Risk Management Magazine

Search for Articles

Surprise in the Snow

Surprise in the Snow

B Troop, 6th Battalion, 17th Cavalry Regiment
Fort Wainwright, Alaska

In December 2014, during a night vision goggle flight 20 miles south of Camp Humphreys, South Korea, another pilot in command and I were working on terrain flight tasks at landing zone Elbow. The LZ was bordered on the south and west sides by water that had frozen over in the cold. On the north side of the LZ were east/west powerlines that were about 150 feet tall. It is one of the only LZs where you can practice terrain flight takeoff and terrain flight approaches to the ground.

That day there had been 4 to 5 inches of snow accumulated on the LZ and frozen water. The weather brief for the flight was broken clouds at 3,000 feet with three miles of visibility. Winds were light and variable.

Our first approach to the LZ terminated in a hover at 3 feet altitude to test the snow to see if we would have whiteout conditions during landing. The pilot and I thought we could see where the LZ met the water. The snow was wet and heavy enough so we wouldn’t have any whiteout problems.

We took off and decided that for the second approach we would land to the surface. As we landed, the pilot on the controls gradually put weight on the skids, which was followed by a sudden drop on the left-side skid. Looking to the left, I could see the skid had broken through the ice and was underwater. The pilot, still in control of the helicopter, smoothly increased power and picked back up to a 3-foot hover. We returned to base and had maintenance conduct a visual inspection on the landing gear for any damage. Fortunately, no damage was found.

We had been overconfident in our knowledge of the LZ and landed too far on the south side with the left skid on the ice. The LZ at night, with fresh snow, and under NVGs, was deceiving. The edge of the LZ covered in snow meshed perfectly with the ice-covered water.

In hindsight, we should have inspected the LZ more closely and used the white light on the first approach to ensure there were no new obstructions and confirm the edge of LZ Elbow. The only reason we didn’t have a dynamic rollover on the second approach was the fact that the pilot on the controls had treated the landing as a slope landing, gradually reducing power, and was able to quickly recover and pick up to a hover.

“Every landing is a slope landing” was always preached to me during flight school and progression to Readiness Level 1. Now, instead of just doing it because I was told to, I believed in it from experience. We would continue to use LZ Elbow for terrain flight training. But after fresh snow, we would be sure to make a thorough recon in daylight prior to using it for landing at night and, that’s right, treat every landing like a slope landing.

  • 1 March 2016
  • Author: Army Safety
  • Number of views: 1167
  • Comments: 0
Categories: On-DutyAviation
Tags: DVEsnow