I’ve never used Deep Stall Landing, but wouldn’t it be perfect solution to this problem - if you trigger “terminate flight”, instead of just driving itself into the ground, it could set a waypoint then initiates the very smart Deep Stall Landing, where it circles to determine wind speed and direction, calculates the ideal approach angle, then heads into the wind and tries to land exactly on the waypoint while decending in a flat straight-down glide. seems like it would be the perfect use of DS Landing.
Is this already an option, or is this a feature request?
You can try that. But your airframe has to be capable of deep-stalling
while maintaining attitude, and taking significant impacts. They’re not
for the faint of heart.
we’re talking about how to best deal with a poorly planned flight where the battery is almost dead before the plane has made it home. Given the options, a DS landing sounds like the least terrible.
the question is how to reliably trigger a DS landing on demand, perhaps based on the pilot viewing a safe landing spot via the FPV camera, and knowing that the plane will execute the landing to completion, without triggering RC failsafe as it decends below the altitude where the RC link works. no good if it get low, looses RC signal, failsafes, and tries to climb back up and RTH.
Ideally, I wish I could program a button on the RC that would trigger this, without having to do other dangerous things like disable RC failsafe for the whole flight.
I’ve been following this discussion and actually there is something fundamentally wrong:
Running out of battery power should never happen.
Flying beyond line of sight (and I guess you did with 7km away) comes with great responsibilities. We also fly our UAV’s here in Thailand on autonomous missions beyond LOS.
We have license to do so.
We follow strict procedures before take off
We have checklists that have to be completed
We make sure our pilots and equipment are in top condition
I think the question of this thread should not be on how to land incase of battery running low, but on how to prevent such case.
Our emergency procedure in case of a failure is to ditch the UAV in an as remote as possible area to prevent casualties. We all know coming close to the ground will cause signal loss and the aircraft becomes uncontrollable.
Judging batteries is not enough. Measuring and making sure the battery is charged and is in good condition will prevent such case. In case of doubt, just don’t take off or fly within LOS.
We, as pilots and operators of flying UAV’s beyond LOS have the responsibility of safety. One accident will make headlines and damage our reputation as an industry and probably lead to more restrictions being implemented by governments all over the world.
How about executing a RTL cancellation + FBWA activation at the same time via 2 switch combo+ putting an another level of safety where it can only happen when the battery cell voltage is lower than X volts? In that way even accidental switch combo would not execute this command until arduplane see battery lower than X volts.
This kind of battery situation can happen to anyone when lets say your one cell dies midflight.
Or call it a “emergency landing mode” (functionality similar to FBWA mode) that can only be activated with 2 channel combination with additon of voltage check in place. I mean pilot can’t activate it accidently unless voltage is lower than the set point.
I 100% agree with what you’re saying here. I considered making a similar argument. However we could consider this discussion from a technical point: When there is no other option, What is the safest way to ditch when we know the plane will loose signal close to the ground?
Have a look at the answer from @Eosbandi in the early days of this discussion. I think his solution is a very good one:
Quote:
“Before flight, search for suitable areas for landing. Set up rally points for that areas. If you see that you have to ditch, then switch to RTL, plane will go to the closest rally point, then start loitering around that point. If you add low voltage cutoff to your motor ESC, then the plane will simply circle down when battery depleted.”
Unquote.
What happens if your plane doesn’t have enough battery to get to a rally point? I think the
Situation in question would be Your flying and with time counting down your battery is going dead and you are miles from home going into a head wind and you only have enough juice to land it. How do you land without triggering a RTL event? No matter how much you planning you do, what can happen will happen.
I presume you had telemetry since you could see it switching to RTL, right? Though I haven’t tried it, I imagine you could disable the RC failsafe no? If you could do that, then it could be a simple case of putting it in STABILIZE, putting throttle to zero, pointing it somewhere not too ouchy and hoping.
I was flying with OSD telemetry and there was no way to disable RTL.
I did try to put it in stabilize and Manual mode in a panic but then i realized that there is no way to disable failsafe other than disarming by switch which i didn’t have and hesitate to have disarming on a switch.
Yes i will be using bi directional for long ranges from now on as I have just finished my Yagi antenna setup for Dragonlink 433mHz.In that way i will have 100km bi-directional telemetry and control. My tripod ground station has mission planner running on a Dell Win10 tablet. So in future i can at least disarm via mission planner if needed.
That incident happened when i went out for a quick fast flight on nano goblin. Sometimes you don’t want the hassle to carry all that ground station gear for quick flights:)
Personally I would hesitate not having disarming on a switch. Maybe it’s the multi-rotor and RC background but I’ve seen too many close calls to go without.
I use a double switch setup on my TX for arm/disarm. There’s lots of ways to set it up, but for me the two switches are on opposite sides of the TX and in a combination that’s natural but there’s almost zero chance of an accidental arm/disarm.