Wind Turbine FAQs (latest revision 10/19/2023)

You are required to determine whether the proposal will be located on or off of airport property. All proposals for wind turbines and met towers that are on airport property should be filed as On Airport Construction. All other stand-alone Turbines or Mets should be filed as Off Airport Construction. Turbines added to another structure, such as on top of another building should be filed as an alteration to the other structure, not as a wind turbine study.

No, there are no fees associated with any part of an aeronautical study or obtaining a determination from the FAA.

You may use the Notice Criteria Tool link on the home page to determine whether notice is required. The tool is based on Title 14, Code of Federal Regulations, Part 77 (14 CFR Part 77). There is a link to Part 77 on the home page of the website. Section 77.9 identifies construction or alteration requiring notice; Section 77.9(e) identifies construction or alteration not requiring notice.

If notice is required, you may submit the FAA Form 7460-1 electronically on the website. If you don't have an account for e-filing, there are instructions on the home page for setting up your account and e-filing the notice ("Click Here for Instructions on how to E-file your proposal with the FAA").

Because of the extensive studies that wind turbines require, we request that you file notice at least 90-120 days before planned construction. The aeronautical study process includes evaluations by various lines of business, and any identified impacts must be resolved before a final agency determination is issued. A public notice may also be required which includes a 30-day comment period, adding additional time to the aeronautical study. There is no guarantee that a final agency determination will be issued by your planned construction date, so file as early as possible. 14 CFR Part 77 does not carry provisions for waivers or exemptions, so there is no way to shorten or bypass this process. We also recommend that you provide early notice to DOD and DHS to determine if your proposal may impact their mission. Please see FAQ #23 – the FAA needs the exact location/height of each wind turbine along with specific information in order to evaluate any potential impacts to the National Airspace System (NAS).

Please submit them sequentially in the order of the wind turbine layout.

Select the Instructions link in the OE/AAA Account section and refer to the Attaching Documents Desk Reference Guide. (https://oeaaa.faa.gov/oeaaa/external/content/instructions.jsp)

Unless you are filing via the import spreadsheet option, you must submit a spreadsheet identifying the turbine ID number, latitude and longitude in degrees, minutes and seconds (NAD 83), site elevation, height above ground level (AGL), overall height above mean sea level (AMSL), and preferred marking and lighting (if you have a preference; please see the paragraph below concerning obstruction marking and lighting proposals). The FAA ASN number should be in ascending order if listed on the spreadsheet.

Please submit a map depicting the layout with the turbine number next to each site.

Please note the following concerning submission of obstruction marking and lighting proposals: You may submit a marking and lighting plan to the FAA with your proposed project, but it is not a requirement, and there is no guarantee that a submitted plan will be the plan outlined in any final determination. If you don't have a marking/lighting preference you may select "Other" in the "Requested Marking/Lighting" field, then type in "No Preference" in the "Other" field. The wind turbine specialist handling your studies will make the final determination concerning which structures should have obstruction lights based on guidance in the current version of FAA Advisory Circular 70/7460-1, Obstruction Marking and Lighting. The determinations for those wind turbines that require obstruction lights will include a condition of WPSRL (white paint/synchronized red lights). The determinations for turbines that require daytime marking only will include a condition of WP (white paint only).

Due to the propensity for changes within wind turbine project, our policy is to include a recommendation for white paint/synchronized red lights for all turbines within the project. The proponent must then confirm that the layout is final (no changes, no additions, no removals) and that all turbines can and will be built at their determined location and height. The proponent may contact our office with that confirmation and request a re-evaluation of the marking and lighting recommendations. We will then determine whether a portion of the turbines may qualify for the removal of the lighting recommendation. A Marking and Lighting letter will be issued only for those turbines that we determine can be changed to White Paint Only.

If the airfield is strictly military, proposals for temporary or permanent structures should be filed as off-airport structures. If the airfield is joint-use (military and civilian operations), proposals for temporary or permanent structures should be filed as on-airport structures. Any proposed changes to the pavement on an airfield (military or joint-use), i.e., construction/modification/resurfacing of runways, taxiways, aprons, etc. should be filed as on-airport proposals.

The sponsor can be you, your company, or your client. The sponsor is the person or business ultimately responsible for the construction or alteration. The sponsor appears as the addressee on all correspondence from the FAA.

The FAA is not responsible for tracking changes in ownership. Therefore, if the FAA receives ownership changes it shall not make those corrections to issued determinations.

However, the original e-filer of the case can update the sponsor information through their registered e-filing account to reflect the new owner and ensure that the FAA has a means of contacting responsible parties with subsequent correspondence regarding the aeronautical study and determination.

The geographic coordinates may be obtained by utilizing a U.S. Geographical Survey 7.5-minute quadrangle map or equivalent, a GPS receiver or a certified survey. The coordinates should be accurate to within the nearest second or hundredth of a second. If a certified survey is available, please DO NOT submit it with your filing. We will ask for it if we need it.

