Safety Recommendation A-96-030

Notation 6704D: The National Transportation Safety Board has reviewed the Research and Special Programs Administration (RSPA) notice of proposed rulemaking (NPRM), “Hazardous Materials Regulations: Transportation of Compressed Oxygen, Other Oxidizing Gases and Chemical Oxygen Generators on Aircraft,” Docket No. RSPA-04-17664 (HM-224B), which was published at 69 Federal Register 88 on May 6, 2004.

The Safety Board notes that RSPA previously issued regulations addressing the transportation of chemical oxidizers and compressed oxygen cylinders aboard aircraft on August 19, 1999, under docket HM-224A. Under that rulemaking, RSPA amended the Hazardous Materials Regulations by requiring that no more than a combined total of six compressed oxygen cylinders be stowed in inaccessible cargo compartments that were not equipped with fire or smoke detection systems and fire suppression systems.

The amendments also required that no more than six compressed oxygen cylinders and one cylinder of medical-use compressed oxygen per passenger be carried in a crew-accessible cargo compartment equipped with a fire or smoke detection system but not a fire suppression system. Every compressed oxygen cylinder was also required to be placed in an overpack or outer packaging that met Air Transport Association (ATA) specifications for a 300 Type 1 container. According to RSPA, testing by the Federal Aviation Administration indicated that these shipping containers provided an “incremental” level of thermal protection.

Finally, the amendments prohibited the transportation of any other package containing an oxidizing material in an inaccessible cargo compartment that did not have a fire or smoke detection system or fire suppression system.

The Safety Board notes that, in this NPRM under docket HM-224B, RSPA proposes to require that overpacks or outer packaging for cylinders of compressed oxygen and chemical oxygen generators not only meet the specifications for an ATA 300 Type I container, but also meet the same flame penetration resistance standards that are required for cargo compartment sidewalls and ceiling panels in transport-category aircraft. The outer packaging must also provide certain thermal protection capabilities so as to retain its contents during an otherwise controllable cargo compartment fire.

The Board also notes that if these new standards are adopted, RSPA would remove the present limitation on the number of cylinders of compressed oxygen that may be transported in cargo compartments that are not equipped with a fire suppression system.

The Safety Board has reviewed the flame penetration resistance standards and believes that overpacks meeting these standards will provide an improved level of protection for compressed oxygen cylinders. However, the Board believes that RSPA should not remove the present limits on the number of compressed oxygen cylinders that may be transported until sufficient data on the performance and durability of the new overpacks are collected, analyzed, and proved to provide adequate protection with regular use.

The Safety Board also notes that RSPA is proposing to revise requirements for pressure relief devices on compressed oxygen cylinders to reduce the release of oxygen when the cylinder is exposed to fire, and to prohibit the transportation of all other oxidizing gases aboard cargo and passenger aircraft. The Safety Board notes that RSPA is also proposing new standards that would require chemical oxygen generators without any packaging to withstand a drop test without actuation or loss of contents, and to have one of four designated features to prevent inadvertent activation.

RSPA also proposes to require chemical oxygen generator overpacks that meet the same flame and thermal resistance standards as would be required for compressed oxygen cylinders overpacks.

The Safety Board believes that these proposed amendments would enhance the safe transportation of hazardous materials by air and therefore supports the rulemaking as noted. The Safety Board appreciates the opportunity to comment on this proposed rulemaking. If additional clarification or information is needed regarding our comments, please feel free to contact us.

On February 12, 1998, the FAA issued a final rule to upgrade the fire safety standards for cargo or baggage compartments in certain transport-category airplanes by eliminating Class D compartments as an option for future type certification. The Class D compartments in certain transport category airplanes manufactured under existing type certificates and used in passenger service were required to meet the fire or smoke detection and fire suppression standards for Class C compartments by March 2001.

The Class D compartments in certain transport category airplanes manufactured under existing type certificates and used only for the carriage of cargo were also required to meet such standards or the corresponding standards for Class E compartments by the same date. The FAA's elimination of Class D cargo compartments effectively removes any need for RSPA to take action. Therefore, Safety Recommendation A-96-30 is classified "Closed-No Longer Applicable" for the RSPA.

