Proper Post-flight Inspections
CHIEF WARRANT OFFICER 5 TIM BURKE
U.S. Army Central, G32
Shaw Air Force Base, South Carolina
While conducting daily maintenance on an AH-64D, a crew chief discovered a 2-inch hole in the No. 5 driveshaft cover (tail rotor driveshaft). Upon opening the cover, he found a 30 mm round lodged underneath the driveshaft. He notified production control, his commander and the safety officer, and an investigation started immediately.
The investigation revealed the aircraft had been flown the previous night on a two-ship live-fire exercise. The team of two Apaches had conducted multiple engagements during the exercise in day and night vision device conditions. The hole was not seen during the post-flight inspection.
This incident could have been much worse. Luckily, the round, although it was under the No. 5 driveshaft, was not in direct contact with it. We don’t know if the round was from gun No. 1 or No. 2. It is possible the round was a ricochet from either aircraft. It definitely did not hit the aircraft in free flight or the damage would have been more significant. The end result was replacement of a tail rotor push-pull tube and sheet metal repair on the driveshaft cover.
As a safety officer, the incident brought to light some serious issues, including team tactics and post-flight procedures. The basis of our Apache pilot training is working in a team of two while engaging targets. We do this constantly. One thing that is often overlooked, though, is the spacing and timing between aircraft and not overflying the target.
Aircraft spacing and timing in a real engagement varies depending on the tactical situation. This is a broad and general statement, but it’s true. Timing, in this sense, is defined as gun No. 2 firing as gun No.1 is breaking. It is possible that gun No. 2 may have fired too soon and a ricochet hit gun No. 1. It is also possible that gun No. 1 overflew the target while engaging it and received a ricochet from his gun. The fact is we will never know.
Post-flight procedures are critical. In the above incident, if the aircraft was going out with another crew that night, the new crew may not have seen the hole in the driveshaft cover and ultimately would not have known about the round bouncing around under their No. 5 driveshaft. Do a thorough post-flight inspection and check the fuselage.
This incident could have been prevented by not overflying the target and using proper timing of ordnance between aircraft in the team of two. After the aircraft was on the ground, a proper post-flight would have at least prevented the possibility of another crew taking the aircraft that same night with potentially catastrophic results.
Brief and rehearse your team tactics and remember that the ricochet potential is real. It could bring your aircraft down long before the enemy does. A thorough post-flight gets maintenance on the job quickly and also prevents another crew from taking a malfunctioning aircraft.