Q. How big a problem is smoke in the cockpit?

A. As an airliner cruises, it is twice as likely to land due to a smoke event as from an engine malfunction. Smoke is the leading defined cause of unscheduled landings of long-range commercial aircraft. According to a report from the Airline Pilots’ Association (ALPA), during a 10-month period, there were three smoke events per day. Indeed, there was one unscheduled landing per day to prevent the potential consequences of not being able to see to land because of smoke in the cockpit. And that was from only one of several databases that report such events.

Q. Have any aircraft crashed due to smoke in the cockpit obscuring the pilots’ vision? If so, how many?

A. Close to 20 aircraft have crashed due to smoke in the cockpit from intentional and unintentional sources such as engine smoke, wire fires, and incendiary devices. (See Attachment A for a list.) There were also at least three aircraft that crashed after being bombed by terrorists. These aircraft were flyable after the bombing but the aircraft crashed because the pilots could not see due to the smoke.

Q. Which airliners were involved in terrorist attacks and when did it happen?

  • 21 February 1970 Swissair flight 330 was the target of a terrorist attack. Although the structural integrity of the aircraft remained flight-worthy, the airplane subsequently crashed. The Swissair Convair 990 took off on February 21 at 13 minutes and 10 seconds after Noon (12:13:10). Less than eight minutes later (12:21:00) the pilots radioed that they had an explosion on board. Five minutes subsequent (12:26:00) the pilots requested an immediate landing. Seven minutes later, the pilots radioed at 12:33:00 “smoke on board I can’t see.” Thirty seconds later they radioed “good bye everybody.”

    The former head of safety for Swissair, Otto Rentsch, concluded that “the record clearly shows that the aircraft was flyable but ultimately crashed because the pilots couldn’t see their flight instruments, which are so critical to maintaining safe flight.”

  • 6 October 1976 A small incendiary device exploded on a Cubana Airlines DC-8 northwest of Bridgetown, Barbados. The safety commission determined that the cause of the crash was due to a bomb. The commission added that when the pilots attempted to make it back to the runway, “it became impossible to see the flight instruments because of the smoke.” The commission of Enquiry recommended that the “certification of large Commercial aircraft should include requirement for a positive means of smoke removal, particularly from the cockpit area.”

  • 23 September 1983 The British Civil Aviation authorities held that the cause of a Gulf Air Boeing 737 crash was due to possible sabotage. The cockpit voice recorder indicated that the “pilots unable to see instruments due [to] smoke.”

Q. What does the National Transportation Safety Board say about continuous smoke?

A. Beginning in the early 1980s, the National Transportation Safety Board (NTSB) became so concerned about continuous smoke that it recommended the Federal Aviation Administration “evaluate and change as necessary the procedures contained in the FAA-approved airplane flight manuals (AFM) of transport category airplanes relating to the control and removal of smoke to assure that these procedures address a continuing smoke source. . . .”

Q. How much time does a pilot have between the first indication of smoke and getting the aircraft on the ground?

A. It varies. The FAA claims from 8 to 20 minutes. Dr. Barbara Burian, a researcher from the NASA Ames Research Center, noted that, in a study of 15 in-flight fires that occurred between January 1967 and September 1998, the Transportation Safety Board of Canada found that the average amount of time between the detection of an onboard fire and when the aircraft ditched, made a forced landing, or crashed was 17 minutes.

In some cases the time to react is much shorter. For example, when the pilots from ValuJet 592 radioed in May 1996 for an immediate return to Miami International airport because of “smoke in the cockpit,” they had only been airborne for six minutes and 17 seconds. In slightly over three minutes from that initial request, interspersed with a frantic plea for the “nearest available airport,” the ValuJet DC-9 fatally crashed.

Q. Is there any technology that will permit a pilot to see when smoke in the cockpit cannot be stopped and is too dense to see through?

A. Yes. It is known as “smoke displacement technology.”

Q. Is “smoke displacement technology” required on airliners?

A. No.

Q. What does the National Transportation Safety Board say about “smoke displacement technology?”

A. As a result of its investigation of the ValuJet 592 accident, the NTSB formally recommended, referring to “smoke displacement technology” that the FAA evaluate “the cockpit emergency vision technology and take action as appropriate.”

Q. If “smoke displacement technology” can permit pilots to see in the presence of blinding, continuous smoke, why hasn’t the Federal Aviation Administration (FAA) mandated it for the airlines?