ALTHOUGH THIS ACTION APPEARS TO MEET THE INTENT OF THE SAFETY RECOMMENDATION, THE SAFETY BOARD IS CONCERNED ABOUT OXIDIZING MATERIALS NOT COVERED BY THE FINAL RULE. A-96-30 INCLUDED THE PROHIBITION OF OXIDIZING MATERIALS (FOR EXAMPLE, NITRIC ACID) NOT CLASSIFIED AS A DIVISION 5.1 "OXIDIZER." HOWEVER, THE FINAL RULE ONLY AFFECTS THE TRANSPORTATION OF DIVISION 5.1 MATERIALS. ON 10/17/97, IN COMMENTS SUBMITTED TO RSPA IN RESPONSE TO SUPPLEMENTAL NOTICE OF PROPOSED RULEMAKING, DOCKET NO. HM-224A (WHICH WAS PART OF THE REGULATORY DEVELOPMENT PROCESS FOR THE 8/19/99, FINAL RULE), THE BOARD NOTED CONCERNS ON OXIDIZING MATERIALS NOT CLASSIFIED AS AN OXIDIZER.

THE SAFETY BOARD'S CONCERNS INCLUDED THE FOLLOWING: *NITRIC ACID. LESS THAN CONCENTRATED OR FUMING NITRIC ACID IS PERMITTED ON CARGO-ONLY AIRCRAFT. *DICUMYL PEROXIDE. THE PREAMBLE OF THE FINAL RULE INDICATES THAT ORGANIC PEROXIDES ARE OUTSIDE THE CONTEXT OF THIS RULEMAKING. HOWEVER, ORGANIC PEROXIDES ARE A SUBGROUP WITHIN CLASS 5 "OXIDIZING SUBSTANCES." *OXIDIZERS SHIPPED AS CONSUMER COMMODITIES, ORM-D. THE PREAMBLE INDICATES THAT THESE OXIDIZERS WILL NOT BE PROHIBITED BECAUSE RSPA BELIEVES THAT THESE OXIDIZERS ARE OF A FORM AND QUANTITY THAT WILL NOT POSE AN UNACCEPTABLE RISK TO THE SAFETY OF AN AIRCRAFT, EVEN IN CARGO COMPARTMENTS THAT LACK A FIRE AND SMOKE DETECTION SYSTEM.

ALTHOUGH THE PREAMBLE TO THE FINAL RULE NOTES THE SAFETY BOARD'S CONCERNS WITH REGARD TO OXIDIZING MATERIALS AND INDICATES THAT RSPA DOES NOT BELIEVE THAT THE EXCEPTIONS IN THE RULE REPRESENT A SAFETY HAZARD, NO ANALYSIS IS PRESENTED TO JUSTIFY THIS BELIEF. THE 8/19/99, FINAL RULE ALSO PROVIDES EXCEPTIONS TO THE PROHIBITION OF CYLINDERS CONTAINING COMPRESSED OXYGEN, SUBJECT TO NEW PACKAGING AND STOWAGE REQUIREMENTS AND LIMITS ON THE NUMBER OF CYLINDERS.

THE RULE REQUIRES OXYGEN CYLINDERS TO BE PLACED IN AN OVERPACK MEETING THE PERFORMANCE CRITERIA IN AIR TRANSPORT ASSOCIATION SPECIFICATION 300 BEFORE TRANSPORTING THESE CYLINDERS IN CARGO COMPARTMENTS THAT DO NOT HAVE FIRE OR SMOKE DETECTION SYSTEMS. THE PREAMBLE OF THE FINAL RULE DISCUSSES TESTING PERFORMED THAT INDICATES THAT THE OVERPACKS PROVIDE SUFFICIENT THERMAL PROTECTION TO THESE CYLINDERS TO DELAY THE OPENING OF THEIR PRESSURE RELIEF DEVICES FOR AT LEAST 1 HOUR. THE RULE FAILS TO JUSTIFY THE SIGNIFICANCE OF THIS 1 HOUR TIME PERIOD AS IT RELATES TO A CARGO COMPARTMENT THAT DOES NOT HAVE FIRE OR SMOKE DETECTION SYSTEMS.

