The Martin-Marietta AAS-38A mounted on an F/A-18C

The AAS-38 pod came in 2 varieties: The AAS-38 (non LASER Designator/TV FLIR only) AAS-38A LASER Target Designator/Ranger (LTD/R). The LASER Spot Tracker (LST) capability came from the use of the ASQ-173 pod. The AAS-38A and ASQ-173 pods are meant to be used together to be able to Designate for Laser Guided Weapons (Example: GBU-12) and "see" another source's LASER designator (LST capability of the ASQ-173 pod. The AN/AAS-38A is commonly referred to by the US Navy as TFLIR or Targeting FLIR. The AAS-38 pod system, as of May 2008, is being phased out and replaced by the ASQ-228 ATFLIR pod. This will be a sequential replacement as the ATFLIR pods become available. The introduction of the ATFLIR is seen as a significant capability increase in all Hornet US Navy fleet aircraft.

Litening II/ER/AT[edit]

Northrop Grumman Corporation and Rafael Advanced Defence Systems completed product improvements on the "Basic Pod" including a third generation FLIR, laser marker and software upgrades (LITENING II) which was fielded beginning in 1999.

Northrop Grumman and Rafael Advanced Defence Systems subsequently replaced the "320x256" FLIR with a latest technology "640x512" FLIR. This pod, known as LITENING ER, extended the target detection range and was fielded in 2001. The newest version, LITENING AT, is in production and was fielded in 2003. It further extends target detection and recognition ranges, improves the target coordinate generation accuracy, and provides multi-target cueing.^[3]

LITENING AT features a plug-and-play bay configured to accept a wide variety of data-links and recorders. Plug and Play II data-link capability offers warfighters increased range, digital data recording and an option to incorporate secure, two-way communications over ultra-high frequency (UHF) radios. LITENING's Plug and Play I, introduced in 2003, was the first data-link to be incorporated in a third generation targeting pod.^[4]

The 553 was superseded by the DEFA 554, which incorporates a number of detail improvements. The DEFA 554 uses three, rather than two, of the chambers for reloading, increasing rate of fire. Barrel life and mechanical reliability are improved, and an electrical control unit now allows the pilot to select two rates of fire: 1,800 rounds per minute for air-to-air use or 1,200 rounds per minute for air-to-ground attacks. The 554 also provides three pyrotechnic cartridges rather than one, allowing the pilot to cock the weapon only after take-off while still having two cartridges to recock in flight.

RAF and Fleet Air Arm Harriers did not adopt the Equalizer for their Harrier GR7 and GR9s. The British had originally planned a pair of ADEN 25 guns (using the same ammunition as the GAU-12/U, but based on the 30 mm ADEN cannon). That gun was canceled in 1999 after protracted development problems, and British Harrier GR7/9s were without gun armament until retirement.^{[citation needed]}

The Equalizer is also used in the AC-130U Spooky gunship, where one cannon is mounted on the port side, and the U.S. Marine Corps LAV-AD air-defense vehicle. Other applications have been planned for the GAU-12/U, including a mounting for the AH-1 Cobra attack helicopter.

The Equalizer was also used as the basis for the Sea Vulcan 25, a turret mounted gun for naval ship self-defense, although not as a Close-In Weapon System, as the gun was not automatic nor did it use radar tracking. Instead the gun was manually aimed using a digital gun sight and fire control. Sea Vulcan consisted of a 540-round helical drum magazine, a one-piece aluminum turret that can be opened with just a screwdriver, and the main gun. One unique advantage of the system was that it was capable of operating independently of ships power; the gun and ammunition magazine were powered by a 3,000 psi pneumatic drive and the turret motor by twin lead-acid batteries.

Intended as a higher-firepower alternative to conventional deck-mounted machine guns and cannon, the weapon employs the Navy's Mk 24 target designator and laser range finder for enhanced accuracy. The gun was developed in the mid 1980s as a cost effective protection for ships smaller than frigate or corvette or patrol boats but did not enter service.

The GAU-12 was utilized as the principal armament for the Rutan ARES.

Mk 4 Mod 0[edit]

Developed by the US Navy, this pod is fitted with the Mk 11 Mod 5 20 mm cannon, along with 750 rounds of ammunition.^[20] This pod is said to have been used on a variety of US Navy and Marine Corps aircraft including the A-4 Skyhawk, F-4 Phantom II, A-7 Corsair II, and OV-10 Bronco.^[1] Approximately 1200 Mk 4 Gun Pods were manufactured by Hughes Tool Company, later Hughes Helicopter, in Culver City, California. While the system was tested and certified for use on the A-4, the A-6, the A-7, the F-4, and the OV-10, it only saw extended use on the A-4, the F-4, and the OV-10. In the case of the OV-10, the unit was used by VAL-4, a Navy squadron assigned to Binh Thuy, Vietnam, and was used extensively for close air support missions.