BAe/HS 748 AEW
The HS 748 was originally conceived by Avro as an attempt to overcome the anticipated decline in military orders by re-entering the civil aircraft sector. Designed in the late 1950’s the aircraft first flew on 24 Jun 1960. Various improvements were incorporated over the years to increase the payload, improve the aerodynamics and update the engines. Powered by 2 Rolls-Royce Dart turboprops, the 748 had a ceiling of 25,000ft and a range of just over 700 miles when fully loaded with 58 passengers and a flight deck crew of 2.
Eventually 382 examples were built, 52 of this total were delivered to military customers for use as a short/medium range transport. Customers included Australia, Belgium, Brazil and Ecuador. In RAF service the aircraft was known as the Andover C1 and was equipped with rear-fuselage loading doors and an unusual undercarriage which could ‘kneel’ to allow easier access to the rear doors. However, many believe the RAF were ‘encouraged’ to buy the Andover, to help boost overseas sales. However, the Andover didn’t easily fit into any particular role, having insufficient range/payload to compete with the C-130 and lacking the real STOL performance of the DHC-4A Caribou. Unsurprisingly, the RAF got rid of the Andover as soon as decently possible, selling a number of the aircraft to New Zealand, where they soldiered on for a number of years. As well as being used as tactical transport aircraft, the Royal Australian Navy also operates 2 aircraft as EW trainers to simulate EW threats to RAN ships.
India also licensed built 20 aircraft and India’s Defence Research and Development Organisation (DRDO) began the Indian Airborne Surveillance Platform (ASP) utilizing the 748 airframe to provide an AEW capability in an experimental capacity. Using a large rotodome mounted above the fuselage, the aircraft was planned to also house a hybrid navigation system together with secure communication and data links. Design studies began in Jul 1985 as Project Guardian, which was later re-named Airawat. By the late 1980’s one aircraft had been fitted with a 24ft by 5ft rotodome mounted on two pylons and was flown by Nov 1990. The radar antenna inside the rotodome is a low side lobe slotted wave guide planar array and weighs 160kgs. The rotodome is driven by the aircraft hydraulics power supply. Three aircraft were eventually fitted with a rotodome. However, the 748 was only ever intended as a testbed and the long-term plan was to install the system on a number of the 72 Ilyushin Il-76 licensed built for the Indian Air Force by Hindustan Industries.
On 12 Jan 1999 the prototype ASP crashed, killing all 8 people on board, including 4 scientists and is believed to have been caused by fire or engine failure. Since the crash, many critics have suggested that the engines and metal fuselage of the 748 were unsuited to safely operating the additional weight of the rotodome, pylons and associated equipment and a number of eyewitnesses reported that the rotodome collapsed onto the plane. Even to an untrained eye, the rotodome assembly simply looks too big for the airframe and I imagine trying to control a fully loaded aircraft, that suffered an engine failure shortly after take-off, would have been extremely demanding. The crash put the ASP programme back a number of years and it remains very doubtful that this over-ambitious indigenous AEW programme will ever enter service.
It was reported in August 2003 that American State Department objections to Israel selling the Phalcon AEW radar system to India had been removed. It is understood that India will pay around $1 billion for 3 Phalcon systems to be integrated onto three Ilyushin Il-76 aircraft operated by the Indian Air Force. This purchase has almost certainly spelt the end for the ASP and it is only a matter of time before this ill-conceived project is finally abandoned for good.