An aeronautical study will be conducted by the FAA Air Traffic Organization, Obstruction Evaluation Group (OEG) for off-airport studies. The OEG technician will verify that the information submitted is accurate and complete. If the information is inaccurate or incomplete the technician will request additional information. If additional information is required for any of the studies within the project, none of the other studies will be processed until all required information has been received.

Once the technician has determined that all information is accurate and complete he/she will verify the studies in our system, which will change the status in your account to "Work in Progress." When the status is changed to "Work in Progress" your information is made available to other FAA offices and military representatives that need to review the proposal. Those offices will provide comments to the OEG and after all comments have been received, the OEG technician or specialist will issue the appropriate letter; when it's been issued the status in your account will change to "Determined." After the letter has been issued it will be available on the website. Select "Search Archives" and enter the ASN for a link to the study.

Supplemental Notice for the start of construction, Part 1 of the 7460-2, must be filed if requested on your determination; however, you are not prohibited from filing it when it was not requested. 14 CFR Part 77 says, in part, “Actual structural work of the proposed construction or alteration, such as the laying of a foundation”. In the past, we have applied this literally as if the words, “such as” were not there. Due to the nature of most wind farm projects, substantial construction may be started prior to the foundation of the actual turbine being laid. You may file 7460-2 Part 1 when you can guarantee that the turbines will be constructed AND substantial construction has started. This could be substations, transmission lines, maintenance and operations control buildings, etc. Part 1 is used to ensure aviation safety is maintained. An extension to the determination is not needed if the construction has started and a 7460-2 Part 1 has been accepted by the FAA.

Select the Instructions link in the OE/AAA Account section and refer to the Request Extension Desk Reference Guide. (https://oeaaa.faa.gov/oeaaa/external/content/instructions.jsp)

For proposals studied as off-airport structures, in the field entitled "If construction or alteration IS NOT LOCATED on an airport:" you may select the link at the bottom of that box, "QUESTIONS? Please contact the appropriate representative." Select the state in which the structure would be located. The contact information for the technician, backup technician and specialist assigned to that state for wind turbine (WT) studies will be provided.

For proposals on airport property, find the FAA Airports Region / District Office having jurisdiction over the airport on which the construction is located, and contact the office responsible for the state in which your structure would be located. Also, please contact that office with any questions pertaining to documents/sketches associated with on-airport structures that are e-filed.

Generally, a new study is not required if the coordinates are within one second of the coordinates AND the overall AMSL is equal to or lower than the AMSL as listed on the determination letter.

A new study (7460-1) is required for any of the following changes:

(a) A survey was required to mitigate an adverse effect and there is any change in coordinates.

(b) The latitude and/or longitude changes by exactly 1 second or more. For example: Initial latitude 37-00-50.00 – new study is not required for 37-00-49.01 to 49.99, or 37-00-50.01 to 37-00-50.99; a new study is required for 37-00-49.00 or 37-00-51.00.

(c)The overall AMSL (site elevation + height above ground level [AGL]) increases by 1 foot or more.

(d) A new filing is required any time there is a change to the frequencies or use of greater power.

If a new study is required based on a height increase or coordinate changes of 1 second or more, you must submit a New Case (Off Airport) prior to the start of construction so the FAA may evaluate your proposal at the revised height or location. If you do not file for a new study prior to the start of construction as required and you submit the Supplemental Notice (FAA Form 7460-2) instead, the system will recognize the changes and initiate a new study. When the new study is initiated you will be required to certify the new information and submit a new filing so the FAA may evaluate your structure under a new Aeronautical Study Number (ASN). NOTE: It is not a given that the proposal at the revised height or location will result in a favorable determination.

The FAA receives requests for conditional type determinations so that projects can obtain funding or be in compliance with production tax credit requirements, or for other reasons. It is our policy to have all outstanding issues resolved prior to issuing final agency determinations. The FAA does not control land use issues and cannot issue determinations with conditions applicable to an event taking place in the future. We have no way to enforce or track these type of conditions and therefore cannot comply with requests for "conditional" type determinations.

There is no guarantee that any project will get a determination of no hazard when it is studied again. The national airspace system is dynamic and changes must be taken into consideration during aeronautical studies. It is to your benefit to build the project prior to the expiration date for the initial determination.

After conducting a review, if no issues are identified that would cause a significant adverse effect, the FAA may grant one extension. After one extension is issued, if the structure has not been built, the FAA must receive a new filing and restudy the proposal.

If you refile for a height increase on a proposed structure, your previous determinations will be terminated. It is our policy to terminate any previous determinations if you refile for a greater height. It causes an administrative hardship on the FAA to carry multiple filings at the same location. Other organizations that evaluate impacts cannot filter out the filings, and this creates a cumulative impact issue. With the multitude of wind turbine filings throughout the U.S., cumulative impact is based on the total number of turbines in an area. Multiple filings in the same location creates a cumulative impact issue that could result in erroneous data analysis. Additionally, obstruction evaluation specialists cannot work out an accurate lighting plan with multiple filings.

