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Safe descent speed?

Discussion in 'Pro/Adv Discussion' started by biggdave92, Nov 10, 2015.

  1. biggdave92

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    I learned with my hubsan that if you descend too quick you can lose stability and lose control. What is a safe descent speed with the p3a? When descending do you watch your speed or just listen to the bird?

    Sent from my SM-G920V using Tapatalk
     
  2. msinger

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    When descending straight down, I like to descend at a slow speed -- somewhere around 3 ft/sec. If you're coming down too quickly and are in danger of getting caught in VRS, you normally hear a change in the sound of the props before it's too late. If you descend at a slow speed though, you won't ever have to worry about that.

    If moving horizontally, you can descend with the stick in the full down position with no problem. I will often do this as I'm flying back toward the home point. Once I get to the point where I want to land, I then descend slowly straight down.
     
  3. dronie326

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    I have a question about this as well. Sometimes I want to descend with the throttle all the way pulled back but am worried the motors will stop if held there for longer than 3 seconds (as it does when powering the unit down). Is there something preventing it from shutting off? Like knowing it is still descending and not on the ground or something?
     
  4. msinger

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    Your Phantom will only shut off in the air if you do a CSC. Want to make that impossible? Get one of these.
     
  5. dronie326

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    What causes it to shut down when pulling the stick all the way back for 3 seconds after flying then?
     
  6. msinger

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    When the left stick is in the full down position, your Phantom will shut off 3-5 seconds after it stops descending. When flying in the air, it's not possible to hold the left stick in the full down position without descending.
     
  7. dronie326

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    I gotcha. So it is linked to the altitude. That's what I needed to know. Thanks!
     
  8. BigAl07

    BigAl07 Moderator
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    If you maintain forward flight you won't be descending directly through the rotors nasty turbulence and you'll avoid VRS which msinger mentioned. Some believe that VRS isn't possible with a fixed pitch rotor but that's a whole other topic.

    I land with a forward motion in a similar pattern to a fixed wing and land with the stick full aft until I'm ready to almost touch down.
     
  9. Jayfdee

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    My one and only crash was, I think VRS ,I always descend slowly and with a spiralling motion. IE forward,back,left and right and modest down on the left stick.
    It can take a while to get down from a high altitude,so I watch out for battery life.
     
  10. flyNfrank

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    I think the current rate on the P3P is slightly on the edge, but just right. I would hate to see it be any slower. And so would anyone else that got caught in a critical landing situation. It's nice to have the ability to descend quicker and then use the option to manually descend at a slower rate. But to be slow from the get-go like 4ms sucks.
     
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  11. Oso

    Oso

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    I normally descend straight down and at full speed with no fear at all of VRS. I'm not saying to do the same, just adding a data point for your consideration.
     
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  12. BillG

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    I also have often descended at maximum speed straight down. Never noticed a problem, FWIW.
     
  13. denodan

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    I have desendex with stick right down with no issues. The Phantom 3 has angled motors to stop most wash like the inspire. So much more stable on fast decent than your average quad.
     
  14. BigAl07

    BigAl07 Moderator
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    I think the preset rate is fairly safe (I admit I've descended straight down with stick full aft) with no problems. My other MR I had to watch it because it would descend into it's own crappy air and start wobbling and falling quickly. Talk about pucker factor LOL
     
  15. Wibble

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    The angled motors and slow decent speed of the P3 make it almost idiot proof. almost impossible to descend too fast sigh. It is annoying there should be an expert mode with an overide or else they could detect motion and allow you to descend a lot faster if you are moving forwards.
     
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  16. John Locke

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    Well kinda, the motors will also turn off with the left stick full down if you hand catch it 6' off the ground. When you hold it firm in the air 6' off the ground, it senses that it cannot descend, so it shuts off after about 3 seconds of holding the L stick down..
     
  17. Ti22

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    Hahaha… Suffered this no damage gem the other day. Heavily loaded P1 running big props.



    By comparison, when I remain closer to spec weight and stock props (8” for P1) I likely wouldn’t have suffered this crash.

    Big props definitely produce a larger wash so more likely to upset lift during rapid descent.