Boeing 737-5H4 N508SW

Summary

On 31 October 1995 at about 02:10 local time, a Boeing 737-5H4 registered N508SW, operated by Southwest Airlines, Inc., was involved in an incident near Las Vegas, Nevada, United States. 97 people were on board and one had minor injuries. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 October 1995 at 02:10

Classification

Incident

Location

Las Vegas, Nevada, United States

Nearest airport

McCarran International (LAS)

Coordinates

36.0807, -115.1408

Aircraft

Boeing 737-5H4

Registration

N508SW

Category

Airplane

Engines

2

Operator

Southwest Airlines, Inc.

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → San Antonio

Aircraft damage

Not recorded

Weather

VMC

Light

Night/Dark

NTSB number

LAX96IA032

1 person had minor injuries.

The flying pilot's inadvertent exposure to an unidentified ground-based laser beam. A factor in the incident is the lack of appropriate standards by the FAA and FDA for laser light exposure levels to aircrew in navigable airspace.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The aircraft was climbing through about 4,500 feet agl on a standard instrument departure route when the first officer, who was the flying pilot, said a laser beam swept past the cockpit and he immediately experienced eye pain and was completely blinded in the right eye. After image effects also induced a blind condition in his left eye. He said the total inability to see lasted 30 seconds, and for an additional 2 minutes, he could not focus on or interpret any instrument indications and was completely disoriented in his spatial relationship to the vertical. The captain was not irradiated by the beam and assumed control of the aircraft and continued the climb. Many of the larger hotels in Las Vegas have some sort of outdoor laser light show. Most of these installations have both fixed/stationary (static) beams of relatively high power and 'dancing' beams of lower power which flash about the sky in irregular patterns. Recorded radar data was used to perform a trajectory and vehicle attitude study to determine the relative position of resorts with laser shows to the position and orientation of the aircraft. As the aircraft passed through 7,000 feet, the positions of three resorts relative to the aircraft were all located in the clear vision field of view of the first officer, and at a position of less than 90 degrees relative azimuth from the first officer's eye reference point. One had the shortest three dimensional distance to the aircraft at 4.7 nautical miles, while the other two were at three dimensional distances of about 7 nautical miles. The source of the laser could not be established with certainty. Fifty-one prior incidents of laser irradiations to pilots have been recorded by the Las Vegas air traffic facility over the past 2 years. FAA Order 7400.2D in effect at the time contains guidelines for FAA personnel in the approval process for determination of whether a proposed outdoor laser light display is compatible with navigable airspace. The order defines two areas: the Nominal Ocular Hazard Distance (NOHD); and the Eye Safe Distance (ESD). NOHD is defined as the distance from the point source where the irradiance level in power and area footprint can cause permanent thermal damage to the retina. ESD encompasses all other irradiance exposures where biological damage to the eye should not occur. Approval requires only that the laser beam be classed as ESD in navigable airspace. The approval process does not consider such laser exposure effects as flashblindness, afterimage, startle, and high glare conditions on pilot performance.

Quoted verbatim from the NTSB record.