• SAE International (SAE) documents related to outdoor laser operations and aviation safety: Aerospace recommended practices (ARP) and aerospace standards (AS).
o SAE ARP5290: Laser Beam Divergence Measurements Techniques Comparison.
o SAE ARP5293A: Safety Considerations for Lasers Projected in the Navigable Airspace.
o SAE ARP5535: Observers for Laser Safety in the Navigable Airspace.
o SAE AS4970: Human Factors Considerations for Outdoor Laser Operations in the Navigable Airspace.
o SAE AS6029B: Performance Criteria for Laser Control Measures Used for Aviation Safety.
• United States Geological Survey (USGS): Use the following methods as examples to contact USGS and/or acquire topographical (quadrangle) maps.
o USGS National Center: 12201 Sunrise Valley Drive, Reston, Virginia, 22092, or
(703) 648-5953.
o https://www.usgs.gov/products/maps/topo-maps or https://store.usgs.gov/maplocator.
Appendix A A-1 Appendix A. Instructions for Completing FAA Form 7140-1, Notice of Proposed Outdoor Laser Operation(s) A.1. Introduction This appendix provides detailed instructions to assist those completing FAA Form 7140-1. For additional information on MPE limits or visual correction factors to assist with completing the form, consult Appendix B.
A.2. Submission, Preparation, and Processing General: Fill out Form 7140-1 completely. If the form requires information that does not apply to the submission (e.g., fax number), enter N/A. Submit any additional information sufficient for FAA to analyze the proposed laser operation via attachments to the form. This additional information may include necessary details that require more space to explain, e.g., diagrams, or worksheets requested on the form or within these instructions. Failure to provide all requested information may delay processing.
Data sources: This form requires calculations based on data concerning characteristics of the laser beam(s). Proponents may obtain data from direct measurement, manufacturer specifications, or specialized instruments. Proponents may also derive data by making reasonable, conservative assumptions, e.g., that a certain value makes the beam more hazardous than it could be in reality. All data should err on the side of safety. In borderline situations where data accuracy is crucial to compliance, provide additional information on measurement techniques, data sources, and assumptions.
Alternative analysis: This AC and its tables (see Appendix B) cover a wide variety of laser configurations. They are necessarily simplified and make conservative assumptions. Some laser configurations may warrant a more complex analysis. Use the ANSI Z136 series of standards or other established methods as basis for any such alternative analysis. Document the method(s) and calculations and include them when submitting Form 7140-1 to FAA.
Laser configurations: A single outdoor laser operation may have a number of lasers or “laser configurations.” A laser configuration is a laser, or group of similar lasers, aimed in a given direction or area that needs airspace protection.
If a setup operates with more than one laser, with different beam characteristics (e.g., power setting, pulse mode, divergence, or wavelength), or has multiple output devices (e.g., projector heads) aimed into the airspace, it has multiple configurations and requires analysis as a separate laser configuration. For each configuration, fill out one copy of the Laser Configuration Worksheet (page two of the form). An example and resulting requirements follows.
Appendix A A-2 Example: At a laser light show, there may be two configurations.
• A group of lasers all aimed in the same general direction over the audience, e.g., 10 RGB (red-green-blue) diode laser projectors above a stage, aimed horizontally along an azimuth ranging from 30 to 45 degrees and elevated vertically from 5 to 45 degrees.
• A beacon laser pointing straight up.
In the group example above, report all 10 laser projectors and their beam characteristics (power, divergence, and wavelength) to FAA on the form or an attachment. Since, however, all lasers have similar characteristics and are all aimed into the same area of airspace, complete as few Laser Configuration Worksheets as required.
• If the laser with the longest eye hazard distance (NOHD) is also the laser with the longest visual interference distance (laser-free exposure distance/LFED):
o Complete one worksheet.
o Rationale: The other, less-powerful projectors have shorter protection distances that remain within the longest distances needed to protect airspace.
