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Altitude Conundrum

Scott White

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#1
Maybe someone here can answer this question. FAA CFR Part 107 dictates that our maximum altitude is 400FT. (I hope I read this correctly otherwise this whole conversation is moot.)

It is my understanding that for the Spark, and most other drones near this class, altitude is based on the take off point being ZERO. It's not barometric or measured altitude to ground.

So in my rudimentary drawing, if I take off from the top of a 100 foot hill and fly up to 400 feet, then fly out over the slope that is dropping off, my telemetry data is still going to read 400 FT yet, actually ground altitude is 500 FT.

While I know the FAA doesn't necessarily have "altitude police" running around looking for drones flying too high. It is technically violating established policies.

Is this your guys take as well?

 

msinger

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#2
FAA CFR Part 107 dictates that our maximum altitude is 400FT. (I hope I read this correctly otherwise this whole conversation is moot.)
That's correct. However, if you're flying as a hobbyist, that does not apply to you.

So in my rudimentary drawing, if I take off from the top of a 100 foot hill and fly up to 400 feet, then fly out over the slope that is dropping off, my telemetry data is still going to read 400 FT yet, actually ground altitude is 500 FT.
That's correct.
 

Scott White

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#3
That's correct. However, if you're flying as a hobbyist, that does not apply to you.
What is this based on? I see exceptions for structures and avoidance but nothing that dictates it does not apply to a hobbyist. I very well may be missing something of course. Just trying to learn.
 
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#5
Sometime small plane and heli will be flying below 400ft/120m depends on the cloud ceilings,so its our responsible to drop altitude immediately even we're below 120m when there are manned aircraft's flying nearby...
 

Scott White

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#6
If you're flying as a hobbyist, you need to follow Section 336. See the table at the bottom of this page.
This is where it gets confusing. This page, does say 400 feet for "model aircraft".

See Advisory Circular 91-57, Model Aircraft Operating Standards (June 9,1981).

These operating standards included restricting operations over populated areas,limiting use of the devices around spectators until after the devices had been flight testedand proven airworthy; restricting operations to 400 feet above the surface; requiring that the devices give right of way to, and avoid flying near manned aircraft, and using observers to assist in operations.​
 

msinger

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#7
This is where it gets confusing. This page, does say 400 feet for "model aircraft".
From that same document:

"The FAA first recognized in 1981 that “model aircraft can at times pose a hazard to full-scale aircraft in flight and to persons and property on the surface,” and recommended a set of voluntary operating standards for model aircraft operators to follow to mitigate these safety risks. See Advisory Circular 91-57, Model Aircraft Operating Standards (June 9, 1981)."

I agree that it's a great recommendation. It's not the law though.
 

Scott White

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#8
I agree that it's a great recommendation. It's not the law though.
Yeah I get that.

To be fair, in my type of flying I can not find (or have not found) a reason to go above the 400 FT threshold anyway. But, like in the scenario I opened this thread with it "could" happen. And it can be confusing. And frustrating if someone is truly trying to stay within the law and community standards.
 

strobing_nyc

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#9
It has happened to me, with the same scenario that you just brought up. I took off from a top a mountain, while heading down the slope I had to constantly change altitude to stay below 400' by the time I reached the bottom lil Spark was reading negative altitude values lol. It's not easy and should be kept in VLOS at all times because of the altitude change.
 

Teq

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#10
It’s 400 ft above ground level at the aircrafts location not the takeoff point. It still applies even if flown as a model aircraft. There is an exception within the vicinity of a building or structure of not more than 400 feet above the structure which could be much higher than 400 feet above ground level.
Always yield to manned craft.
 
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Teq

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#12
In the US, it only applies to those people flying under FAA Part 107 (according to US law).
Agreed. Although the FAA does recommend operation at or below 400 ft for all small UAS it looks like you could legally fly higher as long as you were not violating the safety code for whatever organizations rukes you were flying under and not violating an airspace restriction which in many places extends all the way down to the ground.
 
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#13
For recreational purposes there is not a height limit. However it does have to be within line of sight.
The definition of line of sight is without visual obstruction. From my experience 400 ft is above that during the day. But at night with the Spark lights flashing I can take it up to 400 and still have it within line of sight. What do you guys think?
 
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Coconut Pete

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#15
The FAA measures altitude 2 ways. Above sea level and above ground level. The 400' restriction is AGL above ground level. What you do need to be careful of is that as a hobbyist you do need to get prior permission from even dirt strip airports to fly within a 5 mile radius of them.
 

FLYBOYJ

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#16
This is where it gets confusing. This page, does say 400 feet for "model aircraft".

See Advisory Circular 91-57, Model Aircraft Operating Standards (June 9,1981).

These operating standards included restricting operations over populated areas,limiting use of the devices around spectators until after the devices had been flight testedand proven airworthy; restricting operations to 400 feet above the surface; requiring that the devices give right of way to, and avoid flying near manned aircraft, and using observers to assist in operations.​
Advisory Circulars are not regulatory and are only "advisory" unless a specific FAR is referenced.
 

