Airspace waivers granted by the FAA require that the operator have a written contingency plan to handle the following.  

3. EMERGENCY/CONTINGENCY PROCEDURES - Lost Link/Lost Communications Procedures:  a. If the UAS loses communications or loses its GPS signal, the UA must return to a pre-determined location within the operating area and land.


If properly configured for automatic RTH then it is well defined how P4P handles lost control link, and if GPS lost then aircraft can be flown home manually.  However, there was some discussion if this means there must be a plan for loss of control link AND GPS, even if that is very unlikely.  First question is, what will the aircraft do if link and GPS lost, will it use digital compass to calculate relative heading to home point based on last good GPS point?, hover (using VPS) until low battery procedure takes over and lands?  Does anyone know what P4P will do if aircraft loses both at once?   

First question is, what will the aircraft do if link and GPS lost, will it use digital compass to calculate relative heading to home point based on last good GPS point?, hover (using VPS) until low battery procedure takes over and lands?  Does anyone know what P4P will do if aircraft loses both at once?    
Without GPS the Phantom cannot calculate a heading to anywhere since it would need to know where it is.
Without GPS it's up to you to bring the Phantom back as it won't be able to do anything except drift on the breeze in atti mode.

But unless you have a fault in your GPS receiver or cable connection, your Phantom won't lose GPS unless you fly in a canyon or under cover.
And if you had a faulty GPS receiver or connection you would probably already be aware of that and had it fixed.

For FAA requirements, you'd be telling them that you won't be flying out of sight and you can bring it back manually without GPS.

Labroides Posted at 2018-6-23 17:33
First question is, what will the aircraft do if link and GPS lost, will it use digital compass to calculate relative heading to home point based on last good GPS point?, hover (using VPS) until low battery procedure takes over and lands?  Does anyone know what P4P will do if aircraft loses both at once?   
Without GPS the Phantom cannot calculate a heading to anywhere since it would need to know where it is.
Without GPS it's up to you to bring the Phantom back as it won't be able to do anything except drift on the breeze in atti mode.

So it was my understanding that P4P stores points along its flight path along with home point.  Although it doesn't know where it is after it loses GPS, it has a last known point stored and if it goes into a hover if GPS lost then it could calculate a heading to home point and use its digital compass to fly in that direction.   However, there seems little point in doing that because it would fly along that heading drifting in the wind until low battery procedure took over.     It seems to me the best option would be to have it use VPS to hover relatively in place, waiting for control link to be reestablished or GPS to be regained until low battery procedure forces a controlled landing.    You should also be able to use the find my drone feature of the GO app to show that last reported location as starting point for search.   But this is specualtion, does anyone know for sure?

wataero Posted at 2018-6-23 18:23
So it was my understanding that P4P stores points along its flight path along with home point.  Although it doesn't know where it is after it loses GPS, it has a last known point stored and if it goes into a hover if GPS lost then it could calculate a heading to home point and use its digital compass to fly in that direction.   However, there seems little point in doing that because it would fly along that heading drifting in the wind until low battery procedure took over.     It seems to me the best option would be to have it use VPS to hover relatively in place, waiting for control link to be reestablished or GPS to be regained until low battery procedure forces a controlled landing.    You should also be able to use the find my drone feature of the GO app to show that last reported location as starting point for search.   But this is specualtion, does anyone know for sure?

The Phantom can't and won't do anything to RTH if it has no GPS.
The Find my drone feature would only be of use if the Phantom had GPS where it ended up.
If you were to hypothetically lose GPS and drift a mile in atti mode, there woyuld be no record of anything after it lost GPS.
But since you won't be losing GPS it's all hypothetical anyway.

MY PHONTOM 4 PRO V2.0
IT KEEPS THROWING UP A WARNING THAT SAYS "GPS ENCOUNTERS DATA EXCEPTION, ASK A TECHNICAL ASSISTANCE FOR HELP". BUT OM GOING ON A TRIP AND DO NOT HAVE TIME FOR THIS.. IF ANYONE HAS ANY IDEA HOW THEY CAN HELP ME PLZZ LMK

Katie Strazz Posted at 2018-6-23 19:20
MY PHONTOM 4 PRO V2.0
IT KEEPS THROWING UP A WARNING THAT SAYS "GPS ENCOUNTERS DATA EXCEPTION, ASK A TECHNICAL ASSISTANCE FOR HELP". BUT OM GOING ON A TRIP AND DO NOT HAVE TIME FOR THIS.. IF ANYONE HAS ANY IDEA HOW THEY CAN HELP ME PLZZ LMK

Where is the aircraft when it throws up this warning? Inside? Outside?

It’s outside, every time we connect to the drone it keeps saying that I have not even gotten to fly it yea...I was thinking about sending it in but thought maybe I could find help here??

wataero Posted at 2018-6-23 18:23
So it was my understanding that P4P stores points along its flight path along with home point.  Although it doesn't know where it is after it loses GPS, it has a last known point stored and if it goes into a hover if GPS lost then it could calculate a heading to home point and use its digital compass to fly in that direction.   However, there seems little point in doing that because it would fly along that heading drifting in the wind until low battery procedure took over.     It seems to me the best option would be to have it use VPS to hover relatively in place, waiting for control link to be reestablished or GPS to be regained until low battery procedure forces a controlled landing.    You should also be able to use the find my drone feature of the GO app to show that last reported location as starting point for search.   But this is specualtion, does anyone know for sure?