• If the laser with the longest eye hazard distance (NOHD) is not the laser with the longest visual interference distance (LFED):
o Complete an additional worksheet for the laser with the longest visual interference distance (LFED).
o Use the data to determine the other protection distances, e.g., SZED and CZED.
o Rationale: While this laser is similar to the one in the some group with the longest NOHD, the visual interference value is different. This laser does not remain within the protection distances of the other laser and therefore requires additional analysis to protect airspace.
In the beacon example above, a separate beacon laser is aimed straight up (90 degrees vertically). This is another configuration, requiring completion of an additional Laser Configuration Worksheet and associated attachments.
Aeronautical study: FAA service center personnel will use the submitted information to perform an aeronautical study to evaluate the safety of a proposed laser operation. Provide all requested information to FAA to enable service center personnel to perform the study. If a proponent needs to include additional details not requested on the form, list these in cell 7b and include with the submission.
Appendix A A-3 A.3. Section 1. General Information 1a. Enter the FAA service center responsible for the area that includes the laser operation site.
For airborne laser operations, enter the service center where the majority of aircraft basing will occur. Consult Appendix E for FAA service center contact information.
1b. Enter the proponent's name and contact information; e.g., address, telephone, fax, and e-mail.
The proponent is the party primarily responsible for the laser safety of this operation. When the proponent is a manufacturer or a governmental agency (e.g., NASA) and the laser is located at a different site, list the proponent’s information here then reference cell 1f.
1c. Enter the event name (for temporary shows) or the facility name (for permanent installations).
1d. Enter the date the proponent prepared or sent the report to FAA. The date in this cell is not the date of the laser operation.
1e and 1f. If the laser user is different from the proponent, complete these cells. If not, enter “Same as proponent.” Enter the customer and site address in 1e and 1f.
A.4. Section 2. Date(s) and Time(s) of Laser Operation 2a and 2b. Enter the date(s) and time(s) of the testing, alignment (if applicable), and operation.
Include the time zone at the site. Example: May 20, 2021, 7:00 p.m. to 12:00 a.m. (midnight), Central Time.
A.5. Section 3. Brief Description of Laser Operation Provide a general overview of the operation. Describe specific laser configurations of the operation in detail using the Laser Configuration Worksheet found on page two of Form 7140-1.
If necessary for multiple configurations, attach additional copies of the Laser Configuration Worksheet.
A.6. Section 4. On-site Operation Information List the names and titles (if available) of the laser operators in 4a. Proponents should provide one (or more) working, direct telephone links to the laser operator or an equivalent method of quickly reaching the operator, e.g., telephoning a central station that reaches the operator via radio. FAA provides space for two telephone numbers on the form. List the primary phone number in cell 4b and the secondary/alternate/backup number in cell 4c. The on-site phone numbers in cells 4b and 4c must be U.S. phone numbers.
A.7. Section 5. FDA/CDRH Information If the operation uses or is a “demonstration laser” (generally, a laser light show) regulated by FDA/CDRH, enter the variance number for the laser light show, the variance expiration date, and the accession number. The accession number may or may not have an “RH” prefix or a suffix,
e.g., “-001.” At a minimum, enter the seven alphanumeric digits provided by FDA/CDRH.
NOTE: The variance number may remain valid even if issued in the past. FDA/CDRH may require periodic reports (usually annually) to keep variances active as stipulated in the variance
Appendix A A-4 if approved. If the report is acceptable, FDA may send an acknowledgement letter that may or not contain a new variance expiration date. The variance number may not change.
A.8. Section 6. Brief Description of Control Measures Describe the proposed method(s) to protect airspace from the laser, e.g., termination on a building or surface (where the beam path from the laser origin to the termination point is not accessible by aircraft, including helicopters), use of observers, use of radar and/or imaging equipment, or physical methods of limiting the beam path. As the level of reliance on the control measure(s) to ensure safety increases, FAA expects a commensurate increase in the level of detail used to describe the control measure(s).
