Refueling Control Panel

This is the place where control for refueling process took place. Located at the forward edge of right hand lower surfaces. Amount of fuel required base on the flight plan will be routed to certain tanks by controlling the switch of each tank. What unique about BBJ is that, there is additional control for auxiliary fuel tank which is located in forward and aft cargo compartment.

Normally the wing tank will be filled up first followed by the center tank, any extra fuel required then will be routed to the auxilliary tank. Depend on the density of the fuel for that day (fuel density varies mainly due to temperature) the maximum quantity for each wing tank is 3800 kg (4800 liters) and center tank 12750 kg (16200 liters). For auxilliary tank, on BBJ that i work on it has 1 auxiliary tank at the forward cargo and 3 tank in the aft cargo, each can be filled up to 1500 kg (1900 liters) and 2900 kg (3600 liters) respectively.

In each tank there is an instrument that will measure the capacitance of the fuel and from that through fuel processing unit will convert it to kilogram. Weight of the fuel is more relevant for aircraft as it will be added to total weight of an aircraft to determine take off thrust setting for engine for that particular flight.

Cockpit Window Cracked

One of our BBJ aircraft came back with number 2 cockpit window cracked. No 2 window is the only window that can be opened, it slide backward. This is very dangerous situation where it might lead to rapid decompression however by knowing the construction of the window itself, we can be assured that the safety is not tolerated.






This window is a laminated assembly of layers of glass and vinyl or urethane. The structural inner glass pane carries pressure loads. The vinyl interlayer is structural for bird impact resistance and fail-safe pressure loads.

The current window manufactured by PPG has these layers: an non-structural outer glass pane, a non-structural urethane interlayer, a structural vinyl interlayer, a non-structural urethane interlayer and an structural inner glass pane.

A conductive film is located on the inner surface of the outer glass pane, which is a part of the window heat system that supplies the anti-fog and the anti-ice function.

Rest of the cockpit window have almost the same construction. The passanger window however in stuuctured in layers as well minus the heating element.

Few months earlier one of our Gulfstream had a similar incident where the number 1 cockpit window cracked during flight, from the sign of arcing at the top left corner of the window, overheated is the probable caused for the damaged.

Heat Exchanger Cleaning

Summer already started and ambient temperature is now getting higher and higher everyday until September when it will start to drop again.

In hot weather like this, the airconditioning system (a/c) will have to work harder in order to produce sufficient cool air to chill out the cabin. The heat exchanger is part of airconditioning system where transfer of heat from the engine bleed air back to ambient before the air further process by the air cycle machine (heart of a/c system) to produce cool air.

With dusty enviroment such as here in middle east, the dust or dirt can accumulate in between the fins of the heat exchanger thus reduce the efficiency. Cleaning of the heat exchanger is necessary, with heat exchanger backfush cleaning process.

Here is the photo that i took while we doing it on one of the BBJ, the mix of hot air and water was injected from backside of the heat exchanger so it force out the dust and dirt that trapped inside the heat exchanger itself.

There is slight improvement for the output of the a/c system after we did this, however with ambient temperature of 45 deg C, getting sufficient cool air out of the a/c is seems difficult, we still need the use external ground airconditioning cart.