I have the Phantom 3 4k version.

I started flying my drone again mid-march after the winter is done and I had a few successfull first few new year flights, then 25th of april I got the following warning:

- Motor Idling (Loose or Missing Propeller)

The warning came when hovering after takeoff, and since 25th of april I have been worried and knocked my head against this trying to figure out what went wrong 25th of april. The drone never hit propellars to the ground, it flew last year when I got it before winter came and then just waiting for calmer weather. So I didnt have that much data to go on. But my 10 logfiles from early april and march show that this issue was not there at the time. I used same set of propellars that came in a black bag inside with drone. The 2 spare sets still have plastic on them. about 5-6 years ago I used to fly RC heli's so Im pretty good with the sticks and got the feeling, and knows how to check the props for sure.
Sometime in april I patched my drone to 1.10.90, got the app version 3.1.5 on android (Samsung S6 edge), and remote controller is 1.8.0. I was in contact with support trying to patch my drones firmware as the app said it had to be patched. After the remote controller and drone upgrade I got this warning message every time I fly. Scary thing for such an expencive toy..
The IMU and compass and gimbal and controller was calibrated after the patch. This is why it took some time from march to 25th of april until I flew again, as I went through this whole process in my spare time.

Now, for those who claim it is a loose propellar  - its NOT.. lets start with that. I have landed it many times to check the propellars and they are firm tied to the motors. The craft flies just fine up to its top speed. I have checked the motors and they turn around equally all 4. No loose screws below the motors. Propellars that came with the drone is intact. The drone even flew yesterday up to 150 meters (maximum altitude allowed in Norway unfortunately).

But I started noticing a pattern, every time I used the GUI on my phone to auto take off as the kids want to touch the panel to do that, and also those few times wind allows it for auto land the kids get to touch the auto land slider, the message pops up. It dont show up during flight.

Like this, typically flight where the warning message shows:


I have spent every evening hours to the end last week googling this and trying to match some explanation to my setup and ignoring those who crashed their drone, and kept reading on with those with Mavic, P3 adv/pro/4k also have same isse, and reading about people having to send it back to DJI support centre. I didnt accept to ship it back for something personally I believe is a software patch and something might have gotten too sensitive.

Today I have been working hard to figure this out, and I believe I did!

I had fully charged batteries and decided to go outside with all my propellars (including the spare new ones) and do different things. Change one Prop at a time, do auto take off's, auto landings, and manual takeoffs and manual landings. I think I took off and landed more than 100 times, in a little windy situation.

First I reproduced the issue with using my original propellars and auto take off, and auto land. Easy, 10 takeoff's/landings and error came every time. Just like the typically flight pattern. Out of the few auto landings I did, the message came up every time, but the manual landings the message did not show up.

Then I did manual take offs. No error came. Manual landing, manual take off, manual landing. 10 times. no error. Back to auto, message came up. out of 20-30 take offs, only one manual take off got the error message to show. Every 5 take offs, I lifted the drone 50 meters just to get it to fly to double check that I dont get the warning up in flight. So a pattern definetely is there. The auto takeoff/landing reproduces the warning message. I checked props 3-4 times and they were firmly tied.

I took off the props. changed to a brand new set which I had to take off the plastic from. I did a auto take off - NO WARNING MESSAGE. I did this about 10 times also tried manual mode, no message at all.

Then I took a good look at my original propellars. On top side I can see 2 black ones, and 2 silver ones, and 2 of them are blue markings on the edges. Below the propellars one is black, 2 white, and one has some kind of metal alloy inside where the motor is attached.
I checked the new propellars, and they are all white and plastic inside the propellars where the motor is attached, 2 black and 2 silver up top.



So logically the new propellars went back on except for one where I put in the one old one which has metal inside where the motor goes. I figured if Drone senses something is loose, it have to be the metal one.

BINGO. I got the warning message immediately. every auto take off it came, and sporadically it came with manual take offs. Then off with the "silver metal" one and on with a new one, no error message.

Then the 3 other ones of the old propellars came on, no error message with those either. I did 4-5 take offs to verify it. Pretty happy with my findings.
Now whats special with this single propellar ? It is NOT damaged, but I have noticed the following:
- Silver propellar where the top is more blank than the other silver ones. Seems like metal in the middle on top.
- Silver metal alloy inside where the motor attaches.
- The propellar attaches fine and firm. so its not loose.
- The propellar has blue stripes on the edges (so does one of the black ones of the original props which has black plastic inside)
- I did notice the silver metal propellar is 1-2mm closer to the housing than the other ones on one side only. (Could this be the reason?).
- I have not noticed drifting or spinning of the drone with the original propellars.

The original propellars that came with the drone and were inside the nice DJI black bag.


If the wind doesnt get any rougher here in Norway by later tonight, I will take my Phantom 3 4k and fly it 2 fully charged batteries as a last verification.