NOTE: If a proponent is utilizing an electronic protection system in lieu of safety observers, enter the description into Section 6 of FAA Form 7140-1 and provide additional documentation to certify that control measure meets the performance criteria in the SAE AS6029, Criteria for Laser Control Measures Used for Aviation Safety (current edition).
A.9. Section 7. Attachments 7a. List the total number of laser configurations submitted with this notice (see the example described earlier in paragraph A.2.).
7b. List all attachments/associated file names and the correlation between each attachment (and/or file) and the specific configuration listed in cell 10a. This will assist FAA in evaluating the proposal. Examples of attachments are maps, diagrams, and details of control measures.
A.10. Section 8. Designated Contact Person Specify the person who FAA may contact for additional information. This contact should be the person most knowledgeable about the laser safety of this operation. The person could also be the laser operation central contact who interfaces with FAA. The designated contact person should work for or represent the proponent listed in cell 1b.
A.11. Section 9. Statement of Accuracy The person signing the form must have the authority to bind the proponent to follow the control measures described in the submitted notice. This person may also serve as the contact person.
A.12. Section 10. Configuration Information 10a. Enter the configuration number of the specific configuration entered on this Laser Configuration Worksheet. If there is only one configuration, enter “Configuration number 1 of
1.” If there is more than one configuration, enter the number of the specific configuration entered on this page and the total number of configurations submitted. Example: “Configuration number 7 of 9.”
10b. Describe the system that aims and projects the beam(s) into airspace, e.g., fixed mirror, scanning galvanometers, or manually aimed. Include a description of the site layout. Attach additional pages if needed to describe the laser use.
Appendix A A-5 A.13. Section 11. Geographic Location 11a. Enter the ground elevation of the site in feet mean sea level (MSL).
11b. Enter the height of the laser above the site elevation. This value should reflect the total height including any tall structure or building on which the laser may be located.
11c. Enter the overall laser elevation (site elevation plus height above site elevation). This number is the total height of the laser in MSL. For laser operations from aircraft or spacecraft operations, attach additional information on the flight locations and altitudes.
11d. Select global positioning system (GPS), map (e.g., USGS topographical or quadrangle), or other as the method used to determine data in section 11. If selecting “other,” describe the method (e.g., application or software name, program, or service) to FAA in cell 10b (Brief description of configuration) and mention cell 11d in the description.
11e and 11f. Enter the latitude and longitude in degrees, minutes, and seconds. Some maps or devices may provide this information in “decimal degrees” form. If the source provides decimal degrees, convert this value into degrees, minutes, and seconds. The Federal Communications Commission furnishes a website with a converter (https://www.fcc.gov/media/radio/dmsdecimal).
A.14. Section 12. Beam Characteristics and Calculations Determine the laser’s mode of operation (single pulse, continuous wave [CW], or repetitively pulsed). Check the appropriate column header and complete only that column for section 12.
For the purposes of this form, use these characteristics:
• “Continuous wave” refers to a laser that produces a continuous (non-pulsed) output for a period greater than 0.25 seconds.
• “Repetitively pulsed” refers to a laser with a pulse repetition frequency (PRF) of equal to or greater than one hertz.
NOTE: Repetitively pulsed versus scanning lasers “Repetitively pulsed” refers to lasers that naturally emit repetitive pulses, such as Q-switched lasers.
The intent of the design of the form and the tables within this Advisory Circular does not include safety analysis of pulses of a beam scanned over a viewer or aircraft, such as graphics or beam patterns used in laser displays, or scanned patterns used for light detection and ranging (LIDAR).
Pulses resulting from scanning are often extremely variable in pulse width and duration. For a conservative analysis, assume the beam is static (non-scanned). If a proponent relies on scanning to remain in compliance, they must provide a more comprehensive analysis that
Appendix A A-6 documents methods and calculations, and must document and use scan-failure protection devices.
A.14.1. Considerations for Multiple Visible CW Laser Beams Aimed Within the Same Area For a configuration that aims multiple lasers in the same direction, all of which emit visible wavelengths (from 400 nm to 700 nm), consider the following before completing cell 12a.
