Sports Mode speeds?

Mavicsailor · Jan 25, 2017

I had my first opportunity to fly my mavic in sports mode. It seemed screaming fast, but the gps speed only indicated about 35mph average over about 1 minute, (first going with about a 5 mph wind, then against it) I know the spec is 40mph (with no wind) and some have reported well over that. I thought I read something about DJI decreasing the top speed a bit in the latestest firmware. (Maybe internet speculation)

What is everyone seeing as their top speed in Sports Mode? (No wind or average going with and against the wind). Wondering if this spec to some degree is a temperature related. I've heard some question the accuracy of the gps reported speed, but at least judging by my experience with other GPS instruments, this should be extremely accurate on average over a 30 second period.

BAPaik · Jan 25, 2017

Just tinkering around today, got to 41 MPH

Nathan Hoover · Jan 25, 2017

You should be able to fly at 40mph in no wind, and quite a bit faster with wind. There are some screenshots here showing the difference between what the app reports and what the controller shows (reality): Speed in Sport Mode is incorrect in Go app

WestTexas · Jan 26, 2017

I've had mine up a little over 40mph. I've seen 43+. However, in a 20mhp tailwind...it's still a little over 40. Must have a governor of some sort.

Nathan Hoover · Jan 26, 2017

My fastest speed in Sport mode was a bit over 45 mph in moderate wind. I haven't taken the Mavic up in strong winds. Mavic fastest: HealthyDrones.com - Innovative flight data analysis that matters

In strong winds, I once hit just under 70 mph with my old Phantom 2 Vision http://www.flytrex.com/mission/quadcopter-phantom-2-vision-nathan-hoover-W4ewkurr/ and have flown over 65 mph with a Phantom 3: HealthyDrones.com - Innovative flight data analysis that matters

Mavicsailor · Jan 26, 2017

WestTexas

It's interesting your observation on the top speed still about 40 mph with a tail wind. A Mavic YouTube video that documented speeds at various settings pretty much showed the same thing. He had a strong wind and understandably was going considerably slower than the rated 40 mph when headed into the wind (I believe the wind was 15-20), but did not exceed much over 40 mph when flying with the wind. Maybe the mavic uses the GPS to limit the speed to around 40mph and just decreases the rpm.

This would explain my averages with and against the wind as being below the 40 mph spec. My top speed was 42 mph with the wind. Against the wind was obviously slower.

Sent from my iPhone using MavicPilots

Squamer · Jan 26, 2017

Fastest I've gotten up to is 44.5 mph accordingly to my flight logs on healthy drones.

Mavicsailor · Jan 26, 2017

Squamer said:
Fastest I've gotten up to is 44.5 mph accordingly to my flight logs on healthy drones.

Plus or minus a few MPH around 40 still won't account for a 20 mph tailwind where the ground speed should be close to 60 mph. Unless someone can show ground speeds far above the 40 mph spec when flying with the wind, seems like the mavic is using the gps speed to throttle down and keep it around 40 mph. It wouldn't seem too surprising if DJI did this to minimize the possibility of the drone very quickly getting away at higher altitudes and much higher wind.

It appears the mavic uses the gps speed combined with the rpm to generate heavy wind warnings. Their engineers know that for a given rpm and pitch, there should be a certain speed in no wind. Also may be possible that they use the gps speed to throttle back to about 40 mph in a tailwind.

Squamer · Jan 26, 2017

Mavicsailor said:
Plus or minus a few MPH around 40 still won't account for a 20 mph tailwind where the ground speed should be close to 60 mph. Unless someone can show ground speeds far above the 40 mph spec, seems like the mavic is using the gps speed to throttle down and keep it around 40 mph.

Anyone have a radar gun? Anyone a cop? I will say regardless of whether it's been windy and a tailwind or not I can't get any faster than that. Believe me I've tried. So I'd agree it's reading something other than ground speed

BlakPhoenix · Jan 26, 2017

Fastest I've hit so far was 19.5m/s (43.6 mph / 70.2 kmh). That was over quite a long stretch with a slight tailwind. Took about 30-45 seconds to reach this speed.

I should note that on the return flight I was only getting 14-15m/s, so can probably calculate the average windspeed from that.

Mavicsailor · Jan 26, 2017

Squamer said:
Anyone have a radar gun? Anyone a cop? I will say regardless of whether it's been windy and a tailwind or not I can't get any faster than that. Believe me I've tried. So I'd agree it's reading something other than ground speed

GPS only measures ground speed. It appears their algorithms limit potential total speed...AC speed + wind speed to the Sport Mode 40 mph spec measured as ground speed. Guess a good way to prove this would be to clock the time over a given distance. Regardless, this thing is screaming fast in Sports Mode.

Makes sense that they would limit collision avoidance speeds to their spec of about 20 mph. A 10 mph breeze could turn that 20 mph into 30 mph ground speed where the obstacle avoidance would likely have a hard time stopping in time.