AC 450.161-1

Advisory circular · Control of Hazard Areas

Approved
December 21, 2022
Last reviewed
November 29, 2023
Family
AC 450.161-1 · 1 version
14 CFR parts
450

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 21, 2025.

Show pages 1–12

8 PERFORMING SURVEILLANCE OF HAZARD AREAS.

Surveillance must be performed for two reasons:

1. As required by § 450.161(a), an operator must publicize, survey, control, or evacuate each flight hazard area to the extent necessary to ensure compliance with § 450.101.

2. As required by § 450.161(b), an operator must perform surveillance sufficient to verify or update the assumptions, input data, and results of the flight safety analyses.

8.1 External Entities.

An operator may perform the necessary surveillance or have an entity conduct the surveillance on its behalf. This may be a Federal Entity, as authorized under § 450.45(b), or another entity. If an operator utilizes an entity to provide land surveillance services, it must have a written agreement specifying roles and responsibilities, as required by § 450.147(b).

8.2 Sufficiency.

To determine whether surveillance is “to the extent necessary” and “sufficient to verify or update assumptions,” the effectiveness of the surveillance approach should be commensurate with the individual and collective risks posed by the operation. Any method or combination of methods for surveillance has some amount of effectiveness.

8.2.1 For example, extremely high effectiveness might be obtained by a high-density set of visual and infrared cameras that are monitored with both automated motion detection and humans monitoring feeds. A much lower effective surveillance method might be a request via radio to provide position updates. A measure of effectiveness is the probability of detecting a person in a particular environment.

8.2.2 No surveillance method is perfect, but there should be a much lower likelihood of an undetected person in a region where the risk to the person is well above the individual risk criterion. For example, if a location has an individual risk, also known as probability of casualty (PC), of 1×10-4, it is a factor of 100 above the safety criteria, so there should be less than a 1 in 100 chance of failing to detect a person being present.

For surveillance systems where quantitative effectiveness is not known, a qualitative justification for a quantitative estimate should be used.

8.3 Methods for Day-of-Flight Surveillance.

There are multiple methods for conducting day-of-flight surveillance of hazard areas.

An operator may use a combination of methods, if appropriate.

8.3.1 Land Hazard Areas.

Observers and/or security personnel may be used to monitor access points or hazard areas using electronic, video, or direct visual surveillance. Piloted or remotely-piloted aircraft may also be used for surveillance of land hazard areas. An operator may use its own personnel to survey land hazard areas, or it may enter into agreements with local law enforcement, launch site operators, or other entities to conduct surveillance.

8.3.2 Waterborne Vessel Hazard Areas.

An operator may monitor marine traffic using information received from Automatic Identification System (AIS) transmissions from waterborne vessels, which is an automated tracking system that displays vessels in the vicinity. An operator may utilize service providers to obtain real-time AIS surveillance data or use direct surveillance methods, such as marine radar or sonar to detect waterborne vessels. Visual observers (launch operator personnel or contractors) on land may be used to survey waterborne vessel hazard areas within visual range. Waterborne vessels may be used to assist in surveying hazard areas at sea. Piloted or remotely-piloted aircraft may also be used to survey areas of sea from above. An operator may use its own personnel to survey waterborne vessel hazard areas, or it may enter into agreements with the USCG, launch site operators, or other entities to conduct surveillance.

8.3.3 Airspace Hazard Volumes.

Surveillance methods may include data from Automatic Dependent Surveillance – Broadcast (ADS-B), Radio Detection and Ranging (RADAR), Multilateration (MLAT), visual observers, or other methods. An operator may use web or mobile-application-based ADS-B flight tracking applications to access real-time ADS-B data to survey aircraft hazard areas. Since not all aircraft may have operating ADS-B equipment,1 additional methods may be used to supplement ADS-B surveillance. An operator may also use visual observers, either on land, airborne, or both to survey for aircraft. Additionally, an operator may utilize service providers to obtain real-time airspace surveillance data. It may also choose to survey airspace hazard volumes using its own personnel and resources.