Example: Multiple lasers on a stage projecting over the audience into the same area of airspace requiring protection.
• Simplest, most conservative analysis.
o In cell 12a, enter the data for the laser with the highest power. All other lasers will have a shorter hazard distance.
o In cell 12c, enter “1” as the Visual Correction Factor (VCF).
o Notes for this approach follow.
▪ The pre-corrected power (PCP) and the Visually Corrected Power will be the same as the power from the highest-power laser.
▪ Because of no allowance for the beams’ visibility, the SZED, CZED, and LFED distances will be longer than analyzing each laser separately.
• Analyze each laser separately: This analysis will determine which laser beam has the longest NOHD, and which has the longest LFED.
o For each laser projector, determine the NOHD, SZED, CZED, and LFED. Attach documentation showing the data and calculations. See Appendix B for an example.
o Cells 12a and 14a: Enter the data for the projector with the longest NOHD.
o Cells 12c, 14b, 14c, and 14d: Enter the data for the projector with the longest LFED.
A.14.2. Section 12a. Laser and Beam Characteristics Laser type: Enter the lasing medium, e.g., CO2, copper-vapor, diode, or Nd-YAG.
Laser hazard class: Enter the hazard class for the laser, e.g., Class 2, Class 3R, Class 3B, or Class 4.
Power: If a continuous wave laser, enter the maximum power in watts (W). If a repetitively pulsed laser, enter the average power in watts (W).
Pulse energy: If a single pulse or repetitively pulsed laser, enter the pulse energy in joules (J).
Appendix A A-7 Pulse duration: If a single pulse or repetitively pulsed laser, enter the pulse duration in seconds
(s).
Pulse repetition frequency: If a single pulse or repetitively pulsed laser, enter the pulse repetition frequency in hertz (Hz).
Beam diameter and divergence: Provide the diameter using the 1/e peak-irradiance points in centimeters (not millimeters). The divergence is the full angle given at the 1/e points in milliradians (mrad). If measuring the diameter or divergence at the 1/e2 points instead of 1/e, multiply by 0.707 to convert to 1/e diameter or divergence.
NOTE: Diameter and divergence measurements can be complex. If necessary, use conservative (smaller diameter or smaller divergence) simplifications.
Wavelength(s): Based on the number of wavelengths and their relation to the visible spectrum, use the following information to assist with determining what information FAA requires.
• Single-wavelength laser beam: For a laser emitting a single wavelength:
o Enter the wavelength in nanometers (nm) in 12a.
o If the emitted wavelength is:
▪ Within the visible range (400 nm to 700 nm): Enter “2.6” as the MPE value in 12b and enter the results of the visual effect calculations in cell 12c.
▪ Not within the visible range: Determine the MPE value as described in paragraph A.14.2. and enter the value into cell 12b. Enter “N/A (nonvisible laser)” in all cells of the applicable column of section cell 12c.
• Multiple-wavelength laser beam: For a laser simultaneously emitting multiple wavelengths in the same beam (from the same aperture), see Appendix C.
A.14.3. Section 12b. Maximum Permissible Exposure (MPE) Value Provide MPE calculation results in the applicable cell, expressed in milliwatts per square centimeter (mW/cm2) or joules per square centimeter (J/cm2). For convenience, the tables in Appendix B provide simplified, conservative MPE values. If a proponent requires less conservative values, use the ANSI Z136 series of standards or other established methods. If using a method other than the values in Appendix B, document and attach the approach and results when submitting the form.
NOTE: Exposure duration Unintentional laser exposure to the eye of a person in an aircraft is not estimated to last more than 0.25 seconds based on various factors including the human aversion response (for visual lasers) and the natural relative motion between the beam and aircraft related to wind and other
Appendix A A-8 stabilization issues. The analysis in this document applies to laser wavelengths between 400 nm and 1050 nm for exposures less than 0.25 seconds. This analysis also provides conservative results for wavelengths from 1050 nm to 1400 nm.