"It seems to me the best option would be to have it use VPS to hover relatively in place"

The VPS only works up to 10m. As mentioned here before, if you lose GPS the drone switches into Atti mode - which results in disabled VPS anyway.
You don't want to explain the FAA the fancy safety features of your drone and how you would set it up so it returns by itself.
If you are asked such a question, only answer can be what Labroides said.

Your contingency plan is that you don't fly beyond VLOS and that you keep your drone so close, that you can always determine the ATTITUDE of the drone.
That way all you need to bring it back is an inserted battery :-)

Katie Strazz Posted at 2018-6-24 09:33
It’s outside, every time we connect to the drone it keeps saying that I have not even gotten to fly it yea...I was thinking about sending it in but thought maybe I could find help here??

I suggest you read through some of these threads ...
  
https://www.google.com/search?rl ... 9...0.0.WPxznlPN_GU

Good luck

Katie Strazz Posted at 2018-6-24 09:33
It’s outside, every time we connect to the drone it keeps saying that I have not even gotten to fly it yea...I was thinking about sending it in but thought maybe I could find help here??

Don't hijack other threads with your issue!

I'm trying to apply for daylight waiver 107.29 but I do not know how to answer this one question the FAA is asking. Can anyone help?
The reply states “Prior to flying in the area of our operation, we will create a printed map or diagram of the area. The map will depict the positions of our Remote PIC and Visual Observers (VO), ensuring we have continuous VLOS of our sUA during its entire flight. The map will also show a highlight of our flight route, along with pre-selected emergency landing areas and alternative/emergency routes that are free from congested airspace or any departure or approach paths of other aircrafts to mitigate the risk of our sUA from entering the path of another aircraft during a loss of communication link situation.”

The reply mentions landing areas, alternate/emergency routes, and VLOS but none of these are a method that prevents (mitigates the risk) the sUA from entering the path of another aircraft (manned or unmanned) during Return to Home mode while in lost link communication operation. During lost link the RPIC has NO communication with the sUA so the sUA is uncontrolled; it can’t be maneuvered by anyone or commanded to land by anyone. With the sUA flying uncontrolled there is a chance it’s flight path, pre-programmed or not, could result in the sUA entering the path of another aircraft that has entered the operational area (or is near the operational area). Keep in mind manned and unmanned aircraft may be operating in or near your operational area at any altitude at any time without prior notice.

Please provide a method to satisfy the above mentioned concern.

djiuser_5Tmt5qbUjlzL Posted at 2018-10-18 19:12
I'm trying to apply for daylight waiver 107.29 but I do not know how to answer this one question the FAA is asking. Can anyone help?
The reply states “Prior to flying in the area of our operation, we will create a printed map or diagram of the area. The map will depict the positions of our Remote PIC and Visual Observers (VO), ensuring we have continuous VLOS of our sUA during its entire flight. The map will also show a highlight of our flight route, along with pre-selected emergency landing areas and alternative/emergency routes that are free from congested airspace or any departure or approach paths of other aircrafts to mitigate the risk of our sUA from entering the path of another aircraft during a loss of communication link situation.”

To me it is obvious the FAA does not want to grant a wavier. The question they ask is impossible to overcome if you loose control. The UAV does not have on board radar or aircraft collision avoidance so without operator input there is no way to 100% prevent a collision.

There is one possible answer that could throw them off.

Tell them your return to home (failsafe) altitude is set at 1 meter. The UAV aircraft upon loss of control signal or GPS after 10 seconds will utilize its internal barometer and descend to its failsafe altitude, hover and await opertor input. If there is no operator input when the battery reaches 0% it will land.
Note: At a 1 meter fail safe altitude it is extremely unlikely the UAV aircraft will encounter other aircraft manned or unmanned. The only possibility is a runway or landing pad and the UAV will not be operated near those areas.

Good luck.

Eric13 Posted at 2018-6-24 10:39
Don't hijack other threads with your issue!

Eric, give the fact that new members cannot start their own threads, this is what they have to do, it was a stupid idea in the 1st place but nonetheless, you will see this from time to time, even more so when posting unrelated issues, thats down to the forum search being pants too.

djiuser_5Tmt5qbUjlzL Posted at 2018-10-18 19:12
I'm trying to apply for daylight waiver 107.29 but I do not know how to answer this one question the FAA is asking. Can anyone help?
The reply states “Prior to flying in the area of our operation, we will create a printed map or diagram of the area. The map will depict the positions of our Remote PIC and Visual Observers (VO), ensuring we have continuous VLOS of our sUA during its entire flight. The map will also show a highlight of our flight route, along with pre-selected emergency landing areas and alternative/emergency routes that are free from congested airspace or any departure or approach paths of other aircrafts to mitigate the risk of our sUA from entering the path of another aircraft during a loss of communication link situation.”

I do NOT believe multiple VOs can replace the vLOS of the PIC.

If you give that info to the FAA you will get denied.

Randy

n55w132 Posted at 2018-10-18 19:46
There is one possible answer that could throw them off.  Tell them your return to home (failsafe) altitude is set at 1 meter. The UAV aircraft upon loss of control signal or GPS after 10 seconds will utilize its internal barometer and descend to its failsafe altitude, hover and await opertor input.  If there is no operator input when the battery reaches 0% it will land.

I think you need to read your manual.  

n55w132 Posted at 2018-10-18 19:46
To me it is obvious the FAA does not want to grant a wavier. The question they ask is impossible to overcome if you loose control. The UAV does not have on board radar or aircraft collision avoidance so without operator input there is no way to 100% prevent a collision.

There is one possible answer that could throw them off.

'Tell them your return to home (failsafe) altitude is set at 1 meter.'

The aircraft does not descend to the RTH altitude. If it is already higher than that, it returns home at the current height.