I have noticed that Black Hawk helicopters have tires, but I have not seen one take off like a plane.
When would a helicopter need to use a running take off or landing?
When is it determined whether a helicopter gets skids or wheels?
$\begingroup$
$\endgroup$
Add a comment
|
$\begingroup$
$\endgroup$
7
AOPA has a nice little blog post on the matter
Skid landing gear is simple and lighter weight, so it is the best choice for small helicopters as weight is always a consideration. Also, skid landing gear needs very little maintenance, but the drawback is that ground handling is more difficult.
And for wheels
On larger more powerful twin-engine helicopters weight is not as big of a concern and retractable wheels make sense. Wheels are nice because a helicopter can ground taxi (as opposed to hover taxi) around other aircraft and people without worrying about producing a high downwash. Retracting the gear also reduces drag, allowing for a higher cruise speed.
So skids are light and simple and wheels are convenient when you have the useful load and space.
This article also notes thats skids are preferred when parking on an non-level surface to prevent accidental rolling around and or sliding off the deck of a carrier.
The answer seems to be that they are chosen based on the mission profile of the helicopter as well as the size to some extent.
-
1$\begingroup$ When would a helicopter need a running take off? $\endgroup$ – Muze Jun 25 '19 at 22:52
-
4$\begingroup$ When it is over weight, high altitude, or hot weather. $\endgroup$ – Ron Beyer Jun 25 '19 at 23:15
-
4$\begingroup$ The rotor's lift jumps when the rotor starts to get clear of its own downwash and is biting undisturbed air. It's called "translational lift". At about 20-30 kt. If you have wheels you can roll until you have translational lift and takeoff in conditions where you're too hot/high to hover in ground effect. If you have skids you have to try to get the machine sliding along on the skids. On grass not so difficult, but tougher on pavement. Performance and ground maneuvering wise, wheels are always better. But the wheels are single-point of surface contact and can be a problem on soft terrain. $\endgroup$ – John K Jun 25 '19 at 23:40
-
1$\begingroup$ For embarked helicopters, wheels are the only practical way to maneuver on the flight deck. $\endgroup$ – AEhere supports Monica Jun 26 '19 at 11:20
-
1$\begingroup$ @Åsmund If you were still too heavy to hover in ground effect, say because you had to return right away before burning off fuel, you would do a run on landing at some minimal forward speed and slide along to a stop if on skids. If you had no option but a little helipad with no horizontal space, you would have no choice but to start a hover with the engine maxed out and just let it settle vertically to a firm touchdown. $\endgroup$ – John K May 10 at 15:32
