From prefl ight through takeoff roll, many factors enter into the decision every pilot makes on every takeoffrn— whether to continue as planned or abandon the attempt. Fortunately, in almost every case, the decision isrneasy. However, when circumstances arise that put the successful takeoff in question, the pilot’s decision becomesrncritical and must be made correctly. If all factors that might affect the aircraft are known, the pilot theoreticallyrnhas the information necessary to make the right decision. However, if any of those factors remain unknown, thernsafety of the rejected takeoff (RTO) maneuver may be in jeopardy.rnThe RTO accident and incident problem is not limited to a single operator or any one country. Clearly, this is anrninternational problem in need of an international solution. In terms of the number of runway overruns as a functionrnof phase of fl ight, those that occur during the landing phase will outnumber those occurring during the takeoffrnphase. Exposure to a possible overrun exists on every landing but, since the RTO is an abnormal maneuver, thernexposure during takeoff exists only if an RTO is initiated. Because of increased traffi c levels, during recent years,rnthe number of RTOs may have increased, and with each RTO there is a risk of an overrun incident or accident.rnThere are at least three areas of improvement that would signifi cantly reduce this risk: 1) readily available aircraftrnperformance information on contaminated runways, 2) training and 3) aircraft system technology.rnIn August 1989, a LADE Fokker F-28 lost directional control during a takeoff from San Carlos de Bariloche,rnArgentina. The takeoff was aborted, but the aircraft ran off the end of the runway. Reportedly, the runway wasrncontaminated with slush and snow.1rnThe event mentioned above shows that contaminated runways continue to be problematic for both takeoff andrnlanding. Each winter, aircrews experience problems such as inadequate removal of contamination, the lack ofrntimely and accurate runway condition reports, and the lack of performance data for operations on contaminatedrnrunways. Although much attention has been focused on the landing phase, the rejected takeoff situation is similarrnbecause of the reduction in aircraft braking coeffi cient of friction due to runway contamination.rnIn July 1988, an Air France B-747, departing Delhi at close to maximum takeoff weight, experienced a no. 4rnengine fi re warning during the takeoff roll. The alert came 2.5 seconds after the captain called “V1.” The fi rstrnoffi cer, who was the fl ying pilot, aborted the takeoff after he noticed the captain’s hand was moving towardsrnthe throttles. Maximum speed reached was 172 knots (V1 was 156 knots). The airplane overran the 1,000-footrnoverrun area, tearing off the landing gear. Had the fi rst offi cer better understood the importance of V1, he wouldrnnot have initiated the abort at a speed higher than the V1 callout.rnThe event mentioned above, as well as previous data, indicate that a statistically signifi cant number of RTOrnaccidents were the result of pilots initiating the RTO at speeds greater than the maximum safe abort speed. Thisrnindicates a misunderstanding of the critical takeoff speeds, which would be remedied through fl ight crew andrnoperator education on the certifi cation criteria for transport category airplanes. In the early 1990’s, industry andrngovernment developed the Takeoff Safety Training Aid in an effort to reduce the number of RTO accidents.rnHowever, not all operators have included the elements of the Training Aid in their training programs. Understandingrnof certain certifi cation requirements is essential to aircrews to aid them in their decision making. In addition,improving the understanding of certifi cation requirements will assist training departments in their developmentrnof fl ight procedures.rnIn January 2000, a Kenya Airways Airbus A310 crashed on takeoff from Runway 21 at Abidjan. On takeoff, thernaircraft used more runway than normal and was “still very low” as it passed over a sea wall 500 meters beyondrnthe runway end. The aircraft failed to gain height and struck water one mile off shore in darkness.1rnAs a potential remedy to events like the Kenya A310 accident, current technology exists that could be usedrnto develop a takeoff monitoring system to assist pilots in making that critical goo-go decision. In 1994, thernU.S. National Aeronautics and Space Administration (NASA) published a technical paper on their research inrndeveloping a Takeoff Performance Monitoring System (TOPMS). This is a software and hardware system thatrnvisually displays aircraft runway position, acceleration, engine status and other situation advisory information.rnAlternatively, an aural alert system may be more appropriate, allowing the pilot to “watch the road” whilernmonitoring the takeoff. A system such as this would improve reaction time and be more economicallyrnfeasible.rnFor older generation aircraft still in service, implementation of “takeoff line speeds” could provide the necessaryrninformation about that aircraft’s acceleration characteristics against predicted values for the runway in use.rnIn November 1992, an Aerolineas Argentina B-737 ran off the end of the runway following an aborted takeoff.rnThe abort was initiated because of poor acceleration during the takeoff roll due to failure of two main gear tires.rnIf this crew had at their disposal a set of predictive line speeds, they would have been able to detect the poorrnacceleration earlier in the takeoff run.1rnThis paper will present a summary of RTO issues from the pilot’s perspective. Improvements in delivering timely,rnaccurate, standardized information to fl ight crews will be outlined and their practicality discussed. The authorrnwill discuss possible training advancements, including greater use of existing tools that will serve to increase thernlevel of knowledge of the RTO maneuver among fl ight crews. Feasibility of employing emerging technology onrnnew aircraft, and potential means to improve the operation of older aircraft will also be discussed.
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