter vessel by turning anti-clockwise – this opens the valve on the No.2 pump delivery line
  • Take the dummy nozzle from pump No.2 (which will start pump No.2) and replace the fuel nozzle in pump No.1
  • You should now be able to continue refuelling
  • When refuelling is complete, replace the fuel nozzle in pump No. 2


Filter Vessel – Daily Fuel Checks


  • Use the correct sample jar for the day and empty the previous week’s fuel sample into the waste Avgas jar.
  • Use clean tissue to wipe the inside of the jar to remove any particulates and water droplets sticking to the glass from the previous sample.
  • Operate the water drain into the jar WITHOUT the pump running – this should result in a small amount of fuel in the jar before the flow stops and should clear any free water in the filter vessel – discard into the waste Avgas jar.
  • Remove the fuel nozzle from the pump which will start the pump and pressurise the filter vessel. Take a sample from the water drain at full flow to at least half fill the jar.
  • Put the lid on the jar and allow the sample to settle for a few seconds.
  • ‘Swirl’ the fuel in the jar so that a vortex forms – this will help to collect any particles or free water on the bottom of the jar at the base of the vortex.
  • If free water is observed or the sample is hazy (water in suspension) repeat the sampling process until a clear and bright sample is observed.
  • Note – A small number of rust particles in the sample seem to be ‘normal’ at Dunstable.



  • Remember to attach the earthing cable to an unpainted metal part of the aircraft to dissipate any static electricity BEFORE the fuel nozzle comes anywhere near the aircraft


  • Do not leave the aircraft unattended while you are fuelling. Occasionally the automatic fuel cut-off mechanism in the nozzle doesn’t !!


  • Take care with the position of the nozzle in the aircraft to avoid fuel pouring out of the fuel overflow pipe as you are fuelling

….and don’t forget the paperwork !



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