Mavic vs P4P stability

[PhantomEvan]

Just curious. From what I've seen, the p4p is very stable and holds its own really well. Out of most videos I've seen on comparisons, the p4p is more stable in high winds because stronger motors, but I'm just curious as to which handles wind better. Thanks!

 

[msinger]

The P4P is going to be more stable in stronger winds since it's a larger aircraft. If you want something more stable than a Phantom, then you'll want to step up to the Inspire.

 

[PhantomEvan]

The P4P is going to be more stable in stronger winds since it's a larger aircraft. If you want something more stable than a Phantom, then you'll want to step up to the Inspire.

No, the p4p is plenty stable, I'm just curious. I know the Inspire 1 is supposed to be stable, but when I went to a festival someone had a inspire 1 there. From what I could see, it drifts much more then I figured.

 

[msinger]

Aircraft can drift for many reasons. As far as wind goes though, it's going to have more of an effect on lighter aircraft.

 

[PhantomEvan]

Aircraft can drift for many reasons. As far as wind goes though, it's going to have more of an effect on lighter aircraft.

Yes that's true. The person with the I1 must not have calibrated it or something. It was drifting quite a bit!

 

[John Locke]

It was likely in ATTI mode. With the Inspire 360 camera, that's a technique often used to capture areas. Just fly it to an area, then let it drift in ATTI and spin the camera around slowly using gimbal only. This produces smooth and consistent cinematic pans. The Phantom cannot provide the same precise consistency by yawing the craft around, as easy as the Inspire 360 camera when drifting in ATTI.

 

[Meta4]

Just curious. From what I've seen, the p4p is very stable and holds its own really well. Out of most videos I've seen on comparisons, the p4p is more stable in high winds because stronger motors, but I'm just curious as to which handles wind better. Thanks!

They are both quite capable of resisting wind.
Resistance to being moved by wind is a product of weight, surface area and power
The Mavic is smaller and so is the area it exposes to catch the wind.
DJI specs say:
P4
Max Wind Speed Resistance 10 m/s (22mph)

Mavic
4. What’s the highest level of wind the Mavic can resist?
The Mavic can withstand a level 5 wind, also called a fresh breeze. This is defined as wind speeds of 19–24mph

 

[desert phantom]

Anecdotally I hear of alot of Mavics being literally 'blown away', or at least running out of battery when returning home into a headwind. I wonder if this is because of pilot / beginner error, or Phantoms are more resistant to this?

 

[Meta4]

Anecdotally I hear of alot of Mavics being literally 'blown away', or at least running out of battery when returning home into a headwind. I wonder if this is because of pilot / beginner error, or Phantoms are more resistant to this?

Flying downwind and up high with a strong wind is one of the most common causes of incidents that inexperienced owners call flyaways.
It doesn't matter what drone you fly, if the wind is too strong to fight, you go home without your drone.

 

[Loz]

Flying downwind and up high with a strong wind is one of the most common causes of incidents that inexperienced owners call flyaways.
It doesn't matter what drone you fly, if the wind is too strong to fight, you go home without your drone.

So true - I've been flying for over a year now & should know better, yet had a very close call over Easter break at the coast - perfect sunset over rolling waves so off I flew - with the wind [emoji43]. Took me nearly 10 mins to get back - phew..

 

[PhantomEvan]

Flying downwind and up high with a strong wind is one of the most common causes of incidents that inexperienced owners call flyaways.
It doesn't matter what drone you fly, if the wind is too strong to fight, you go home without your drone.

Yeah, that always scares me. Sometimes when I go up to 100-200 feet when there's 10-15 mph winds, my phantom warns me of wind and I'm pretty sure the winds get MUCH stronger the higher you go.

 

[AlanTheBeast]

Anecdotally I hear of alot of Mavics being literally 'blown away', or at least running out of battery when returning home into a headwind. I wonder if this is because of pilot / beginner error, or Phantoms are more resistant to this?

P-mode fighting a headwind is probably what's happening. Same thing with P4P - but need a more wind.

 

[AlanTheBeast]

I don't agree much with the notion that the P4P is more stable because it is heavier. It also has a lot more surface area that the wind can push around. (Plus the legs and camera dangling underneath)

The MP has this nice dense packaging to it. 750 g in a small volume.

I'll get my MP back tomorrow - I hope. Another windy day and I'll hover both side by side and film them - 360° heading rotations to compare.

Here's a comparison that estimates the MP may have a slightly higher P/W ratio. In any case they are very close.

Max hover minutes for the P4P is based on the MP's 24 minute hover v 27 max endurance times the 30 minute max endurance for the P4P.

 

[sar104]

I don't agree much with the notion that the P4P is more stable because it is heavier. It also has a lot more surface area that the wind can push around. (Plus the legs and camera dangling underneath)

The MP has this nice dense packaging to it. 750 g in a small volume.

I'll get my MP back tomorrow - I hope. Another windy day and I'll hover both side by side and film them - 360° heading rotations to compare.

Here's a comparison that estimates the MP may have a slightly higher P/W ratio. In any case they are very close.
View attachment 80773

Max hover minutes for the P4P is based on the MP's 24 minute hover v 27 max endurance times the 30 minute max endurance for the P4P.