A. That is a question the Inspector General of the Department of Transportation (DOT) pondered. In response to questions during a Senate aviation subcommittee hearing on 18 May 2004, the DOT Inspector General replied in writing: “It is perplexing that FAA has equipped its own aircraft but has not mandated similar action for the commercial transport fleet.”

Q. In addition to officials of the Federal Aviation Administration, are there any other government officials that fly with “smoke displacement technology?” if so, which ones?

A. Yes. In addition the FAA officials, aircraft designated to fly officials in the Department of Homeland Security, senior military officers, and senior Department of Defense officials fly with aircraft equipped with “smoke displacement technology.”

Q. Is “smoke displacement technology” experimental?

A. No. It is fully tested, certified, and approved to STC standards by the Federal Aviation Administration.

Q. Are there any airlines that fly with “smoke displacement technology?”

A. Yes. JetBlue. In addition, Federal Express, NetJets, and over 1,000 corporate aircraft fly with “smoke displacement technology.”

Q. Are there any federal aviation regulations that specifically state that pilots must be able to see their vital instruments or out the window in the presence of continuous dense or opaque smoke?

A. There are no regulations that specifically state that in the presence of opaque or dense continuous smoke, the pilot must be able to see. However, airlines, aircraft manufacturers, and aviation authorities have a duty to ensure that pilots can see-at all times-to safely control and land their aircraft regardless of the cause of the interference. This follows from the following status and regulations:

  1. The FAA administrator is required to “exercise and perform his powers and duties . . . in such a manner as will best tend to reduce or eliminate the possibility of, or recurrence of, accidents in air transportation, . . . .”1

  2. FAA is required to certify that an aircraft has “no feature or characteristic [that] makes it unsafe. . . .”2

  3. An “unsafe condition is any condition that would cause - jeopardize the continued safe flight and landing of the aircraft.”3

  4. When an unsafe condition exists, the FAA Administrator is required to issue an “airworthiness directive,” (AD) and “[n]o person may operate a product to which an airworthiness directive applies, except in accordance with the requirements of that airworthiness directive.”4

Notes

1Federal Aviation Act of 1958, as amended, Title VI, Section 601(b)

214 C.F.R. §21.21 (b) 2.

3FAA Associate Administrator Tom McSweeney, testimony before the Senate Aviation Subcommittee of the Committee on Commerce, Science & Transportation, Nov. 8, 1993.

414 C.F. R. §§ 39.1, 39.3

If properly interpreted, the smoke regulation, 14 CFR 25.831(d), would suffice: “If accumulation of hazardous quantities of smoke in the cockpit area is reasonably probable, smoke evacuation must be readily accomplished, starting with full pressurization and without depressurizing beyond safe limits.”

Q. Regulation 14 CFR 25.831(d) above appears to address the issue completely. Why can’t the pilot eliminate the smoke according to this regulation?

A. If the smoke is a one-time event, pilots can depressurize the aircraft and over time eliminate the smoke, but with difficulty (See [attachment]). However, once the pressure on the outside of the aircraft is equal to the inside, there is no method for eliminating the smoke if it continues. That is why “continuous” smoke is such a problem. Secondly, the regulation has not been interpreted to deal with continuous smoke. For example, former FAA administrator Thomas Richards stated that its purpose is to provide “an adequate view of the instruments and the outside world,” whereas former Deputy FAA Administrator Tony Broderick said that the FAA has “never applied the regulation to require that the pilots be able to see in conditions of dense smoke. . . .” Finally, the regulation only applies to the certification of new aircraft. Consequently, if the FAA interpreted the regulation to apply to continuous smoke, it would only apply to new certifications.

Q. Are there other regulations that imply a requirement to see under all conditions?

A. It would be impossible for a pilot to comply with many of the sections under title 14 of the Code of Federal Regulations without the ability to see either his or her instruments or out the window. Here is a partial list:

  • Sec. 91.111 “Operating near other aircraft;”
    [This implies that the pilot should be able to see other aircraft.]

  • Sec. 91.117 “Maintaining aircraft speed;”
    [Implies the pilot should be able to see his or her airspeed indicator.]

  • Sec. 91.119 “Minimum safe altitudes;”
    [Implies the pilot should be able to see his or her altimeter.]