I am interested to hear from DJI and other people if anyone got this kind of experience, and if those who do have this issue can check the propellars and see if they got something similar to what I have found  - the metal silver propellar that reproduces the warning message ?

I have noticed during my research that the Mavic drone owners also get this warning message, and I'm thinking that if something in the software either on phone OR firmware on these drones got patched during spring to be too sensitive, I can imagine the moving arms on the Mavic can make this warning message worse, especially IF the 1-2mm difference in height towards the body is the reason.

I think the first step towards checking if this is related to possible software fix is the manual / auto take off and landings. I definetely see this issue with the Auto take off/landings. and only saw it once with manual take offs and landings with the silver metal propellar. I got the warning message every single time with that one propellar with auto take off's.

The metal hubs were used on Phantom 2 and aren't intended to be used with the Phantom 3.  The stripes on the props are an extra cost item option, and are just for looks, the propeller is the same otherwise.  I haven't seen a black hub version.  The shape of the tip of the black one seems slightly different than the others;  the rounded part looks bigger.  It's unusual if these have come out of the box as new.  It's probably more likely it was replaced with aftermarket copies by a previous owner or tampered with at the store.

If the props have blue stripes, I would say they may not be genuine DJI props, I have only ever seen them come in red, silver or gold (and yellow for carbon-fibre).  If you examine the blade on the top, you should see "DJI" moulded in raised plastic on the leading edge near the widest part of the blade towards the hub.  Non-genuine copies won't have that.  I would highly recommend using DJI genuine props only, they tend to be already well-balanced out of the packet; copies typically aren't.  It's not worth being cheap on replacement parts, especially because a set of propellers is reasonably inexpensive.  It could be responsible for an expensive crash and affect any warranty.

It is possible that the metal hub prop, even though it is tightly attached, may have a different weight or profile shape.  This may cause it to accelerate or spin at a different speed than the others, making it behave like a loose prop would and thereby generating that error.  It isn't a good idea to mix and match props, keep them all the same type.  It appears the latest firmware update is more sensitive to reporting discrepancies in motor performance (indicating damaged/loose/missing props).

endotherm Posted at 2017-5-2 10:59
The metal hubs were used on Phantom 2 and aren't intended to be used with the Phantom 3.  The stripes on the props are an extra cost item option, and are just for looks, the propeller is the same otherwise.  I haven't seen a black hub version.  The shape of the tip of the black one seems slightly different than the others;  the rounded part looks bigger.  It's unusual if these have come out of the box as new.  It's probably more likely it was replaced with aftermarket copies by a previous owner or tampered with at the store.

If the props have blue stripes, I would say they may not be genuine DJI props, I have only ever seen them come in red, silver or gold (and yellow for carbon-fibre).  If you examine the blade on the top, you should see "DJI" moulded in raised plastic on the leading edge near the widest part of the blade towards the hub.  Non-genuine copies won't have that.  I would highly recommend using DJI genuine props only, they tend to be already well-balanced out of the packet; copies typically aren't.  It's not worth being cheap on replacement parts, especially because a set of propellers is reasonably inexpensive.  It could be responsible for an expensive crash and affect any warranty.

Hi, thank you for a good explanation. The speed of the metal alloy prop makes sense. It also makes sense for alot of the forum posts about the same issue when I have read them.

I did a throughful examination of the 4 original propellers I got with my P34k. They all state DJI on one side of the blade just like you pointed out. also the blades have the following numbers:
- Silver bullet / silver metal alloy one : 9443 number on oppsite side of the blade as the DJI logo
- Second silver, but white plastic inside, 9450 (DJI branded)
- Black with black plastic, DJI branded, 9443 R
- Black with white plastic, DJI branded, 9450cw

fans1a00807e Posted at 2017-5-2 16:52
Hi, thank you for a good explanation. The speed of the metal alloy prop makes sense. It also makes sense for alot of the forum posts about the same issue when I have read them.

I did a throughful examination of the 4 original propellers I got with my P34k. They all state DJI on one side of the blade just like you pointed out. also the blades have the following numbers:

The blue painting on one of the black with black plastic, and  the silver one with metal alloy is not painted on TOP of the original painting. It is not possible to rub off like it was out on after the first paint job. I cant get it to remove itself from the blade. It seems its part of the plastic itself.

fans1a00807e Posted at 2017-5-2 16:52
Hi, thank you for a good explanation. The speed of the metal alloy prop makes sense. It also makes sense for alot of the forum posts about the same issue when I have read them.

I did a throughful examination of the 4 original propellers I got with my P34k. They all state DJI on one side of the blade just like you pointed out. also the blades have the following numbers:

for the record, the replacement props I used have the following numbers, all DJI branded:
2x 9450 and 2x 9450cw

fans1a00807e Posted at 2017-5-2 16:52
Hi, thank you for a good explanation. The speed of the metal alloy prop makes sense. It also makes sense for alot of the forum posts about the same issue when I have read them.

