Wednesday, April 01, 2009

Everything you ever wanted to know about commercial jet runway excursions

Australian Transport Safety Bureau logoThe Australian Transport Safety Bureau (ATSB) has issued a hefty, but fascinating, report on commercial jet aircraft runway excursions around the world. Here's an excerpt from the summary of 117-page report, which was just made available on the ATSB website:
Over the last decade there has been a noticeable reduction in the number of non-fatal and fatal accidents involving the worldwide commercial jet aircraft fleet. Despite this, runway excursions continue to remain prevalent, accounting for approximately a quarter of all incidents and accidents in air transport, and 96 per cent of all runway accidents. Runway excursions involve aircraft running off the end of the runway (overrun) or departing the side of the runway (veer-off).

A number of catastrophic runway excursions occurred across the world in 2007 and 2008, resulting in hundreds of fatalities and significant property damage in communities adjacent to the airport. This report, the first in a two-part series, provides a statistical picture of runway excursion accidents over a 10-year period how frequently they occur, why they occur, and what factors contributed to those accidents.

A search of the Ascend World Aircraft Accident Summary identified 141 runway excursion accidents involving the worldwide commercial jet aircraft fleet between 1998 and 2007. Those accidents resulted in 550 fatalities. Of those 141 accidents, 120 occurred during the landing phase of flight. An in-depth analysis of those 120 accidents was conducted in order to identify the types of flight crew technique and decision-related, flight crew performance-related, weather-related, and systems-related factors that contribute to runway excursions.
The report first summarizes 141 runway excursion accidents, and then follows with sections providing detailed analysis of:
  • Crew technique and decision-related factors
  • Crew performance-related factors
  • Weather-related factors
  • Systems-related factors
The analysis concludes by identifying factors contributing to runway excursion accidents during the landing phase of flight, including:
  • flying an unstabilized approach
  • landing too fast, too far down the runway, or conducting an extended flare
  • delayed or incorrect flight crew action when using braking systems, and less than adequate awareness of minimum equipment list items and their effect on braking performance
  • 'press-on-itis' and not conducting a go-around or diversion when conditions for landing are unsafe or at a higher risk
  • fatigue, stress, and visual illusions
  • less than adequate awareness of the effect of weather on the landing rollout length, possibly due to inconsistent or a lack of adequate approach and landing standard operating procedures
  • water-affected and contaminated runways, often associated with aquaplaning
  • inconsistent reporting of runway conditions and braking action at airports across the world
  • unusual runway design or lighting at some airports
The report warns, "If not identified and effectively managed by the flight crew, these factors can increase the risk of an accident occurring."

Part 2 of the study, which will focus on "procedural and physical safeguards that could assist airline and airport operators to reduce the frequency of runway excursion accidents" will be forthcoming.

Meanwhile, do have a look at Part 1 of the report. Here is the link to the landing page on the ATSB website that has a brief summary, and a link to the actual report.

Or download the whole report directly: Runway excursions: Part 1 - A worldwide review of commercial jet aircraft runway excursions - 117-page 'pdf' file