M2P headwind speed

[Aether]

This topic might’ve already been extensively discussed already, although I could really find the answer to my question. What is the normal expected top speed when going into around 9 mph headwind?

I was in sport mode and could barely muster 22 mph. I’ve flown in lots of wind, although couldn’t remember a time when it seemed like my drone was barely moving like today.

 

[bumper]

How and where did you measure the windspeed at 9 mph? What was wind speed at the altitude the drone was flying at? The M2 is supposed to have a max air speed at sea level, standard conditions, of almost 45 mph. Winds aloft can be much stronger than surface winds.

 

[Aether]

How and where did you measure the windspeed at 9 mph? What was wind speed at the altitude the drone was flying at? The M2 is supposed to have a max air speed at sea level, standard conditions, of almost 45 mph. Winds aloft can be much stronger than surface winds.

I just use a standard weather app to check wind conditions like windy.com. I was able to go around 45 mph on the return home, although the headwind sure seemed stronger than 9 mph, so obviously it’s probably stronger winds at 150 ft. I was just curious mostly what the expected average speed is when going into a headwind that Isn’t seemingly that strong on the surface.

 

[Meta4]

What is the normal expected top speed when going into around 9 mph headwind?
I was in sport mode and could barely muster 22 mph.

As hinted above, very few people are equipped to accurately tell what the actual wind speed is, on the ground or up higher.
And there are many reasons why the actual wind at your location could be very different from what you'll see in a prediction app.

If your M2 in sport mode could only manage 22 mph, the headwind component it was fighting against would have been about 23 mph.

 

[Aether]

As hinted above, very few people are equipped to accurately tell what the actual wind speed is, on the ground or up higher.
And there are many reasons why the actual wind at your location could be very different from what you'll see in a prediction app.

If your M2 in sport mode could only manage 22 mph, the headwind component it was fighting against would have been about 23 mph.

So are you actually saying the headwind was 23 mph and not around 9 mph?

If that’s the case then I should’ve technically been able to fly 68 mph on the way back.

 

[bumper]

You are assuming the drone was flying directly into the wind on the way out, and away from the wind (direct tailwind) on the way home!

Firstly, wind direction aloft has little bearing on surface wind direction. Being a pilot of small aircraft and gliders, I can attest to the fact that's rarely the case. Sometime there will even be a shear line, sometimes at fairly low altitude of say several hundred feet, where wind direction can be markedly different from surface wind.

In a worst case scenario with a direct 90* crosswind to an aircraft's course, the aircraft will have to crab into (or correct for) the wind to maintain the desired track. This will slow the aircraft's ground speed on both out and return. In real life, it seems, head winds in both directions are more prevalent than tailwinds (at least that's been my bum luck! ).

And on a few occasions, while flying mountain wave out of Minden, NV, I've had my glider nose pointed directly into a 70 knot wind, going up at 2000 feet per minute, while staying stationary over the ground or even moving backwards if I pull the stick back a bit to slow down!

My self-launch ASH26E over Minden:

 

[rehkram]

Bumper, my wife learned to fly at Minden NV, I'll show her this thread!

 

[Meta4]

So are you actually saying the headwind was 23 mph and not around 9 mph?

If that’s the case then I should’ve technically been able to fly 68 mph on the way back.

I'm saying that your app forecasting 9mph winds was not the winds you flew in.
Unless there's something wrong with your Mavic, the numbers show that it was dealing with a 23 mph headwind.
But your Mavic won't pick up a big boost from a tailwind unless you can switch to atti mode.

Try some testing and you'll see that it gets no tailwind boost unless the tailwind is quite strong.
And even then, the added speed is not very much.

 

[boblui]

can you post the flight log file ?

 

[BadWolf1]

So are you actually saying the headwind was 23 mph and not around 9 mph?

If that’s the case then I should’ve technically been able to fly 68 mph on the way back.

A normal aircraft has its airspeed and heading. When you add wind (with a speed & direction) you get the ground speed and track. (See @bumper above). So if you fly with an airspeed of 100 kts, into a 50 kt head wind, your ground speed is 50kts and if it's a tail wind your ground speed is 150kts.

