How to Exceed Max Altitude for Mountain Flying?

[SeaComms]

What would be ideal is if it knew the ground level directly below the Mavic's location so that the 500m rule applied to above ground level and not above takeoff point. Even flying around buildings, if I am limited to 120m it's above relative ground under the Mavic. So if I was (legally) flying over a 50m tall building and my max height was set to 120 then it should be 120 above takeoff yes, but also 120 above the building (or hill or mountain etc). Obviously this would require either some very sophisticated data based on GPS coordinates or much more effective ground positioning sensors, but could be possible I guess.

 

[ASA51N]

I'm surprised no one has mentioned this... it's a bit of a creative solution, and certainly a very risky one, but it might work.

Fly up to 500m.
Turn off rotors with the sticks.
Immediately afterwards turn the rotors on while the Mavic is in free fall.
I believe it would pick up the new point as the zero level and you could add another 500 meters to that. If you do it fast you could only lose about 100m effectively going to 900m. And then again and again and again, but at some point you might lose radio signal... would love to see someone buy experiment with that [emoji23]

I would live to see the genius from the other thread who designed/developed the parachute (would love to buy one) try the stick shutdown altitude hack.

I suppose this also could be tested buy:
1. Start the drone on the ground
2. Fly to second storey of house
3. Emergency shutdown to person waiting on terrace
4. Drop/lower drone to person below
5. Quickly hand launch

I will try the above once the weather clears up here in SYD.

 

[dwallersv]

I've done a partial tear down on the Mavic to repair some cosmetic damage after a crash (not really that difficult, just have to be careful). I might just do it again and put some aluminum tape over that baro sensor hole just to see what happens.

IMO this is a very bad idea, and may result in a flyaway.

Remember that this is not a proportional-control quad like the simple ones, that simply respond to stick movement with proportional power control.

Rather, this is fly-by-computer; you request a certain behavior out of the aircraft, and the controller tries to fulfill it. This is why, for example, it will fly at 20mph at full stick in P mode in any direction under a variety of wind conditions, for example. You're giving a particular command (full-speed), the controller uses GPS groundspeed and course to control each rotor to keep you moving at the requested speed, and stay on a fixed course. Regardless of wind (up to a limit).

So, if you command ASCEND and the controller sees no ascent from the baro sensor, it might spin up to max power and zoom away uncontrollably. And/or large inconsistency between the baro altimeter and the GPS altitude might make it go schizo.

I'd do it on an older, simple proportional control quad. I wouldn't try it on one of these fly-by-wire babies.

 

[WIMMPYIII]

IMO this is a very bad idea, and may result in a flyaway.

Remember that this is not a proportional-control quad like the simple ones, that simply respond to stick movement with proportional power control.

Rather, this is fly-by-computer; you request a certain behavior out of the aircraft, and the controller tries to fulfill it. This is why, for example, it will fly at 20mph at full stick in P mode in any direction under a variety of wind conditions, for example. You're giving a particular command (full-speed), the controller uses GPS groundspeed and course to control each rotor to keep you moving at the requested speed, and stay on a fixed course. Regardless of wind (up to a limit).

So, if you command ASCEND and the controller sees no ascent from the baro sensor, it might spin up to max power and zoom away uncontrollably. And/or large inconsistency between the baro altimeter and the GPS altitude might make it go schizo.

I'd do it on an older, simple proportional control quad. I wouldn't try it on one of these fly-by-wire babies.

Ya seem like it would attempt to gain altitude and keep going unable to read until battery died and fall out of the sky from 1000s of FT.
I have held off on trying it. Too unsafe for the drone and other aircraft.

 

[dwallersv]

EGPW relies on a radar altimeter so add another $1,000 or so to the price tag.

And what did drones with capabilities like the Mavic cost 2-3 years ago, and how big were they?

I am 110% certain -- no doubt at all -- that given innovation and economies of scale we will see future consumer-grade drones in the same class as Phantoms and Mavics that have precise radar altimeters and aircraft warning and collision avoidance systems.

I give it 2 years.

 

[cobra46]

I'm impressed you can get anywhere close to 2 miles away near mountains. With antenna extender I can't get past 2000 feet on flat labs due to I'm assuming trees.

Sounds like you antenna extender is an issue as most everyone can fly 2000' anywhere.

 

[PT_Mavic]

I live and fly alot in mountainous terrain as well. The only work around I know of is to hike to a high point such as a high ridge or mountain top and take off from there. I haven't tried it yet, but I'd wager that the DJI GO app will allow you to descend more than 500 m below your starting point allowing you "override" the altitude barrier.

That's creative thinking and an interesting idea; looking forward to hearing whether it works or not.

 

[Rnl]

Seal a meal bags sucks the air out like a vacuum .

 

[Hans112]

Feel the sarcasm? To be honest, I find it lame not to share vital information and just talk around the subject. Are we helping each other out here or not?

I don't mind sharing, but I am on the receiving part for now. Did not have time to look around yet... So, if you are willing to share, that would be great

 

[DomoDan]

So...I remember somewhere in this thread someone pointed out that landing doesn't reset your home point and therefore your max altitude. That is INCORRECT. I've been playing around lately with landing at other places where I am not, then taking off again just to see what happens. Your home point updates when you take off again...and that includes altitude. I have confirmed this multiple times.