  • Sec. 91.125 “ATC light signals”
    [Implies that the pilot should be able to see out the window];

  • Sections 91.126 through section 91.141 involving various classes of airspace, proximity to an airport, or restricted areas;
    [Implies that the pilot should be able to see out the window]

    • and

  • Sec. 91.155 “Basic VFR weather minimums;”
    [Implies that the pilot should be able to see out the window]

Q. It is difficult to believe that the Federal Aviation Administration has remained silent on smoke in the cockpit. Hasn’t it said anything about this problem?

A. Yes. It issued an Advisory Circular, (AC) No. 25-9A, entitled “Smoke Detection, Penetration and Evacuation Tests and Related Flight Manual Emergency Procedures.” The AC is designed to explain how airline manufacturers can comply with Federal Aviation Regulation (FAR) §25.831(d), the cockpit smoke regulation. Its three weaknesses are that it (1) permits three (3) minutes to evacuate the smoke, (which would not have helped ValuJet 592), (2) it mandates that the applicant for certification turn off the smoke, a demonstrably unrealistic requirement, and (3) it does not apply to any current aircraft.

Q. How expensive is this “smoke displacement technology?

A. In quantity, it averages $35,000 per cockpit over 10 years. That equates to $3,500 per aircraft per year or pennies per ticket.

Q. Is there any other technology that will permit pilots to see through the smoke?

A. Some aircraft have “Heads Up Displays” (HUDs) that pilot claim are so bright that they can see through the smoke. But some smoke is too thick to see through regardless of brightness. Furthermore, even if pilots could see the HUD through the smoke, it does not solve the lack of visibility through the cockpit window. NASA is testing a Synthetic Vision System that uses a Heads Up Display (HUD) to see the outside world in bad weather. While an interesting innovation for flying under instrument flight rules (IFR), neither the HUD nor the display is not visible in a smoke filled cockpit.

Cockpit smoke is often associated with wire-related events. The FAA acknowledges this: “a majority of hidden in-flight fires are the result of electrical arcs along wire bundles.” Electrical arcs are often accompanied by electrical failure that would render the Heads Up Display inoperative. This would also apply to a devise with which is currently experimenting. For the cost of one Heads Up Display, an airline could equip 15 to 20 aircraft with “smoke displacement technology.”

Q. Is there a trend associated with deaths from terrorists’ attacks on aircraft?

A. Yes. The trend is increasing. (See the illustration below.) Source: www.airdisasters.co.uk The significant number of fatal aircraft deaths due to terrorist attacks are indicated by black boxes. It is not known how many could have been averted if equipped with the ability to see in the presence of a smoke-filled cockpit. Note the upward trend of deaths due to terrorist attacks. This chart does not include the two Russian Terrorist attacks in August 2004 that would most likely increase the trend.

Q. Is there any indication that there are future smoke-related terrorists threats that could increase the trend?

A. Yes. There are two: smoke bombs and man portable surface-to-air missiles or MANPADS.

Smoke bombs

On a July 2003 flight from Missoula, Montana to Seattle, Washington, a passenger passed security with a four-inch knife and a golf-ball sized explosive. His act was discovered only after he showed some children a “smoke-bomb-like device.” The children testified that the passenger asked them if he should “light the device.” As recently as September 2004, USA Today wrote an article with some confidence entitled, “Terrorists could bring down U.S. jets with hidden bombs;” More to the point, even after the 1998 crash of Swissair 111, only a few airline pilots would be able to see in a smoke-filled cockpit.

MANPADS

In the Intelligence Reform and Terrorism Prevention Act of 2004, signed by President Bush on December 17, 2004, Congress expressed an “urgent” concern about man-portable surface-to-air missile systems or MANPADS. Although there are no examples of an airliner having been shot down by these ubiquitous missile systems, they do have the potential to create problems for airliners. These systems are usually search for a heat source, normally found in the exhaust of an engine. Accordingly, they are likely to damage and cause a fire with associated smoke. Consequently, the need for pilots to see in cockpits potentially filled with smoke is even greater.

Q. Congress has mandated a restriction on carrying “butane lighters” and “any other modification [to the restricted items list] that the Assistant Secretary [of the Department of Homeland Security] considers appropriate.” Shouldn’t this enlargement of prohibited items eliminate the concern over smoke bombs since they require an ignition source?

A. Even if the Transportation Security Administration eliminates every type of lighter, it would still be easy for a terrorist to carry matches on board. Indeed, there are strike-anywhere matches that would be easy to conceal on a person’s body.