PENDING ISSUANCE OF A REGULATION THAT PROHIBITS CARRYING OXIDIZING MATERIALS (LIKE THE TYPES DESCRIBED ABOVE) IN CARGO COMPARTMENTS OF AIRCRAFT THAT DO NOT HAVE FIRE AND SMOKE DETECTION SYSTEMS AND CARRYING OF COMPRESSED OXYGEN CYLINDERS IN CARGO COMPARTMENTS OF AIRCRAFT THAT DO NOT HAVE FIRE AND SMOKE DETECTION SYSTEMS, OR A JUSTIFICATION THAT 1 HOUR IS A SUITABLE PERIOD OF THERMAL PROTECTION FOR OXYGEN CYLINDERS, A-96-30 IS CLASSIFIED

Letter Mail Controlled 9/29/99 4:30:12 PM MC# 991089 RSPA PUBLISHED A FINAL RULE IN THE FEDERAL REGISTER ON 8/19/99 (64FR 45388; DOCKET HM-224A). THIS FINAL RULE PROHIBITS THE CARRIAGE OF OXIDIZERS ON AIRCRAFT IN INACCESSIBLE CARGO COMPARTMENTS THAT DO NOT HAVE FIRE OR SMOKE DETECTION AND FIRE SUPPRESSION SYSTEMS. FOR THE REASONS SET FORTH IN THE FINAL RULE, NO CHANGES WERE MADE TO PROVISIONS FOR OXIDIZERS WHICH ARE RECLASSED AS CONSUMER COMMODITIES. ALSO, EXCEPTIONS TO THE PROHIBITION ARE PROVIDED FOR CYLINDERS CONTAINING COMPRESSED OXYGEN, SUBJECT TO NEW PACKAGING AND STOWAGE REQUIREMENTS AND LIMITS ON THE NUMBER OF CYLINDERS.

THE BOARD STATED THAT RSPA & THE FAA NEED TO EVALUATE THE EFFECTS OF AUTHORIZED HAZARDOUS MATERIALS IN FIRES IN CARGO COMPARTMENTS. IN RESPONSE TO THE 12/30/96 NPRM, THE BOARD SUPPORTED A STUDY INITIATED BY RSPA, IN COORDINATION WITH THE FAA, TO ASSESS THE RISKS ASSOCIATED WITH THE TRANSPORTATION OF HAZARDOUS MATERIALS IN AIRCRAFT CARGO COMPARTMENTS. THE BOARD AGAIN URGES RSPA & THE FAA TO COMPLETE THIS STUDY & TO BAN ANY HAZARDOUS MATERIALS, INCLUDING OXIDIZERS, THAT CANNOT BE SAFELY TRANSPORTED IN AIRCRAFT CARGO COMPARTMENTS. THE BOARD LOOKS FORWARD TO THE PUBLICATION OF THE FINAL RULE. PLEASE KEEP THE BOARD INFORMED OF YOUR SCHEDULE & PROGRESS.

A-96-30 IS CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

(Letter Mail Controlled 5/8/98 3:25:29 PM MC# 980596) WITH REGARD TO A-96-30, SEVERAL RULEMAKING ACTIVITIES UNDER DOCKET IIM-224A HAVE BEEN PUBLISHED. SPECIFICALLY, ON 8/20/97, RSPA PUBLISHED A SUPPLEMENTAL NOTICE OF PROPOSE RULEMAKING (62 FR 44375), PROPOSING TO PROHIBIT OXIDIZERS ABOARD AIRCRAFT. THE EFFECT OF THIS PROHIBITION WOULD BE TO LIMIT OXIDIZERS TO ACCESSIBLE LOCATIONS ON CARGO AIRCRAFT. THE COMMENT PERIOD FOR DOCKET HM-224A WAS REOPENED IN A NOTICE ON 11/28/97, (62 FR 63301) TO INVITE ADDITIONAL COMMENTS CONCERNING PROPOSALS TO PROHIBIT THE TRANSPORTATION OF OXIDIZERS IN PASSENGER-CARRYING AIRCRAFT & IN INACCESSIBLE LOCATIONS ON CARGO AIRCRAFT.

THE COMMENT PERIOD CLOSED ON 2/13/98.

Notation 6818: The National Transportation Safety Board has reviewed your Notice of Proposed Rulemaking (NPRM), Docket No. HM-224A, Prohibition of Oxidizers Aboard Aircraft, published on December 30, 1996. The notice proposes prohibiting the carriage of oxidizers, including compressed oxygen, in Class D compartments of passenger-carrying and cargo aircraft.

The notice further proposes eliminating an exception for the transportation of personal chemical oxygen generators as checked baggage, creating a shipping name that specifically identifies chemical oxygen generators, requiring special approval for chemical oxygen generators, and initiating a study to assess the risks associated with the transportation of hazardous materials, other than oxidizers, in aircraft cargo compartments.

