Grampaw Pettibone

Grampaw Pettibone

Gramps

Illustration by Ted Wilbur

Gramps from Yesteryear

Naval Aviation News May – June 2001

Danger Zone

A  CH-53D Sea Stallion was conducting practice landings at confined-area landing sites. As a demonstration, the helicopter aircraft commander (HAC) would make the first landing at each of a succession of different sites, after which the copilot would take over and make two landings at each site.

One of the locations had an upward sloping landing zone when approached on a southerly heading and was 150 feet in diameter with trees around the perimeter. The HAC made his demonstration approach and landing to the upper portion of the site on a southerly heading. The aircraft experienced an unexplained loss of lift on short final. The HAC initiated a moderate flare and power application to arrest the sudden rate of descent, and landed uneventfully. On deck, the HAC transferred the controls to the copilot who took off and established a downwind pattern 400 feet above the ground at 80 knots.

The copilot then began a descending, decelerating turn onto the final approach to the site at 60 knots. All was normal until the final portion of the approach when the helo seemed to lose lift just prior to commencing a hover on short final.

The aircraft settled and the rotor blades struck the trees, damaging the CH-53D. The tail rotor drive system was severed between the #4 and #5 drive shafts, producing uncontrolled right yaw as the helo landed.

Although the Sea Stallion had been on a southerly heading, when it struck the ground it had come around to 300 degrees. There were no injuries.

GramPaw Pettibone saysGrampaw Pettibone says:
Methinks the copilot was placed in a situation beyond his experience and abilities. Me also thinks the HAC failed to keep pace with what was goin’ on. The HAC may have looked danger in the face on his approach to the landing zone and survived, but he failed to recognize a repeat occurrence. Remember the old, simple and enduring axiom: stay ahead of the aircraft, not the other way around.