“You’re Gonna Need A Longer Runway”


Just when you thought it was safe to land on that rain-slick runway, the FAA may be about to change the rules. A formal FAA document, published in the Federal Register on June 7 and labeled an “advance notice of policy statement,” says the agency on June 30 will issue a revision to existing policy governing turbojet operators and the landing distances they require. The change in policy stems from December 2005’s landing overrun accident at Chicago’s Midway Airport, involving a Southwest Airlines Boeing 737 and a fatality, the carrier’s first. As a result of that accident — helped along, no doubt, by the NTSB — the FAA says it conducted an internal review of regulations, orders, notices, advisory circulars, ICAO and foreign country requirements, airplane manufacturer-developed material, independent source material and the current practices of air carrier operators to develop its new policy. And what does that policy say? Just this: “No later than September 1, 2006, turbojet operators will be required to have procedures in place to ensure that a full stop landing, with at least a 15% safety margin beyond the actual landing distance, can be made on the runway to be used, in the conditions existing at the time of arrival, and with the deceleration means and airplane configuration that will be used.” In other words, according to the FAA, “absent an emergency, after the flightcrew makes this assessment using the air carrier’s FAA-approved procedures, if at least the 15% safety margin is not available, the pilot may not land the aircraft.” To implement the policy change, the FAA will issue mandatory OpSpec/MSpec C082, “Landing Performance Assessments After Dispatch,” for all turbojet operators. The FAA says all “turbojet operators shall be brought into compliance with this notice and [its requirements] no later than October 1, 2006.” The new OpSpec/MSpec C082 will be available from the FAA by June 30. 2006.

The policy change comes after the FAA’s internal review revealed several issues. Among them:

  • Fifty percent of the operators surveyed do not have policies in place for assessing whether sufficient landing distance exists at the time of arrival.
  • Not all operators who perform landing distance assessments at the time of arrival have procedures that account for runway surface conditions or reduced braking action reports.
  • Many operators who perform landing distance assessments at the time of arrival do not apply a safety margin to the expected actual (unfactored) landing distance. Those that do are inconsistent in applying an increasing safety margin.
  • Some operators have developed their own contaminated runway landing performance data or are using data developed by third party vendors. In some cases, these data are less conservative than the airplane manufacturer’s data for the same conditions.
  • Credit for the use of thrust reversers in the landing performance data is not uniformly applied and pilots may be unaware of these differences. In one case, the FAA found differences within the same operator from one series of airplane to another within the same make and model.
  • Airplane flight manual (AFM) landing performance data are determined during flight-testing using flight test and analysis criteria that are not representative of everyday operational practices.
  • Wet and contaminated runway landing distance data are usually an analytical computation using the dry, smooth, hard surface runway data collected during certification. Therefore, the wet and contaminated runway data may not represent performance that is achieved in normal operations.
  • Manufacturers do not provide advisory landing distance information in a standardized manner. However, most turbojet manufacturers make landing distance performance information available for a range of runway or braking action conditions using various airplane deceleration devices and settings under a variety of meteorological conditions.
  • Manufacturer-supplied landing performance data for conditions worse than a dry smooth runway is normally an analytical computation based on the dry runway landing performance data, adjusted for a reduced airplane braking coefficient of friction available for the specific runway surface condition.