Low battery, auto gear/land and refusal to land.

[NickU]

It's a bit of a long read... but please bear with it... it might save your inspire from yourself!

So, so far in 12hrs flight time and 67 flights on the I2, I've never had a "problem" landing... until today.

I was doing a flight test to iron out any gremlins in settings from the new .140 firmware update and had deliberately set the critical low battery level to 7%, with a warning at 20%. So, get the warning at 20% and come back home in plenty of time. Came in with gear already down over landing pad and got a bit lower than normal and for the first time ever it triggers the auto land response (or so I thought!), so cancelled it to land manually. At that point, the I2 refused to follow my stick command and land. Ok, lift up a bit and try again... still wouldn't land. Um, ok, toggle gear up, lift up, gear down, land... nope.... not going near that nasty ground, looks cold and damp! Now got 10% on the gauge (forgive me Editor.. the voltage values are not prominent to read, and remember )

Starting to run out of ideas, try ATTI mode, no dice... critical battery warning arrives... oh %}*{%#*! .. try again... still doesn't want to go down! Fortunately the autoland safety then kicks in and it lands and sits there looking smugly at me . Landing power.. 5%!

So, change batteries, set autoland to off, Reset critical back to (pre update) 10%, take off, lift gear, move a few feet, gear down, back over pad, lands with no fuss whatsoever.

Go do the rest of flight testing, come back and land by 10%. Shutdown, reset battery critical warning to 7% and take off again (it wouldn't allow it on .135 firmware), and yes it will, lift off. So now hover over pad with gear down.

Now I have autogear turned off.. however the ground protection is turned on, so it buzzes, tells me I'm close to the ground and asks me if I want to land... cancel that and try to land... errrr, nope not letting you.... WTF!! Refuses to budge until critical battery kicks in, at which point it plonks itself on the ground.

Looking at the log files, what was happening is that it was trying to land itself with a critical battery warning, I'm (unwittingly) overriding it, the ground protection feature is holding the aircraft from landing while it makes sure that the landing zone is clear and level - while it's doing that, it's also overriding me from landing (as it's aircraft-in-command, although I don't know it), and slows down the descent rate (aka response to left stick down).

This is intentional behaviour on the part of the I2, but it's ensuring things get close to the bone when the battery levels are getting low.

Before anyone jumps down my throat, yes I was deliberately flying with values cut to the bone to test the aircraft response. I do this so I can learn what happens and how the aircraft handles while I've a cool head and a controlled environment, and not in the middle of everything hitting the fan with people running around me! My everyday flying values are set far more conservatively .

So, some thoughts for you all (and these go to re-inforce the points the Editor made in another thread about battery voltages and percentages )....

• Turn off auto gear sensing - it makes you think it'\s getting in the way
• Keep your critical battery levels at or above 10% to give you some real reserve airtime on the battery life. Don't go to 7% just 'cause DJI allow you to .
• The landing area protection feature can get in the way of landing!
• Voltage (aka airtime) drops very quickly after 10%.
• If it asks if you want to land around critical battery, it might not be the autogear feature asking... it might be the critical power asking! So answer yes and allow it to land itself
• Best of all, be on the ground before critical power warning level
• If the autoland has engaged (and disengaged), then the landing protection feature may remain active and block (slow) you from landing. This is where you need that extra battery juice to give it enough volts to figure itself out and let it land. If you've too little volts, or a dodgy cell or two, your I2 will be in trouble... (this is possibly what happened with the guy in the video who's I2 shut-off and crashed as he tried to land).
• What you think is happening, isn't always what is actually happening

Beneath is an extract from the 1st time I encounteed the 'issue' - reading it, some of the warnings didn't appear on screen, only in the logs. Also, examining it, it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking me to let it land...

P 10m 46s 9.5 ft 3 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
Q 10m 47s 9.5 ft 3 m Warning Gimbal Pitch Reached Movement Limit
R 10m 55s 4.9 ft 2 m Mode Mode changed to AutoLanding
S 10m 55s 4.9 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
T 10m 55s 4.9 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
U 10m 55s 4.9 ft 2 m Tip Ground Plain. Safe to Land.
V 11m 01s 2.0 ft 1 m Warning Warning:Command Failed
W 11m 39s 2.3 ft 2 m Warning Flight Mode Set to Atti:Set flight mode to GPS to ensure safety.
X 11m 46s 6.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
Y 11m 48s 3.0 ft 2 m Tip Ground Plain. Safe to Land.
Z 11m 54s 2.3 ft 1 m Mode Mode changed to Confirm_Landing
a 11m 54s 2.3 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.