Your observations regarding surface area are certainly pertinent, but I would look at this from a different perspective than the power specifications, depending somewhat on exactly what is meant by "stability" in the context.

In terms of holding against a steady wind, all that matters is the maximum rated airspeed of the aircraft. If it can achieve an airspeed equal to or greater than the steady wind speed then it can hold station.

In turbulent or gusty conditions, the same criteria apply but now with unsteady, rather than steady, dynamics. If there is a sudden change in wind speed then additional factors come into play; the aircraft is no longer in force equilibrium and, in the absence of a change in thrust, it will start to move off station. For equivalent forces, a heavier aircraft will accelerate more slowly, giving it more time to react to the change. Higher drag factors will increase the forces though, so that matters too. So under these conditions, the positional resolution (not accuracy) of the aircraft's location system, the response time of the FC, the spool up or down rate of the motors, the mass of the aircraft, and the aerodynamic drag of the aircraft must all factor into the transient stability question.

 

[AlanTheBeast]

I don't disagree with what you say. That said, given that it's the same engineers, the same control loops (with different weighting/time constants), same IMU and baro (I assume), etc. the thing that stands out is reserve power to do something about an upset and the sail area of the drone in question. The P4P is massive in sail area to power compared to the MP. (IMO; I don't have a simple clear way of measuring their cross sections (via photograph perhaps?)).

The MP has a head on X-section (in hover) that is tiny. The camera is "in the nose" and not hanging down. The landing gear is two little stubs (not worth mentioning the tail gear). In cruise (or hover in a stiff headwind), however, the head on drag area of the MP increases a lot as the nose pitches down. This seems less so, to me, than for the P4P - though still present. The "down lift" in forward flight would seem to me greater for the MP than the P4P resulting in less power margin.

A couple months ago in the MP group we discovered a funny thing about the MP. Because it's designed to fold, the engineers made some compromises on rotor plane angles. Such that the difference between fore and aft rotor planes is a whopping 10.2°. This results, in a stable, no wind hover, in the front rotors working 61% more than the rear (without accounting for the slight nose-heaviness of the MP). So the MP may be headroom limited due to that. (How those angles play in forward flight is harder to say...).

 

[sar104]

I don't disagree with what you say. That said, given that it's the same engineers, the same control loops (with different weighting/time constants), same IMU and baro (I assume), etc. the thing that stands out is reserve power to do something about an upset and the sail area of the drone in question. The P4P is massive in sail area to power compared to the MP. (IMO; I don't have a simple clear way of measuring their cross sections (via photograph perhaps?)).

The MP has a head on X-section (in hover) that is tiny. The camera is "in the nose" and not hanging down. The landing gear is two little stubs (not worth mentioning the tail gear). In cruise (or hover in a stiff headwind), however, the head on drag area of the MP increases a lot as the nose pitches down. This seems less so, to me, than for the P4P - though still present. The "down lift" in forward flight would seem to me greater for the MP than the P4P resulting in less power margin.

A couple months ago in the MP group we discovered a funny thing about the MP. Because it's designed to fold, the engineers made some compromises on rotor plane angles. Such that the difference between fore and aft rotor planes is a whopping 10.2°. This results, in a stable, no wind hover, in the front rotors working 61% more than the rear (without accounting for the slight nose-heaviness of the MP). So the MP may be headroom limited due to that. (How those angles play in forward flight is harder to say...).

Reasonable assumptions. The only thing I would add to that is mass - since that determines acceleration given the force imbalance from the wind drag.

 

[AlanTheBeast]

Reasonable assumptions. The only thing I would add to that is mass - since that determines acceleration given the force imbalance from the wind drag.

Yep I forgot my father's standard: "F=ma but you can't push on a rope."

 

[PhantomEvan]

Yep I forgot my father's standard: "F=ma but you can't push on a rope."

Yeah, I do see your point. Although, out of countless videos and reviews I've seen on comparisons on both drones, the majority of the reviews stated the p4ps can hold gusts much better. I mean, logically they can, because of the stronger motors. Although, I have to hand it to the mavic when it's close to the ground on stability. All phantoms have a tendacy to throw themselves when close to the ground.

 

[AlanTheBeast]

Yeah, I do see your point. Although, out of countless videos and reviews I've seen on comparisons on both drones, the majority of the reviews stated the p4ps can hold gusts much better. I mean, logically they can, because of the stronger motors. Although, I have to hand it to the mavic when it's close to the ground on stability. All phantoms have a tendacy to throw themselves when close to the ground.

You have to be careful with the "stronger motors" thing since F=ma applies to applying power as well as resisting movement due to wind. My table above shows that the MP might actually have a slight P/W advantage.

But, the MP is also pitch limited in P mode to 16° (IIRC) and the P4P may have more pitch range. That would make a big difference in gusty winds.

The P4P almost toppled in a gust on the ground my first "real" flight out - just starting the motors as a gust came along.

I'll have my MP back tomorrow and I'll test the two "side by side" (ish) on video when there's a nice windy day.

 

[AyeYo]

Both Mavic and P4P are very stable in wind. The difference is the Mavic can't fight much more than a 15mph wind, while I've flown the P4P in 25mph wind without running out of power.