Controlled Airspace altitude limit and structures

[brett8883]

When you have a LAANC authorization with an altitude limit of less than 400 ft AGL in controlled airspace is that limit strictly from the ground or does that include within xxx feet from a structure as well?

We know that the 400’ AGL general height limit is no higher than 400’ from ground but it also allows you to be within 400’ of a structure even if that puts you higher than 400’ from the actual ground. Can that same concept be applied to a LAANC authorization height limit within controlled airspace?

For example, last night (before sunset) I had a LAANC authorization to fly 100’ in SLC class B airspace downtown. Now what I noticed and found kind of funny was that in my area almost all the buildings were taller then 100’. Near my site in particular was a building I’d guess was about 350’ tall. Now my question is would I be staying within the limits of my authorization if I were to stay within 100 feet of the structure even if that put me at more than 100’ AGL? If I were to fly to the top of the building but stayed within 100’ laterally would that be ok? What if I flew up to 450’ but stayed within a 100’ radius of the structure?

 

[AMann]

Excellent question, and you will get good answers here, but I’d also go straight to the horse’s mouth to ask that question, not the other end!

Contact

Contact FAA, get answers to frequently asked questions, contact your local Flight Standards District Office (FSDO)

www.faa.gov

 

[sar104]

You cannot add the authorization altitude to the height of structures:

https://www.faa.gov/uas/programs_partnerships/data_exchange/laanc_for_industry/media/FAA_sUAS_LAANC_Ph1_USS_Rules.pdf

3.5 CommercialAuthorizations:SpecificProvisions​

​

Commercial authorizations are provided via LAANC in accordance with 14 CFR Part 107.41. LAANC supports both auto-approved and further coordination types for commercial authorizations. USSs may opt to include one and/or the other type in their service offerings.​

​

When Part 107 authorizations are provided, the USS must [3.5a] generate, display, and store the following text (including the context-dependent information shown in brackets):​

​

“[LAANC Reference Code / FAA Facility Code, Start Date & Time – End Date & Time, Max Alt numft]: In accordance with Title 14 CFR Part 107.41, your operation is authorized within the designated airspace and timeframe constraints. Altitude limits are absolute values above ground level which shall not be added to the height of any structures. This Authorization is subject to cancellation at any time upon notice by the FAA Administrator or his/her authorized representative. This Authorization does not constitute a waiver of any State law or local ordinance. [Name of operator] is the person designated as responsible for the overall safety of UAS operations under this Authorization. During UAS operations for on-site communication/recall, [name of operator] shall be continuously available for direct contact at [contact phone number] by ATC or designated representative. Remote pilots are responsible to check the airspace they are operating in and comply with all restrictions that may be present in accordance with 14 CFR 107.45 and 107.49 (a)(2), such as restricted and Prohibited Airspace, Temporary Flight Restrictions, etc. Operations are not authorized in Class E airspace when there is a weather ceiling less than 1,000 feet AGL. If the UAS loses communications or loses its GPS signal, it must return to a predetermined location within the operating area and land. The pilot in command must abort the flight in the event of unpredicted obstacles or emergencies.”​

​

“Start Date & Time” and “End Date & Time” must [3.5b] unambiguously include the year, month, day, hour, minute, and time zone (or UTC).​

​

The USS must [3.5c] provide a method for quick access to the operation-specific authorization information (including text above) in a form that could be produced by the operator to authorities if necessary.​

 

[brett8883]

You cannot add the authorization altitude to the height of structures:

https://www.faa.gov/uas/programs_partnerships/data_exchange/laanc_for_industry/media/FAA_sUAS_LAANC_Ph1_USS_Rules.pdf

3.5 CommercialAuthorizations:SpecificProvisions​

​

Commercial authorizations are provided via LAANC in accordance with 14 CFR Part 107.41. LAANC supports both auto-approved and further coordination types for commercial authorizations. USSs may opt to include one and/or the other type in their service offerings.​

​

When Part 107 authorizations are provided, the USS must [3.5a] generate, display, and store the following text (including the context-dependent information shown in brackets):​

​

“[LAANC Reference Code / FAA Facility Code, Start Date & Time – End Date & Time, Max Alt numft]: In accordance with Title 14 CFR Part 107.41, your operation is authorized within the designated airspace and timeframe constraints. Altitude limits are absolute values above ground level which shall not be added to the height of any structures. This Authorization is subject to cancellation at any time upon notice by the FAA Administrator or his/her authorized representative. This Authorization does not constitute a waiver of any State law or local ordinance. [Name of operator] is the person designated as responsible for the overall safety of UAS operations under this Authorization. During UAS operations for on-site communication/recall, [name of operator] shall be continuously available for direct contact at [contact phone number] by ATC or designated representative. Remote pilots are responsible to check the airspace they are operating in and comply with all restrictions that may be present in accordance with 14 CFR 107.45 and 107.49 (a)(2), such as restricted and Prohibited Airspace, Temporary Flight Restrictions, etc. Operations are not authorized in Class E airspace when there is a weather ceiling less than 1,000 feet AGL. If the UAS loses communications or loses its GPS signal, it must return to a predetermined location within the operating area and land. The pilot in command must abort the flight in the event of unpredicted obstacles or emergencies.”​

​

“Start Date & Time” and “End Date & Time” must [3.5b] unambiguously include the year, month, day, hour, minute, and time zone (or UTC).​

​

The USS must [3.5c] provide a method for quick access to the operation-specific authorization information (including text above) in a form that could be produced by the operator to authorities if necessary.​

Thanks! Doesn’t get much more definitive than that!

 

[Chris-KC]

@sar104 is correct. However there's also FAA JO 7200.23A, which says you can add 100' to the height restriction in the UASFM cell if flying within 400' laterally of an obstacle. I believe you'd still want to obtain explicit LAANC authorization for the height you intended to fly at and you may need to reference 7200.23A as justification. ATC would want to know what you were doing. (Note that it does not say you can go to the height of the obstacle, or X feet over it.)

https://www.faa.gov/documentLibrary/media/Order/JO_7200.23A_Unmanned_Aircraft_Systems_(UAS).pdf

I have a job starting in a 100' ceiling area with 117' and 90' tall buildings in it. I'm interpreting that the taller one is an "obstacle" but the lower one is not. I measured 400' laterally from the taller building and it only covers a corner of my area. At any rate I can get my job done at <100' and will stick with that.