Purpose
To simulate landing the aircraft in the event of a power loss while in a hover or during hover taxi.
Description
- Demonstrate response to an engine failure in a hover (or hover taxi).
- Allow the student to practice response to engine failure in a hover.
Instructional aids and pre-requisites
Lessons PS-1 through PS-2 are pre-requisites
Content
- Position the aircraft into the wind over the taxiway in a 2-3΄ hover
- Identify a distant vertical structure the student can use as a reference
- Reposition hand so that the throttle can be completely closed
- After a 3-count, smoothly roll the throttle into the overtravel position and simultaneously correct yaw with right pedal
- As the aircraft settles, increase collective to cushion the landing
- Keep the throttle in full detent
- Correct sideward drift with cyclic
- Apply slight forward cyclic as the aircraft makes ground contact
- Once firmly on the ground, lower the collective to full down
Common errors
- Excessive yaw
- Encourage the student to slowly and smoothly roll of throttle to allow ample time to make compensating ATP inputs
- Hard landing
- Early application of collective, causing loss of rotor RPM prior to touchdown
- Not using all available collective
- Rightward yaw on set down
- Failing to move the throttle all the way against the stop, or allowing the throttle to open slightly when pulling collective
Completion standards
- Heading ±10°
- Touchdown in a level attitude
Teaching considerations
- Teach “Throttle-Pedal, Settle-Pull”
- Guard against aft or sideward drift
- Performing this maneuver during a slow forward taxi may help isolate the inputs
- Guard against student inadvertently increasing throttle
- Practice rolling throttle down several times while on the ground, just prior to initiating the maneuver
- Ensure the student completely closes the throttle and holds it against the overtravel stop
- Practice this maneuver over a smooth, hard surface. Soft surfaces increase the risk of dynamic rollover or a tail boom strike if there is any lateral or fore/aft movement on ground contact
- Discuss with students what other applications this emergency procedure is used for
Video on how to perform hovering autorotations
Additional practice
- Not applicable
Additional resources
- None currently
#1 by Dave Smith on August 12, 2010 - 08:02
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arrgh! “full detent!” there is no R22 industry agreement on what the word “detent” means–CFI’s throw it around as though we all meant the same thing, but on interrogation some describe detent as the first resistance of the correlator spring, some describe it as the zone from first spring resistance to the firm throttle stop, and some attribute it to the final firm throttle stop. Too much confusion, bad word, start over! Throw out “detent,” instead develop terms for the correlator stages (still working on this) such as “idle stop” and “first correlator spring contact” and “final throttle stop, correlator fully compressed” or even new terminology: “soft stop” for idle-position-at-first-spring-contact, and “hard stop” for correlator-fully-compressed. (I now realize this comment belongs somewhere else, looking to moderator for diversion/guidance.)
#2 by Chris on August 24, 2010 - 18:12
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And the problem is that you don’t discover the difference in terminology until an unfortunate time (like when flying with another instructor, transitioning to another aircraft, or learning a new maneuver). In the POH, Robinson refers to the throttle positions in several different ways, and it’s here that the “detent” term is introduced. From looking at their terminology though, it looks like there are only 2 relevant positions:
Closed, or against the idle stop, which is the position used during start-up and shut-down.
Overtravel/detent/hard idle stop. This is the position where the throttle is fully closed past the idle stop and held against the hard stop.
Just from looking at the POH, the confusion is that Robinson does use “into the over travel spring” when (at least in my experience) they mean “against the hard idle stop”, where the throttle is closed and will not open at all when the collective is raised. The distinction that I see is that there are times where you simply want the throttle closed, and there are times where you want to override the operation of the correlator to prevent the engine from adding power (=torque), regardless of collective changes.
This would be a worthwhile lesson in a systems or pre-flight section, where the throttle operation is reviewed. Thanks for the comment.
#3 by Dave Smith on August 13, 2010 - 07:52
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How about a vote? Issues: the industry calls it a hovering auto, but everybody agrees (yes?) there is no autorotation involved. Can we retitle the maneuver “hovering power failure?” Or something like that? Can we also slip in a warning against trying to do this on SOFT SURFACES like turf or sand (hitting soft surfaces bends helicopters, it doesn’t protect them!)
#4 by Chris on August 24, 2010 - 17:14
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Agreed–”hovering autorotation” isn’t correct!
Also, your points about not doing simulated engine failures in a hover to soft surfaces is good. Anybody can make changes to these lessons easily by registering, then clicking “edit this entry” at the end of the lesson, right below the Post Revisions section. For more info on how it works, click here, or you can watch this short YouTube tutorial here.