Combat Aircrew Coordination in the AC-119G/K

By Larry Juday

Crew coordination, discipline, and teamwork are important in operating any crew aircraft, but these were critical elements for AC-119G (Shadow) and AC-119K (Stinger) gunships flying in Vietnam. Gunship crews consisted of pilots, navigators, sensor operators, flight engineers, gunners and illuminator operators. Other military aircraft, such as the EC-121, flew with large crews, and like Stinger and Shadow, they were propeller aircraft that often flew at night. However, the similarities end there. Gunships flew eight and ten man crews in active combat. They did it using old, noisy airframes that required both pilots on the flight controls at the same time; scanners leaning into the wind stream calling out anti-aircraft fire; gunners loading ammo under a rolling, pitching g-loads, and; with everyone relying on a single intercom system.

Two Pilots Simultaneously Flying the Gunship in the Firing Circle

“Flying” means controlling aircraft pitch, roll, yaw and power. In ordinary flying, only one pilot flies the aircraft. This was true for the AC-119 – except when on target when two pilots flew the aircraft simultaneously. The need for two pilots on the controls would have been unnecessary had the AC-119 had an independent autopilot altitude-hold feature like the AC-130. With altitude-hold, the pilot need only follow fire-control computer guidance and roll on to the firing circle. But, this was not the case with the AC-119.

Once in the firing circle the pilot had no reference to level flight since his head was turned left and his eyes fixed in the gun site. The pilot (aircraft commander) controlled only bank (roll and yaw) while the right-seat pilot (copilot) controlled aircraft altitude.

Two pilots simultaneously controlling the aircraft required considerable practice, anticipation, coordination, and smoothness to maintain the steady platform required for accurately placing 7.62 mm and 20 mm rounds on target. The challenge for AC-119 pilots was overcoming the fundamental requirement for maintaining level flight in a turn: always increasing pitch (increasing back pressure on the yoke) and adding power. Instead, gunship pilots had to concentrate on not adding back pressure and learn to trust the task to the copilot whose duty was to control altitude by holding constant back pressure on the yoke and instinctively compensating for inadvertent input by the pilot.

The copilots’ challenge was further complicated by the fact nearly every mission was flown at night making it nearly impossible to rely on using the horizon as an attitude reference. Consequently, the copilot focused on the aircraft’s artificial horizon. Unfortunately, the copilot artificial horizon (attitude indicator) was the J-8 original equipment. J-8 gyros were notorious for rapidly precessing – meaning the instrument quickly became unreliable after about one turn in the firing circle. To compensate, right seat pilots learned to “fly” the highly sensitive vertical velocity indicator (VVI), an instrument that instantly indicates a change in aircraft pitch (up or down). Stinger copilots had an additional aid of the pilot’s attitude indicator – the sophisticated and more reliable ADI/HSI display.

Engine Power Control in the Firing Circle

The copilot and flight engineer worked together in configuring the R-3350 engines for combat. In Shadow, the copilot set the prop levers for desired RPM (Flying with un-synchronized props at night was sometimes used to help against enemy gunners detecting the exact location of the gunship). In Stinger, the flight engineer managed all recip engine tasks while the copilot managed the auxiliary jet engines.

In both Stinger and Shadow, the flight engineer’s role was continuous and complex. He typically situated himself on an empty ammo can positioned aft of the throttle control quadrant that separated the pilots. He performed his duties without the aid of a seat belt or harness. Moreover, because of the cramped space and the need for mobility the engineer frequently wore no parachute, but instead stashed his chute at a convenient location, usually against the fuselage behind the pilot’s seat

The engineer’s first task was leaning the engine fuel-to-air mixture to achieve near-maximum efficiency, and in the process, avoiding red-hot glowing exhaust stacks that could identify the gunship as a target in the night sky. This delicate setting required listening for a “pop” that occurred just as the engine reached the red exhaust zone. Once established, the engineer focused on watching the engine exhaust gas temperatures (EGT) to avoid damage from over-boosting. In addition, the engines required hourly de-fouling to clear the spark plugs.