1 See 14 CFR § 91.225.

8.4 Surveillance Plans to Submit with an Application.

Pursuant to § 450.161(d)(1), an operator must provide in its application a description of how the applicant will provide for day-of-flight surveillance and control of flight hazard areas, if necessary, to ensure that the presence of any member of the public in or near a flight hazard area is consistent with flight commit criteria developed for each launch or reentry as required by § 450.165(b) to meet the risk criteria in § 450.101. Paragraphs

8.4.1 and 8.4.2 of this AC address day-of-flight surveillance while chapter 9 of this AC addresses control of flight hazard areas.

8.4.1 Description for providing Day-of-Flight Surveillance.

The description should cover methods used for surveillance of all hazard areas identified in compliance with § 450.133. Day-of-flight surveillance should ensure that the presence of any member of the public in or near any flight hazard area is consistent with the assumptions and inputs to the operator’s flight safety analysis.

8.4.2 Surveillance of Land, Sea, and Air.

If the presence of any member of the public in or near any flight hazard area is not consistent with the flight commit criteria developed under § 450.165(b), an operator must not commence launch or reentry until such time that any public presence is consistent with those criteria required by § 450.165(a)(1). If surveillance is stopped prior to launch, latency should be taken into account. The launch decision should be based on surveillance that shows no public, including ship or aircraft, will transition into the hazard area during flight. For instance, the time it takes for a ship to traverse from the edge of the surveyed area to the waterborne vessel hazard area should be taken into account when deciding when to end surveillance prior to launch. It is recommended that the surveillance assets account for a buffer between the recommended clearance area and an area encompassing the distance a vessel could travel in this time. An operator’s surveillance plan should also include atmospheric limitations of sensors or observers, if applicable. For example, if observers will be used to determine if aircraft are in the airspace hazard volume below 5,000 feet, then a minimum 5,000 feet visibility requirement should be in the surveillance plan during the time when these observations take place.

9 CONTROLLING FLIGHT HAZARD AREAS.

As required by § 450.161(a), an operator must publicize, survey, control, or evacuate each flight hazard area identified in accordance with § 450.133 prior to initiating flight of a launch vehicle or reentry of a reentry vehicle to the extent necessary to ensure compliance with § 450.101. While surveillance may help an operator detect or identify the presence of members of the public, control includes actions or methods of actively preventing access or facilitating exit of members of the public from flight hazard areas.

The entities providing surveillance services may also provide control services if they have the legal authority to control access to those hazard areas. For example, security guards may both survey an area and control an area by preventing members of the public from entering a flight hazard area, or by escorting persons out of the area. The USCG may provide similar control measures for waterborne vessels at its discretion, provided that the requisite assets are available and the area under control is within U.S.

territorial waters. As noted above, operators are required under § 450.147 to execute an agreement with the USCG establishing procedures for NOTMAR issuance, to be included with their application. The USCG and the FAA have developed a template Letter of Intent (LOI) that the FAA will accept as a means of compliance with § 450.147(b) when submitted with an application, provided the LOI follows the template (including any mission details) and is signed by the applicant and relevant USCG office. If an operator utilizes an entity to provide flight hazard area control services, it must have a written agreement specifying roles and responsibilities, as required by § 450.147.

9.1 Methods for Day-of-Launch Control of Land Hazard Areas.

Security checkpoints, roadblocks, fences, barriers, or other physical controls may be used to control access to an area of land. An operator should determine appropriate locations for any physical controls, as necessary, to prevent access to the defined hazard areas. Appropriate locations may include highways, walkways, trails, beaches, or other areas that would enable access by persons on foot or in vehicles. It may be helpful to develop a map of the hazard area depicting locations of access points, checkpoints, roadblocks, and other physical controls. Security guards may also be employed to escort unauthorized persons out of an area or prevent persons from entering an area. For areas with speaker systems coverage throughout, aural warnings and directions may be used to direct people out of the area. In the event that a hazard area is breached, the applicant should have a communications plan to address how to communicate to individuals responsible for the launch commit criteria. Real time calculations may be accomplished to determine if the members of the public who are present cause the risk to exceed the flight commit threshold criteria. If the risk criteria threshold is exceeded, an operator must not commence flight of a launch vehicle or reentry of a reentry vehicle until such time that any public presence is consistent with those criteria, in accordance with § 450.165(a)(1).