That said - you need to (obviously) be VERY careful with this. Just tonight I was flying around the neighborhood and surround neighborhoods. One neighborhood over there is a road that dead ends in a culdesac which has a field all the way around it. No houses in the culdesac. I decided...what the heck, let's do a landing in the middle of the culdesac. Everything was great...until a second or two before the bird touched down and my screen went blank and the remote said DISCONNECTED. I panicked. I started running down the street...with the way the roads go I have to go about twice as far on foot as the drone has to fly to get over there. I get about half way, risking taking a longer route but one that gets me closer to it partway through, and it connects again. I was able to successfully take off and fly back home as I walked home. I'm not going to lie...that was nerve racking for a few minutes! I was envisioning all sorts of bad things that could have happened to Mavic.

I'm tempted to hike up the mountain, find a spot I know I can land cleanly, then hike back down to fly up to that point, land, and take off again just to see how many feet I can successfully get it above me, all while staying no more than 400' AGL. I may have time to do it this weekend.

 

[prelator]

I haven't tried landing the Mavic at any distance, but with my fixed wing all that matters is that you have a clear line of sight to the landing location. I've successfully landed my fixed wing a couple miles away in the bottom of a valley when I was on top of a pass above it (I ran out of battery to make it back to the top of the pass) with a clear FPV feed the whole way. The same principle would apply landing higher than your launch point as long as you have good line of sight to that point.

Something I'd like to try at some point is take the Mavic up to a high point like the top of Loveland Pass, seal it in a plastic bag, then take it to the bottom of the valley and turn it on, and see if it thinks it is still higher up. That would be a good way to test the vacuum chamber trick without having to actually build a vacuum chamber.

 

[VZ2]

Something I'd like to try at some point is take the Mavic up to a high point like the top of Loveland Pass, seal it in a plastic bag, then take it to the bottom of the valley and turn it on, and see if it thinks it is still higher up. That would be a good way to test the vacuum chamber trick without having to actually build a vacuum chamber.

Plastic bag will not work. Vacuum chamber will keep low pressure inside when you will be down the valley but plastic bag will not. It will just shrink equalizing pressure inside.

 

[prelator]

Ah, good point. So I need something both airtight and rigid.

 

[cobra46]

I haven't tried landing the Mavic at any distance, but with my fixed wing all that matters is that you have a clear line of sight to the landing location. I've successfully landed my fixed wing a couple miles away in the bottom of a valley when I was on top of a pass above it (I ran out of battery to make it back to the top of the pass) with a clear FPV feed the whole way. The same principle would apply landing higher than your launch point as long as you have good line of sight to that point.

Something I'd like to try at some point is take the Mavic up to a high point like the top of Loveland Pass, seal it in a plastic bag, then take it to the bottom of the valley and turn it on, and see if it thinks it is still higher up. That would be a good way to test the vacuum chamber trick without having to actually build a vacuum chamber.

Why not simply use a plastic bag and a vacuum cleaner?

 

[prelator]

It sounds like the bag would just shrink and equalize the pressure. So I'd have to make a rigid vacuum chamber.

 

[cobra46]

It sounds like the bag would just shrink and equalize the pressure. So I'd have to make a rigid vacuum chamber.

The bag would only shrink to the outside of the case. The pressure sensor inside would be under lower pressure that outside the bag. This would be like those food saver vacuum packer systems.

My only worry is if the bag shrinking would distort the plastic enough to cause damage. I would only do this with the arms folded in, gimbal cover on, and the props off.

I may try this although, if it works, I won't use this technique to fly above about 400' near my house.

 

[VZ2]

The bag would only shrink to the outside of the case. The pressure sensor inside would be under lower pressure that outside the bag. This would be like those food saver vacuum packer systems.

My only worry is if the bag shrinking would distort the plastic enough to cause damage. I would only do this with the arms folded in, gimbal cover on, and the props off.

I may try this although, if it works, I won't use this technique to fly above about 400' near my house.

You need to start Mavic from inside that low pressure chamber before pulling it out.

 

[prelator]

You need to start Mavic from inside that low pressure chamber before pulling it out.

The Chinese video interestingly showed staring the Phantom outside the pressure chamber, then increasing the pressure so it showed a negative altitude, then arming the motors to set the home point when it was still negative, then removing the lid and taking off. I hadn't thought of that procedure before, but it seemed to work.

 

[Rnl]

Fold the mavic up, props off gimble cover on put in bag and vacuum then you could turn it in on in the bag. Watch bird you can stop vacuum at any point, so just watch as you go.

 

[Lt Shanks]

I live at the base of a very tall mountain. I like to use my Mavic to explore, but the 500m Max Altitude restriction is cramping my style. I know there are people crouched and ready to finger wag whenever someone talks about flying above 500m, but we all know that the actual FAA restriction is 400 ft above ground level. I've attached a frame grab that was taken at 500m and you can see that I'm definitely not anywhere close to 400 ft AGL. I'm wondering if I find a flat rock whether I could put down and reset the ground altitude. Not my first choice since a sudden gust could instantly create a Mavic-or-your-life mountain climbing decision. Any (worthwhile) suggestions?

I accomplish this by simply hiking up and finding the best mid point and launching - Then fly up and or down from that point giving you more altitude capability the further you climb. This worked well for me filming the ski hill in my town which has 3200ft base to top vertical at a "Home" starting elevation of about 8000ft.

Hope this will get you to the summit - Lt. Shanks