High-explosive incendiary (HEI) rounds fired by most US Air Force fighters may soon be replaced in the inventory by inert 20mm bullets.
The General Dynamics PGU-28 A/B 20mm semi-armour piercing HEI round entered service during the last decade with the M61 cannon installed on the Boeing F-15, Lockheed Martin F-16 and Lockheed F-22. As of 2001, the USAF and US Navy had stockpiled 8 million PGU-28 rounds, each of which features a pyrotechnic fuze and a pyrophoric explosive.
But the USAF is now seeking a replacement round, launching a market survey on 1 June to identify potential sources for a "non-fuzed, non-explosive round with PGU-28/B [aerodynamic] performance", an acquisition notice says. The market survey is being conducted by the Joint Munitions and Lethality acquisition centre at Picatinny Arsenal, New Jersey.
The current stockpile of PGU-28/B rounds "limits mission effectiveness," the notice adds. Concerns about the safety of the HEI round have surfaced involving in-bore explosions. An upgraded version of the PGU-28/B has satisfied the navy's Boeing F/A-18 community, but not the air force.
Unlike the F-18, the air force's fighters have cannons mounted directly beside the cockpit, making in-bore explosions an injury risk for the pilot.
Anticipating the requirement long in advance, Alliant Techsystems (ATK) has licensed manufacturing rights in the USA for a round designed by Germany's Rheinmetall.
The Penetrator with Enhanced Lateral Effect (PELE) round would provide a tungsten casing that would be shattered on impact by a plastic slug. The effect is a blast of shrapnel spreading outward, or laterally, from the impact area.
The 20mm PELE round for the M61 cannon was designed with the air-to-air role of the fighter as the main focus. However, its utility in strafing runs against ground targets - an increasingly important mission for the USAF - has never been tested, says Rodney Ward, a business development director for ATK Ammunition Systems.
In 2004, ATK received a USAF contract to test the air-to-air effectiveness of the PELE round, Ward says. An operational test and evaluation phase is ongoing and should be completed in the fourth quarter of this year.
The market survey is an indication that the air force will seek alternatives to the PELE round to replace the PGU-28/B. Ward says the programme reflects a major change in combat capability for the air force, rather than just a straightforward replacement for a round already in the inventory.
"This is a whole new capability," he says. "They [will] have a round that is effectively inert that has a lot of blast effect."
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Source: FlightGlobal.com