This is an extract from the 2nd time when I deliberately triggered the 'issue' - again, some of the warnings didn't appear on screen, only in the logs. And again it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking to land. (The "H Warning Warning:Command Failed" extract is me cancelling out the on-screen landing request, same as at V in the 1st log extract.)

A 21m 25s 0.0 ft 0 m Mode Mode changed to Motors_Started
B 21m 26s 0.0 ft 0 m Mode Mode changed to Assisted_Takeoff
C 22m 16s -0.3 ft 2 m Mode Mode changed to GPS_Atti
D 22m 16s 0.0 ft 2 m Tip Home Point Recorded. RTH Altitude: 50m.
E 22m 21s 2.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
F 22m 31s 3.3 ft 2 m Mode Mode changed to AutoLanding
G 22m 31s 3.3 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
H 22m 36s 4.3 ft 2 m Warning Warning:Command Failed
I 22m 47s 8.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
J 22m 48s 5.9 ft 2 m Tip Ground Plain. Safe to Land.
K 22m 49s 5.6 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
L 22m 52s 5.2 ft 2 m Mode Mode changed to Confirm_Landing

For comparison, this is from a normal landing, no issues, no critical low battery...

E 00m 04s 0.0 ft 0 m Tip Home Point Recorded. RTH Altitude: 50m.
F 00m 09s 9.2 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
G 00m 21s 1.3 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
H 00m 27s 1.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
I 00m 34s 1.3 ft 1 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.


Sorry, as I said, it's a bit long winded... but I hope it helps people understand a little bit of what is happening when something like this occurs. If it helps you keep a slightly cooler head and land safely... jobs a good'un

 

[Lesmess]

It's a bit of a long read... but please bear with it... it might save your inspire from yourself!

So, so far in 12hrs flight time and 67 flights I've never had a "problem" landing... until today.

I was doing a flight test to iron out any gremlins in settings from the new .140 firmware update and had deliberately set the critical low battery level to 7%, with a warning at 20%. So, get the warning at 20% and come back home in plenty of time. Came in with gear already down over landing pad and got a bit lower than normal and for the first time ever it triggers the auto land response (or so I thought!), so cancelled it to land manually. At that point, the I2 refused to follow my stick command and land. Ok, lift up a bit and try again... still wouldn't land. Um, ok, toggle gear up, lift up, gear down, land... nope.... not going near that nasty ground, looks cold and damp! Now got 10% on the gauge (forgive me Editor.. the voltage values are not prominent to read, and remember )

Starting to run out of ideas, try ATTI mode, no dice... critical battery warning arrives... oh %}*{%#*! .. try again... still doesn't want to go down! Fortunately the autoland safety then kicks in and it lands and sits there looking smugly at me . Landing power.. 5%!

So, change batteries, set autoland to off, Reset critical back to (pre update) 10%, take off, lift gear, move a few feet, gear down, back over pad, lands with no fuss whatsoever.

Go do the rest of flight testing, come back and land by 10%. Shutdown, reset battery critical warning to 7% and take off again (it wouldn't allow it on .135 firmware), and yes it will, lift off. So now hover over pad with gear down.

Now I have autogear turned off.. however the ground protection is turned on, so it buzzes, tells me I'm close to the ground and asks me if I want to land... cancel that and try to land... errrr, nope not letting you.... WTF!! Refuses to budge until critical battery kicks in, at which point it plonks itself on the ground.

Looking at the log files, what was happening is that it was trying to land itself with a critical battery warning, the ground protection feature is holding the aircraft from landing while it makes sure that the landing zone is clear and level - while it's doing that, it's also overriding me from landing (as it's in command, although I don't know it), and slows down the descent rate (aka response to left stick down).

This is intentional behaviour on the part of the I2, but it's ensuring things get close to the bone when the battery levels are getting low.

Before anyone jumps down my throat, yes I was deliberately flying with values cut to the bone to test the aircraft response. I do this so I can learn what happens and how the aircraft handles while I've a cool head and a controlled environment, and not in the middle of everything hitting the fan with people running around me! My everyday flying values are set far more conservatively .

