American Airlines Flight 331 – Aviation Definitions in the News – Kingston Jamaica

On Tuesday, December 22, 2009,  American Airlines aircraft N977AN, a Boeing 737-800 aircraft operating as Flight 331, overran the runway on landing at Kingston, Jamaica’s Norman Manley International Airport. The aircraft crossed a road and stopped on a beach during  heavy rain. 

The National Transportation Safety Board and the Boeing company have dispatched a team of investigators to assist the government of Jamaica in its investigation. 

Kingston Airport – KIN

KIN has a single, asphalt (not grooved), runway measuring 8900 x 150 feet (2713 x 46 meters). ILS is available for runway 12 only. Current information indicates that given the wind direction of 320 degrees at 8 knots, the airplane carried out a tailwind approach and landing on runway 12. 

It will be months before all aspects of the event are thoroughly investigated. One thing that may be reliably speculated is that there are most likely a series of events that led up to the crash rather than one single cause. Most Aviation accidents can be traced back to multiple “Human Factor” errors. Additionally a study of FAA and NTSB data indicates that the following hazards increase the risk of a runway overrun:  

A non stabilized approach,

 

Excess airspeed,

 

Landing beyond the intended touchdown point, and

 

 Failure to assess required  landing distance to account for slippery or contaminated runway conditions or any other changed conditions existing at the time of landing

 

The following are some of the Aviation terms and definitions that may be related to the investigation of the incident. 

Accident:

 

An accident is often caused by a variety of contributing factors that interfere with good judgment and may cause inadvertent errors (events).. This permits a series of events to develop eventually resulting in damage to people or property. In every accident there are a series of events (errors) that link together to form a chain. This is a chain of events that if anyone of the events (errors) in the chain were eliminated the accident would have not occurred or would been replaced by a less severe incident.

 

Accident – Aviation Human Factors

 

FAA & ICAO Accident Definitions

 

 

Landing Requirements – Transport Category Aircraft

 

To determine the allowable landing weight for a transport category airplane, the following details must be considered:• Airfield pressure altitude
• Temperature
• Headwind component
• Runway length
• Runway gradient or slope
• Runway surface condition

 

With these details, it is possible to establish the maximum allowable landing weight, which will be the lower of the weights as dictated by:

 

• Landing runway requirements
• Approach climb requirements

 

Crash Damaged or Disable Aircraft Recovery (CDDAR)

CCDAR – Crash Damaged or Disable Aircraft Recovery: The ability to move damaged or disabled aircraft using specialized equipment 

Engineered Material Arresting System (EMAS)

The Federal Aviation Administration (FAA) requires that commercial airports, regulated under Part 139 safety rules, have a standard Runway Safety Area (RSA) where possible. At most commercial airports the RSA is 500 feet wide and extends 1000 feet beyond each end of the runway. The FAA has this requirement in the event that an aircraft overruns, undershoots, or veers off the side of the runway. The most dangerous of these incidents are overruns, but since…  Read entire definition here 

Dynamic Hydroplaning

Dynamic hydroplaning: A condition that exists when landing on a surface with standing water deeper than the tread depth of the tires. When the brakes are applied, there is a possibility that the brake will lock up and the tire will ride on the surface of the water, much like a water ski. When the tires are hydroplaning, directional control and braking action are virtually impossible. An effective anti-skid system can minimize the effects of hydroplaning. See entire definition here.. 

Viscous Hydroplaning

Viscous hydroplaning is due to the viscous properties of water. A thin film of fluid no more than one thousandth of an inch in depth is all that is needed. The tire cannot penetrate the fluid and the tire rolls on top of the film. This can occur at a much lower speed than dynamic hydroplane, but requires a smooth or smooth acting surface such as asphalt or a touchdown area coated with the accumulated rubber of past landings. Such a surface can have the same friction coefficient as wet ice. When confronted with the possibility of hydroplaning, it is best to land on a grooved runway (if available) ( The runway at Norman Manley International Airport is constructed of asphalt and is not grooved as most are in the United States) . Touchdown speed should be as slow as possible consistent with safety. After the nosewheel is lowered to the runway, moderate braking should be applied. If deceleration is not detected and hydroplaning is suspected, the nose should be raised and aerodynamic drag utilized to decelerate to a point where the brakes do become effective.   See entire definition here.. 

 

Reverted Rubber (steam) Hydroplaning

Reverted rubber (steam) hydroplaning occurs during heavy braking that results in a prolonged locked-wheel skid. Only a thin film of water on the runway is required to facilitate this type of hydroplaning. The tire skidding generates enough heat to cause the rubber in contact with the runway to revert to its original uncured state. The reverted rubber acts as a seal between the tire and the runway, and delays water exit from the tire footprint area. The water heats and is converted to steam which supports the tire off the runway. Reverted rubber hydroplaning frequently follows an encounter with dynamic hydroplaning, during which time the pilot may have the brakes locked in an attempt to slow the airplane. See entire definition here.. 

Runway visual range (RVR)

Runway visual range (RVR) –  RVR is the instrumentally derived horizontal distance a pilot should be able to see down the runway from the approach end, based on either the sighting of high-intensity runway lights, or the visual contrast of other objects. 

JCAA – Jamaica Civil Aviation Authority

JCAA – Jamaica Civil Aviation Authority: The Jamaican equivalent to the United States FAA. 

Runway Protection Zone – RPZ

Runway Protection Zone – RPZ is an area off the runway end to enhance the protection of people and property on the ground. RPZ’s  function is to enhance the protection of people and property on the ground. This is achieved through airport owner control over RPZs. Such control includes clearing RPZ areas (and maintaining them clear) of incompatible objects and activities. Control is preferably exercised through the acquisition of sufficient property interest in the RPZ. 

National Transportation Safety Board (NTSB)

National Transportation Safety Board (NTSB) – A United States Government independent organization responsible for investigations of accidents involving aviation, highways, waterways, pipelines, and railroads in the United States. NTSB is charged by congress to investigate every civil aviation accident in the United States.