# NTSB ANC00IA010: Boeing 737-400, N792AS, Juneau, AK, November 2, 1999 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: November 2, 1999, 06:40 local (10:40 UTC) - Place: Juneau, AK - Coordinates: 58.579456, -134.770935 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=58.5795&lon=-134.7709&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 58 uninjured - Status: Completed, report May 17, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 47764 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC00IA010 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47764/pdf - Page: https://openairdocs.org/ntsb/ANC00IA010 ## Probable cause The failure of the flight crew to provide a recommended landing traffic advisory, and the failure of flight service station personnel to provide a flight advisory to the arriving airplane concerning men and equipment operating on the runway. Factors in the incident were operations at an airport when the control tower was closed, and the failure of the snow plow driver to verify the eminent arrival of the airplane. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, landing - roll - airport equipment,snow removal - other - control tower - closed (contributing factor) - traffic advisory - not performed, flightcrew (cause) - flight advisories - not issued, atc personnel(fss) (cause) - air/ground communications - not verified, driver of vehicle (contributing factor) ## Analysis The scheduled passenger flight was inbound for landing during the period of dawn. A cargo airplane was also inbound, preceding the passenger flight. The airport air traffic control tower (ATCT) was closed. An automated flight service station (AFSS) was in operation. AFSS personnel cannot see the runway. An airport maintenance crew was conducting snow removal training on the runway in a plow equipped truck. The passenger flight crew contacted the AFSS at the VOR (25.2 miles away), and advised they were inbound for landing. At that time, the plow was off the runway, waiting for the cargo airplane to arrive. The crew of the passenger airplane was not advised of any airfield maintenance activity. After the cargo airplane landed, the plow driver informed the AFSS of his intentions, and drove onto the runway to continue training. AFSS personnel advised the driver of the plow that the passenger airplane was about 10 minutes behind the cargo airplane. Without any further communication, the passenger flight touched down on the runway while the plow was driving along the right edge of the runway, facing away from the arriving jet. The passenger jet swerved to the left during the roll out to miss the plow truck. The right wing tip of the jet passed about 32 feet from the plow truck. The verbal report of men and equipment on the runway, given by the plow driver to the AFSS is a local NOTAM only. The local NOTAM was not transmitted to the arriving passenger flight. When the ATCT is closed, there are no mandatory reporting points for arriving airplanes. There are only recommended traffic advisories for position reporting of arriving traffic. The recommended traffic advisories are contained in the company flight operations manual. ## Factual narrative HISTORY OF FLIGHT On November 2, 1999, about 0640 Alaska standard time, a Boeing 737-400 airplane, N792AS, nearly collided with a snow plow during landing on runway 08 at the Juneau International Airport, Juneau, Alaska. The airplane was being operated by Alaska Airlines, Seattle, Washington, as Flight 73, an instrument flight rules (IFR) scheduled passenger flight under Title 14, CFR Part 121, when the incident occurred. The captain, the first officer, three cabin crew members, and the 53 passengers, were not injured. Neither the airplane or the snow plow were damaged. Visual meteorological conditions prevailed. An IFR flight plan was filed. The flight originated at the Rocky Gutierrez Airport, Sitka, Alaska, about 0600. After departing Sitka, Flight 73 proceeded toward Juneau. The Juneau Air Traffic Control Tower (ATCT) was closed, and was not scheduled to open until 0700. A Federal Aviation Administration (FAA) Automated Flight Service Station (AFSS) was in operation at the time of the incident. Juneau AFSS personnel cannot see the runway. The driver of Plow 11, a Juneau Airport field maintenance dump truck equipped with a snow removal blade, was training a new driver on the airport. The plow was moving eastbound along the right edge of runway 08, about 3,000 feet from the approach end of the runway. According to the driver of Plow 11, the right edge of the plow blade was about 5 feet inside the runway edge stripe. At 0629:10, a Beech 1900 cargo airplane, call sign ACE Air 41, contacted the Juneau AFSS on the common traffic advisory frequency (CTAF) of 118.7 MHz, at BARLO intersection (the final approach fix on the instrument approach to runway 08, 9.2 nautical miles west of the Juneau airport), stating: "Ace Air 41, BARLO, inbound for (runway) eight." The AFSS specialist at the in-flight one position acknowledged the radio contact, and then asked the driver of Plow 11, who was also monitoring the CTAF, if he heard the radio call from ACE Air 41 reporting BARLO. The driver acknowledged the call by stating: "Ground, that's affirmative, maintenance, at this time men and equipment are clear of the runway, I'd like to get back out after he's down and clear." The in-flight one AFSS specialist then advised Plow 11, "Airfield maintenance, roger, after ACE Air, about 10 minutes behind him is the other Alaska jet." The driver of Plow 11 acknowledged the information. At 0632:28, Alaska Flight 73 contacted the Juneau AFSS stating: "Juneau radio, Alaska 73 is with you, just leaving SISTERS (VOR) for the LDA 2 (localizer type directional aid) to runway 08." The AFSS specialist at the in-flight one position acknowledged the radio call. The SISTERS VOR is 16 miles from BARLO intersection, and 25.2 miles from runway 08. At 0633:35, Ace Air 41 reported, "Juneau, Ace Air 41 down and clear, if you'd close us out please." The AFSS specialist at the in-flight two position acknowledged the radio call. At 0634:51, the driver of Plow 11 called the AFSS and stated: "Juneau radio, airfield maintenance, if you have no reported traffic, like to have men and equipment on the