Coordination with the South Vietnamese was not the only concern of the Marine artillerymen. They also had to worry about low-flying aircraft due to the proximity of major airbases. The intensity of both air operations and artillery fire in the air space above the TAOR presented problems which demanded solution.

The doctrine limiting helicopters to designated routes proved to be too restrictive for both artillery supporting fires and helicopter operations because of the ever increasing volume of helicopter traffic in the TAORs. To alleviate the situation, the wing and the 12th Marines worked out a more flexible policy. The new system provided the pilots with the location of which areas were ' 'hot'' and which were ' 'safe.'' It enabled the aviators to plan their flights accordingly. If the pilot had to fly into a 'hot' area, he would receive additional information which enabled him to avoid impact areas and firing positions. The plan operated as follows:

The pilot reports in to the Direct Air Support Center

upon becoming airborne, the DASC gives the pilot the firing and gun positions which are ' 'hot,' with times of firing, if applicable. The pilot can then proceed throughout the remaining (safe) portions of the TAOR without restrictions. If the pilot is required to proceed through a 'hot' area, the DASC will provide him with fixes to allow the helicopter to proceed within 'hot' areas with maximum safety.6

This method of coordinating air and artillery fire allowed the Marines to employ artillery more extensively. Artillery missions fired in September show the degree of Marine artillerymen's support of HI MAF infantry operations:

Observed combat missions................... 650

Unobserved call fires ....................... 439

USMC Photo A185923

Marine gunners from the 12th Marines fire off a round from a 4.2-inch mortar. The Marine Corps in 196�) was replacing its howtars (a mortar tube mounted on a 75mm howitzer frame) with the 4-2-inch mortars in the artillery mortar batteries.