Turn props off in mid-air for fast descent (and on again :-)

jason38 · Mar 21, 2019

I wonder if it really works in facts....
To cut motors off in flight, you need to pull both sticks backward and to the middle for a few seconds... So before motors cut off, the drone will go backward/left and turning on itself while descending .... So I ask myself what it will do when motors are off... Will it continue to spin and drift ? The "starting" flight position can't be flat and stable due to the stick position....

For me it's clearly an emergency manoeuver... If there is no way to do another way, you can do it, and pray to succeed the manoeuver ...I'm skeptic , too many parameters and variables.... :/

sar104 · Mar 21, 2019

jason38 said:
I wonder if it really works in facts....
To cut motors off in flight, you need to pull both sticks backward and to the middle for a few seconds... So before motors cut off, the drone will go backward/left and turning on itself while descending .... So I ask myself what it will do when motors are off... Will it continue to spin and drift ? The "starting" flight position can't be flat and stable due to the stick position....

For me it's clearly an emergency manoeuver... If there is no way to do another way, you can do it, and pray to succeed the manoeuver ...I'm skeptic , too many parameters and variables.... :/

This post, that I linked above, shows exactly how it works, three times. There is absolutely no need to speculate when the data are available to look at.

Diablol · Oct 3, 2019

So a midair restart will reset the altitude...?!
A way to go over 500m ground, isnt it
Just in theorie, of course..

hiflyer201 · Oct 3, 2019

Experiment with new trick decent method....then...
Go straight to DJI store. Purchase new drone at the D.T. tariff price. Do not expect to receive much sympathy from fellow forum followers. The video could go viral

Diablol · Oct 5, 2019

I can confirm a restart in mid air with a mavic 2 is possible. Done three times worked three times. 50m altitude loss including stabilization.
Altitude does NOT reset.
Tried some simulations with my mavic mounted under a RC helicopter without blades. Some restarts reset altitude some not....idk.

Thomas B · Oct 5, 2019

Diablol said:
So a midair restart will reset the altitude...?!
A way to go over 500m ground, isnt it
Just in theorie, of course..

It likely would be. I use land and restart to get up above mountains near me when flying. BUT, I always land to do it. All data in this thread noted, I’d rather have to walk or climb to get a lost drone that is certainly going to be intact rather than in pieces. Landing is the safest way IMHO.

kidroc · Oct 5, 2019

Inspirephil said:
There’s no need to be rude about it. Quite possibly they can’t read a graph as well as you.

He already Apologized!!!

PropSpin · Oct 5, 2019

mariachi76 said:
Hello,
a rather theoretical question:
The Mavic 2 props can be turned off by pulling both sticks down/inside. With the same function they can be turned on again.
Can that be used in mid-air for a fast descent?

When flying up to 500m, the descent takes very long because the descent rate is rather slow (~2-3 m/s). So what would happen if I just turn off the props at 500m above ground, and turn them on ~200m above ground? Would the Mavic 2 stabilize again, or crash?
Anyoney ever tried?

best regards
mariachi76

LOL, this is great. Never really thought too much about doing this, although the thought crossed my mind. I have thought that it would be neat to try a hand toss launch of the M2P. Why? Well, why not? Other than the risk of damaging a $1400 piece of equipment.
Idle the motors, let it acknowledge home point, etc. then lob it overhead, sort of like lobbing a grenade but instead of going for distance, go for height. Somebody would have to do the lobbing, and the pilot would immediately punch the throttle. I can't see any practical reason for trying this other than curiosity.

zxcflyer · Oct 6, 2019

PropSpin said:
LOL, this is great. Never really thought too much about doing this, although the thought crossed my mind. I have thought that it would be neat to try a hand toss launch of the M2P. Why? Well, why not? Other than the risk of damaging a $1400 piece of equipment.
Idle the motors, let it acknowledge home point, etc. then lob it overhead, sort of like lobbing a grenade but instead of going for distance, go for height. Somebody would have to do the lobbing, and the pilot would immediately punch the throttle. I can't see any practical reason for trying this other than curiosity.

If you hold the Mavic, start the motors and then just lower your hand and let go, it will fly. That's the way I launch my Mavic Pro.

