India's poor air safety record

It is still not clear what caused the latest crash

By BBC News Online's Sanjoy Majumder

The air crash in the eastern Indian city of Patna is one of 10 major air disasters that has taken place in India in the past 15 years.

Over 1,000 people have lost their lives in a series of serious accidents.

Despite fleet upgrade programmes, several old aircraft are still flying in Indian skies - some well over 20 years old.

India's air traffic control system has also been criticised for being inadequate.

The 1990s saw a series of major air disasters in India involving civilian aircraft, which prompted the government to invest in new air traffic equipment.

• November 1996 - 349 dead when a Saudi airliner and Kazakh cargo plane collided over Delhi

• April 1993 - 56 killed when an Indian Airlines Boeing 737 crashed in Aurangabad, western India

• August 1991 - 69 dead when an Indian Airlines 737 crashed while landing in Imphal, Manipur

• February 1990 - 92 killed in an Indian Airlines Airbus 320 crash at Bangalore airport

Following the 1996 crash of a Saudia jumbo jet over Delhi, a judicial inquiry was set up to investigate India's air traffic facilities and recommend measures to improve them.

It concluded that Indian air traffic controllers lacked sufficient training in modern handling procedures, making it difficult to cope with the sharp rise in traffic.

Even modern airports like Delhi were found to still be using outdated airport surveillance radar.

Since then, new air traffic control systems have been put in place at India's two major international airports at Bombay and Delhi.

But a lack of funds has hampered the modernisation of other airports around the country, including Patna.

Alliance Air, whose Boeing 737 aircraft crashed at Patna airport on Monday, was launched in 1996 as a subsidiary of Indian Airlines.

The airline's ageing fleet has a poor reputation among frequent air-travellers and Indian travel agents.

Srinivas Laxman, aviation correspondent with The Times of India newspaper, told BBC News Online that some in the airline business had expressed concern over the age of the company's planes.

Mr Laxman said a programme to replace the aircraft was still under review.

While some experts say money seems to be a major constraint, others say the delay has more to do with a dispute over which type of aircraft is best suited for India.