9.2 Methods for Day-of-Launch Control of Airspace Hazard Volumes.

An operator should coordinate with FAA air traffic control (ATC) to manage or reroute aircraft so that they avoid any active airspace hazard volume(s). An operator’s agreement with the FAA ATO should include roles, responsibilities, and procedures for managing airspace hazard volumes. Operators should have a communications plan to address how to communicate any breach of an airspace hazard volume to the individual responsible for launch commit criteria. If an aircraft breaches the area, an operator may coordinate with the local FAA ATC facility to monitor the aircraft’s progress and, if possible, direct the aircraft out of the hazard area. If the presence of any member of the public on an aircraft in the flight hazard area is not consistent with the flight commit criteria developed under § 450.165, an operator must not commence launch or reentry until such time that any public presence is consistent with those criteria in accordance with § 450.165(a)(1).

10 CONTROLLING WATERBORNE VESSEL HAZARD AREAS.

10.1 Commercial Space Operator Requirements for Waterborne Vessel Hazard Areas.

Unless otherwise addressed in agreements with a launch or reentry site operator, for overflight of navigable water, § 450.147(a)(2) requires an operator to establish a written agreement with the USCG or other applicable maritime authority to establish procedures for the issuance of a NOTMAR prior to a launch or reentry and other measures necessary to protect public health and safety. To satisfy this requirement an operator should submit an LOI using the template LOI in appendix B as provided in the FAA’s Statement of Policy on Use of Letter of Intent (LOI) Between the United States Coast Guard (USCG) and a Commercial Space Operator in Appendix A.

11 EVACUATION AREAS.

11.1 Evacuation Area Procedures.

In order to manage risks to the public, there are often areas that are evacuated where people are normally present. These often include public recreation areas and on-site non-mission personnel, and may include other areas as well. The approach to effecting the notification and enforcement of evacuations should be described. In some cases, not everyone would need to be evacuated from the area, either because the evacuation is to reduce collective risk or there are people who are not the public that are allowed in the area. Evacuation areas should become controlled areas, where there are active measures to prevent entry of unauthorized personnel, or surveillance areas to the extent necessary to ensure compliance with the risk criteria found in § 450.101.

11.2 Evacuating the Public from Flight Hazard Areas Having Toxic Risk.

An operator must provide a description of how it will establish flight commit criteria based on the results of its toxic release hazard analysis, toxic containment analysis, or toxic risk assessment for any necessary evacuation of the public from any toxic hazard area, as required by § 450.161(d)(3). The FAA recommends that an operator anticipating toxic hazards on its vehicle or payload reference AC 450.139-1, Toxic Release Hazard Analysis for means of compliance on determining sizes of hazard areas, flight commit criteria, as well as mitigations and controls for toxics.

Appendix A.

Appendix A. Statement of Policy on Use of Letter of Intent A.1 STATEMENT OF POLICY ON USE OF LETTER OF INTENT The following is a copy of the Statement of Policy on the use of a Letter of Intent between the United State Coast Guard (USCG) and a Commercial Space Operator to issue a Notice to Mariners (NOTMAR) and the measures necessary to protect public health and safety.

The updated version of the USCG Letter of Intent (LOI) Policy Statement is located here:

https://www.faa.gov/space/legislation_regulation_guidance

DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Parts 417,420,431,433,435,437, and 450 Statement of Policy on Use of Letter of Intent (LOI) Between United States Coast Guard (USCG) and a Commercial Space Operator2 to Establish Procedures for Issuance of Notice to Mariners (NOTMAR) and Other Measures Necessary to Protect Public Health and Safety for a Launch or Reentry.

AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT) ACTION: Policy Statement SUMMARY: This action establishes the FAA's policy for accepting the attached LOI as a means of compliance with FAA regulations that require a written agreement between the operator and the USCG establishing procedures for the issuance of a NOTMAR prior to a launch or reentry. If additional measures beyond NOTMAR issuance are necessary to protect public health and safety, as specified in FAA regulations, the FAA will accept an LOI including those additional measures as an equivalent level of safety.

