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Limited Descent Speed

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Apr 13, 2016
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So I was on flight #122 for me and experienced a critically low battery warning much earlier than anticipated. (which is another subject) The copter being a ways a way I elected to land where it was and recover later. I was on top of a hill and the H was lower than myself. I found a nice grassy area to land and began my descent. It was painfully and annoyingly slow less than a foot per second. So while inching towards the ground I had my first crash when the battery gave out before it reached terra firma. Yuneec, there NEEDS, to be an option for this to prevent unneeded mishaps. I would have been fine but this limitation caused a crash.
 
So I was on flight #122 for me and experienced a critically low battery warning much earlier than anticipated. (which is another subject) The copter being a ways a way I elected to land where it was and recover later. I was on top of a hill and the H was lower than myself. I found a nice grassy area to land and began my descent. It was painfully and annoyingly slow less than a foot per second. So while inching towards the ground I had my first crash when the battery gave out before it reached terra firma. Yuneec, there NEEDS, to be an option for this to prevent unneeded mishaps. I would have been fine but this limitation caused a crash.
hi
i don't fly an H but i thought that when the battery in the H gets low it will land it self and then the motors will turn off . how low did the battery go down to . did you have a sd card in your TX .
 
The max descent rate is listed as 3m/sec or about 18'/sec. Since it was below the takeoff point I suppose it is possible that the descent rate was reduced by the flight controller because it was seeing a negative altitude.
 
I experience once, while I was flying in the NFZ near the helicopter air base test flight for the new FW update at about 6m heights suddenly a apache was on top, and I know this is an offense I quickly descend full throttle but the H seems like not responding or descending very very very very slow
 
Thanks for the negative publicity, NOT.
 
I was seeing voltages around 9 volts before it gave out. No SD card in transmitter (?) Yes, it wrongly assumes the ground is closer than it is under such circumstances. Goh that's a great point, hard to get out of the way when the **** thing won't come down. I do a lot of top down stuff, you can see farther from a hilltop than a valley, please add option to GUI Yuneec!!!
 
So I was on flight #122 for me and experienced a critically low battery warning much earlier than anticipated. (which is another subject) The copter being a ways a way I elected to land where it was and recover later. I was on top of a hill and the H was lower than myself. I found a nice grassy area to land and began my descent. It was painfully and annoyingly slow less than a foot per second. So while inching towards the ground I had my first crash when the battery gave out before it reached terra firma. Yuneec, there NEEDS, to be an option for this to prevent unneeded mishaps. I would have been fine but this limitation caused a crash.

What caused the crash was the operator failing to periodically review battery voltage and land the aircraft prior to reaching a critical voltage level. You caused the crash but prefer putting the blame on the manufacturer rather than accept responsibility for your failure to perform critical flight duties. If you observed voltages of 9 volts before the battery gave out there's a high probability you don't understand the minimum cell voltages of the batteries used in the H. You have a 4 cell battery with each cell having a lower voltage level of 3.2v. AT 9v you had to have almost destroyed the battery through deep discharge.

The telemetry still resides in the ST-16, you don't need to have an SD card present for the telemetry to be recorded. It will be interesting to see what Yuneec says if you download the telemetry and send it to them. If they see a 9v flight battery level along with the voltage at the start of the flight I have a hunch you won't do well with warranty work.
 
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What caused the crash was the operator failing to periodically review battery voltage and land the aircraft prior to reaching a critical voltage level. You caused the crash but prefer putting the blame on the manufacturer rather than accept responsibility for your failure to perform critical flight duties. If you observed voltages of 9 volts before the battery gave out there's a high probability you don't understand the minimum cell voltages of the batteries used in the H. You have a 4 cell battery with each cell having a lower voltage level of 3.2v. AT 9v you had to have almost destroyed the battery through deep discharge.

The telemetry still resides in the ST-16, you don't need to have an SD card present for the telemetry to be recorded. It will be interesting to see what Yuneec says if you download the telemetry and send it to them. If they see a 9v flight battery level along with the voltage at the start of the flight I have a hunch you won't do well with warranty work.
Is 9V even possible? I'm no expert on batteries, but from all I've read here I thought the H would drop from the sky at about 14V, maybe the op means 14.9V?
 
Without completely losing a cell 9v is not possible, and it would indeed fall like a rock. I'm trusting the OP proof reads before posting. With 122 flights it's quite possible batteries had been flown to absolute minimums for enough cycles to cause cells to self destruct. 14.9v would significantly alter my assessment of the incident. The OP has telemetry and should review it.
 
The software assumes the earth is a flat plane and that the takeoff point will also be the landing point both of which are flawed programming. This governed descent speed should only be invoked when using RTH and only when within a small perimeter of the takeoff point. This is a problem for flying below takeoff elevation and also rears its' ugly head when performing a descending follow me function. As pointed out by another poster there are also instances when you need to get out of the way quickly and have the need to override. There are additional reports elsewhere. I'm not the only one having problems with this.

