The postponements have been blamed for accidents involving Dhruv Advanced Light Helicopters (ALHs), the first in August 2013 and a second in March. Both crashes took place while the helicopters were ferrying supplies to soldiers deployed in Ladakh and on the Siachen Glacier, which borders Pakistan and China, at heights above 5000 m.
"The heavy ALHs have not yet been stabilised for such high altitudes and should never be employed there," Lieutenant General BS Pawar (retd), a former head of the Army Aviation Corps (AAC), told IHS Jane's .
"However, the continuing shortage of LUHs is compelling the army to use ALHs in Siachen with disastrous consequences," he added.
The LUH programme, under which 133 platforms would be bought for the AAC and 64 for the Indian Air Force (IAF), is intended to replace the licence-built Chetak (Aerospatiale Alouette III) and Cheetah (Aerospatiale SA-315B Lama) helicopters inducted into service more than four decades ago.
However, defence industry officials have told IHS Jane's that commercial bids to replace them submitted in 2008 by Eurocopter for its AS550 Fennec and Kamov with its Ka-226 Sergei expire on 30 June.
This deadline follows a six-month extension granted in January by India's Ministry of Defence (MoD) to the helicopter manufacturers to resolve complex corruption allegations in the LUH tender, field trials for which concluded in 2010.
On 4 January the Central Bureau of Investigation (CBI) charged a serving one-star Indian Army officer with offering to favour AgustaWestland's AW119 Koala helicopter, which competed in the LUH tender, for a EUR5 million (USD6.68 million) bribe.
The AW119 helicopter was eliminated from the competition following the first round of winter trials in 2009-10 on technical grounds, but the allegations persisted, culminating in the CBI registering a case despite an internal Indian Army inquiry revealing no wrongdoing.
At this point, it is unclear whether India's newly installed BJP government will permit Eurocopter and Kamov to extend their commercial bids to enable the CBI to conclude its inquiries and keep the LUH tender active.
It is also considering issuing a fresh request for proposals - the third for the LUH programme since 2002-03 - a development that would add another three-to-four years of trials and negotiations.
The LUH procurement was first terminated in late 2007 after the MoD revealed discrepancies in the evaluation process that had shortlisted the AS550 C3 Fennec model over the Bell 407 platform.
COMMENTRepeated delays in procuring new LUHs resulted in the AAC and the IAF opting for 30-35 stopgap Cheetals from Hindustan Aeronautics Limited (HAL) three years ago.
A Cheetah derivative, the Cheetal is powered by the more powerful Turbomeca TM-333-2M2 free turbine turboshaft engine and equipped with marginally better avionics. However, it also faces problems as HAL has procured outdated Series 85 high-altitude rotor blades for only 20 helicopters for the AAC - with no spares - and none for the IAF as the blades are no longer manufactured.
HAL tried to substitute Type 30 rotor blades, which failed to meet not only the high-altitude requirements of its own test pilots but also those of the IAF as they generated excessive vibration and provided inadequate lift.