Near fly away and crash after extended no stick input

[CactusJackSlade]

My Brother has a Phantom 1 that he has flown for about a year now. It has a Futaba r/c Tx, not the white stock one.... if it matters.

Anyway, he said he was going to have a friend learn to fly and he had it in GPS mode and was basically hands off hovering at 20 feet while he was explaining all the control inputs (for about 2 minutes) to his "student" and then the Phantom started climbing for no reason. He tried to cut the throttle but to no avail.

He switched it to ATTI mode and then the motors shut down and it dropped like a rock from 50 feet damaging the gimbal. He said he gave it full throttle and nothing....

He said he has MANY times gone from GPS to ATTI and even Return To Home (RTH) with no problems.

It sounds like it started to go into RTH because there was no stick input for a long time??... has anyone heard of this condition?

Furthermore, when he went from GPS to ATTI mode why did the motors shut down?

Anyone ever have any of these issues?

Thanks for any ideas....

 

[CactusJackSlade]

Anybody?..... Beuller..... Beuller.....

 

[4wd]

If you don't touch the controls for an extended period it assumes it has lost contact and will RTH, you should be able regain control by switching to ATTI and back to GPS.
No idea why it would shut down except 'trying to cut the throttle to stop climbing' might not have been wise especially if he did a CSC.
Switching to ATTI mode can't in anyway shut it down.
Could the battery have been flashing red while they were distracted?
On the P1 the battery monitoring is a bit crude and you can hardly be sure the one you put in is fully charged.

 

[N017RW]

This sounds like the 'cousin' to the issue of:

If you fly and then land and do not shut down the motors they will slowly rev up and cause a tip over.

People would do this thinking they can run the battery down by just letting it idle on the ground.

You cannot idle on the ground after a flight.

If you want to idle on the ground it must be before a flight.

 

[darwin-t]

It sounds like it was in Failsafe, climbing to 60 feet in order to return home.

As for the shut off, under Advanced and Motor, there is a setting for Cut Off Type. Immediately or Intelligent. Check to see that this is set to Intelligent.

 

[OI Photography]

I read this the same as the others, RTH was triggered after a period of no input. However I suspect the crash was caused by switching in to manual mode when he thought he was choosing ATTI. The Phantom would have dropped very suddenly and be much harder if not impossible to recover by throttle at that point.

 

[4wd]

It sounds like it was in Failsafe, climbing to 60 feet in order to return home.

As for the shut off, under Advanced and Motor, there is a setting for Cut Off Type. Immediately or Intelligent. Check to see that this is set to Intelligent.

Yes good point, I had an incident with that on my P1
If set on Immediate you can shut the motor off in flight by holding it on minimum throttle setting.

(This option is not available in newer Assistant Software for P2s)

 

[darwin-t]

I suspect the crash was caused by switching in to manual mode when he thought he was choosing ATTI. The Phantom would have dropped very suddenly and be much harder if not impossible to recover by throttle at that point.

Only if they set S1 to Manual for the bottom position. The default for that switch is GPS, ATT, ATT

 

[OI Photography]

I suspect the crash was caused by switching in to manual mode when he thought he was choosing ATTI. The Phantom would have dropped very suddenly and be much harder if not impossible to recover by throttle at that point.

Only if they set S1 to Manual for the bottom position. The default for that switch is GPS, ATT, ATT

Well yes, only if the switch is set up that way lol. I just had a feeling that was the case based on the way it was described

 

[CactusJackSlade]

Very good points about the intelligent or immediate throttle, I will re-check his settings but I think we already fount it to be in intelligent mode.

Either way it sounds like extended period of hovering without stick input causes some unwanted issues....

As for the switching into the manual mode I do not think it's set up that way, I believe it is GPS/ATTI/RTH but again will re-check.

Thanks all for the input!

 

[gringorio]

Hi everyone,

It was my Phantom my brother is talking about. Just to clarify:

It was hovering in GPS mode only a few feet off the ground for at least a couple minutes as I was explaining the controls to my friend. When it started rising on its own I first gave a brief input to lower the throttle (switch still in GPS mode). When that didn't work and with the quad still rising I switched to ATTI mode and was probably at about 50% throttle thinking the issue was with the GPS mode. Instantly, when switching from GPS mode to ATTI mode, the motors quit. No slow spinning down, but like turning a light off by a switch. It fell to the ground from about 50' more or less. The whole incident happened in only a few seconds once the quad stated rising. I have the manual mode of the witch set to RTH (so GPS, ATTI, RTH). At no point is this lesson for my friend did we have it in manual mode since it's not even an option.

