NEW DELHI, Feb 19: The Advanced Light Helicopter (ALH) which recently landed atop the Siachen Glacier and cleared cold weather trials does not fully meet the Indian Air Force (IAF) weight and altitude requirements.The ALH, overweight by 350 kgs, cannot carry the specified 200 kgs pay load to 20,000 feet altitude in the Siachen Glacier area. This is a major crib of the IAF which affects their air transport efficiency quantified in tonnes per hour. A major element of the defence expenditure incurred on the heights stems from the air maintenance operations to sustain troops fighting there.As a result, the IAF might not actually be able to effect any economy in the Indo-Pakistan military hostilities on the glacier.For instance, the much older Cheetah helicopter carries a 200 kgs pay load to 20,000 feet.This helicopter already in service with the IAF is the only other rotary wing aircraft capable of landing on the glacier.The IAF air staff requirements (ASR) specified a basic empty weight (BEW) of2,450 kgs but the Hindustan Aeronautics Ltd (HAL)-designed ALH weighs 2,800 kgs. The ALH designed by HAL and Eurocopter, Germany is a medium lift aircraft in the 4.5 ton class and the company has ambitious plans for export to Southeast Asian and European markets. The ALH has potential both as a civil and military aircraft. And Indian and foreign aeronautical industry observers rate the ALH as a hi-tech flying machine.HAL has originally fitted the ALH - a twin-engined aircraft - with the French designed TM 333 engine but subsequently switched to the LHTEC 800 engine made by the US company Allied Signal. While the French engine was underpowered and unable to provide the required thrust the US engine has proved more suitable.Despite this major change, the ALH going by book calculations will not be capable of delivering the goods at the required height.Till now HAL has built only 13 ALHs under `limited series production' and hopes to shave off the excess weight during the serial production phase bychanging the avionics and other systems. HAL sources say that the excess weight arises due to over provisioning of certain parameters.
