A Little-known and Surprisingly Strict Private Standard: NFPA 408
One of the comments the FAA never formally responded to was a suggestion that the agency adopt a private standard for hand-held aircraft fire extinguishers, NFPA 408. That the FAA did not do so is not surprising—government regulators often look on private standards with disfavor. What seems unusual is that the FAA (at least the staff member in charge of drafting the standard on fire extinguishers) was unaware of the existence of NFPA 408 until the agency received the suggestion (which, incidentally, came from NFPA). Ignorance in this instance was a function of poor communication within the FAA and, more broadly, of the waning influence of private, industrywide aviation safety standards.
As with several other areas of regulation, aviation safety used to be addressed entirely by the private sector. When NFPA first got involved in the subject, government regulation was minimal, and the future of private aviation regulation looked promising. Responding to requests from the National Aircraft Underwriters' Association, UL formed an Aviation Department in 1920, and two years later it started offering a service that the FAA would later take over: certifying the airworthiness of aircraft. Insurance groups, interested in standards to use in making
underwriting decisions, asked the NFPA to develop various aviation standards.
NFPA is a membership organization similar to the American Society for Testing and Materials. "Volunteer" committees write the 260 NFPA codes and standards, and the membership at large votes on various standards at semiannual meetings. NFPA has over thirty-two thousand members, including architects, engineers, firemen, and representatives of manufacturers, insurance interests, labor, and government.
One of the standards NFPA developed in the aviation area was NFPA 408, which contained recommendations concerning the "type, capacity, location and quantity of aircraft hand fire extinguishers and accessory equipment provided essentially for the protection of aircraft compartments occupied by passengers and crew. It was drafted between 1947 and 1955 by a technical subcommittee of NFPA's Aircraft Rescue and Firefighting Committee. The group had twenty-four members, including seven from government agencies in the United States and Canada, six from commercial airlines, two from academia, and one each from UL and UL of Canada. NFPA 408, with appendices, was less than six pages long. It provided information on the two most prevalent types of extinguishers (dry chemical and water) and mandated that airlines carry one small extinguisher in the cockpit and, depending on occupancy, between one and three in the passenger compartment. The standard also set forth a suggested training outline on the use of fire extinguishers. Unfortunately, NFPA has no record of how these specific provisions were developed. (Only in recent years have comments and committee minutes routinely been retained.)
Over time, interest in private, industrywide aviation safety standards diminished—at least in this country. The Civil Aeronautics Board, predecessor to the FAA, displaced UL's entire Aviation Department. Insurers began using compliance with the FAA's airworthiness standards as a condition of insurance. As technology became more complicated, airframe manufacturers (for example, Boeing, Lockheed, McDonnell-Douglas) assumed much of the responsibility earlier undertaken by commercial carriers. Currently, "most carriers will accept what the airframe manufacturer offers," according to the fire protection engineer at the only major airline to employ one.
This apathy affected NFPA 408. Although reissued in 1965, 1970, and 1973, the standard was largely unchanged from its original version. The main reason, suspects a current member of the Aircraft Rescue and Firefighting Committee, is expressed by the adage about letting sleeping
dogs lie: "There had never been a demonstrated problem warranting attention." There also was little interest in such standards among domestic airlines and airframe manufacturers. The in-house standards at Boeing were more important than NFPA 408. The primary interest in NFPA 408, and in many of NFPA's other aviation safety standards, was from foreign countries. As one committee member put it, "There is no FAA in Greece." Many foreign governments thus look to these standards for guidance. But the foreign contingent on the committee did not attend meetings regularly, and many lacked sufficient technical background to suggest improvements. Moreover, given the limited demand for the standard, NFPA 408 generated almost no income for NFPA. (The sale of publications accounts for two-thirds of NFPA's income.) But NFPA 408 is one of many NFPA standards offered more as a public service than as a money-making proposition, and at times these standards suffer from lack of attention.
NFPA 408 languished in the late 1970s when changes in technology rendered it out of date (it did not take into account the new jumbo jets, which could hold over three hundred passengers). The relevant provision in the 1973 version (for occupancies "over 61 passengers") called for three fire extinguishers. "An airframe manufacturer would never provide so few extinguishers [for a jumbo jet]," notes an NFPA committee member. Halgonated extinguishing agents also came into use in the 1970s, but NFPA 408 made only a passing reference to them. The 1973 version still allowed carbon dioxide extinguishers, which had long since fallen out of favor with most fire protection engineers because of the damage they can do to electrical equipment.
The 1980 Revival of NFPA 408
The Standards Council, the general oversight group within NFPA, recognized the problem in 1980, when nine aviation safety standards, including NFPA 408, were overdue for revision and reissue. The chairman of the Technical Committee on Aircraft Rescue and Firefighting considered 408 so inadequate that he proposed that NFPA withdraw it and start over from scratch. Withdrawing the standard as outdated was not in the interest of the Standards Council, however, which seeks to protect NFPA's reputation and is aware that the organization obtains its income largely from the sale of standards. Even though the income from this standard is minimal, it is in NFPA's general interest to keep its standards available. The Standards Council instructed the committee to
expedite the process of bringing the standard up to date. A technical subcommittee met several times in the following year and drafted a new version. The new standard included changes in the number of extinguishers required, the type of extinguishers, and the nature of employee training. All of these changes were in the direction of being more stringent, although a few were left as suggestions rather than stated as requirements. Most significant, however, the basic requirements of NFPA 408 were more demanding than what the FAA eventually required.
