US aerospace major Boeing has handed over first of the 22 Apache Guardian attack helicopters to the Indian Air Force, nearly three-and-half years after a multi-billion dollar deal for the choppers was sealed.

Senior IAF officials said the addition of AH-64E (I) Apache helicopter is a significant step towards modernisation of the force's chopper fleet.

The helicopter has been customised to suit IAF's future requirements and would have significant capability in mountainous terrain, they said.

"The first AH-64E (I) - Apache Guardian helicopter was formally handed over to the Indian Air Force at Boeing production facility in Mesa, Arizona, the US on May 10," IAF Spokesperson Group Captain Anupam Banerjee said.

The AH-64E Apache is a leading multi-role attack helicopter and is flown by the US Army.

The IAF had signed a multi-billion dollar contract with the US government and Boeing Ltd in September 2015 for 22 Apache helicopters. The first batch of these helicopters is scheduled to be shipped to India by Jul this year.

"Selected aircrew and ground crew have undergone training at the training facilities at US Army base Fort Rucker, Alabama. These personnel will lead the operationalisation of the Apache fleet in the IAF," the IAF said in a statement.

It said the helicopter has been customised to suit the IAF's future requirements and would have significant capability in mountainous terrain.

"The helicopter has the capability to carry out precision attacks at standoff ranges and operate in hostile airspace with threats from ground," the IAF said.

It said the ability of these helicopters, to transmit and receive the battlefield picture, to and from the weapon systems through data networking makes it a lethal acquisition.

"These attack helicopters will provide significant edge in any future joint operations in support of land forces," the IAF added.

Additionally, the Defence Ministry in 2017 approved the procurement of six Apache helicopters along with weapons systems from Boeing at a cost of Rs 4,168 crore for the Army. This will be its first fleet of attack choppers.

Fuselages for this Army order will be produced by Tata Boeing Aerospace Limited, a joint venture between Boeing and Tata Advanced Systems in Hyderabad.