The FAA recommends that wind turbine developers work out necessary financial arrangements that are not dependent on maintaining an existing determination if refiling is necessary. The FAA is not responsible for financial arrangements associated with determinations that may have been placed upon you by your financial institute, insurance provider, etc.

Due to resource limitations, the FAA can no longer support feasibility studies or filings of a speculative nature for proposed Wind Turbine projects. The FAA must have all Wind Turbine configurations including latitude/longitude, height and layout plan at the time of your filing to accurately evaluate the cumulative effect of the entire project as it pertains to the national airspace system. Your proposal may warrant further detailed study including math modelling.

Select the Instructions link in the OE/AAA Account section and refer to the Request Termination-Dismantled-Abandoned Desk Reference Guide. (https://oeaaa.faa.gov/oeaaa/external/content/instructions.jsp)

A Determination of No Hazard to Air Navigation will be valid for 18 months. This is the maximum time as specified by 14 CFR Part 77.

Map services and data are available from U.S. Wind Turbine Database, provided by the U.S. Geological Survey, American Clean Power Association, and Lawrence Berkeley National Laboratory via https://eerscmap.usgs.gov/uswtdb

Yes- there is no restriction on heights for filing notice. File electronically on our website for your wind turbines at the highest height and the FAA will conduct an aeronautical study just like any other structure. Please note that at 500 feet or higher, your proposed structure will be in altitudes available to general aviation aircraft. A public notice may be issued to gather aeronautical information, and this includes a 30-day comment period. In order to be considered, the comments must be relevant to the effect the structure would have on AVIATION and must provide sufficient detail to permit a clear understanding of the effect. Only valid aeronautical comments will be factored into the FAA’s decision. Example: Comments concerning land values or aesthetics would not be considered valid aeronautical comments.

Communication with the FAA about a specific aeronautical study is allowed only for the sponsor and representative identified in the e-filing. Written permission can be uploaded to a study, or e-mailed to the specialist handling the study, by the sponsor or representative, identifying any individual authorized to communicate with the FAA about that specific study. The permission should include the individual’s name, phone number, and email address.

(a) On initial notice of filing of your wind farm project, check the ADLS request box.

(b) File notice for a Marking and Lighting study, check the ADLS request box.

(c) Notice has been filed, study is still work in progress, email specialist with ADLS request.

(a) You must submit showing an approved vendor. A list of approved vendors is available via the useful links on the left hand side of our website.

(b) The ADLS request should be made for all turbines in your project (even the ones that may have white paint only) for consideration.

(c) You must identify where the radar sensors will be mounted – which turbines. If the sensors are to be mounted on stand-alone towers, the towers must be filed as “MET Tower” so that we may associate it with the wind farm. The radar frequency and Effective Radiated Power (ERP) must be included only for the structure the sensor will be mounted onto.

(d) Additional documents will need to be submitted. (see current edition of Advisory Circular 70/7460-1)

a. Radar coverage maps submitted depicting the volume of coverage area at 200 feet above ground level and 1000 feet above the wind turbine with the greatest AMSL height included in the ADLS request. If the required coverage does not exist at 200 feet AGL, additional coverage maps may be requested (e.g. 500 feet AGL, 1000 feet AGL). The ADLS vendor will be able to assist you with this request. Example: If the tallest wind turbine in the ADLS request is 1500 feet AMSL, add 1000 feet to show ADLS coverage at 2500 feet AMSL.

b. Example of manufacturer certifying statement:

(company/name of manufacturer) certifies that the proposed installation of the ADLS for the project will meet the requirements of the current version of AC 70/7460-1 Obstruction Marking and Lighting, and will be in accordance with the most recent Technical Note issued for this system.

(signature of company official) (and date signed)

c.Example of developer certifying statement:

(company/name of developer) certifies that the proposed ADLS for the project will be continuously monitored in accordance with the current version of AC 70/7460-1 Obstruction Marking and Lighting, and the Technical Note issued for the system. We will insure this responsibility is specifically transferred to any subsequent owners of the project.

(signature of company official) (and date signed)

You will need to contact the OEG specialist responsible in your area. At a minimum you will be required to upload all new documentation from the new vendor in accordance with the current version of Advisory Circular 70/7460-1.

The DoD Preliminary Screening Tool was not properly maintained and is no longer being hosted by the FAA. The FAA will continue to coordinate with DoD, for formal review, all completed submissions of proposed energy projects received in accordance with 49 U.S.C. 44718 - Structures interfering with air commerce. However, the DoD has a structured process for developers to request a mission compatibility evaluation of proposed energy projects, as documented in Part 211 of Title 32 CFR. (§ 211.7 Initiating an informal DoD review of a proposed project). Please visit https://www.dodclearinghouse.osd.mil/Project-Review/ for more information about the DoD's Military Aviation and Installation Assurance Siting Clearinghouse's informal review process. Note: the DoD's informal review does not relieve you of your obligation to file notice with the FAA when your proposal meets 14 CFR §77.9 notice requirements.