PropSpin · Oct 6, 2019

zxcflyer said:
If you hold the Mavic, start the motors and then just lower your hand and let go, it will fly. That's the way I launch my Mavic Pro.

Interesting, I'll have to try that. You're saying that the motors will go from idle to hover RPMs?

zxcflyer · Oct 7, 2019

PropSpin said:
Interesting, I'll have to try that. You're saying that the motors will go from idle to hover RPMs?

Yes. Just lower your hand a few centimeters. It is a bit tricky to pull both sticks to start the motors while you hold the quad in one hand up in the air. You can put the RC on the table or rest it on your leg ao arm.

Elude · Oct 8, 2019

Easy to launch by hand.

PropSpin · Oct 8, 2019

Elude said:
Easy to launch by hand.

I've launched by hand plenty of times. Never by idling the motors, then lowering my hand though.

sar104 · Oct 8, 2019

PropSpin said:
I've launched by hand plenty of times. Never by idling the motors, then lowering my hand though.

This technique works, but I'm not sure what advantage it has over hand launching by applying throttle or auto-takeoff. Other than looking rather cool of course. But you have to be pretty quick to get out of the way of the initial drop before the motors spool up.

zxcflyer · Oct 21, 2019

sar104 said:
This technique works, but I'm not sure what advantage it has over hand launching by applying throttle or auto-takeoff. Other than looking rather cool of course. But you have to be pretty quick to get out of the way of the initial drop before the motors spool up.

I am not sure how I discovered this, I just got used to it and do it most of the time. Mavic is just programmed to hold its position from the moment you start the motors and I like to hold it high up, turn on the motors and let it stay there, while I check recorded home position, camera settings and RTH height (allways).

joeorsi28 · Jan 9, 2020

Once, my mavic air's prop hit my finger while I was trying to land on my hand. It spun out of control, flipped over, shot to within inches of the ground before flipping back over, ascending to its starting point, and hovering like nothing happened. I think 9 times out of 10, this maneuver would work.

JAW · Jan 9, 2020

joeorsi28 said:
<snip>......I think 9 times out of 10, this maneuver would work.

It's that 10th time ya gotta worry about.?

Mavic Pro Platinum · Jan 9, 2020

mariachi76 said:
Hello,
a rather theoretical question:
The Mavic 2 props can be turned off by pulling both sticks down/inside. With the same function they can be turned on again.
Can that be used in mid-air for a fast descent?

When flying up to 500m, the descent takes very long because the descent rate is rather slow (~2-3 m/s). So what would happen if I just turn off the props at 500m above ground, and turn them on ~200m above ground? Would the Mavic 2 stabilize again, or crash?
Anyoney ever tried?

best regards
mariachi76

I’ve witnessed someone do it with a M2Z, he tried to restart it and it fell to the ground in the middle of a cornfield. He went and retrieved it and the drone wasn’t damaged except for a stress mark on the body and his props were broken. I definitely wouldn’t recommend doing it. If you want to descend fast you could try a parameter mod, I did it on my old MPP and it descended at 17mph but you would need to allow at least 50 feet for it to return to a hover. I really wouldn’t recommend that either. Thumbswayup

[emoji1417][emoji16]

sar104 · Jan 9, 2020

Mavic Pro Platinum said:
I’ve witnessed someone do it with a M2Z, he tried to restart it and it fell to the ground in the middle of a cornfield. He went and retrieved it and the drone wasn’t damaged except for a stress mark on the body and his props were broken. I definitely wouldn’t recommend doing it. If you want to descend fast you could try a parameter mod, I did it on my old MPP and it descended at 17mph but you would need to allow at least 50 feet for it to return to a hover. I really wouldn’t recommend that either. [emoji1417][emoji16]

It's possible.

The Terminal Velocity of a Falling Mavic 2

First second it travels 16' but in that one second it has accelerated to 32 FPS. (Starts at 0 FPS, accelerates to 32FPS, and thus averages 16FPS for the first second.) It travels 48' in the second second, and accelerates from 32FPS to 64FPS, and so on.

mavicpilots.com