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Low Battery Autoland feature nearly casued a crash AGAIN!

Discussion in 'Inspire 1 Discussion' started by World Media, Jul 30, 2015.

  1. World Media

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    Flew my inspire around a friends villa this morning, little wind, uneventful flight.

    I flew the battery down to about 30% and brought the inspire in to land manually at my relocated position.

    As I am in the landing sequence the battery drops off quickly and the warning comes up.
    So I am actually on the ground and just about to shut down when the battery low autoland to home feature decides to spool up the props and take off again, climb 10 metres and start flying back to my original takeoff point.... regardless of any line of sight obstacles!

    This is the second time this dangerous process has happened to me. Please let me turn it off and do not take control of my aircraft when I have landed it or am in the process of landing.
    when I had eventually regained control and avoided the obstacle it was about to fly into I brought the inspire down and hovered it for a further five minutes to fully discharge the battery pack.
     
  2. FangsCPO

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    1st mistake...........flying until your battery is close to 30%, 2nd mistake, not setting your safety to 20 meters or greater. The good think is that you have now discharged your battery and will get a fresh charge.
     
    Kilrah likes this.
  3. World Media

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    Its not a mistake to fly a battery to close to 30%. I would be very interested in seeing a directive in an operating manual that says that it is a mistake to fly to close to 30% of battery power.
    The safety was and is set to 20 metres. where I had landed had a slight overhang. The ascending , out of control, aircraft was in danger of flying itself into the overhang.
    However IT IS an issue to take off an AC that is already landed and on the ground. Isnt there there somethnig in nearly all regulations either in effect or planned to come into effect that the operator must at all times have control over the AC?

    Its happenned to me twice and it is plain dangerous in my opinion.
     
  4. IrishSights

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    Sorry but I don't fully get this. The solution is simple, you know at 30% this happens. You let it happen twice, without modifying your procedures. You now know a little more about the characteristics of your aircraft. Solution, don't let it get that low and immediately on touchdown turn off. You are just pushing the envelope a little to close to the edge. In my experience 20m is also way to low for safety reasons. Mine is set to 60m. If you consider what is being advised you would not have these issues and have a safer flight. We are just advising you, not finding fault. It's the way we all learn. I personally don't think that further logic additions is required in the firmware. The pilot has the means to mitigate.
     
    Kilrah likes this.
  5. sanderx

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    I agree, flying a battery to close to 30% should be absolutely safe and is described in the manual as a safe procedure. Very strange that the quad took off again while it was already on the ground....
     
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  6. World Media

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    it isnt strange, it is programmed to go into this sequence at a predermined battery level, a warning comes up on screen giving you a few seconds to cancel but that is not appropriate at the point your manuall landing. IMO
     
  7. sanderx

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    I agree, especially when you are already on the ground.
     
  8. Frank508

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    I see what you mean, but within the limits of the software, this is what we get. Landing away from the home point at the end of the battery useful lifecycle is a somewhat unusual scenario. So knowing the aircraft, and it's systems, it is up to us to work around it. One possibility is to set a new home point when one begins the loiter at the new landing position. Another, as has been mentioned above, is under these circumstances, terminate the flight with more battery remaining.

    It's hard to blame the pile of poop the second time you step in it. :p
     
  9. The Editor

    The Editor Moderator
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    What levels do you have your 'low' and 'critical' set at?
    When was the last time you did a battery calibration on the pack(s)?
    How many flights has the pack(s) had?
    The answer to the last two questions should be readily available from your battery logs if you keep them.
     
  10. Scotflieger

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    I do agree that when the aircraft once on the ground (zero VPS ht) that it should not enter Smart RTH mode.

    All RTH functions (manual, LOS, smart) can be cancelled at any time by flicking to ATTI and back to GPS or pressing the RC RTH button. Also your original HP must have been over 20m from where you were landing; the logic is that under 20m from HP the aircraft will land at its present position.
     
    #10 Scotflieger, Jul 31, 2015
    Last edited: Jul 31, 2015
    damoncooper likes this.
  11. RGD

    RGD

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    How do you calibrate the battery packs and where do you find the battery logs?
     
  12. #AIRSTRIPONE

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    Sounds like unfortunate timing, and a little bit of unsafe flying.

    I have brought betty home to land and been thwarted by the low battery feature on inspire before its a flick of a switch to let her know your aware of the situation and carrying on your landing.

    If the area you were landing in had an "overhang" above the safe return height it then the flight planning should have reflected that...

    and if she had time to fly 20m up and cause a scare then your probably a little slow with your trigger finger.

    A1RSTR1P 0NE
    war is peace, freedom is slavery, ignorance is strength.
     
  13. Queen1944

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    Had the same experience and learned a lot. When past 30 percent battery + a high fail-safe value and on the final moment of a manual landing you don't cancel the 30% RTH warning, it will likely engage a power consuming climb to fail-safe height and in the process exponentially increase the power curve leading to an immediate landing from a height higher than you intended during the manual landing. You have to be ready to cancel the RTH immediately and recover from the shock your bird is doing something you didn't plan on. (Actually you did when you 1st programed it..but didn't know it) If you want to drain the battery to get a good pack calibration, set fail-safe to zero, takeoff and land at the same spot, keep gear down and do so no higher that you can afford to do a hard landing. I held altitude for 5 minutes when past 20% mark going down to 8% before I shut her down. Ground effect probably helped as I was a foot or less over the grass.
     
    Leszek Kedziora likes this.