Section 2. Evaluating Aeronautical Effect

29-2-1. SERVICE CENTER COORDINATION

The designated Service Center (SC) Point of Contact (POC) normally serves as the single agency contact with the laser proponent. The SC POC is responsible for:

1. Reviewing the information and data submitted by a proponent for an outdoor laser proposal for completeness.
   1. Coordinating with all parties affected by the proposal (for example, state or local aviation authorities, DoD, airport operators, etc.).
   2. Air Traffic analysis, including any IFR and VFR flight operations that may be affected by the proposal.
2. Determining on a case-by-case basis that aspects of certain flight operations require consultation and joint analysis by the ATO and AFS to ensure safety during a proposed laser operation. The SC POC will contact the RNGB designee for assistance in those situations.
3. The Flight Standards safety analysis will be conducted by the designated RNGB AWO. AFS analysis will include reviewing potential effects on flight crews operating under IFR or VFR. Special attention will be afforded examining unique local VFR operations and special instrument procedures. The safety analysis provided to the SC POC will state any AFS objections or concerns and indicate whether mitigations, if proposed, appear adequate. The SC POC is responsible for evaluating all input from the affected Air Traffic Facilities/RNGB and resolving conflicting concerns or issues.

29-2-2. AERONAUTICAL REVIEW

1. At a minimum the following items must be studied as part of any aeronautical review:
   1. Location of the proposed laser operation.
   2. Aircraft operations affected by the proposed operation.
   3. Air traffic flows in the proposed area of the operation.
   4. An analysis of adverse effect conducted by the ATC facility having control over the affected airspace.
   5. A safety analysis conducted by the Flight Standards Division regarding the effects on flight crews.
   6. For visible laser systems, plot the LFZ, CFZ, and SFZ (if applicable) for all potentially affected airports and evaluate any control measures, which may mitigate any adverse effect.
   7. The effective irradiance levels listed below must not be exceeded in the corresponding zones.
      1. A laser-free zone is limited to 50nW/cm² or less.
      2. A critical flight zone is limited to 5℞W/cm² or less.
      3. A sensitive flight zone is limited to 100℞W/cm² or less.
      4. A normal flight zone, as well as the above zones, is limited to the MPE or less.

         EXCEPTION-
         The LFZ, CFZ, and SFZ need only be considered for visible laser systems. Further, when control measures (e.g., safety observers) mitigate all hazards or other issues raised by the aeronautical review, irradiance levels may exceed the above levels.

2. Consult FDA/CDRH personnel for technical advice. (for example, regarding repetitively pulsed laser calculations)
3. Scientific/research lasers in accordance with 21 CFR § 1010.5 may be exempt from Title 49 and, in addition, may not be able to comply with the above procedures. Regardless of whether or not a proponent is exempt from the provisions, a proposal is still reviewed using the above procedures.

29-2-3. LOCAL LASER WORKING GROUP (LLWG)

When necessary, the Service Center OSG may convene and chair an LLWG to assist in evaluating proposed laser operation.

1. The Service Center OSG will forward all available information on a proposed outdoor laser operation to the appropriate parties of the LLWG.
2. Participants may include, but are not limited to, representatives from the ARTCC, TRACON, ATCTs, Flight Standards Division designee (either the assigned AWO or a designated field office representative), airport management, airspace users, city/county/state officials, other government agencies, military representatives, qualified subject experts, and laser manufacturers, etc.
3. The LLWG will identify and attempt to resolve issues regarding local laser operations.

