Staff Writer (Updated: 6/30/2016):
The AC-130, having been derived from the armed AC-47 gunship series, saw extensive and successful action against enemy forces in the Vietnam War. Appearing very much like the base C-130 transport model - a system that already came into its own as one of the most successful transport designs ever made - but were armed with a lethal array of miniguns, cannons and howitzers. From a basic design perspective, the AC-130 is a shoulder-mounted straight wing system with a single large rudder aft. Four Allison turboprops are mounted underwing, with two per wing. The spacious cargo bay of the base C130 allows for the carrying of the powerful 105mm cannon along with additional weaponry, ammunition and necessary systems.
AC-130's gain their lethality through support of troops in contact, often referred to in the short form as "TIC". AC-130 systems are charged with loitering above combat zones, often working in the darkness of night or inclement weather, using advanced targeting and fire control systems to assist ground troops in need. Though mounting an impressive array of armament, the AC-130's are not up to the task of defeating enemy heavy armor or bunkers but can target concrete structures and light armored vehicles with penetrator rounds. Due to the close proximity of engagement to friendly forces, AC-130's often bore sight with live-fire prior to arriving in the target zone. Firing is accomplished from one side of the aircraft only and requires the aircraft to be in a deliberate turn to engage. As a low-flying system, the AC-130 requires air defense threats to be neutralized before entering enemy airspace, though radar jamming and countermeasures are offered the system.
The current breed of AC-130 systems break down into two variants designated as the AC-130H and the AC-130U. Different avionics and subsystems aside, the two aircraft share many similarities. In terms of armament however, the AC-130U incorporated a 25mm gun to compliment the standard 40mm cannon and 105mm howitzer. The accepted callsign for the AC-130H series is the threatening "Spectre" while the AC-130U series enjoys the mysterious "Spooky" callsign.
Cost estimates per unit in 2001 were slated at $132,400,000 for the AC-130H system and $190,000,000 for the AC-130U system. The AC-130U also employs more crew to function and consists of a pilot, co-pilot, fire control officer, flight engineer, navigator, TV operator, four aerial gunners, a loadmaster, infrared detection set operator and an electronic warfare officer. The AC-130H maintains a crew of just 8 personnel.
Seeing action in Vietnam, the AC-130 crews went on to prove the value of the system time and again in Operation Just Cause to retake the tiny island nation of Panama in 1989. From there, Operation Desert Storm threw the AC-130's into action once more, warming crews up for the inevitable action over Bosnia Herzegovina. Currently seeing action in Operation Enduring Freedom, the AC-130 has solidified its place in the US military inventory - for both wartime and even through emergency evacuation of American non-combatants overseas. The AC-130 is kept in limited supply of just eight AC-130H models and thirteen AC-130U models.