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VRS at 8,000 Feet

Discussion in 'Phantom 2 Discussion' started by Gary E, Jul 28, 2014.

  1. Gary E

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    Had my first VRS experience a few days ago. I'm posting here so others can learn from my experience and mistakes.

    I was located mountain top at 7,700 feet during calm air, temperature about 60 dgrees. A mountain top launch and accended to 1,000' AGL. Did some video 360's and then began a slow decent with slow horizontal flight. Slow decent was at 1.5 m/s with concurrent horizontal flight at aprroximately 2-4 MPH.

    At 266' AGL the aircraft entered VRS. Remedial RC action was immediately performed without much success. As others have experienced and reported, full up throttle does not work. The whole event lasted about 10 seconds, so a few seconds were lost to pilot reaction time as I had not experienced VRS before, so it was a bit of a surprise. With that, only about 7 seconds were available to correct the stall.

    The P2 looked like a sheet of paper falling. It shook and did large uncontrolled left and right pitch banks of approximately 30 degrees. The decending horizontal area of the continuous pitch movement was estimated at 20' wide from one 30 degree pitch angle in one direction to the next 30 degree pitch angle in the other direction.

    At about 40' AGL and 3 seconds before ground impact I applied full right aileron. The P2 increased speed to 10 MPH and travled about 20' horizontal distance during the last 40' AGL of decent. Impact was at a sideways flying pitch of about 30 degrees. I didn't see the impact as it was over a slight downward knoll. From the FPV monitor view, I knew the P2, or at least the camera was on it's side.

    Fortunately, very minimal damage was sustained, which was just a small piece of the leading prop tip missing. It impacted in soft dirt just short of lots of P2 size rocks. I cleaned the dust and dirt off of the P2 and camera and after an aircraft inspection, did a short 5' AGL flight to ascertain its flying capabilities. A check of the gyro calibration on the DJI Assistant back at my desk indicated no recalibration was needed. Unfortunately, the last 2 of 4 videos on the camera SD card are corrupted, so I cannot view the VRS flight (that ought to be the subject of another thread in itself). I do though, have Flytrex data that I studied.

    New knowledge:
    An appreciation of thinner air at altitude. I'm a long time pilot, so I should know better.
    At higher altitudes, the need for more horizontal speed while decending.
    It is noted that at the altitudes I typically fly at (1,300'-1,700') decents of 3m/s are common with no ill effects or indications of VRS.

    The other various threads on tips for surviving VRS are very good, informative, and are recommended reading. Too bad I didn't read them until after this VRS event.

    I hope others can benefit from the details of this particular flight.
     
  2. damoncooper

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  3. Haze

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    MY VRS Recovery

    https://www.youtube.com/watch?v=IJnjqzu ... 2Uq_Ck1fxA
     
  4. EMCSQUAR

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    Thank you for the helpful reminder.
     
  5. Gary E

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    I read the thread the other day damon. It's a good one.

    Haze, My VRS event was much more violent and very wide horizontally, as yours looks somewhat benign.
     
  6. Haze

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    i lost abot 25m in 3 sec and as u see my video has a gimbal but u see the craft come into view a few times u know by that its rocken and rollen all over the place, but i got out of it. have been in it before and learned side stick out of it, no throttle at all ( leave centered as mine has self center stick).

    Here is a VRS Crash i Had to learn from

    https://www.youtube.com/watch?v=TrnH-No ... 2Uq_Ck1fxA
    crash is at 20:00
     
  7. damoncooper

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    Haze, not sure if you noticed but you actually entered VRS at around 18min or so in on the trip home when you began descent. You actually exited cleanly by pushing forward on the stick. But the next descent got you.
     
  8. Gary E

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    I will also add, regarding my VRS event, that although horizontal flight in any direction is recommended as action to get out of VRS, it was not the panacea in this case, as The P2 simply ran out of altitude. Quicker action at applying horizontal flight at a higher altitude may have saved the day.