29-2-4. PROTECTION DISTANCE CALCULATIONS

1. The laser system power range table (TBL 29-2-1) provides the applicable protection distances along the axis of the laser beam with a 1mrad divergence. This table must not be used to determine the protection distances for repetitively pulsed (RP) lasers. Proponents are required to resolve RP laser system calculations with the FDA or laser manufacture before submitting a completed Laser Configuration Worksheet to the FAA.
2. TBL 29-2-2 lists sine and cosine values to be used in determining the vertical and horizontal distances to be protected from the laser source. The distances obtained from TBL 29-2-1 are multiplied by these values to determine the appropriate vertical and horizontal distances to be protected based on the minimum and maximum vertical angles. Differences in site/ground elevations should be considered.
3. The vertical component of the protection distance may be determined by multiplying the laser distance from TBL 29-2-1 by the sine of the maximum elevation angle of the laser beam from TBL 29-2-2. For example, vertical component = protection distance x sine of the maximum elevation angle.
4. The horizontal component of the protection distance may be determined by multiplying the laser distance from TBL 29-2-1 by the cosine of the minimum elevation angle of the laser beam from TBL 29-2-2. For example, horizontal component = protection distance x cosine of the minimum elevation angle.
5. Do not reduce calculated distances for correction factor techniques unless validated by FDA/CDRH.
6. All distances must be rounded up to the next 100-foot increment. See example problems 1, 2, and 3 that follow the Vertical and Horizontal Component Table, TBL 29-2-2.

29-2-5. CONTROL MEASURES

Physical, procedural, and automated control measures, or some combination of the three, may be used to ensure that aircraft will not be exposed to levels of illumination greater than the respective maximum irradiance levels established for the various protected zones, or any additional restrictions established as a provision, condition, or limitation of a determination.

1. Physical beam stops at the system location or at a distance may be used to prevent laser light from being directed into protected zones.
2. The beam divergence, azimuth, elevation, and output power may be adjusted to meet appropriate irradiance levels.
3. Beam direction should be specified by giving bearing in the azimuth scale 0 - 360 degrees and elevation in degrees ranging from 0 - 90 degrees, where zero degrees is horizontal and +90 degrees is vertical. Bearings must be given in both true and magnetic north.
4. Manual operation of a shutter or beam termination system can be used in conjunction with safety observers. Observers must have an adequate view of the airspace surrounding the beam's paths to a distance appropriate to the affected airspace.
5. Scanning of a laser system that is designed to automatically shift the direction of the laser beam can be used. However, scanning safeguards must be found to be acceptable by the FDA and the FAA. The FDA recommendation must be included in the proposal to the FAA.

   NOTE-
   Scanning may reduce the level of illumination; however, it may also increase the potential frequency of an illumination.

6. Any laser operator planning to use an automated system designed to detect aircraft and automatically terminate the beam, redirect the beam, or shutter the system, must provide documentation to the Service Center OSG that validates the system's compliance with SAE International Aerospace Standard (AS) 6029, Performance Criteria for Laser Control Measures Used for Aviation Safety, before the use of the device may be accepted as a control measure and eliminate the need for safety observers.

   TBL 29-2-1
   LASER SYSTEM POWER RANGE TABLE
   CW Laser Beam Divergence: 1 Milliradian
   * NOT TO BE USED WITH RP SYSTEMS

   W/cm^2 --->	2.60E-03	1.00E-04	5.00E-06	5.00E-08
   CW Laser Power (W)	Nominal Ocular Hazard Distance NOHD (ft)	Sensitive Zone Exposure Distance SZED (ft)	Critical Zone Exposure Distance CZED (ft)	Laser-Free Zone Exposure Distance LZED (ft)	LZED (NM)
   1	726	3701	16553	165527	27
   2	1026	5234	23409	234090	39
   3	1257	6411	28670	286700	47
   4	1452	7403	33105	331053	54
   5	1623	8276	37013	370129	61
   6	1778	9066	40546	405456	67
   7	1920	9793	43794	437942	72
   8	2053	10469	46818	468180	77
   9	2178	11104	49658	496580	82
   10	2295	11704	52344	523441	86
   11	2407	12276	54899	548990	90
   12	2514	12822	57340	573401	94
   13	2617	13345	59681	596815	98
   14	2716	13849	61934	619344	102
   15	2811	14335	64108	641082	106
   16	2903	14805	66211	662106	109
   17	2993	15261	68248	682484	112
   18	3080	15703	70227	702270	116
   19	3164	16134	72151	721514	119
   20	3246	16553	74026	740257	122
   25	3629	18506	82763	827633	136
   30	3976	20273	90663	906626	149
   35	4294	21897	97927	979268	161
   40	4591	23409	104688	1046882	172
   45	4869	24829	111039	1110386	183
   50	5133	26172	117045	1170450	193
   55	5383	27449	122758	1227578	202
   60	5623	28670	128216	1282163	211
   65	5852	29841	133452	1334518	220
   70	6073	30967	138489	1384895	228
   75	6286	32054	143350	1433502	236
   80	6492	33105	148051	1480515	244
   85	6692	34124	152608	1526079	251
   90	6886	35113	157032	1570323	258
   95	7075	36076	161335	1613353	266
   100	7259	37013	165527	1655266	272
   105	7438	37927	169614	1696143	279
   110	7613	38819	173606	1736057	286
   115	7784	39692	177507	1775075	292
   120	7952	40546	181325	1813253	298
   125	8116	41382	185064	1850643	305
   130	8276	42201	188729	1887293	311
   135	8434	43005	192324	1923245	317
   140	8589	43794	195854	1958537	322
   145	8741	44569	199320	1993204	328
   150	8890	45331	202728	2027278	334
   155	9037	46081	206079	2060789	339
   160	9182	46818	209376	2093764	345

