Flying 400 ft above a "structure". What is a "structure"? §107.51

[Kristina Fowler]

RE: §107.51 Operating limitations for small unmanned aircraft.
A remote pilot in command and the person manipulating the flight controls of the small unmanned aircraft system must comply with all of the following operating limitations when operating a small unmanned aircraft system:

(a) The groundspeed of the small unmanned aircraft may not exceed 87 knots (100 miles per hour).

(b) The altitude of the small unmanned aircraft cannot be higher than 400 feet above ground level, unless the small unmanned aircraft:

(1) Is flown within a 400-foot radius of a structure; and

(2) Does not fly higher than 400 feet above the structure's immediate uppermost limit.

I've asked the FAA twice over the last year for the definition of "structure" as it pertains to Part §107.51 and have yet to hear back. Anybody care to take a stab at it?

Thanks in advance....

 

[BigAl07]

structure


[struhk-cher]
noun
1.
mode of building, construction, or organization; arrangement of parts, elements, or constituents:
a pyramidal structure.

2.
something built or constructed, as a building, bridge, or dam.

In Manned Aviation flight school they dumbed it down as "Man made of parts & pieces".

Building, Tower, Bridge, Dam, Pyramid, Light Pole...... Not created by earth, wind, and/or fire.

 

[Rodger]

I agree withBigA anything man made is close enough.

 

[Kristina Fowler]

I agree withBigA anything man made is close enough.

What about movable structures? 200-300 ft high?

 

[Z06Aggie]

What about movable structures? 200-300 ft high?

Like a drilling rig or something? I would assume that still applies.

 

[Kristina Fowler]

Like a drilling rig or something? I would assume that still applies.

Industrial crane, actually. Absent anything to the contrary, I agree.

 

[BigAl07]

What about movable structures? 200-300 ft high?

No reference to movable or not. A structure is a structure.

 

[Russ Still]

I agree with others' replies. If you asked the FAA and didn't get a reply, you probably asked the person. Questions about interpretations should go to the FAA General Council office in DC.

 

[Terry Ketron CFI-I]

According to Black's Law Dictionary ( which would serve as a precedent but not necessarily agree w/ FAA definition ) a STRUCTURE is
:a thing constructed; a complex entity constructed of many parts
It doesn't touch on mobility or fixed status.

 

[JRremote]

Cranes are obstructions not structures. If you read a NOTAM it will state obstructions in airport vicinity.
Note text in link below.

Notification of Proposed Construction or Alteration on Airport Part 77 – Central Region

 

[Kristina Fowler]

Cranes are obstructions not structures. If you read a NOTAM it will state obstructions in airport vicinity.
Note text in link below.

Notification of Proposed Construction or Alteration on Airport Part 77 – Central Region

I have to disagree with that generalization. Cranes are always structures that may, under certain conditions, also be considered obstructions. The crane I referred to previously is 8 miles from the nearest airport. Would it still be considered an obstruction? What would it be obstructing? I think the circumstances in this case (Airport vacinity) not only make it a structure but also an obstruction, considering the environment in which it exists. Being an obstruction seems to be more of a condition (near the airport) vs a physical definition. If you move the structure noted here out to the middle of the desert, I think it's no longer an obstruction, but it remains a structure.

 

[Terry Ketron CFI-I]

I am with Kristina. It is indeed listed as an obstruction on the Notam... The "obstruction" in this case is a crane, which by legal definition is a "structure" since it is :a thing constructed; a complex entity constructed of many parts (Black's Law Dictionary).

 

[Terry Ketron CFI-I]

One other thing...
I wouldn't fly any drone anywhere near those "structures" which are presenting as obstructions since they are in the vicinity of an airport.

 

[Darren Gahan]

I'm in Canada and I'll have to check out what it says with Transport Canada as I have a client who uses cranes to lift house sections into place. In my case the cranes wouldn't be more than 150 feet, and were legally allowed to fly up to 300 feet. In your case I would consider a crane to be a structure. Looking at the reason for the regulation, I think they want any piloted aircraft to be at least 500 feet above a crane (a structure) and are allowing you to fly your drone to a point 400 feet above the highest part of the structure. Personally I don't think you'd need to go that far above, but who knows. As a drone pilot your responsibility is to see and avoid other aircraft. I would suspect your biggest threat in regards to other aircraft would be helicopters. If it was a TV tower, I would still say it is a structure, and your 400 foot radius would be based on a couple of feet in diameter. If you think flying your drone this high would cause interference with a local airport (8 miles is not close and I wouldn't worry) give them a call and talk to them. Get their name and contact number and keep it in your site survey. I'd also file a NOTAM. Doing this will cover your bases. The FAA doesn't go after responsible drone operators. The bottom line is safety. If you aren't able to see and avoid other aircraft from your launch or flight position, that will get you into trouble.

 

[Kristina Fowler]

One other thing...
I wouldn't fly any drone anywhere near those "structures" which are presenting as obstructions since they are in the vicinity of an airport.

Remember - this thread is about flying above structures that are not obstructions.