I understand the initial rise of the quad was likely the initiation of RTH after hovering with no stick input as mentioned above, but what I don't understand is how the motors turned off completely like the flick of the switch. Even in RTH mode, I would think switching back to ATTI would be seamless and in fact had done that very thing a week earlier when it worked fine.

gringorio

 

[Paul K]

I don't thing there is option GPS-ATTI-RTH on P 1 ; you can have GPG-ATTI-ATTI or GPS-ATTI_Manual.
To recover from RTH on P 1 if the radio is off to switch to ATTI quickly lower the throttle turn the radio on and rise throttle , this has to be done in split second to prevent motors to stop ( if you don't lower throttle wile switching the radio on you will get sound warning the throttle is up)

 

[gringorio]

I don't think this is the Phantom 1, because the programming allows me to set it the way I described it and it had worked fine using those setting form many flights. It is from a kit from DSLR Pros that had the 2 axis gimbal attached and a Futaba transmitter (not the white one that is paired with the original Phantom). I'm not home now so I can't go into my desktop and get a screen capture of the settings, but will try to do that soon...

 

[Paul K]

I don't think this is the Phantom 1, because the programming allows me to set it the way I described it and it had worked fine using those setting form many flights. It is from a kit from DSLR Pros that had the 2 axis gimbal attached and a Futaba transmitter (not the white one that is paired with the original Phantom). I'm not home now so I can't go into my desktop and get a screen capture of the settings, but will try to do that soon...

Sorry I just noticed P1 in the first post ; then it might be set to GPS ATTI- RTH on your futaba by DSLR pros .
In this case I think the throttle was held down for longer period of time and cost motors to stop. In panic situation is hard to recall things that happened ,it is just split of seconds.

 

[gringorio]

Thanks for the reply... I think my brother thought it was a Phantom 1, actually I'm not sure what version it is, since I have the original Phantom and a Phantom 2. This looks like the original Phantom, but with the better TX. I set the settings to those mentioned above, not DSLRPros and I never moved the throttle to down in any way that would have cut the motors. I was not panicked, but calm, just going through the logical steps as it happened. I've flown RC for a long time. I'll take the time to make a video of the settings when I get back home.

 

[darwin-t]

Going into Failsafe after no input from the sticks is not inherent in Failsafe, but is part of Receiver Advanced Protection Function

 

[OI Photography]

All P1's have the option for "failsafe" (the RTH trigger) as the bottom position on the S1 switch, set in the NAZA Assistant software.

gringorio, did that DSLRPro's kit include the telemetry display on the FPV screen that showed GPS coordinates in addition to other data?

 

[CactusJackSlade]

Going into Failsafe after no input from the sticks is not inherent in Failsafe, but is part of Receiver Advanced Protection Function

WOW.... I'm sorry but that is scary!.... what if I'm just loitering taking video???!

 

[yorlik]

i never heard of no stick action hover going to rth by itself, unless called by low battery setting...

On one of my first newbee flights I lost it over trees. RC still had contact but all I could seem to do was make it go farther away. I lost FPV of course, so jumped in golfcart and starting hightailing it thru the fields looking for it or trying to get FPV again. no luck for a good 10 minutes; THEN I got far enough away to loose RC and it flashed returning to home and I rushed back to where I took off and it landed right there. So I believe a P2 will stay hovering up there until Rc lost or battery low triggers RTH, not just no activity.

Anyone have proof it does that too?

 

[JKDSensei]

Something to consider maybe....

The Phantom creates a pretty strong downdraft below it. If the Phantom throttle is cut for any reason and it drops a few feet, and the winds are fairly calm, it will end up right inside this already descending column of turbulent air. If you hover 5 or 6 feet above leaves or dust you'll clearly see it.

Think of it as a microburst or downdraft such as affects landing full size aircraft.

That in turn deprives the Phantom of lift. And at 50 feet, you only have a second or so. Only way out is to attempt to move in ANY direction VERY quickly to regain thrust (vertical lift in this case).

Just outside that descending column of air is stable air just waiting to support the Phantom again.

So, if you ever find yourself descending rapidly and out of control, try to instinctively move the right stick in ANY direction fast. I have a cheap, nearly indestructible UAV that I can practice with.