So, some thoughts for you all (and these go to re-inforce the points the Editor made in another thread about battery voltages and percentages )....

- Turn off auto gear sensing - it makes you think it'\s getting in the way
- Keep your critical battery levels at or above 10% to give you some real reserve airtime on the battery life. Don't go to 7% just 'cause DJI allow you to .
- The landing area protection feature can get in the way of landing!
- Voltage (aka airtime) drops very quickly after 10%.
- If it asks if you want to land around critical battery, it might not be the autogear feature asking... it might be the critical power asking! So answer yes and allow it to land itself
- Best of all, be on the ground before critical power warning level
- If the autoland has engaged (and disengaged), then the landing protection feature may remain active and block (slow) you from landing. This is where you need that extra battery juice to give it enough volts to figure itself out and let it land. If you've too little volts, or a dodgy cell or two, your I2 will be in trouble... (this is possibly what happened with the guy in the video who's I2 shut-off and crashed as he tried to land).
- What you think is happening, isn't always what is actually happening

Beneath is an extract from the 1st time I encounteed the 'issue' - reading it, some of the warnings didn't appear on screen, only in the logs. Also, examining it, it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking me to let it land...

P 10m 46s 9.5 ft 3 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
Q 10m 47s 9.5 ft 3 m Warning Gimbal Pitch Reached Movement Limit
R 10m 55s 4.9 ft 2 m Mode Mode changed to AutoLanding
S 10m 55s 4.9 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
T 10m 55s 4.9 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
U 10m 55s 4.9 ft 2 m Tip Ground Plain. Safe to Land.
V 11m 01s 2.0 ft 1 m Warning Warning:Command Failed
W 11m 39s 2.3 ft 2 m Warning Flight Mode Set to Atti:Set flight mode to GPS to ensure safety.
X 11m 46s 6.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
Y 11m 48s 3.0 ft 2 m Tip Ground Plain. Safe to Land.
Z 11m 54s 2.3 ft 1 m Mode Mode changed to Confirm_Landing
a 11m 54s 2.3 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.

This is an extract from the 2nd time when I deliberately triggered the 'issue' - again, some of the warnings didn't appear on screen, only in the logs. And again it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking to land. (The "H Warning Warning:Command Failed" extract is me cancelling out the on-screen landing request, same as at V in the 1st log extract.)

A 21m 25s 0.0 ft 0 m Mode Mode changed to Motors_Started
B 21m 26s 0.0 ft 0 m Mode Mode changed to Assisted_Takeoff
C 22m 16s -0.3 ft 2 m Mode Mode changed to GPS_Atti
D 22m 16s 0.0 ft 2 m Tip Home Point Recorded. RTH Altitude: 50m.
E 22m 21s 2.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
F 22m 31s 3.3 ft 2 m Mode Mode changed to AutoLanding
G 22m 31s 3.3 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
H 22m 36s 4.3 ft 2 m Warning Warning:Command Failed
I 22m 47s 8.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
J 22m 48s 5.9 ft 2 m Tip Ground Plain. Safe to Land.
K 22m 49s 5.6 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
L 22m 52s 5.2 ft 2 m Mode Mode changed to Confirm_Landing

For comparison, this is from a normal landing, no issues, no critical low battery...

E 00m 04s 0.0 ft 0 m Tip Home Point Recorded. RTH Altitude: 50m.
F 00m 09s 9.2 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
G 00m 21s 1.3 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
H 00m 27s 1.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
I 00m 34s 1.3 ft 1 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.


Sorry, as I said, it's a bit long winded... but I hope it helps people understand a little bit of what is happening when something like this occurs. If it helps you keep a slightly cooler head and land safely... jobs a good'un

Thanks for taking the time to share this. I'm off to check my settings.

 

[The Editor]

It's a bit of a long read... but please bear with it... it might save your inspire from yourself!

So, so far in 12hrs flight time and 67 flights on the I2, I've never had a "problem" landing... until today.