It's also worth saying that on a normal aircraft the stick works differently, hold it to one side the aircraft rolls and keeps rolling, hold it back and the aircraft tries to fly a loop. On a DJI drone controller the stick / mode requests a forward speed and/or sideways speed (You can't loop or roll your drone). If you request 20 MPH forward and there is 20 MPH tail wind the drone will hover and let the wind carry it forward at that speed - it will reduce pitch to compensate for the tail wind: you can't ask for full pitch + wind assist and exceed the drones stated top speed.
Flying into a headwind the drone will increase pitch to get a faster airspeed to overcome the wind and give you your requested ground speed. There's a maximum pitch (with the motors at top speed , enough force must be vertical to balance the drones weigh), and if you request 20MPH into a 20MPH wind the drone will adopt the pitch for an airspeed of 40MPH or the Maximum pitch whichever it hits first.
[It's assumed that maximum speed in still air uses maximum motor speed / maximum pitch, it's possible there is something in reserve]

Wind speed varies a lot. A forecast app might only be able to predict an average over an hour or two for a broad area. "Will it be flyable, around here this afternoon" not "What is the speed where I am standing right now". Wind changes with height and other things like the shape of the ground, trees, buildings, all mean that you can feel something very different to a drone 200 feet above a point a little way off. An app can have reasonable accuracy and quite a large difference from what the drone sees.

 

[Aether]

You are assuming the drone was flying directly into the wind on the way out, and away from the wind (direct tailwind) on the way home!

Firstly, wind direction aloft has little bearing on surface wind direction. Being a pilot of small aircraft and gliders, I can attest to the fact that's rarely the case. Sometime there will even be a shear line, sometimes at fairly low altitude of say several hundred feet, where wind direction can be markedly different from surface wind.

In a worst case scenario with a direct 90* crosswind to an aircraft's course, the aircraft will have to crab into (or correct for) the wind to maintain the desired track. This will slow the aircraft's ground speed on both out and return. In real life, it seems, head winds in both directions are more prevalent than tailwinds (at least that's been my bum luck! [emoji4] ).

And on a few occasions, while flying mountain wave out of Minden, NV, I've had my glider nose pointed directly into a 70 knot wind, going up at 2000 feet per minute, while staying stationary over the ground or even moving backwards if I pull the stick back a bit to slow down!

My self-launch ASH26E over Minden:

I really enjoyed your reading reply, thank you!

can you post the flight log file ?

I’ll try and post one tomorrow. It almost seems like something isn’t right, because today there was literally no wind and in sport mode no matter which direction I flew I could only get 31 mph max.

(Replies to posts directly above mine I don’t quote)

Wow, that’s a wealth of information, Thank you! I’ll be reading it a few times more I’m sure to grasp everything you’re explaining [emoji4]

 

[boblui]

I’ll try and post one tomorrow. It almost seems like something isn’t right, because today there was literally no wind and in sport mode no matter which direction I flew I could only get 31 mph max.

That is definitely not normal. In sport mode, you should get about 70 km/hr or about 45 mph. The flight logs will be useful. pls post both the .TXT and .DAT files if possible.

 

[Aether]

That is definitely not normal. In sport mode, you should get about 70 km/hr or about 45 mph. The flight logs will be useful. pls post both the .TXT and .DAT files if possible.

Will do definitely! One question, would not updating the firmware have anything to do with it? I haven’t updated for a while and was hoping not to really.

 

[Meta4]

Will do definitely! One question, would not updating the firmware have anything to do with it?

That would make no difference at all.

I’ll try and post one tomorrow.

Please do ASAP .. it only takes two minutes and will probably clear up the mystery.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides

 

[vindibona1]

So are you actually saying the headwind was 23 mph and not around 9 mph?

If that’s the case then I should’ve technically been able to fly 68 mph on the way back.

Don't forget that DJI programs this bird to fly at a maximum of 44.x mph. I'm not sure how they achieve that speed governor but would assume via GPS measuring rate of position change. Bottom line is that the motors only have so much power to swim upstream.

 

[Deleted member 103366]

''............. If you request 20 MPH forward and there is 20 MPH tail wind the drone will hover and let the wind carry it for...............

Cracking post.
I pretty much saw the quoted behaviour a few evenings ago with a mavic mini. Flying FLAT OUT in P mode down wind, at all of 8m/s, and it was darn near in a hover attitude. It was really a rather strange thing to watch.
For the upwind leg I turned it side on to the wind and switched the camera to FPV, it was rather impressive to see the tilt.
A M2Z 'barely rev'd its motors' to fly upwind in the same conditions lol

 

[Aether]

That would make no difference at all.

Please do ASAP .. it only takes two minutes and will probably clear up the mystery.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides

Sorry I took so long to get back. It had been a bit gusty that past week so I wanted to wait until the wind conditions were calm.

I took the bird up just for a few minutes this evening and in sport mode had no problems with speed whatsoever. It topped out right at 45.1 mph in several different headings. I did notice when I landed that the engines seemed unusually hot. I do live in the southwest United States, so the temperature was probably right around 100 F, which I’m sure doesn’t help.

Regardless of tonight’s outcome, I’ll upload the logs hopefully in the next day in case there might be some intermittent anomaly or anything that might seem unusual — Thank you, I appreciate your help!