DATES: The policy described herein will be effective 19 October 2022.

FOR FURTHER INFORMATION CONTACT: For additional information concerning this action, contact Daniel Murray, Executive Director, Office of Operational Safety, via letter: 800 Independence Ave, SW, Washington, DC 20591; via email:

9-AST-Inquiries@faa.gov; via phone: (202) 267-7793.

2 An operator is a holder of a license or permit under 51 U.S.C. Subtitle V, chapter 509, but in this document it may also refer to an applicant applying for a license or permit.

Appendix A.

SUPPLEMENTARY INFORMATION: The Commercial Space Launch Act of 1984, as amended and codified at 51 U.S.C. §§ 50901-50923, authorizes the Department of Transportation, and the FAA through delegation, to oversee, license, and regulate commercial launch and reentry activities, and the operation of launch and reentry sites as carried out by U.S. citizens or within the United States. The FAA, through regulations, exercises this responsibility consistent with public health and safety, safety of property, and the national security and foreign policy interests of the United States.

51 U.S.C. 50905. To satisfy the FAA regulations, operators may use a means of compliance that has already been accepted by the FAA or propose an alternate approach.

For flexibility, the FAA regulations3 allow an operator to demonstrate that an alternative approach provides an equivalent level of safety to a regulatory requirement.

I. Background.

Unless otherwise addressed in agreements with the site operator, for overflight of navigable water, 14 CFR § 450.147(a)(2) requires an operator to provide a written agreement with the USCG or other applicable maritime authority establishing procedures for the issuance of a NOTMAR prior to a launch or reentry and other measures necessary to protect public health and safety. Section 450.147(b) requires the agreement to clearly delineate the roles and responsibilities of each party to support a safe launch or reentry. The FAA requires a similar agreement between the applicant and USCG in §§ 420.31(a), 431.75(b)(l), and 437.63(b)(l) that establishes procedures for the issuance of a NOTMAR.4 Furthermore, under part 417, which sets forth the safety requirements for launch of an expendable launch vehicle, § 417.111(i)(5) requires an operator to describe its procedures to provide hazard information and communicate with the local USCG office to ensure that a NOTMAR is issued.

In the past, operators complied with this requirement by entering into a Memorandum of Agreement (MOA) with the USCG for the issuance of a NOTMAR. The USCG recently advised the FAA that it will no longer enter into MOAs with commercial entities due to restrictions on its legal authority. In order to ensure that operators can continue to meet the requirement for an agreement with the USCG regarding procedures for NOTMAR issuance, the FAA and USCG have developed an LOI template that will serve as a means of compliance with the FAA regulations requiring such an agreement between the applicant and USCG.

3 Sections 417.1, 420.1, 431.1, 435.1, 437.1, and 450.37 of title 14 of the Code of Federal Regulations provide applicants an option to demonstrate an equivalent level of safety to the requirements in parts 417 (Launch Safety), 420 (License to Operate a Launch Site), 431 (Launch And Reentry Of A Reusable Launch Vehicle), 435 (Reentry Of A Reentry Vehicle Other Than A Reusable Launch Vehicle), 437 (Experimental Permits), and 450 (Launch and Reentry License Requirements). An applicant for a license or permit to conduct a launch or reentry or to operate a launch or reentry site must demonstrate compliance with the requirements of the aforementioned parts of 14 CFR unless the applicant clearly and convincingly demonstrates that an alternative approach provides an equivalent level of safety to the requirement.

4 Section 43l.75(b)(l) also applies to a reentry per§ 435.51. In addition to the requirements of part 433, per § 413.13, the FAA identified additional information necessary (similar to § 420.31(a)) for a determination that public health and safety, safety of property, and national security and foreign policy interests of the United States are protected during operation of a reentry site.

Appendix A.