runway." The AFSS specialist at the in-flight two position said "stand by" and at 0635:23 stated: "and Juneau airfield maintenance, no known traffic at this time, the jet's due in, in about 10 minutes at 45 (minutes past the hour)." The driver of Plow 11 acknowledged the radio call. At 0642:25, Alaska Flight 73 called the Juneau AFSS and stated: "ah we just landed and there was a truck on the runway, we ah just barely missed it... ah it, we had to swerve very far to the left of the runway to miss the truck." The AFSS specialist at the in-flight one position acknowledged the radio call, and replied, "Alaska 73 roger, sorry, I missed your last report, I didn't hear a BARLO area report, I thought it was ASORT, was the last one." ASORT intersection is 21 miles from the SISTERS VOR. It is usually a reporting point for airplanes arriving from the north, not from Sitka. Alaska Flight 73 then stated: "We don't think that's correct, but in any event, I think we called the report, but we just, the truck was on the runway." The driver of Plow 11 then stated: "radio, maintenance was just outside the lights, I never got a call, it's the grace of God that we're all right." Following the incident, ground maintenance personnel from the Juneau Airport measured and diagrammed the scuff marks on the runway produced by Flight 73 swerving to avoid the snow plow. Their measurements revealed that as the Alaska Airlines jet passed the plow truck, the airplane's right main landing gear was about 18 feet to the left of the runway center stripe. The outboard end of the right wing was about 16 feet to the right the center stripe. The left side of the plow truck's blade was about 27 feet to the left of the right runway edge stripe. The distance from the right wing tip, to the plow truck, was about 32 feet. Plow 11 was facing east, away from the approaching jet. The truck is equipped with strobe lights on the back of the truck, and a rotating beacon on the top of the cab. According to an FAA inspector with the Juneau Flight Standards District Office, the strobe and beacon lights were functional and operating at the time of the incident. The incident occurred during the period of dawn. METEOROLOGICAL INFORMATION On November 2, 1999, at 0653, an Aviation Routine Weather Report (METAR) for the Juneau Airport was reporting in part: Wind, calm; visibility, 10 statute miles; clouds and sky condition, 1,600 feet scattered, 2,800 feet scattered, 3,800 feet overcast; temperature, 35 degrees F; dew point, 33 degrees F; altimeter, 29.69 inHg; remarks, variable broken ceiling, lower to the east, higher to the west. COMMUNICATIONS Ground and airborne communications at the Juneau airport are all conducted on the Juneau CTAF when the ATCT is closed. The driver of Plow 11, and the crew of Flight 73, were utilizing the CTAF. When the Juneau ATCT is closed, there are no mandatory reporting points for arriving aircraft to the Juneau airport. When Flight 73 made their initial radio call at the SISTERS VOR, no men or equipment were on the Juneau runway. No advisory of men and equipment on the runway was provided to Flight 73 by the Juneau AFSS. After reporting SISTERS VOR, Flight 73 made no other radio calls. A transcript of communications with the Juneau AFSS is included in this report. AERODROME AND GROUND FACILITIES The Juneau International airport is owned and operated by the City and Borough of Juneau. The airport has a hard-surface runway on a 080 to 260 degree magnetic orientation. Runway 08 is 8,456 feet long by 150 feet wide, and is equipped with sequenced lead-in lights to runway 08, high intensity runway lights, runway end identifier lights, medium intensity approach lighting, and a visual approach slope indicator. ADDITIONAL INFORMATION AFSS specialists provide assistance in emergency situations, in-flight services, and preflight services to airman. In-flight services are provided to aircraft in flight, or operating on an airport surface, and may include NAVAID monitoring, local airport advisories (LAA), delivery of air traffic control clearances, advisory services to pilots, notice to airman (NOTAM), search and rescue services, weather information, flight planning, and other services. Under two letters of agreement between the Juneau Airport, and the Juneau AFSS, airport conditions which could affect the safe operation of the airport are provided to the AFSS by Juneau airport personnel via fax, radio, telephone, or in person. Airport personnel will keep the AFSS informed of personnel authorized to issue NOTAM information. Airport personnel will advise the AFSS before moving onto an airport movement area, and when vehicles are clear of movement areas. They will ensure the work force supervisor has two-way radio communicat ## Aircraft - Registration: [N792AS](https://openairdocs.org/deregistered/N792AS-2018-03-02), registration cancelled 2018-03-02, S/N 28887, built 1997 (OpenAirDocs) - Reported make and model: Boeing 737-400 - Registry model: [Boeing 737-490](https://openairdocs.org/model/boeing-737-490) (registry code 138449M) (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: 28887 - Airframe hours: 8788 - Engines: Cfm CFM-56-3C-1 22000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: Alaska Airlines - Registered owner: First Security Bank - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, October 29, 1999, 96 hours before - Departed: PASI, SITKA, AK - Destination: PAJN - Flight plan: IFR - Airport: PAJN, Juneau International, runway 8, 4,900 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; commercial, airline transport, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 14,793 total, 857 in this make and model, 5,700 as pilot in command, 46 in the last 90 days ## Weather - Conditions: Visual (VMC), Dawn - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 3,800 ft overcast - Temperature: 36 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: PAJ ## 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 19991102038649I](https://openairdocs.org/incident/19991102038649I), Nov 2, 1999: Boeing 737400, Juneau, AK. Alaska airlines flight 73, was landing on runway 8 at the Juneau airport. Weather was VFR, but it was drak, early morning. The jnu afss was providing local… 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.