# NTSB LAX97IA161: Boeing 737-500, N930UA, Rialto, CA, April 17, 1997 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: April 16, 1997, 21:10 local (Apr 17, 1997, 04:10 UTC) - Place: Rialto, CA - Coordinates: 34.099372, -117.379364 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.0994&lon=-117.3794&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 99 uninjured - Status: Completed, report September 30, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 29644 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97IA161 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29644/pdf - Page: https://openairdocs.org/ntsb/LAX97IA161 ## Probable cause a laser light source of undetermined origin, directed by unknown person(s) toward the cockpit window of the aircraft, while the aircraft was on an approach to land. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, approach - iaf to faf/outer marker (ifr) - light condition - bright night - light condition - other (cause) - miscellaneous - intentional, unknown (cause) ## Analysis The aircraft was on a standard instrument arrival when the captain, who was on the controls, noticed a green light illuminating the aircraft. It appeared to him that the light was tracking the aircraft, but as he pointed out that fact to the first officer, the light disappeared. The captain reported that although the light caused a minimal yet persistent loss of night vision, he was able to maintain control of the aircraft throughout the remainder of the flight. He told ATC that the light appeared to emanate from the western edge of the city. A medical examination by Air Force specialists revealed no permanent evidence of eye damage. Investigators were unable to locate the source of the light. There were no NOTAMs for laser light activity at the time of the incident. ## Factual narrative On April 16, 1997, at 2110 hours Pacific daylight time, the captain on United Airlines Flight 2327 was exposed to a laser beam during a descent into Ontario, California. The aircraft, a Boeing 737-500, N930UA, was operated by United Airlines as a regularly scheduled domestic passenger flight under 14 CFR Part 121 when the incident occurred. The flight originated in San Francisco, California, at 2029 on the evening of the incident. Visual meteorological conditions prevailed at the assigned altitude and an IFR flight plan was filed. The aircraft was at 13,000 feet msl about 5 DME from Hitop intersection on the Ziggy 3 arrival when the incident occurred. The captain was on the controls when he noticed a green light illuminating the aircraft. It appeared to him that the light was tracking the aircraft, but as he was pointing out that fact to the first officer, the light disappeared. He reported that, although his exposure to the light caused a minimal yet persistent loss of night vision, he was able to maintain control of the aircraft throughout the remainder of the flight. He told air traffic control (ATC) that the source of the light seemed to emanate from the western edge of the city of Rialto. He was advised that there were no reports of laser activity in the area. After landing, he notified United Airlines dispatch of the incident. The captain was subsequently examined by the staff at the Visual Psychophysics Branch, Armstrong Laboratory, Brooks AFB, Texas. Their examination revealed no evidence of permanent effects from the exposure. Investigators from the FDA, FBI, and the San Bernardino County Sheriff's Aero Bureau were notified; however, the source of the light remains undetermined. According to the FAA, there were no NOTAMs in effect for laser light activity in the Ontario area at the time of the incident. ## Aircraft - Registration: [N930UA](https://openairdocs.org/deregistered/N930UA-2019-09-06), registration cancelled 2019-09-06, S/N 26655, built 1992 (OpenAirDocs) - Reported make and model: Boeing 737-500 - Registry model: [Boeing 737-522](https://openairdocs.org/model/boeing-737-522) (registry code 138449F) (OpenAirDocs) - Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 26655 - Airframe hours: 15042 - Engines: Cfm CFM56-3C 20000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Registered owner: United Airlines - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, April 16, 1997, 1 hours before - Departed: SFO, SAN FRANSISCO, CA - Destination: ONT, ONTARIO, CA - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; flight instructor, airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 5,661 total, 1,160 in this make and model ## Weather - Conditions: Visual (VMC), Night/bright - Wind: 240° at 6 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 39 °F - Altimeter: 29.00 inHg - Observed at: ONT, 11 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19970416022949I](https://openairdocs.org/incident/19970416022949I), Apr 16, 1997: Boeing 737522, Rialto, CA. During descent PIC blinded by green lazer beam. Regained eyesight while SIC flew the plane. Unable locate source. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.