II. Discussion of the Policy.

The FAA's policy with respect to use of the template LOI to satisfy the requirement for an agreement with the USCG for NOTMAR issuance is as follows:

1. The LOI is a means of compliance with FAA regulations requiring a written agreement for issuance of a NOTMAR5 because it expressly provides for NOTMAR issuance by the USCG and contains the same information and coordination requirements previously required of operators under MOAs. The LOI template delineates the roles and responsibilities of the operator and USCG to support safe launch or reentry to the same extent as the MOAs previously used to meet this requirement.

2. If additional measures beyond NOTMAR issuance are deemed necessary to protect public health and safety under 14 CFR § 450.147(a)(2), § 420.31(a), or § 431.75(b)(l), the FAA may accept a version of this LOI specifying all such additional measures as a separate means of compliance or make an equivalent level of safety determination as necessary. The template also contains the language embodied in past MOAs regarding the USCG's intent to conduct a risk assessment to determine what, if any, assets are appropriate to ensure public safety during a launch or reentry.

An applicant may submit an LOI that follows the attached template to demonstrate compliance with the following regulations requiring a written agreement with the USCG that establishes procedures for NOTMAR issuance: 14 CPR § 417.111(i)(S), § 420.3l(a), § 43l.75(b)(l), § 437.63(b)(l), and § 450.147(a)(2). If additional measures beyond NOTMAR issuance are necessary to protect public health and safety under 14 CFR § 450.147(a)(2), § 420.3l(a), or § 43l.75(b)(l), the FAA may accept an LOI that follows the attached LOI template and includes such additional measures as an alternate means of compliance or as an equivalent level of safety to those regulations as appropriate.

The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. It is intended only to provide clarity to the public regarding existing requirements under the law and agency policies.

5 14 CFR § 417.ll l{i)(5), § 420.3l{a), § 431.75(b){l), § 437.63(b)(l}, and§ 450.147(a)(2).

Appendix B.

Appendix B. Letter of Intent B.1 LETTER OF INTENT (LOI) TEMPLATE The following is a copy of the Letter of Intent template for a commercial space operator’s use in providing information regarding their intent to conduct launch and reentry operations to the appropriate Coast Guard District to ensure the safety of the Maritime Domain.

The updated version of the LOI template is located here:

https://www.faa.gov/space/legislation_regulation_guidance

LETTER OF INTENT FOR COMMERCIAL SPACE ENTITY TO PROVIDE INFORMATION RELATED TO [LAUNCH AND REENTRY OPERATIONS] [AND] [LAUNCH AND REENTRY SITE OPERATIONS] TO THE UNITED

STATES COAST GUARD RELEVANT AREA AND APPROPRIATE COAST GUARD

DISTRICT TO ENSURE SAFETY OF THE MARITIME DOMAIN

1. BACKGROUND.

a. 14 C.F.R. Chapter III requires Commercial Space Operators to coordinate with the U.S. Coast Guard to establish procedures for the issuance of a Notice to Mariners and any other measures the Coast Guard deems necessary to protect public health and safety, prior to any launch or reentry activity licensed by the FAA that overflies or affects Navigable Waters. The U.S. Coast Guard’s authority to regulate Navigation and Navigable Waters is implemented in 33 C.F.R. Chapter I.

b. [Commercial Space Entity] has applied for a [license/permit] from the FAA to [conduct a launch / reentry or operate a launch / reentry site] at [location] under 14 CFR [insert applicable part]. Briefly describe operations, nexus with USCG, and USCG Districts affected.

2. PURPOSE. This Letter of Intent is in response to a request made to the U.S. Coast Guard Relevant Area from Commercial Space Entity to establish procedures for issuance of Notices to Mariners [Optional: and provide resources in support of its operations [currently planned for] [on or about] [date] from [location],] including launch, reentry, and recovery efforts involving a [rocket type] that may affect the safety and security of the maritime domain]. The U.S. Coast Guard intends to exercise its statutory authorities and responsibilities to safeguard the maritime transportation system, public safety, and marine environment with regard to these activities, and consistent with its statutory authority, will issue Notices to Mariners in its discretion. This Letter of Intent does not address Air Traffic Control procedures, nor does it cover other notifications required for launch operations.

Appendix B.