I was doing a flight test to iron out any gremlins in settings from the new .140 firmware update and had deliberately set the critical low battery level to 7%, with a warning at 20%. So, get the warning at 20% and come back home in plenty of time. Came in with gear already down over landing pad and got a bit lower than normal and for the first time ever it triggers the auto land response (or so I thought!), so cancelled it to land manually. At that point, the I2 refused to follow my stick command and land. Ok, lift up a bit and try again... still wouldn't land. Um, ok, toggle gear up, lift up, gear down, land... nope.... not going near that nasty ground, looks cold and damp! Now got 10% on the gauge (forgive me Editor.. the voltage values are not prominent to read, and remember )

Starting to run out of ideas, try ATTI mode, no dice... critical battery warning arrives... oh %}*{%#*! .. try again... still doesn't want to go down! Fortunately the autoland safety then kicks in and it lands and sits there looking smugly at me . Landing power.. 5%!

So, change batteries, set autoland to off, Reset critical back to (pre update) 10%, take off, lift gear, move a few feet, gear down, back over pad, lands with no fuss whatsoever.

Go do the rest of flight testing, come back and land by 10%. Shutdown, reset battery critical warning to 7% and take off again (it wouldn't allow it on .135 firmware), and yes it will, lift off. So now hover over pad with gear down.

Now I have autogear turned off.. however the ground protection is turned on, so it buzzes, tells me I'm close to the ground and asks me if I want to land... cancel that and try to land... errrr, nope not letting you.... WTF!! Refuses to budge until critical battery kicks in, at which point it plonks itself on the ground.

Looking at the log files, what was happening is that it was trying to land itself with a critical battery warning, the ground protection feature is holding the aircraft from landing while it makes sure that the landing zone is clear and level - while it's doing that, it's also overriding me from landing (as it's in command, although I don't know it), and slows down the descent rate (aka response to left stick down).

This is intentional behaviour on the part of the I2, but it's ensuring things get close to the bone when the battery levels are getting low.

Before anyone jumps down my throat, yes I was deliberately flying with values cut to the bone to test the aircraft response. I do this so I can learn what happens and how the aircraft handles while I've a cool head and a controlled environment, and not in the middle of everything hitting the fan with people running around me! My everyday flying values are set far more conservatively .

So, some thoughts for you all (and these go to re-inforce the points the Editor made in another thread about battery voltages and percentages )....

- Turn off auto gear sensing - it makes you think it'\s getting in the way
- Keep your critical battery levels at or above 10% to give you some real reserve airtime on the battery life. Don't go to 7% just 'cause DJI allow you to .
- The landing area protection feature can get in the way of landing!
- Voltage (aka airtime) drops very quickly after 10%.
- If it asks if you want to land around critical battery, it might not be the autogear feature asking... it might be the critical power asking! So answer yes and allow it to land itself
- Best of all, be on the ground before critical power warning level
- If the autoland has engaged (and disengaged), then the landing protection feature may remain active and block (slow) you from landing. This is where you need that extra battery juice to give it enough volts to figure itself out and let it land. If you've too little volts, or a dodgy cell or two, your I2 will be in trouble... (this is possibly what happened with the guy in the video who's I2 shut-off and crashed as he tried to land).
- What you think is happening, isn't always what is actually happening

Beneath is an extract from the 1st time I encounteed the 'issue' - reading it, some of the warnings didn't appear on screen, only in the logs. Also, examining it, it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking me to let it land...

P 10m 46s 9.5 ft 3 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
Q 10m 47s 9.5 ft 3 m Warning Gimbal Pitch Reached Movement Limit
R 10m 55s 4.9 ft 2 m Mode Mode changed to AutoLanding
S 10m 55s 4.9 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
T 10m 55s 4.9 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
U 10m 55s 4.9 ft 2 m Tip Ground Plain. Safe to Land.
V 11m 01s 2.0 ft 1 m Warning Warning:Command Failed
W 11m 39s 2.3 ft 2 m Warning Flight Mode Set to Atti:Set flight mode to GPS to ensure safety.
X 11m 46s 6.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
Y 11m 48s 3.0 ft 2 m Tip Ground Plain. Safe to Land.
Z 11m 54s 2.3 ft 1 m Mode Mode changed to Confirm_Landing
a 11m 54s 2.3 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.

This is an extract from the 2nd time when I deliberately triggered the 'issue' - again, some of the warnings didn't appear on screen, only in the logs. And again it's clear that what I thought was a ground proximity trigger (landing request) was actually the critical low battery asking to land. (The "H Warning Warning:Command Failed" extract is me cancelling out the on-screen landing request, same as at V in the 1st log extract.)

