Snow Aviation International (SAI) is close to completing a major sale with a US military customer for a $6.5 million upgrade package for older-model Lockheed Martin C-130s.

Harry Snow, founder and president of Ohio-based SAI, says the company is already talking to a "specific group within the US government and foreign governments" about the "C-130M" modification package. Snow says a deal with the US launch customer could be announced imminently.

The US Air Force and the Special Operations Command have been evaluating replacement and upgrade options for hundreds of C-130Es and C-130Hs still in active service.

USAF C-130
 © USAF

USAF acquisition officials have acknowledged that SAI's upgrade package is being considered among the options for replacing the 1960s-era HC/MC-130 fleet. SAI is also in discussions with potential industry partners for the production phase. Snow says, however, that the company is prepared to produce the upgrade kits independently if the customer prefers.

SAI's upgrade kit is aimed at providing the oldest C-130s with a short take-off and landing capability while strengthening the aging aircraft's weakest structural elements such as the centre wing box. It has completed a three-year series of flight demonstrations for the upgrade package, which includes adding Hamilton Sundstrand NP2000 eight-bladed propellers and 1,940 litre (512USgal) wingtip tanks.

Increases in thrust and lift created by both the eight-bladed propellers and tip tanks allow a modified C-130E to reduce take-off roll by 30% using the same Allison T56-A-7 engines, says SAI.

Compared with the four-bladed propellers, the NP2000 also eliminates aircraft vibration and reduces noise, the company claims. SAI also extends the C-130's chord rudder and enlarges the dorsal fin to improve directional stability in case of a flight critical engine failure and reduces minimum control speeds on the ground and in flight.

The tip tanks also serve the secondary purpose of improving airframe efficiency by removing the need for underwing fuel pylons, which enhances "after take-off climb gradients, climb rates, low-to-mid-altitude fuel specifics, total mission fuel burns and operational ceilings", SAI says.

SAI's upgrade package is offered amid a resurgence of interest for tactical airlift by the USAF, which is already committed to a multi-year purchase of C-130Js and an avionics modernisation programme for 221 C-130Hs and 119 special mission variants.

Source: Flight International