Controllability vs Maneuverability?

Discussion in 'Pilot Training' started by CC268, Nov 2, 2018.

  1. CC268

    CC268 Final Approach

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    The definitions in the PHAK are somewhat confusing to me. I understand controllability, but I am having a difficult time explaining maneuverability in laymans terms.

    PHAK definitions:

    Maneuverability—the quality of an aircraft that permits it to be maneuvered easily and to withstand the stresses imposed by maneuvers. It is governed by the aircraft’s weight, inertia, size and location of flight controls, structural strength, and powerplant. It too is an aircraft design characteristic.

    Controllability—the capability of an aircraft to respond to the pilot’s control, especially with regard to flight path and attitude. It is the quality of the aircraft’s response to the pilot’s control application when maneuvering the aircraft, regardless of its stability characteristics.
     
    Last edited: Nov 2, 2018
  2. eman1200

    eman1200 Touchdown! Greaser!

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    um, one is the ability to control and one is the ability to maneuver?
     
  3. mscard88

    mscard88 Touchdown! Greaser!

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    A3AE17A5-3059-42B6-87BF-B9C182EA292C.gif
     
  4. CC268

    CC268 Final Approach

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    Ok.
     
  5. jsstevens

    jsstevens En-Route

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    How long have you worked for Microsoft Technical Support? (An answer thats exactly correct and entirely useless is the punchline...)
     
  6. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser!

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    But, which is which?

    FAA sometimes defines things in the reverse of what you expect.

    Movement area - where movement is restricted
    Non movement area - movement is not restricted

    Side slip - airplane points forward - not sideways
    Forward slip - airplane points sideways, not forward

    etc.
     
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  7. Salty

    Salty En-Route

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    I can control a dump truck just fine, maybe even easier than a motorcycle if it has power assist everything, but I can’t manuever it like I can a motorcycle.
     
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  8. CC268

    CC268 Final Approach

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    I mean...yea I get that...whether or not an examiner is going to be satisfied with that answer on a checkride? Idk...he might want something with more substance.
     
  9. eman1200

    eman1200 Touchdown! Greaser!

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    tell him "I can show you what a lack of both are. one will probably fail my checkride, the other will ruin both of our day" and see what he says.
     
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  10. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser!

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    From the PHAK Glossary:

    Controllability.
    A measure of the response of an aircraft
    relative to the pilot’s flight control inputs

    Maneuverability.
    Ability of an aircraft to change directions
    along a flight path and withstand the stresses imposed upon it.
     
  11. kath

    kath Line Up and Wait

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    Maneuverability = "Wheeeeeee!"
    Controllability = <terrified scream>
     
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  12. CC268

    CC268 Final Approach

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    Thanks...close to the PHAK Chapter 5 definitions, but "ability of an aircraft to change directions" is better than "it's just maneuverable, man!"
     
  13. Skyrys62

    Skyrys62 Pattern Altitude

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    Controllability vs Maneuverability?

    With children, you need one... if you don't have the other.



    I know that's no help, sorry man. Good answer though Capt. Thorpe.
     
    Last edited: Nov 2, 2018
  14. Eric Gleason

    Eric Gleason Pre-takeoff checklist

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    That’s not the kind of question that gets asked on a check ride.

    For some examples to demonstrate the concept, think of a C-5 Galaxy. Highly controllable. The pilot has full command of the aircraft. Not very maneuverable. Turn radius the size of counties at cruise speed. Rate of roll is pnderously slow.

    For the opposite end of the spectrum, think Gee Bee raceplane of the 1930s. Highly maneuverable, but just barely controllable. It was described as trying to balance a pencil (upright) on your finger tip. Lots of pilots lost their lives trying to master it.
     
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  15. CC268

    CC268 Final Approach

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    Idk the gouge on this examiner is that he is the "kiss of death" lol. So I'm preparing for the worst.

    That is a good practical example and was more along the lines of what I was looking for.

    Thanks!
     
  16. -KLB-

    -KLB- Pre-Flight

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    Maneuverability: what the plane is capable of
    Controlability: how readily an average pilot can make it do what it is capable of
     
  17. CC268

    CC268 Final Approach

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    Nice...that's a good way of putting it as well.
     
  18. gkainz

    gkainz Final Approach

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    to paraphrase "Forged in Fire" ... one is about what the <hard object> does to your knife, while the other is what your knife does to the <hard object>
     
  19. mondtster

    mondtster Pattern Altitude

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    It certainly is, at least around here. Mostly at the CFI level but it isn’t unheard of at the commercial level.

    It would be in an applicant’s best interest to have some basic knowledge of aerodynamics.
     
  20. CC268

    CC268 Final Approach

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    Basic knowledge in aerodynamics is more than covered...just wanted some clarification on this specific topic that’s all.
     
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  21. ateamer

    ateamer Line Up and Wait

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    Maneuverability: How easily ya can whip it into a tight turn.
    Controllability: It won’t get squirrely on ya and start doing stuff on its own.
     
  22. Hank S

    Hank S En-Route

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    FTFY! Now it's better.

    Maneuverability is roll rate, yaw rate, etc. High maneuverability means high rates.

    Controlability = Controllable = it rolls / yaws when you want and as much as you want, and stops rolling / yawing when you want it to stop.
     
  23. -KLB-

    -KLB- Pre-Flight

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    Yeah, I debated how to keep that concise, but one interpretation of the fix suggest that if a pilot wants more than the airframe is capable, it is a lack of controllability, not a limit of maneuverability.
     
  24. Walboy

    Walboy Line Up and Wait

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    Use this visual aid for your checkride and future students. Tie the winglets with reduced induced drag. There's your controlability and maneuverability don't ya know. You're sure to get bonus points from the examiner. Don't worry about CG and stability...minor detail that's a distraction here.

     
  25. Hank S

    Hank S En-Route

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    Most often, bad things happen when the pilot exceeds his own limits, not the limits of the airplane.
     
  26. Silvaire

    Silvaire En-Route

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    I agree this isn't the kind of question that would come up on a check ride and even if it did it's something that could be discussed, maybe even debated but not something that could determine pass or fail. It comes down to splitting hairs. When I started flying the Pilot's Handbook really was a "handbook" - heck, even AD's were rarely more than a couple of paragraphs. To build it into the voluminous tome that it is today government employees must have struggled to fill pages and so we end up with unnecessarily complicated definitions of common words that everyone already knows the meaning of. This is a perfect example.
     
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  27. Stewartb

    Stewartb Final Approach

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    I spent the weekend with my Aerospace Engineering Professor buddy and I asked about stability, controllability, and maneuverability. He said this page sums it up very well. https://aviation.stackexchange.com/...ward-and-aft-cg-limits-indicative-of-the-over

    He also said the topic may be viewed differently by aircraft designers who work on fly- by-wire aircraft because they focus on control feedback. I thought that was an interesting twist.
     
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  28. Lachlan

    Lachlan Pattern Altitude

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    They’re not called “Air Traffic Maneuver” up there in the Maneuver Tower, ya know.