What causes sonic boom? Nowadays, most people have heard the bang caused by an aircraft travelling at the speed of sound, but do you know why it occurs ? Sound is caused by a disturbance which creates waves that emanate from the centre of the disturbance. These waves are sound waves. When these vibrations are picked up by the ear drum they are interpreted by the brain as noise. When someone...

How do jets jump? The Hawker Siddeley Harrier is a fighter that uses such an ingenious system for vertical and short take-off and landing that it has earned the nickname jump-jet’. Powered by a Rolls-Royce Pegasus engine, it has two compressor/turbine systems. Sixty per cent of the exhaust from the front system is discharged by fans through two front nozzles, one on each side of the aircraft. The remaining exhaust, plus...

What is the world’s most successful commercial airliner? While there are more Boeing 727’s flying in the world’s airline fleets than any other aircraft, most airline executives would say that the Boeing 747 or ‘jumbo jet’ is the world’s most successful airliner. This is because it carries more passengers than any other jet airliner and operates so efficiently. When it carries a full pay-load of passengers, it is the most profitable...