The Safety Board has expressed concern about the inadequacies of Class D cargo compartments for some time. On August 8, 1984, the Federal Aviation Administration (FAA) issued a notice of proposed rulemaking, Notice 84-11, that addressed the problem of fire containment in cargo compartments by specifying a new test method for determining the flame penetration resistance of compartment liners.

When the Safety Board provided comments on this rulemaking on October 9, 1984, it advised the FAA that although proposed flame penetration tests were more stringent than previous ones, a fire should not be allowed to persist in any state of intensity in an airplane without the flight crew's knowledge, and that a fire detection system should be required in Class D cargo compartments. While the final rule issued on May 16, 1986, required improved flame penetration resistance for compartment liners, it did not require fire detection systems.

On October 24, 1988, as a result of a February 3, 1988, in-flight tire involving a hydrogen peroxide solution (an oxidizer) aboard an American Airlines DC-9-83 (flight 132) en route to Nashville Metropolitan Airport, Nashville, Tennessee, the Safety Board issued Safety Recommendation A-88-122, which urged the FAA to require fire/smoke detection systems for all Class D cargo compartments. The Safety Board stated that because the cargo compartment on flight 132 was not equipped with fire or smoke dctection systems, the cockpit crew had no way of detecting the safety threat to the airplane until smoke and fumes reached the passenger cabin.

Further, after the smoke was detected in the passenger cabin, the cockpit crew had no means of identifying the fire's location. On August 10, 1993, the FAA responded to Safety Recommendation A-88-l22 by stating that it did not believe that fire/smoke detection and fire extinguishment systems would provide a significant degree of protection to airplane occupants and that it had terminated its rulemaking action to require such systems. On October 14, 1993, Safety Recommendation A-88-122 was classified

THE BOARD NOTES THAT RSPA, WITH ADVICE FROM THE FAA, HAS INITIATED A RULEMAKING PROJECT TO PROJECT THE TRANSPORTATION OF OXIDIZERS IN CLASS D CARGO COMPARTMENTS ON BOTH PASSENGER & CARGO AIRCRAFT. THIS PROJECT ADDRESSES THE INTENT OF THE RECOMMENDATION & PENDING COMPLETION OF THE FINAL RULE A-96-30 IS CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

THE HAZARDOUS MATERIALS REGULATIONS CURRENTLY FORBID THE AIR TRANSPORTATION OF THE HIGHEST RISK OXIDIZING MATERIALS (INCLUDING NITRIC ACID) ON BOARD PASSENGER CARRYING AIRCRAFT. RSPA HAS IN PLACE EXTENSIVE REGULATIONS WHICH LIMIT THE AMOUNT OF PERMISSIBLE OXIDIZING MATERIALS THAT MAY BE CARRIED IN AIR TRANSPORTATION & WHICH SET REQUIREMENT FOR LABELING, PACKAGING, & HANDLING OF THESE MATERIALS. THIS REGULATORY SCHEME GREATLY REDUCES THE RISKS ASSOCIATED WITH THE TRANSPORTATION OF THESE MATERIALS.

HOWEVER, BECAUSE OF THE ISSUES RAISED CONCERNING THE TRANSPORTATION OF OXIDIZERS BY AIR, RSPA, WITH ADVICE FROM THE FAA, HAS INITIATE A RULEMAKING PROJECT TO PROPOSE A PROHIBITION OF THE TRANSPORTATION OF OXIDIZERS IN CLASS D CARGO COMPARTMENTS ON BOTH PASSENGER & CARGO AIRCRAFT. ADDITIONALLY, THE FAA WILL INITIATE A SEPARATE RULEMAKING PROJECT TO REQUIRE AIR CARRIERS TO CLEARLY LABEL THE CARGO COMPARTMENTS AS CLASS C OR D. IT IS ANTICIPATED THE NOTICE OF PROPOSED RULEMAKING WILL BE PUBLISHED BY OCTOBER 1996. WE ARE ALSO EXAMINING THE CURRENT REGULATIONS AUTHORIZING OTHER CLASSES OF HAZARDOUS MATERIALS ABOARD AIRCRAFT. WE WILL KEEP THE BOARD APPRISED OF THE PROGRESS ON THESE PROJECTS.