PHMSA Response Letter

---

Nov 21, 2005

Mr. Jack Hagenmayer                     Reference No. 05-0178

Senior Director, Aircraft Ground Services
Air Transport International, LLC
One Air Cargo Parkway East
Swanton, OH 43558-9490

Dear Mr. Hagenmayer:
This is in response to your June 30, 2005 email requesting clarification of quantity limitations of hazardous materials aboard aircraft under the Hazardous Materials Regulations (HMR; 49 CFR Parts 100-180). Specifically, you state that your company transports unit load devices in the main deck cargo compartment, which, when loaded, with hazardous materials, are inaccessible to the flight crew. You ask whether unit load devices transporting hazardous materials in this manner are permitted aboard aircraft.

As specified in § 175.75, no person may carry on an aircraft more than 25 kg (55 pounds) net weight of hazardous materials and in addition thereto, 75 kg (165 pounds) net weight of Division 2.2 (non-flammable compressed gas) of hazardous materials permitted to be carried aboard passenger-carrying aircraft in: (1) an inaccessible cargo compartment; (2) any freight container within an accessible cargo compartment; or (3) any accessible cargo compartment in a cargo aircraft only in a manner that makes it inaccessible unless in a freight container. If the cargo compartment is accessible, 49 CFR 175.75(a)(2)(ii) permits 25 kg of hazardous materials (reference to the Division 2.2 limit will be ignored for the sake of simplicity) in each freight container, regardless of the number of containers in the compartment. If the cargo compartment is inaccessible, the 25 kg limit applies to the cargo compartment.

I trust this satisfies your inquiry.

Sincerely,

John A. Gale
Chief, Standards Development
Office of Hazardous Materials Standards

175.75 (a)(2)