There is more to this than meets the eye!
The L29 has a total loss air system for the brakes. Prior to flight you have to pump enough air into the brake system from a dive bottle or similar source. The aircraft cannot recharge the air system any other way as it is not fitted with an air pump.
Rumour has it that an expert in jet operations from CAA advised the pilot how to get data to check if the machine could be flown from Dary Flat.