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I'm talking about movement left and right without changing attitude. This is a motion that can be done with a quadcopter and to a limited extent a helicopter (I presume).

On a helicopter a left/right movement of the cyclic will command a roll motion from the rotor, but in a hover the aircraft would only roll slightly then begin to move sideways. Does the pilot just call this a roll or is there another, more appropriate word?

I thought of slip or crab, but those describe specific attitudes associated with forward flight. They don't seem to fit the bill here.

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    $\begingroup$ In the standard 6-axis terminology this is called Sway. I have no idea if there's special helicopter terminology. $\endgroup$ – Dan Sheppard Apr 27 '17 at 0:11
  • $\begingroup$ Are you asking what a pilot uses to describe sideways flight? $\endgroup$ – Simon Apr 27 '17 at 5:09
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    $\begingroup$ @Simon Looks like the term I'm looking for is sway. I've never heard that term before. What do you call sideways flight? $\endgroup$ – TomMcW Apr 27 '17 at 5:42
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    $\begingroup$ "Sideways flight" :) Technically known as "translating". $\endgroup$ – Simon Apr 27 '17 at 7:15
  • $\begingroup$ A quadcopter can't move sideways without changing attitude at least slightly, unless the lateral movement is caused by the movement of the air (wind). $\endgroup$ – Steve Apr 27 '17 at 12:23
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The answer is in the question: lateral, fwd/aft is longitudinal. The cyclic stick directions are cyclic longitudinal and cyclic lateral: move the stick and the rotor tilts, producing direct translational movement. The helicopter fuselage follows the rotor angle and therefore pitches/rolls as well, but more as a (desired) side effect. Desired because they enable instant judgement on the amount of stick applied. In a fixed wing, stick fwd/sideways is pitch stick and roll stick, because stick inputs primarily affect the aircraft attitudes. Longitudinal and lateral are helicopter terms because stick inputs (in a hover) mainly affect translations. And yes on a 6-DoF simulator motion system they are called Surge and Sway.

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  • $\begingroup$ In a helicopter, longitudinal and lateral are only used when referring to the airframe for example when calculating CofG. The attitude is always described as pitch, roll and yaw - the same as aircraft. $\endgroup$ – Simon Apr 27 '17 at 5:08
  • $\begingroup$ Yes the attitude is pitch roll and yaw, same as in a fixed wing aircraft. But the helicopter cyclic stick sideways is not called Cyclic Roll, it is called Cyclic Lateral. $\endgroup$ – Koyovis Apr 27 '17 at 6:17
  • $\begingroup$ Have made the answer more concise. $\endgroup$ – Koyovis Apr 27 '17 at 6:30
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    $\begingroup$ I have never heard from my instructors, QFIs or other pilots anything other than left/right or forwards/backwards (fore/aft) for cyclic input. $\endgroup$ – Simon Apr 27 '17 at 7:17
  • $\begingroup$ Well that makes sense, longitudinal is kind of an inconvenient word to use. It was mentioned that way in the technical documentation of a couple of helicopter flight control projects I did in the distant past. Maybe it's only used in fancy brochures, or in the USA. $\endgroup$ – Koyovis Apr 27 '17 at 8:46
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The term I preferred was "slide"

In our NATOPS manuals, and in our trained procedures in both Search and Rescue ops, and cargo ops, in the Navy the crewman would call for us to "slide left" or "slide right" as he positioned us over the pick up point. (Easy Left/Easy Right as we got closer to the spot).

The FAA term "sideward hovering" suffices, but it is two words. If you want one word, slide is about right.

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  • $\begingroup$ Was unsure which answer to accept. I decided on Koyovis' answer because the technical term I think I was looking for was sway. But slide would make more sense to the photographer I'm working with, so I'll be using your term. +1 $\endgroup$ – TomMcW Apr 28 '17 at 18:36
  • $\begingroup$ @TomMcW Glad to be of help. $\endgroup$ – KorvinStarmast Apr 28 '17 at 18:37
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The FAA Helicopter Flying Handbook discusses maneuvering in chapter 9. This movement is called a sideward hover.

Sideward hovering flight may be necessary to move the helicopter to a specific area when conditions make it impossible to use forward flight. During the maneuver, a constant groundspeed, altitude, and heading should be maintained.

There are also the forward and rearward hovers, and the hovering turn. These hovers are probably all specific to helicopters, where straight and level flight is designed to be performed in the forward direction. Aircraft like quadcopters are less directional and can generally fly "straight and level" in any direction relative to the quadcopter.

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