Comments on: Slope limits

By: Ron Stahla

Ron Stahla — Sat, 13 Oct 2012 02:17:18 +0000

While sitting on a lateral slope the fuel will run to the low tank and will affect how much cyclic you need to use.

By: dom

dom — Mon, 01 Oct 2012 00:17:49 +0000

As an H-60 driver for the army, we have tiltled tail rotors which means left pedal application on the ground = right roll, although having a crew chief or two poking their heads out of the window clearing the aircraft down for you and letting you know exactly how high each of your wheels are lightens the work load. Air Assault!

By: don mclean

don mclean — Sat, 29 Sep 2012 07:06:43 +0000

Also; translating tendancy and wind will affect how much cyclic you need to use. Which is another reason Bell doesn’t give a number to the degree of allowable slope.

By: Alan D. Resnicke

Alan D. Resnicke — Fri, 28 Sep 2012 17:54:19 +0000

While flying military aircraft, especially the UH-1N “Twin Huey,” we routinely practiced slope landings. It was a great contest between pilots to determine how much slope we could set down on and how smoothly we could do so. Occasionally it wasn’t cyclic limited but we’d be right on the edge of mast bumping (semi-rigid rotor system). For that, the Sikorsky HH-53 was much more capable. Still, the comments about surface stability that Avi Weiss references can make a huge difference even without mechanical limitations.

By: Alexis Geacintov

Alexis Geacintov — Fri, 28 Sep 2012 13:06:18 +0000

Another thing to consider is the critical angle at which dynamic rollover will occur, which changes based on the changing center of gravity due to the amount of fuel on the aircraft. Normally, having more fuel on board will cause the helicopter to be heavier, and bring the center of gravity down along the vertical axis. The lower center of gravity will result in a greater critical angle. The difference can be significant.

By: Avi Weiss

Avi Weiss — Thu, 27 Sep 2012 03:28:38 +0000

While available cyclic margin is the primary factor dictating acceptable slope angle, it is also a good idea to keep in mind surface conditions (reduce coefficient of friction) which may not be an issue on level terrain, but could be an issue while at an angle. Such conditions include wet grass, wet hard surfaces close to freezing, and slightly soft terrain.