FLYBOYJ

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#17
Under FAR 107, the 400' AGL altitude has been well established. As a hobbyist, the FAA "recommends" you stay under 400' but legally you just have to stay out of controlled airspace. In most parts of the country, Class E airspace begins as 1200' AGL, but it can go down to 700' AGL close to large airports and even at the surface if the class E is supporting an instrument support procedure.

With that said, Under FAR 101.41(b) you have to operate your hobby drone IAW "community-based set of safety guidelines and within the programming of a nationwide community-based organization." As far as I know the only recognized "nationwide community-based organization" is the AMA. You don't have to be an AMA member to fly as a hobbyists by their guidelines. Under their guidelines they say stay below 400' when you're within 3 miles of an airport (makes sense).

14 CFR 101.41 - Applicability.

14 CFR 101.43 - Endangering the safety of the National Airspace System.

http://www.modelaircraft.org/files/100.pdf

So Between FARs 101.41 and 101.43, you have section 336 of 2012 HR 658

SEC. 336. SPECIAL RULE FOR MODEL AIRCRAFT. (a) IN GENERAL.—Notwithstanding any other provision of law relating to the incorporation of unmanned aircraft systems into Federal Aviation Administration plans and policies, including this subtitle, the Administrator of the Federal Aviation Administration may not promulgate any rule or regulation regarding a model aircraft, or an aircraft being developed as a model aircraft, if—

(1) the aircraft is flown strictly for hobby or recreational use;
(2) the aircraft is operated in accordance with a community-based set of safety guidelines and within the programming of a nationwide community-based organization;
(3) the aircraft is limited to not more than 55 pounds unless otherwise certified through a design, construction, inspection, flight test, and operational safety program administered by a community-based organization;
(4) the aircraft is operated in a manner that does not interfere with and gives way to any manned aircraft; and
(5) when flown within 5 miles of an airport, the operator of the aircraft provides the airport operator and the airport air traffic control tower (when an air traffic facility is located at the airport) with prior notice of the operation (model aircraft operators flying from a permanent location within 5 miles of an airport should establish a mutually-agreed upon operating procedure with the airport operator and the airport air traffic control tower (when an air traffic facility is located at the airport)).
(b) STATUTORY CONSTRUCTION.—Nothing in this section shall be construed to limit the authority of the Administrator to pursue enforcement action against persons operating model aircraft who endanger the safety of the national airspace system.
(c) MODEL AIRCRAFT DEFINED.—In this section, the term ‘‘model aircraft’’ means an unmanned aircraft that is—
(1) capable of sustained flight in the atmosphere;
(2) flown within visual line of sight of the person operating the aircraft; and
(3) flown for hobby or recreational purposes.

(Note the bold text - (b) STATUTORY CONSTRUCTION is a catch all. (2) hobbyists continually ignore this and even put videos on YouTube basically incriminating themselves)

Between FARS 101.41 and 101.43 NOTHING mentions hobbyist altitude restrictions - BUT...

the 2014 policy letter by Huerta, the former FAA Administrator. Pages 16 and 17 mentions sUAV compliance with FAR 91.126 through FAR 91.135 with speaks to operating in controlled airspace.

"Accordingly, as part of the requirements for model aircraft operations within 5 miles of an airport set forth in section 336(a)(4) of P.L. 112-95, the FAA would expect modelers operating model aircraft in airspace covered by §§ 91.126 through 91.135 and part 73 to obtain authorization from air traffic control prior to operating."

https://www.faa.gov/uas/media/model_aircraft_spec_rule.pdf

So putting it all together...

Part 107 - 400' AGL
Part 101.41 - no restriction but
Part 101.43 - don't endanger the NAS
FAA Recommendation - stay below 400' AGL, and finally,
2014 - Huerta Policy Memo - Hobbyists, stay out of controlled airspace.

Yes, this is confusing and convoluted but it's the current law. I work as a volunteer safety counselor with the FAA and in my part of the country this is the way my local FSDO is viewing this. Review for your self, comments welcomed!
 
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beachcombing

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#18
The FAA measures altitude 2 ways. Above sea level and above ground level. The 400' restriction is AGL above ground level. What you do need to be careful of is that as a hobbyist you do need to get prior permission from even dirt strip airports to fly within a 5 mile radius of them.
"prior permission" is not needed. Hobbyists need to NOTIFY the airport tower or airport owner.
 
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FLYBOYJ

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#19
"prior permission" is not needed. Hobbyists need to NOTIFY the airport tower or airport owner.
Actually if you're flying within 5 miles of an airport that is designated as class D, C or B, (all have operating control towers) they can tell you not to fly if you're in their controlled airspace. This is referenced in the Huerta policy letter of 2014. If you ignore them, you could be in violation of FAR 101.43, 91.13
 
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sinaus

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#20
For recreational purposes there is not a height limit. However it does have to be within line of sight.
The definition of line of sight is without visual obstruction. From my experience 400 ft is above that during the day. But at night with the Spark lights flashing I can take it up to 400 and still have it within line of sight. What do you guys think?
I don't get it how you could fly at night as it stated in the rules that no flying after sundown and before day break. I saw guys on youtube doing that and is it legal at all?
 

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