The “K” in AC-119K signified that Stinger aircraft were equipped with two auxiliary J-85 jet engines in addition to the R-3350 radial engines. The right-seat pilot controlled the jets which were required for takeoff, typically shut down during cruise to conserve fuel, and then restarted in the target area and again for landing. Engine RPM was controlled electrically through a pair of toggle switches mounted on the center console. The jet engines were the principle means of controlling airspeed in the firing circle where the copilot flew with the right hand on the yoke to control aircraft altitude and fingers of the left hand toggling the switches to adjust airspeed. The on-target J-85 RPM was typically around 90-92% and could quickly accelerate to 100% as part of the procedure for breaking away from accurate AAA.

Aircraft Communication and Intercom Discipline

With as many as ten crew members actively engaged in target acquisition and engagement, the need for clear, concise, and accurate intercom communication was a vital. It was also highly demanding. The first difficulty was noise. The crew members stationed in the cargo compartment needed to hear and be understood over the roar of engines and guns firing. Flight-deck crew experienced less ambient noise, but was frequently engaged with three or more radio frequencies. Complicating these difficulties was the fact that the gunships had a single intercom system and a requirement for all crew members to use it.

To meet these challenges, gunship crews strictly followed checklist procedures that allowed each member to quickly respond and anticipate the action of others. In addition, all intercom transmissions followed a standardized format stating who was being called and who was calling: “Pilot, Gunner . . .”

While on target, the intercom was a vital link to safety and mission success. Shadow pilots directed full attention to the target while at the same time directing the crew in identifying targets, launching flares, ground markers, and communicating with ground contacts. Shadow copilots monitored radio traffic from all five aircraft radios, plus the intercom. The navigator also monitored all radios while verifying target information. The Night Observation Scope operator, securely strapped in the left forward open doorway, searched for targets and kept the pilot informed of visual sightings including target damage and destruction. Gunners transferred ammo, loaded and reloaded in a blacked out cargo compartment, and made repairs while using only the red light illumination of hand-held flashlights. The illuminator operator, positioned at the right rear of the cargo area near the flare launcher, also functioned using only a flashlight.

Stinger crews operated in a similar manner on truck-hunting missions, but with the copilot providing an initial briefing to fighter escorts circling overhead for AAA suppression and with a Forward Looking Infrared (FLIR) operator searching, tracking and assessing targets.

Evasive Action

Everyone on the gunship, and particularly illuminator operators and gunners, kept a sharp look out for threatening small arms and anti-aircraft artillery fire. Accurate AAA required immediate evasive action to avoid being hit. However, the AC-119 size, weight and air speed typically limited the pilots’ maneuvering to that of rolling left or right, pulling hard on the yoke to turn the aircraft, and increasing speed by adding power or diving – or both. The AC-119 possessed a remarkably rapid roll rate for its size – and could be quickly maneuver to more than 90 degrees of bank as circumstances sometimes required.

Assessing accurate AAA was a judgment call that improved with experience. A crew member seeing what appeared to be accurate AAA immediately called the clock position and action needed: “Triple A, two o’clock! Break left!” Pilots responded by immediately breaking away from the threat while the FE thrust fuel mixture levers to the full-rich and prop levers to full-power. In Stinger, the copilot immediately powered the jets to 100% and cleared the F-4 escort to attack the AAA site. The call to “break” was also a signal to other crew members to hang on. After assessing the circumstances, the crew could initiate the appropriate checklist and re-enter the firing circle.

Aircrew Performance

AC-119 aircrews operated old, slow, noisy, unpressurized aircraft primarily at night but also daytime as missions dictated and in many instances during marginal weather. They attacked targets in the unusual manner of two-pilots simultaneously flying the aircraft. They loaded and repaired guns in the dark. They operated then-new sophisticated sensors to locate and identify targets, enemy, and friendly forces. And, they trusted one another’s judgment in assessing and avoiding hostile ground fire. What could have been chaos was symphony through the exercise of discipline, coordination and teamwork. They accomplished their assigned missions. They were Shadow and Stinger Gunship Aircrews.

About the Author: Larry E. Juday was a 18th SOS “Stinger” Pilot at DaNang during 1970-71.