A 21m 25s 0.0 ft 0 m Mode Mode changed to Motors_Started
B 21m 26s 0.0 ft 0 m Mode Mode changed to Assisted_Takeoff
C 22m 16s -0.3 ft 2 m Mode Mode changed to GPS_Atti
D 22m 16s 0.0 ft 2 m Tip Home Point Recorded. RTH Altitude: 50m.
E 22m 21s 2.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
F 22m 31s 3.3 ft 2 m Mode Mode changed to AutoLanding
G 22m 31s 3.3 ft 2 m Tip Tips__Critically Low Power. Aircraft Landing
H 22m 36s 4.3 ft 2 m Warning Warning:Command Failed
I 22m 47s 8.2 ft 2 m Tip Landing Protection Activated. Aircraft will decelerate during landing.
J 22m 48s 5.9 ft 2 m Tip Ground Plain. Safe to Land.
K 22m 49s 5.6 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
L 22m 52s 5.2 ft 2 m Mode Mode changed to Confirm_Landing

For comparison, this is from a normal landing, no issues, no critical low battery...

E 00m 04s 0.0 ft 0 m Tip Home Point Recorded. RTH Altitude: 50m.
F 00m 09s 9.2 ft 1 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
G 00m 21s 1.3 ft 2 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.
H 00m 27s 1.0 ft 2 m Warning Landing gear lowered.Obstacle Avoidance Disabled.
I 00m 34s 1.3 ft 1 m Tip Tips__Minimum height level reached. Continue pushing the throttle stick down to land aircraft.


Sorry, as I said, it's a bit long winded... but I hope it helps people understand a little bit of what is happening when something like this occurs. If it helps you keep a slightly cooler head and land safely... jobs a good'un

Thank you for taking the time to test this.
This is why I always advocate knowing how your machine behaves fully before you take it out properly and use it in the real world.
I actually have it written into my ops manual that after a firmware update I test fly a minimum of 4 batteries before I am prepared to sign off the aircraft as fit for flight. I actually also go through every setting within the app to ensure nothing has shifted or been reset.
During those test flights I am looking for ANY behaviour which I consider out of the ordinary.
If I'm not happy, the aircraft doesn't get used commercially until I am.
Thanks again for the test.

 

[NickU]

Thing is, while it could be, it's probably not actually linked to the firmware or software updates at all

Landing and Critical Low Battery are two high workload events, and it's very easy to get task-oriented with just one of them! Don't allow them to mix together as it'll really screw your situation awareness... and that's when the incidents (not accidents!) start happening. It was cold yesterday, but if I'd added a third trigger to the scenario, it could have been terminal - freezing temps - that could have been enough to tip the battery to shutting down on me.

Being aware of how something plays out and realising that such a scenario is beginning to happen is a big part of heading it off before it gets bad

 

[NickU]

A bit of flying in this afternoon - I'm definitely all for turning off the ground warning/landing protection feature - it gets in the way.

When they announced the feature at the I2 release, I really thought that it would have been useful for protecting the lens/gimbal, but it's like having a car that when you pull into your driveway then refuses to go in the garage until it's checked it out to see if it's safe

When I land, I want to land. If I wanted the Inspire to park itself, I'd have used the autoland button!!!

 

[Gregp2017]

A bit of flying in this afternoon - I'm definitely all for turning off the ground warning/landing protection feature - it gets in the way.

When they announced the feature at the I2 release, I really thought that it would have been useful for protecting the lens/gimbal, but it's like having a car that when you pull into your driveway then refuses to go in the garage until it's checked it out to see if it's safe

When I land, I want to land. If I wanted the Inspire to park itself, I'd have used the autoland button!!!

If you hold the throttle stick down for a few seconds, the I2 will land, it can be shut off in the app under the obstacle avoidance I think.

 

[EDDSkitz]

While good to know, this really is only a worry for those that run their battery down all the way instead of buying more sets.

I'm gonna leave mine on, because I always land between 15-20% anyway, and if you fly low to the ground for some shots like I do, it's nice to have it drop all the way down without hitting the gimbal.

 

[NickU]

Yep guys, its easier to turn it off!

I don't do a lot of low close flying (terrain here isn't flat enough ), and I usually pitch the gimbal up manually anyway when landing, so the auto-scan-for-alligators-before-I-land feature doesn't add anything for me.... just gets in the way of landing

Just beware of the extra time it adds if you ever do get close to critical battery

 

[EDDSkitz]

Or you could not risk dropping an aircraft on someone...