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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #22-0003

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Ordnance Lab LLC

Individual Name: Sean Lindley

Location State: TX Country: US

View the Interpretation Document

Response text:

April 14, 2022

Sean Lindley
Manager
Ordnance Lab LLC
P.O. Box 295 
Three Rivers, TX  78071

Reference No. 22-0003

Dear Mr. Lindley:

This letter is in response to your January 12, 2022, email and subsequent email correspondence requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to transportation of Division 1.1 explosive devices onboard an aircraft. Specifically, you describe a scenario in which Division 1.1 explosive devices would be loaded aboard a rotorcraft. The rotorcraft would transport the explosives over an explosive testing range, where the explosives would be dropped to observe their explosive effects. The flight of the rotorcraft with explosives on board would occur solely over contiguous private property, to which public access is restricted.

We have paraphrased and answered your questions as follows:

Q1. You ask whether the HMR apply to aircraft loaded with Division 1.1 explosive devices and flown above contiguous private property, to which public access is restricted. You note that the purpose of the flight is to employ the explosives on an explosive testing range, not to deliver them from one location to another.

A1. The answer is yes. The HMR apply to the transportation of hazardous materials in commerce, i.e. in support of a commercial enterprise. Section 171.1(d)(4) specifies that rail and motor vehicle transportation of a hazardous material within a contiguous facility to which public access is restricted is not subject to the requirements of the HMR. However, the transportation of a hazardous material onboard an aircraft in support of a commercial enterprise—even over a contiguous facility to which public access is restricted—is subject to the HMR.

Q2. You ask whether there is a self-executing or default exception that would allow your company to conduct the proposed activities without direct approval from the Department of Transportation if the exception under § 171.1(d)(4) does not apply to this activity.

A2. The answer is no. The HMR forbid transportation of Division 1.1 explosive devices aboard passenger and cargo aircraft. You must obtain a Department of Transportation special permit (DOT SP) from PHMSA authorizing a variance from this restriction before performing the described activity. Additionally, if the use of aircraft includes explosives as an external load operation, you must receive an approval from the PHMSA Associate Administrator for Hazardous Material Safety in accordance with § 175.9(a).

Q3. You ask whether the applicability of the HMR is dependent upon the 14 CFR operational authority for the flight—e.g., if the aircraft is operated under 14 CFR Part 91 as a private general aviation flight—or 14 CFR Part 135 as a chartered aircraft.

A3. The answer is no. The HMR apply to the transportation of hazardous materials in commerce. "Commerce" is defined in § 171.8 as "trade or transportation in the jurisdiction of the United States within a single state; between a place in a state and a place outside of the state; that affects trade or transportation between a place in a state and place outside of the state; or on a United States-registered aircraft." The 14 CFR operational authority under which the flight occurs is not a factor in determining whether the HMR apply to hazardous materials being transported in furtherance of a commercial enterprise.

Q4. You ask whether your company, as the owner of the explosive materials, would be able to secure authorization to conduct the described activity or, alternatively, if the aircraft operator is required to secure any necessary authorizations.

A4. The answer is that both your company and the aircraft operator may need to receive authorization in the form of a DOT SP and/or approval from the PHMSA Associate Administrator for Hazardous Material Safety. As noted above, Division 1.1 explosive devices are forbidden for transportation aboard passenger or cargo aircraft, including rotorcraft. Either your company—as the owner and offeror of the explosives—or the air operator acting as the carrier, may seek a special permit to authorize the transportation of Division 1.1 explosive devices aboard an aircraft. The approval required in § 175.9 for rotorcraft external load operations, if applicable in this scenario, is typically issued to the rotorcraft operator.

Q5. You ask what specific authorizations would be required from the Department of Transportation for the proposed operations.

A5. The answer is dependent on the specific details of the operation. As noted previously, you may require both a DOT SP for the transportation of a Division 1.1 explosive devices aboard an aircraft and a § 175.9 approval for rotorcraft external load operations from PHMSA. Additionally, FAA requirements will apply to this proposed operation. We suggest you engage with the FAA Office of Security and Hazardous Material Safety and the FAA Flight Standards District Office with jurisdiction over your area prior to engaging in the proposed flight.

Finally, you note that you are interested in eventually conducting the described operation with an Unmanned Aerial System (UAS) in place of a manned rotorcraft. Please be aware that as described, transportation of the explosives aboard a United States-registered UAS in support of a commercial enterprise is subject to the requirements of the HMR, as well as all applicable FAA requirements and restrictions. Specifically, please be aware that you will need to seek an FAA Section 363 Letter of Authorization.

I hope this information is helpful. Please contact us if we can be of further assistance.

Sincerely,

Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

171.1(d)(4), 171.8, 175.9, 175.9(a)

Regulation Sections

Section Subject
171.1 Applicability of Hazardous Materials Regulations (HMR) to persons and functions
171.8 Definitions and abbreviations
175.9 Special aircraft operations