   * The FDA may be contacted to validate data for repetitively pulsed lasers.

   * The proponent validates repetitive pulsed information with the FDA and submits a completed laser configuration worksheet.

   TBL 29-2-2
   VERTICAL AND HORIZONTAL COMPONENTS

   VERTICAL COMPONENT

   Maximum Elevation Angle	Sine (vertical component multiplier)
   90	1.0000
   85	.9962
   80	.9848
   75	.9659
   70	.9397
   65	.9063
   60	.8660
   55	.8192
   50	.7660
   45	.7071
   40	.6428
   35	.5736
   30	.5000
   25	.4226
   20	.3420
   15	.2588
   10	.1737
   5	.0872
   0	.0000

   HORIZONTAL COMPONENT

   Minimum Elevation Angle	Cosine (horizontal component multiplier)
   0	1.0000
   5	.9962
   10	.9848
   15	.9659
   20	.9397
   25	.9063
   30	.8660
   35	.8192
   40	.7660
   45	.7071
   50	.6428
   55	.5736
   60	.5000
   65	.4226
   70	.3420
   75	.2588
   80	.1737
   85	.0872
   90	.0000

   LASER PROBLEM SOLUTIONS

   EXAMPLE PROBLEM 1:
   Laser output power = 15 watts
   Laser beam divergence = 1.0 mrad
   Find: Laser protection distances:
   1. Find TBL 29-2-1 at 15 watts in the Laser Output Power column.
   2. Proceed horizontally and read: NOHD of
   2,811 feet, CFZ of 64,108 feet, SFZ 14,335 feet.
   Answer: (with rounded up distances): NOHD
   2,900 feet, CFZ 64,200 feet, SFZ 14,400 feet.

   EXAMPLE PROBLEM 2
   Laser output = 18 watts
   Laser beam divergence = 1.0 mrad
   Maximum elevation angle 60°
   Minimum elevation angle 20°
   Find:Vertical and horizontal distances to be protected:
   1. Laser distance (from TBL 29-2-1) = 3,080 feet.
   2. Sine of 60° maximum elevation angle (from
   TBL 29-2-2) = 0.8660.
   3. Find altitude by multiplying 3,080 feet
   by 0.8660 = 2,667 feet.
   4. Cosine of 20° minimum elevation angle (from TBL 29-2-2) = 0.9397
   5. Find horizontal distance by multiplying 3,080 feet by 0.9397 = 2,894 feet.
   Answer: Minimum required protected airspace
   is 2,700 feet vertically and 2,900 feet horizontally from the laser source.

   EXAMPLE PROBLEM 3
   Power = 25 watts
   Laser NOHD at 1 mrad = 3,629 feet.
   Beam Divergence = .7 mrad
   Find: Actual NOHD
   1. Find actual NOHD by dividing the NOHD at 1 mrad divergence (3,629 feet) by actual divergence
   (.7 mrad).
   2. 3629 feet. ÷ .7 = 5184 feet.
   Answer: NOHD 5,200 feet (rounded up)