02 November 2009
One of the unique features of the Mikoyan MiG-23/27 Flogger fighter aircraft is that compressed air for the pneumatic systems is stored inside the main undercarriage legs and axles. The main pneumatic system fed off a 12.1 liter "bottle" inside the right undercarriage leg to operate the cabin pressurization, canopy operation, moving the sliding panels that cover the gaps on the variable-geometry wings, the main wheel brakes, main fuel valve, braking parachute deployment, activating the emergency drive for hydraulic system and closing the air vents in the avionics bays. A smaller 1.75 liter "bottle" inside the right wheel axle supplied compressed air to the radar bay and avionics heat exchanger which used fuel as coolant.
A 12.1 liter "bottle" in the left main undercarriage leg supplied compressed air for emergency lowering of the landing gear, folding of the ventral fin and operation of the brakes. A smaller 1.75 liter "bottle" in the left wheel axle supplemented the emergency systems on the Flogger. The main valve to fill the compressed air circuits in both main landing gears was located in the left main wheel well.
Source: MiG-23/27 Flogger- Soviet Swing Wing Fighter/Strike Aircraft by Yefim Gordon and Keith Dexter. Midland Publishing/Aerofax, 2005, p52.