If the potential exposure may last for an increased duration or a proponent desires to complete a more precise analysis (e.g., wavelengths from 1050 nm to 1400 nm), refer to the ANSI Z136 standards for additional analysis techniques. Document and include the standards’ MPE exposure limits and calculations with the submission.
A.14.3.1. MPE: Single Pulse Laser Use Table 1 for lasers that produce a single pulse of energy with a pulse width less than 0.25 seconds. Enter the MPE per pulse value in joules per square centimeter (J/cm2) in cell 12b.
A.14.3.2. MPE: Continuous Wave Laser Determine if all wavelengths of a continuous wave laser beam are in the visible spectrum (400 nm to 700 nm).
• If all wavelengths are in the visible range, enter “2.6” in cell 12b.
• If one or more wavelengths are not within the visible range:
o Record all wavelengths on a separate document per A.14.1., Section 12a, Laser and Beam Characteristics.
o Use Table 2 to find the MPE for each wavelength.
o Calculate the NOHD for each wavelength per A.16.2.1., Slant Range (NOHD).
o Enter the MPE value for the wavelength with the longest NOHD in 12b, and use this MPE value for the visual effect calculation values in 12c and the remainder of section 14a.
A.14.3.3. MPE: Repetitively Pulsed Laser Some repetitively pulsed lasers can produce hazards greater than CW lasers with the same average power. Treat the following lasers as CW lasers, use the instructions in A.14.2.2, and enter the MPE value in the repetitively pulsed column:
• 400 nm to 1050 nm: PRF greater than 13 kilohertz (kHz).
• 1050 nm to 1400 nm: PRF greater than 6.5 kHz.
NOTE: The most restrictive MPE for a repetitively pulsed laser is determined from choosing the most conservative MPE considering Tables 1 and 2. The PRF values provided only apply for a
0.25 s exposure with individual pulse widths less than 5 µs for wavelengths from 400 nm to 1050 nm and less than 13 µs for wavelengths from 1050 nm to 1320 nm.
Appendix A A-9 For the purposes of this form, a laser with a PRF of equal to or greater than one hertz is a repetitively pulsed laser. These lasers can produce an additional hazard greater than that of a single pulse or continuous wave laser. The MPE calculation for repetitively pulsed lasers uses its PRF, designated MPEPRF. Determine the MPEPRF using either the per-pulse energy or the average power.
This document provides a simplified method for calculating the MPEPRF for average power with wavelengths in the visible and infrared region (ANSI Z136 series can provide a less conservative value in some cases). Although designated MPEPRF, enter the value in either the “MPE” or “MPE per pulse” cells of the repetitively pulsed laser column (FAA only requires one of the two MPEs). Use the following simplified methods to determine the MPEPRF.
• Ultraviolet wavelengths less than 400 nm: Reference the ANSI Z136 series. Enter the MPE value in cell 12b (“MPE per pulse” row).
• Visible and infrared wavelengths up to 1050 nm. For a laser with a PRF:
o Less than 13 kHz: Use Table 1 to determine the MPE per pulse in J/cm2 and enter the value in cell 12b (“MPE per pulse” row).
o Greater than 13 kHz: Evaluate as if a CW laser. Use Table 2 to determine the MPE in mW/cm2 and enter the value in cell 12b (“MPE” row).
• Infrared wavelengths from 1050 nm to 1400 nm. For a laser with a PRF:
o Less than 6.5 kHz: Use Table 1 to determine the MPE per pulse in J/cm2 and enter the value in cell 12b (“MPE per pulse row”).
o Greater than 6.5 kHz: Evaluate as if a CW laser. Use Table 2 to determine the MPE in mW/cm2 and enter the value in cell 12b (“MPE” row).
