CHIEF WARRANT OFFICER 2 ROBERT L. NORTON
3/126 Aviation Battalion
Massachusetts Army National Guard
Cape Cod, Massachusetts
It was a clear, crisp day in New Hampshire’s White Mountains as we flew visual flight rules in our UH-60A. The pilot in command (PC) and I had departed the Army National Guard Concord Army Aviation Support Facility for some mountain training. The winds were light enough that we practiced mountain approaches to the helipad atop Mount Washington, not far from an observatory.
We were flying without a crew in the back, and the sun coming through the windows kept us from needing to run the heater. As a result, we had very little air circulation in the aircraft. As we hovered over the pad on one of the approaches, the small vent on my pilot-side window popped open and the PC thought he smelled something. I closed the vent, commenting that I hadn’t noticed anything unusual.
We decided to land nearby at Twin Mountain Airport to check the aircraft. As we slowed to land and entered effective translational lift, we both immediately noticed something that smelled like burning plastic. Up to this point, nothing in the cockpit suggested any problems and our engine indications were all within limits.
Once we were on the ground, I told the PC that because of the odor, I suspected we had an electrical problem. He did a walk-around, looking to find the cause. Just as he was finishing, smoke began billowing into the aircraft from the right-rear part of the cabin near the rescue hoist. He immediately reentered the co-pilot’s seat and we performed a dual emergency engine shutdown and exited the aircraft. Luckily, we had another aircraft in the vicinity. Once the smoke and fumes cleared out of the cockpit, we used our high-frequency radio — which operated on battery power — to contact them.
While the other aircraft was en route, we inspected the No. 2 engine cowling. We discovered the V band clamp connecting the engine to the hover infrared suppressor system (HIRSS) baffle deswirler failed. Looking closely, we could see a 1-inch gap between the sections. The smell we noticed was gaskets melting in the No. 2 engine cowling.
The second Black Hawk landed behind us and shut down. Its pilot walked to our aircraft, stopping to pick up a metal fin lying on the tarmac. We soon identified it as a missing fin from the deswirler. Fortunately, the PC in the other aircraft was our facility maintenance officer. He assessed the damage and took pictures of the area. We then secured the aircraft and left it under the supervision of the local sheriff’s department.
The UH-60 was recovered two days later. Upon examination, maintainers found damage to the aircraft’s No. 2 engine cowling and HIRSS baffle deswirler. High temperatures also damaged sheet metal in the engine compartment.
Lessons learned
It definitely pays to play it safe, especially in a peacetime environment. Choosing to land the aircraft at a suitable site and give it a once-over paid huge dividends in this case. I’d hate to think about what could’ve happened had we headed home fat, dumb and happy and something major failed.