Inspecting This Tower - How high?

[N42742]

Here's your scenario: You are hired to do a tower inspection of the tower indicated on this sectional chart. How high may you fly and is a waiver or authorization required?

Don't be shy. Take a shot at it. (For you guys who KNOW the answer, give some other folks time to take a stab at it.)

 

[dronesky]

2027 & yes

 

[sar104]

It's an interesting question because it reveals (IMO) an inconsistency (or gap) in the Part 107 rules.

 

[LoneDrone]

It's also under construction.

 

[dronesky]

It's also under construction.

Doh! I was just answering the questions didn't even think about that LOL

 

[N42742]

It is under construction, but that doesn't affect the answer.

 

[bob_moodytx]

I'll take a shot in the dark ...

1. tower appears to be in the NFZ of Dalton. So yes on the waiver/authorization
2. you were hired ... commercial venture .. so yes on waiver/authorization
2. Sectional indicates multiple obstacles .. MSL is 1627, I assume the highest of the multiple obstacles is 492' above ground level.
3. The tower in question is not specifically known in the cluster of multiple obstacles. If the tower is >400' AGL then yes on a height waiver.

I am not a private or commercial pilot, I am not a 107 pilot.
as I said .. shot in the dark trying to think through the problem using what little I know about the subject ..

and .. I'ts a slow day at work and I wanted to play along ..

Bob

 

[Crack The Sky]

Surface of the Class E airspace that the tower is in, begins @ 700 AGL. Top of tower is 492 AGL. You could inspect the tower, with-out waiver/authorization, as long as you did not exceed 699 AGL, while remaining with-in 500' lateral distance of the tower base.

 

[N42742]

Good effort, Bob, especially since you're not a Remote Pilot (yet?). We aren't born with this knowledge so there is no way to figure it out without study. First thing to note is that, concerning the FAA, there is no such thing as a No Fly Zone. That's a military term that doesn't apply to civilian aviation (unless something really bad happens). You're probably referring to the shaded magenta circle. This identifies an area where Class E airspace starts at 700 feet AGL and extends upward.

 

[N42742]

Good tries all, but we're still waiting on the correct answer...

 

[bob_moodytx]

Thank you for the reply... Actually I was mixing terms and concepts.. bad form on my part.
I didn't even consider the type (class E) of airspace around Dalton until after I posted .. I just let it ride....
As a No Fly Zone, I was thinking in terms of Radio Controlled flight and not flying within 5 miles of an airfield without clearance/notification/authorization..

Looking forward to the answer... interest is piqued now...

 

[N42742]

Roger that, Bob. Yes, under 107 there is no 5-mile anything (that's only for hobbyists). It's all airspace class.

 

[dronesky]

Okay don't need any waiver & must stay within 400ft of tower

 

[sar104]

107.51(b) requires staying under 400 ft AGL, or no more than 400 ft above a structure if within 400 ft laterally of that structure. So from that perspective, one could fly 400 ft over that tower, which, itself, is 492 ft AGL, giving a total of 892 ft AGL.

The complication is that the tower is under 700 ft floor Class E airspace, and so at 892 ft AGL one would be flying in Class E airspace which, one might think, would require authorization or waiver.

However, 107.41 states:

No person may operate a small unmanned aircraft in Class B, Class C, or Class D airspace or within the lateral boundaries of the surface area of Class E airspace designated for an airport unless that person has prior authorization from Air Traffic Control (ATC).
​

Note that this only refers to surface Class E airspace, not 700 ft Class E airspace and so, at best, is ambiguous in this situation.

 

[N42742]

107.51(b) requires staying under 400 ft AGL, or no more than 400 ft above a structure if within 400 ft laterally of that structure. So from that perspective, one could fly 400 ft over that tower, which, itself, is 492 ft AGL, giving a total of 892 ft AGL.

The complication is that the tower is under 700 ft floor Class E airspace, and so at 892 ft AGL one would be flying in Class E airspace which, one might think, would require authorization or waiver.

However, 107.41 states:

No person may operate a small unmanned aircraft in Class B, Class C, or Class D airspace or within the lateral boundaries of the surface area of Class E airspace designated for an airport unless that person has prior authorization from Air Traffic Control (ATC).
​

Note that this only refers to surface Class E airspace, not 700 ft Class E airspace and so, at best, is ambiguous in this situation.

Not ambiguous at all. In fact, it got you to the correct answer. Good job. This question is missed a lot more often than it is answered correctly.

892 feet AGL (or 2027 feet MSL) and no authorization required.

 

[sar104]

Not ambiguous at all. In fact, it got you to the correct answer. Good job. This question is missed a lot more often than it is answered correctly.

892 feet AGL (or 2027 feet MSL) and no authorization required.

I agree that a precise application of the rules that I quoted leads to that answer, though I'm not convinced that was the intent when the rules were written. But perhaps it was.

 

[N42742]

I'm pretty sure that was the intent. The FAA didn't want to arbitrarily close off all Class E to sUAS. Just the Class E that is surface area because those areas will have higher concentrations of manned aircraft on IFR flight plans.

 

[sar104]

I'm pretty sure that was the intent. The FAA didn't want to arbitrarily close off all Class E to sUAS. Just the Class E that is surface area because those areas will have higher concentrations of manned aircraft on IFR flight plans.

Maybe so, but the DNN pattern altitudes are 1510/2210 (light/heavy) so those are altitudes of possible concern in that area. And, of course, the rule is already, de facto, incorrect in another respect since ATC is not permitted to authorize sUAS operations in controlled airspace.

 

[BigAl07]

And, of course, the rule is already, de facto, incorrect in another respect since ATC is not permitted to authorize sUAS operations in controlled airspace.

Russel correct me if I'm wrong or I can go back to the FAA and get this clarification if needed but... with the new "Airspace Authorization/Waiver" system currently in place, technically ATC is the one who has created the "Grid System" for their own areas so from a very broad stroke ATC is the authority who is granting/denying Part 107 operations in the airspace.

Each ATC created the grid (for their controlled airspace) which in effect is the Go/No Go ruling for each submission.

If the above is accurate then the rule is valid and correct. This is purely ALLEN'S interpretation and nothing official or even resembling anything official.

 

[N42742]

Maybe so, but the DNN pattern altitudes are 1510/2210 (light/heavy) so those are altitudes of possible concern in that area. And, of course, the rule is already, de facto, incorrect in another respect since ATC is not permitted to authorize sUAS operations in controlled airspace.

"ATC" is a widely used term with respect to authorizations. When you say "ATC is not permitted to authorize..." are you referring to the fact that the FAA wants to handle all requests through the online portal (as opposed to contacting tower controllers)?