• Infrared wavelengths greater than 1400 nm: For an exposure to a repetitively pulsed laser at these wavelengths, a PRF of just a few hertz results in a more restrictive CW MPE than the pulsed MPE. The MPE that indicates the greatest hazard determines what MPE to enter into cell 12b. Fill in the appropriate “MPE” cell in the Pulsed column, indicating whether the MPE is in J/cm2 or mW/cm2.
NOTE: The simplified methods of Table 2 use the average power to determine the MPE in mW/cm2. Using other methods, it is possible to use the pulse energy to determine the MPE per pulse in J/cm2.
A.14.4. Section 12c. Visual Effect Calculations Non-visible lasers: If the laser has no wavelengths within the visible range (400 nm to 700 nm), enter “N/A (non-visible laser)” in all three cells of the appropriate column of section 12c and proceed to section 13.
Appendix A A-10 Visible lasers: For any laser emitting wavelengths within the visible range (400 nm to 700 nm), proponents must submit visual effect calculations to assist FAA with its evaluation of laser beams bright enough to distract or interfere with a crewmember’s vision, e.g., glare or afterimage. To reduce the risk of distraction or interference, FAA established the following areas wherein crewmembers should not encounter light greater than the values listed.
• Sensitive Flight Zone: 100 microwatts per square centimeter (µW/cm2).
• Critical Flight Zone: 5 µW/cm2.
• Laser-Free Zone: 50 nanowatts per square centimeter (nW/cm2).
Because perceived brightness varies with wavelength (e.g., a green laser appears brighter to the human eye than a red or blue laser of the same power), proponents can apply a visual effect correction factor if desired. This correction factor has the result of allowing more power for red and blue beams than for green beams of equal power and divergence.
A.14.4.1. Determine the Pre-corrected Power (PCP).
The PCP is the total power (sum) of all visible wavelengths. The PCP calculation method depends on the laser’s mode of operation.
• Single Pulse: Multiply the pulse energy (in joules) stated in cell 12a by four and enter the value.
NOTE: This technique averages the pulse’s energy over the 0.25-second maximum pulse duration, and is a conservative approximation of the visual effect of a pulse. If proponents use less conservative calculations, they must document and attach the methods and calculations.
• Continuous wave: Enter the total power (sum) of all visible wavelengths. If the laser emits only visible wavelengths, this will be the same as the maximum power entered in cell 12a.
• Repetitively pulsed: Multiply the pulse energy (in joules) by the pulse repetition frequency (hertz) stated in cell 12a and enter the value.
Appendix A A-11 A.14.4.2. Determine the Visual Correction Factor and Visually Corrected Power.
Use one of the following methods to provide the VCF and the Visually Corrected Power of the laser.
• Simplest/most conservative analysis.
o VCF: Assume no correction factor and enter “1.0 (assumed).”
o Visually Corrected Power: Enter the same value as the PCP.
• Single-wavelength beam.
o VCF: Enter the appropriate value from Table 3.
o Visually Corrected Power: Multiply the VCF by the PCP and enter the resulting value.
• Multiple visible wavelengths: Choose one of the two following methods and enter the resulting value.
o Make a simplifying, conservative assumption.
▪ VCF: Use Table 3 to determine which wavelength has the largest factor (is the most visible), and enter the value.
▪ Visually Corrected Power: Multiply the VCF by the PCP (the sum of all visible wavelengths) and enter the resulting value.
o Analyze each wavelength’s power and VCF individually to find the overall VCF and the visually corrected power. There are two methods to perform this calculation.
▪ Software calculation: Use laser safety software with the ability to enter separate wavelengths and powers for a single laser beam. The software should provide a total VCF calculation for the combined wavelengths and the Visually Corrected Power calculation for the beam.
NOTE: Include attachments (and list in cell 7b) of screenshots or printouts showing the wavelength and power inputs and the software’s resulting VCF and visually corrected power values. Ensure completion of section 15, listing the software name and version.
▪ Manual Calculation: Attach a spreadsheet or worksheet showing the steps of the following calculations:
• For each visible wavelength, list the power at that wavelength.
Sum the listed wattages and enter than number as the PCP in cell 12c.