3. SCOPE. The information contained herein establishes Coast Guard Relevant Area’s intent to issue Notices to Mariners in its discretion and monitor Commercial Space Entity’s launch/reentry operations activity within the Relevant Area’s area of responsibility to ensure safety and security of the maritime domain.

The U.S. Coast Guard’s intent is specific to the locations and proposed operations of the subject launch/reentry areas and is designed to establish Coast Guard conditions and coordination procedures for launch/reentry operations.

4. ABBREVIATIONS & DEFINITIONS.

a. Abbreviations:

i. AST Office of Commercial Space Transportation ii. BNM Broadcast Notice to Mariners iii. COTP Coast Guard Captain of the Port iv. FAA Federal Aviation Administration

v. GMT Greenwich Mean Time vi. LAA Limited Access Area vii. LNM Local Notice to Mariners viii. NAVTEX NAVigation TEleX ix. NGA National Geospatial-Intelligence Agency

x. NSRA Navigation Safe ty Risk Assessment xi. RLV Reusable Launch Vehicle

b. Definitions:

i. Captain of the Port (COTP): Captains of the Port and their representatives enforce, within their respective areas, port safety and security and marine environmental protection regulations. These regulations include, without limitation, the following: the protection and security of vessels, harbors, and waterfront facilities; anchorages; security zones; safety zones; regulated navigation areas; deep water ports; water pollution; and ports and waterways safety.

ii. Limited Access Area (LAA): Tool used to control movement of marine traffic and limit access to all or a portion of the waterway to provide safety and security for mariners, vessels, and maritime critical infrastructure, and manage the use of navigable waterways for commerce and environmental protection. LAAs could be a tool used to mitigate risks identified through a Navigation Safety Risk Assessment (NSRA).

iii. U.S. Coast Guard District: A Coast Guard District Commander is in command of a Coast Guard District and the District Commander’s office may be referred to as a Coast Guard District Office. For the purposes of this letter of intent, the “Local U.S. Coast Guard District” refers to the Relevant USCG District(s) and location (City, State).

Appendix B.

iv. Navigation Safety Risk Assessment (NSRA): Tool used by the COTP when preparing input for the permitting agency regarding port or waterway safety issues associated with a project located on, over, or near the navigable waters of the United States. The assessment helps the COTP identify potential navigation risks and is the basis of any recommendation to the permitting agency.

v. Navigable Waters of the United States (navigable waterway): Navigable Waters refers to the territorial seas of the United States (all waters seaward of the baseline to 12 nautical miles (NM)); internal waters of the United States that are subject to tidal influence; internal waters of the United States not subject to tidal influence, but that are or have been used, are or have been susceptible for use, as highways for substantial interstate or foreign commerce, have been determined by a governmental or non-governmental body, having expertise in waterway improvement, that they are capable of improvement to constitute highways for substantial interstate or foreign commerce; and other waters over which the Federal Government may exercise Constitutional authority. See 33 C.F.R. § 2.36(a).

vi. NAVTEX: The International Maritime Organization has designated NAVTEX as the primary means for transmitting coastal urgent marine safety information to ships worldwide. In the United States, NAVTEX is broadcasted from Coast Guard facilities. NAVTEX is part of the Global Maritime Distress and Safety System, which has been incorporated into the International Convention for the Safety of Life at Sea, 1974, to which the United States is a party. All NAVTEX broadcasts are made on 518 kHz, using narrow-band direct printing 7- unit forward error correcting transmission.

vii. Notice to Mariners:

a. Broadcast Notice to Mariners (BNM): Broadcast Notice to Mariners is the method by which important navigation safety information is disseminated in the most expedient manner. Two agencies within the United States, the U.S. Coast Guard and the National Geospatial-Intelligence Agency (NGA), are responsible for broadcasting navigation information. Each agency has a particular geographic area of responsibility.

i. USCG: Broadcast Notice to Mariners are issued via voice and NAVTEX. As a general rule, VHF-FM voice broadcasts will contain all information that applies to inland waters and seaward to 20 nautical miles. Medium frequency (MF) broadcasts (out to 100 nautical miles) and high frequency (HF) broadcasts (out to 200 nautical miles), delivered via NAVTEX, duplicate the VHF-FM broadcasts.