I thought I had plenty of reserve to return...and the forced landing warning was inducing panic

[Balko]

60km/h on the way there and 45-50km/h on the way back doesn’t sound like the wind was all that strong compared to how fast the battery went down on the return trip.

How old is the battery and it’s general performance during other flights? Maybe worth checking.

Glad you got it back.

Perhaps, another question is the battery level when it took-off and how long ago the battery had been charged?

 

[Aerial West]

Glad you made it back OK. there are apps to show general wind direction, but it can sometimes be different at different altitudes. Short of it all though is to always allow for the unexpected so you don;t get caught.

I think the beeping is the least of your worries.

 

[BerndM]

The other day I was flying out to the sea going to a man-made island about 3.5km away, which has been on the local news lately. I flew with sports mode on and reached it with 78% battery left which means the distance used up just above 20%. I spent about 5 minutes filming there thinking of returning before reaching 50%, which should give me double the battery required to return in case of emergency. At about 58% it gave me a warning that I only have enough battery to return home. I thought for a few seconds and took the advice to start returning with sports mode on. I realized that I must be against wind as the battery kept dropping quicker than the way over, and I descended to about 20m over the water hoping to catch weaker wind...50%...40%...30%...20% and I was still 1km away...15% and 600m away, knowing that it will start forced landing at 10% I ascend to 35m to give me more time to pick a landing spot just in case...10% and 400m to go and reached land I kept it just above some rocks on the coast in case it drop out from the sky, but the forced landing warning is so rapid that my heart was pounding and palms sweating...

Finally it reached home point with 5% left. After turning off everything my hands were shaking...I have lost a Phantom 2 into the ocean before and been flying the Mavic for over 200 flights so I won't consider myself a novice, but that forced landing warning sound was really making me nervous. Also my girl friend heard it and kept asking me what's happening which further induced the stress. In less experienced hands a pilot can easily panic under the pressure and make the wrong decision.

Can DJI make the warning to sound just a few seconds and then go silent? I'm sure we can hear the warning when it goes off and attend to it. Keep it going for the entire duration from 10% onward really does not help the pilot handle it calmly.

Also when we go long distance always leave more reserve than you estimate to be enough. I looked at the log and on the way out the speed under full throttle in sports mode was 60km/h while on the way back was 45-50km/h. Another flight and another lesson for me.

Based on normal average wind direction charts for that exact area, you were flying toward the island with a TAIL wind condition, which means you were flying home against a HEAD wind.
This is plain and simply poor pilot planning since it will obviously require considerably more battery to fight a head wind on the way back to the home point.
This is such an easy thing to avoid by simply flying INTO the wind on your way TO your destination and then use the tail wind to help you get back to your home point.

 

[Aerial West]

This is such an easy thing to avoid by simply flying INTO the wind on your way TO your destination and then use the tail wind to help you get back to your home point.

if you read the original post, it points out this was an island. he didnt have the ability to to fly into the wind from his location.

 

[BerndM]

I obviously did read his original posting since I replied directly to it.
That being the case, some planning should have preceded the flight, knowing that he would need considerably more battery to get back upwind than he used getting there downwind.
This sort of preflight planning, whether for models or full sized aircraft, is what makes the difference between a successful flight and one with a suboptimal outcome.
He was extremely lucky that it didn't end up in the water.
Just sayin'

Looking closer at his flight log, I was amazed to discover that he was only about 4 miles from the western end of what could be one of the busiest runways in the world at the Hong Kong International Airport ( Check Lap Kok).
Assuming I interpreted his flight path correctly, then IMO this would easily qualify as a MAJOR breach of safe flying protocols.

 

[Aerial West]

Oh, because your solution was impossible for his situation, so I thought you didn't.

 

[albatross911]

Albatross911: Of all the replies, only one has commented on the annoying "return to home" beeping. I'm with you on this one. It does get your adrenaline pumping, and (I think) only makes things worse. I realize the software wants you to do something, but like you, I have difficulty concentrating when something is beeping at me. How about this for a software change: Beep for 5 seconds, then mute the beep. Exceptions: if the pilot ignores the warning, then beep for another 5 seconds. But to continually beep only wears down the RC battery and is annoying.

You were smart to lower your altitude on the return trip, since there is generally less wind the lower you are, although I'm not sure if that applies over the ocean. However, when you increased your altitude when you were nearing the home point to "avoid" the water, you were using valuable battery life that could have been used to keep traveling horizontally. Not sure if I would have done that. But it worked out, and you got your aircraft safely back! Now I'm off to watch your footage.

Yes making the warning sound for 5 second should be enough to bring our attention to it. If a pilot still ignores it then it's his own decision to keep on flying and bearing all the risks and consequences.

About rising up at the end, it's the first time I have experienced critical low battery m I've read about the forced landing so I'm not sure how much control on the descend I would have, do I climbed just a bit to give me more time to reach home. Not sure if that's the right decision and I'll make sure I don't have to make it again.

 

[Aerial West]

Mute would be fine. Otherwise people will be posting here that "5 seconds wasnt enough for me to notice what was wrong" or "I thing the alert/danger was over because it stopped".

Remember most people don't read the manual.

 

[albatross911]

There are several websites and apps you can look into to determine current wind speed and direction at your location.
I personal like WINDY. It not only gives you wind at ground level but at higher elevations as well.
On top of checking the app I fly the drone to intended height and switch to Atti to see which way it is drifting.
(Oops - I have a P4P. The MP doesn't have Atti I just realized. I think the Sports Mode can be configured into an Atti mode though.)
When my intended destination is downwind I give it extra leeway for the trip home.
Windy as forecasted
https://play.google.com/store/apps/details?id=com.windyty.android

I've just downloaded windy and will reference it for flight planning. Thanks for the recommendation!

 

[albatross911]

I completely agree with you on this! Most of us don't get into a forced landing situation on purpose, so the constant beeping is just adding stress to a situation we didn't want to be in anyway. I really wish there was a way to mute the controller.

Or give us option to acknowledge it like smart return prompt and then go silent.

 

[albatross911]

I agree with you 100% so yeah DJI make the warning go off to tell you batt is low then every min or so maybe but to make it a constant sound can really rattle a person and then you get distracted you panic you rush to set it down you make mistakes it is far more a hindrance than a help believe me, it takes real inner calm to sty focused and do what you have to do with that noise, thats why they have a mute button on aircraft after the master caution goes off its common sense and basic human nature

Indeed!!

 

[albatross911]

I finally dig out the MP to check the battery and it has 44 charge cycles done. The battery was charged the day before the flight and I started from 100% for the flight. For those asking about the battery status.

 

[Grizzo]

I finally dig out the MP to check the battery and it has 44 charge cycles done. The battery was charged the day before the flight and I started from 100% for the flight. For those asking about the battery status.

I wouldn't mind comparing it's flight time compared to other known good batteries. Looking at the difference in speeds there and back, it just seemed to drain faster than it should have.