Operation Shed Light - Tropic Moon III

Tropic Moon III

Shed Light’s Second phase eventually turned out to be based on the B-57. B-57 aircraft had already been deployed to southeast Asia and had been the subject of initial sensor evaluations under Tropic Moon II. Tropic Moon III was envisioned as an SCNA that made up for the gross shortcomings of Tropic Moon I and II.

Tropic Moon III involved a completely new set of systems, up to date, and infinitely more capable than those previously installed. An entire new aircraft sub-variant, the B-57G, was developed for the purpose with a redefined nose to house the new sensor package. Development of the aircraft experienced major delays during which it was equipped with a laser target designated to be used with the then new first-generation Pave Way laser-guided bombs.

In the end the Tropic Moon III proved to be a capable system, both with conventional ordnance and laser guided weapons, day and night. However, the advent of the side-firing gunship threatened the system. The B-57G conducted its first combat missions in October 1970 during Operation Commando Hunt V. The kill rates per sortie between the AC-130A/E and the B-57G made it clear which system was dominant in the role of "truck hunter," in reference to the primary targets of the campaign. During the course of the operation the B-57G's claimed over 2,000 trucks destroyed, mostly as a result of using precision guided weaponry. In the same period AC-130s were credited with destroying six times this number of trucks. While B-57G operations continued, this led to an attempt to modify the system to incorporate gunship elements. One B-57G was modified to house a special bomb bay installation of one Emerson TAT-161 turret with a single M61 20mm cannon as a gunship under Project Pave Gat. This system proved to still be inferior to the capabilities of the AC-130.

In addition to their laser guided ordnance, Tropic Moon III B-57Gs also used a variety of conventional ordnance, including M36 incendiaries, cluster dispensers, and iron bombs. These other systems were used in light of a shortage of precision guided munitions available.

The B-57G was removed from the theatre in May 1972 coinciding with the withdrawal of the bulk of US Air Elements. Plans remained for the continuation of the B-57G program and there were proposals for multiple wings of aircraft to operate in concert with AC-130s and similar aircraft. Post-conflict spending cuts ended this.