High altitude rotors at sea level

[AMGPilot]

Speed and attitude are inherently linked on a copter. But just because they are a means of inducing power output through the motors doesn't mean an overloaded motor has anything to do with them. An overloaded motor doesn't discriminate over what state of the copter is in - if it's pulling to much current it's pulling too much current.

speed and altitude have nothing to do with each other on a "copter" and really yo need to pick one thing you are going to claim and defend. you can't keep saying one thing on one post and then contradicting that in the next post.

 

[KyleIRYS]

speed and altitude have nothing to do with each other on a "copter" and really yo need to pick one thing you are going to claim and defend. you can't keep saying one thing on one post and then contradicting that in the next post.

ATTITUDE not ALTITUDE

 

[KyleIRYS]

speed and altitude have nothing to do with each other on a "copter" and really yo need to pick one thing you are going to claim and defend. you can't keep saying one thing on one post and then contradicting that in the next post.

I've not contradicted myself, not that you stating that I have without justifying it actually helps anything.

Accepting things are related but don't reflect causality isn't a contradiction. That's what you aren't distinguishing between.

 

[AMGPilot]

Again, citing one specific fact about one specific place and comparing it to one other specific location that you happen to fly doesn't make the two of those things universal facts.

The point is how can it differentiate between environmental conditions and a change in prop? Those two variables have the same affect on power output of the motors and subsequent flight performance, but according to you it just knows which is which?

Okay maybe I need to make this easier for you. In post 10 you stated that air can only lose density with reference to sea level not gain it. I corrected you. You also dont seem to understand what the flight controller is measuring. Temperature, Barometric pressure, GPS altitude and position, Compass / Magnetometer and the inertia measurement unit (Accelerometers and Gyros, 9 axis worth) it is VERY easy for it to differentiate environment conditions vs change in props. Density altitude is a simple comptation of Barometric pressure, Temp and GPS altitude, that then allows the Flight controller to predict the power required to hover, climb etc. it also needs to be know to calculate the RTH point which is dynamically changing.

 

[AMGPilot]

Again, citing one specific fact about one specific place and comparing it to one other specific location that you happen to fly doesn't make the two of those things universal facts.

wow you just dont get it. Santa Monica airport is frequently below sea level density altitude wise same goes for most any location that sees a lower than standard temperature and is at a low altitude when referenced to Mean Sea Level. It is a universal fact

 

[AMGPilot]

The point is how can it differentiate between environmental conditions and a change in prop? Those two variables have the same affect on power output of the motors and subsequent flight performance, but according to you it just knows which is which?

it's easy if you understand the flight control system

 

[KyleIRYS]

Okay maybe I need to make this easier for you. In post 10 you stated that air can only lose density with reference to sea level not gain it. I corrected you. You also dont seem to understand what the flight controller is measuring. Temperature, Barometric pressure, GPS altitude and position, Compass / Magnetometer and the inertia measurement unit (Accelerometers and Gyros, 9 axis worth) it is VERY easy for it to differentiate environment conditions vs change in props. Density altitude is a simple comptation of Barometric pressure, Temp and GPS altitude, that then allows the Flight controller to predict the power required to hover, climb etc. it also needs to be know to calculate the RTH point which is dynamically changing.

I'd already conceded that there isn't a hard and fast sea level limit. But back to the point of the high altitude props which are meant for 2500-5000 metres, 1200 feet below sea level doesn't really compare. Your point was valid, but not to the degree you were stating it to.

I know the FC is measuring all those things, but it can only assume you've changed propellers. Maybe it has a great handle on environmental factors which is great, but it can't actually definitively say it's the props. You could be flying lighter or heavier, vastly different pitch or diameter props. It can't actually identify that.

 

[KyleIRYS]

wow you just dont get it. Santa Monica airport is frequently below sea level density altitude wise same goes for most any location that sees a lower than standard temperature and is at a low altitude when referenced to Mean Sea Level. It is a universal fact

Again, you were insinuating that the most dense atmospheric conditions ever recorded were a common operating condition. And even if it were, it doesn't compare to the relative change in altitude that the high altitude props are design for so it's of little consequence.

 

[KyleIRYS]

it's easy if you understand the flight control system

It's easy to make assumptions, yes.

 

[The Editor]

Phew......so that was all very exciting.

So I go back to my second post where I said don't do it. Why would you?
Aviation is all about mitigating risk wherever possible. HA props (which btw are 13x6 for the Inspire) are meant to be used over 2,500m.
Can you use them at altitudes lower than this? - Yes
Is there a risk/performance hit in doing so? - Yes

Use the correct props for the conditions/environment = One less risk factor taken out of the chain. Pretty simple really

 

[dkotinsky]

Why? They are meant for high-alititude! DJI desgined the props for a different, do you think their is some magic that will happen at sea-level.

 

[Steelej]

If they have more thrust than the normal props would the I2 not go faster?