The most significant and costly provision in NFPA 408 specifies the number of extinguishers required. The revised version requires more than twice the number specified in the old version—and more if necessary, to ensure that there is an extinguisher within thirty feet of any passenger. How did the subcommittee choose these numbers? By doing for aviation safety what the 61B committee would not do for grain elevator safety: a combination of guesswork and fire protection rules of thumb. "If you are asking whether it is like Newton's law, where we can categorically support the conclusion, the answer is no," explained an engineer on the committee. There was surprisingly little disagreement among committee members, however, concerning the specific numbers chosen. Most members, even those representing the airlines, took the general view that the standard should err on the side of safety. In this respect, NFPA 408 reflects the professional norms of aviation safety engineers, who frequently rely on significant margins of safety. The margin of safety in the revised version is more than adequate. This standard is unlikely to produce benefits in excess of costs, however. A candid NFPA staff member admitted that this is probably true of all NFPA aviation safety standards.
The revised version of NFPA 408 also takes into account recent changes in extinguishant technology. The standard prohibits carbon dioxide extinguishers. (The FAA still allows them.) NFPA 408 also specifically requires, for the first time, the use of Halon 1211 extinguishers. Several key committee members knew that Halon 1211 is an extremely effective extinguishant. The toxicity question, raised by several airlines in response to the FAA's general notice, was not a sticking point. Most members consider these concerns exaggerated and inappropriate. "You have to put out the fire before you start worrying about toxicity," explained one member. There was minor disagreement about which Halon agent to require, but the idea of Halon was endorsed largely on the recommendation of the committee's engineers. Represen-
tatives of companies that manufacture such extinguishers naturally supported the idea as well, but those firms make all types of extinguishers and have no particular stake in Halon.
Flexible Nozzles and Special Training
The Technical Committee on Aircraft Rescue and Firefighting considered two other issues to be important—flexible nozzles for extinguishers and special training for the use of Halon—but they acted in a markedly less decisive manner on both. On flexible nozzles, the fire protection engineer from a major airline made a convincing case that extinguishers would be much more effective with this design change. He conducted tests that indicated that models with a flexible hose could be almost ten times more effective than current models in aviation use. The committee was largely unmoved, however, and simply changed the standard to permit flexible hoses but not require them. An appendix section advises that "for access to underseat, overhead, and other difficult to reach locations consideration should be given to using extinguishers with a discharge hose."
This seemingly timid approach is a product of the tangled web between installation standards (such as NFPA 408) and product standards (such as UL's). NFPA does not write product standards per se. It does, however, specify some performance characteristics for products. This creates an awkward relationship with the product standards written by such organizations as UL. Sometimes performance characteristics are closely linked to basic product specifications. For example, requiring high enough temperature tolerances for a chimney necessitates that it be made of metal, not masonry. In some instances, NFPA's requirements seem to drive UL's standards; in others, the UL standard appears to control the NFPA standard. The situation is often compared to the proverbial chicken-and-egg problem. In the case of fire extinguishers, however, it is clear which came first: UL did.
Realistically, NFPA can require something different from UL only when it is sure that UL will change accordingly. This is practically assured when the NFPA standard affects a substantial share of the certification market. But in the case of aircraft fire extinguishers, the NFPA standard affects a minuscule portion of the market regulated by UL. Not only does UL feel little pressure to change its fire extinguisher standard to satisfy the special concerns of aviation use; it foresees a
limited reward for the effort as well. The market for aviation fire extinguishers is too small.
The generic UL standard for fire extinguishers continues to take precedence over any NFPA requirements in 408. UL tests extinguishers under specific conditions and certifies them with different ratings. NFPA 408 depends on these standards to define the capabilities of the fire extinguishers required by NFPA standards. What UL requires is not necessarily what NFPA would choose for aviation use. UL does not require a flexible hose on small hand-held extinguishers, for example. Nor does it require a discharge time of more than eight seconds for the typical small Halon extinguisher. A United Airlines engineer thinks that twelve to fourteen seconds would be much more desirable. And flexible nozzles are clearly a major improvement over fixed nozzles for aviation use.
The other technical issue considered, but skirted, by NFPA involved the training requirements for using Halon extinguishers. The committee settled on a vague requirement that "training shall provide classroom instruction and manipulative skills training." The appendix removes the teeth from this provision, however, by adding that "it is highly recommended that live fire training on representative aircraft fires be conducted … [but this is] not required by this standard."
The mild-mannered approach to this provision also stands in contrast to the other more stringent provisions of 408. It reflects in part NFPA's reluctance to specify training requirements and in part the resistance of the airlines to a significant and recurring expense. The representative of Factory Mutual, who had recently conducted a study of hand-held fire extinguishers under contract to the FAA, recalls that the importance of training costs was repeatedly mentioned by those he surveyed. Fire safety experts agreed that training in realistic test situations would be costly. NFPA has a general position against addressing training or other seemingly managerial tasks. The Aircraft Rescue and Firefighting Committee managed to include more specific statements about the nature of recommended training procedures than are contained in most NFPA standards. But even that language is weak.
The committee members approved the proposed changes in May 1983, a full year before the FAA proposed its own rule. A public comment period followed release of the document to the NFPA membership, and when the committee met the following November it was faced with a total of fourteen comments from only four individuals. UL submitted the most detailed comments, most of them definitional, demon-
strating a better understanding of fire extinguishers than the committee as a whole. There was a minor spat about whether a competing Halon agent—lower in toxicity, but also less effective—should be permitted. The committee rejected those proposals on the grounds that they were not supported by accompanying technical data. NFPA 408 was approved without comment or question by the general membership at the organization's 1984 annual meeting. It became effective on July 5, 1984, a little more than two years after the Standards Council instructed the committee to expedite the revision process.