I did a throughful examination of the 4 original propellers I got with my P34k. They all state DJI on one side of the blade just like you pointed out. also the blades have the following numbers:

Good thing that you checked.  You will notice it will fly a lot smoother with the replacement props.

The mix of odd colours was probably something they did in earlier generations of the Phantom line (I'm not too familiar with their early stuff).  The worrying thing is that you have a mix of 9450 and 9443 props.  The model number actually contains information about the prop.  The first half is the length in inches (9.4") and the second half has to do with the pitch (I think the trailing edge droops down 0.50" from the leading edge).  If you compare them, you will see the 9450's have more "meat" on them and a larger surface area.  The 9443 was used on smaller lighter Phantoms, and was increased for the heavier P3 to provide more lift.  Your aircraft is trying to fly with more lift on some props compared to the others.  Get rid of the 9443's right away.  You can keep the others for emergency replacements, but it is better to have all the props matched, so no more mixing sizes/metal hubs/construction materials etc.

Thing is. I didn't even know the props were different. The craft was purchased as a new one. So I'm really surprised. I'm used to tech and this is really such a small thing to even notice as most people focus on black and silver colour to match the spinning of the motors.

I flew the p34k with a full flight 21 minutes with the right prop set today. And no warning message.

fans1a00807e Posted at 2017-5-3 14:21
Thing is. I didn't even know the props were different. The craft was purchased as a new one. So I'm really surprised. I'm used to tech and this is really such a small thing to even notice as most people focus on black and silver colour to match the spinning of the motors.

I flew the p34k with a full flight 21 minutes with the right prop set today. And no warning message.

I have a 3PA, and also had this issue a while back. I also purchased some aftermarket props to try. My originals ones had been used for over a year so I just decided to retire them before I had an issue. I use both Litchi and DJI GO app. Never had an error with the Litchi, but don't know if it monitors that. I was flying in a pretty strong winds also when this happened. The flights were fine and I was using the GO app, but the error showed up when I landed. At no other time did it give me that error. I double checked the props and none of them were loose. This happened only a couple of times. I did switch props to my spare DJI ones that had never been used and never had the error again. I chalked it up to the aftermarket props and the windy conditions at the time. Wondered if it was using a lot of power to maintain stability, and when I brought it down to land in somewhat calmer air, it sensed something wrong and maybe the aftermarket props were grabbing more or less air  (pitch) than the DJI ones. Don't really know. That was over a month ago and when it was colder out too. Since then, I have used both sets or props and flew in windy conditions again, but I haven't seen the error show up again. the weather though is certainly warmer. As long as my props are tight I am not concerned about it, but I agree with you it gives you a feeling something is wrong.

u r so lucky u did not have a prop fly off! I did... waiting to see if DJI will consider it a warranty fix/replacement or not...  2.5 weeks so far....

Phantomski Posted at 2017-5-4 09:21
u r so lucky u did not have a prop fly off! I did... waiting to see if DJI will consider it a warranty fix/replacement or not...  2.5 weeks so far....

What kind of props did you use ? As you can see from the images I provided the "set" that were in the bag were of different types. apparently the metal version is for a lighter phantom 3 apparently.

fans1a00807e Posted at 2017-5-4 13:16
What kind of props did you use ? As you can see from the images I provided the "set" that were in the bag were of different types. apparently the metal version is for a lighter phantom 3 apparently.

I remember reading that they had trouble with the metal hubs failing. Stick with the all plastic ones.

fans1a00807e Posted at 2017-5-4 13:16
What kind of props did you use ? As you can see from the images I provided the "set" that were in the bag were of different types. apparently the metal version is for a lighter phantom 3 apparently.

I was vague earlier and didn't describe it clearly enough.  Metal hubs and 9443's were used for the Phantom 2.  They shouldn't have been anywhere near the aircraft you bought.

fans1a00807e Posted at 2017-5-2 17:04
for the record, the replacement props I used have the following numbers, all DJI branded:
2x 9450 and 2x 9450cw

Saludos, gracias por tu gran apoyo tenía ese problema de motor y helices floja y me daba miedo volar así ya que mis hélices son nuevas y dicen dji total tengo 8 nuevas y viendo el juego de 4 una decía 9443 y las otras tres decían 9450 osea que la teoría que aquí nos dieron es correcta si una no es igual a la numeraciones falla!! Bingo cambie la que decía 9443por 9450 (4 helices) dicen ahora 9450 y todo ok, resumen comprobé que es la numeración de helices que afecta

I have a similar error message in Phantom 4: the motor is in neutral, one of the propellers has been lost, I have those messages without using propellers .....