My H was 300 feet lower than me when I got the low battery warning, it was quite shortly after the first warning (about 10 seconds) and after I had already began flying back to the takeoff point that the critical warning came up leaving me no choice but to land. Yes the battery was fully charged. Yes it was in rabbit mode. Had I tried to continue to climb the battery would have failed much earlier due to the higher load. The only reason it got down to 9.6 volts was it was hovering and slowly descending for about 90 seconds. I was honest with Yuneec about what happened and they were more than happy to ship me replacement parts. I know where to find the telemetry, I had to look up the final coordinates to find the craft. And I understand perfectly the preferred operating voltages, it's not as if I was oblivious and suddenly realized I needed to land.
 
I was out flying around some of the new bridges around town shooting videos. I routinely take it up to 400' and then do the panorama shots.
Today it just seemed to hang in the sky. Throttle pulled all the way back and it just very slowly sank to wards the earth. I kept checking to be sure it was coming back to the start point. Switch settings made no difference in the descent speed. I was getting a little worried it was going to just run out of power before it got to the ground.
I adjusted my flights to leave more battery for landing even though I still wanted to take more video. I have the latest firm ware installed and other than the slow descent flew like a champ.
 
I was out flying around some of the new bridges around town shooting videos. I routinely take it up to 400' and then do the panorama shots.
Today it just seemed to hang in the sky. Throttle pulled all the way back and it just very slowly sank to wards the earth. I kept checking to be sure it was coming back to the start point. Switch settings made no difference in the descent speed. I was getting a little worried it was going to just run out of power before it got to the ground.
I adjusted my flights to leave more battery for landing even though I still wanted to take more video. I have the latest firm ware installed and other than the slow descent flew like a champ.
I have noticed something similar on occasion. It seems to descend faster if I fly at an angle at the same time as I descend. I haven't checked the telemetry to verify the descent rate but it would be worthwhile to do so. As I recall the max ascent rate is 5 meters\sec and max descent rate is 3 m\s.
 
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I will double check today. I have another trip planned today and I will have my faithful assistant shoot video of the telemetry as I bring it back down. I know the ascent is slower as well. To use the term from another thread, "I hammer it" on the ascent. Sort of the way I ride my motorcycle. Throttle, I don't need no stinking throttle. It is just a on/off switch, yes?
 
You ride motocross or street? The two genres can be pretty similar;)


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I ride Both. When on the street I'm on my Goldwing F6B with stock exhaust. It's so quite when I'm romping it only my passenger and I know it is "FULL on or OFF."
In the dirt what ever is running that day. CZ400, CRF450R.
 
It seems to descend faster if I fly at an angle at the same time as I descend. I haven't checked the telemetry to verify the descent rate but it would be worthwhile to do so. As I recall the max ascent rate is 5 meters\sec and max descent rate is 3 m\s.

Mine all descend much faster on Rabbit than they will on Turtle. Turn OA off. Originally I thought it was my imagination, but after testing over time it is a fact. On my 3 anyway, And yes, they will go up like the bat out of Hades in Rabbit.

Just one more thing: as in a real plane, taking off is easy, landing requires more attention. My personal way to land, regardless of wind, is Angle and Turtle, GPS on, OA off. Legs down (duh).
Move to a hover 12" or 18" above landing spot, gently bump the right stick as needed to correct drift, get hand off right stick, then pull back gently on left stick until it touches ground, then all the way back on left stick. Hold the stick back till motors rev down (3 to 4 seconds). I gently let the stick return to center, then push the red button down and kill it. DO NOT land in a hurry, the beer will stay cold.

Whatever way you use to land that suits you is fine, no argument from me.
 
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Yep, take offs are optional, landings are mandatory. We try not to turn landings into "arrivals" or "events". One more old aviation adage I became fond of; "Better to be on the ground wishing you were in the air than in air the wishing you were on the ground".
 
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Very interesting flight today. I was over 1000 feet away running a video of the Madison Indiana bridge. I flew half way across the river did my Panos and started bringing it back. Slow in forward flight as well as descent. I got tired of watching this "H" floating it's way back to the launch site. I flipped the "HOME" switch and it banked over and started hauling butt right towards the launch site. I thought this might provide a clue as what needs to be done to right the problem.
What I'm thinking is that this is the "Improved Landing Enhancement".
I'm going to call Yuneec CS tomorrow and see what they think.
Is there an adjustment in the Ground Station to control the rate of travel.

I only fly in RABBIT MODE and until today I have never used the home button.
 
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Very interesting flight today. I was over 1000 feet away running a video of the Madison Indiana bridge. I flew half way across the river did my Panos and started bringing it back. Slow in forward flight as well as descent. I got tired of watching this "H" floating it's way back to the launch site. I flipped the "HOME" switch and it banked over and started hauling butt right towards the launch site. I thought this might provide a clue as what needs to be done to right the problem.
What I'm thinking is that this is the "Improved Landing Enhancement".
I'm going to call Yuneec CS tomorrow and see what they think.
Is there an adjustment in the Ground Station to control the rate of travel.

I only fly in RABBIT MODE and until today I have never used the home button.
Open the Hardware Monitor and make certain you are getting full output from your sticks.
 

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