1971 — Sep 4, Juneau Approach Crash, Alaska Air flight 1866, Mt. Fair (Chilkats), AK-111
–111 Gottehrer, Dean M. The Associated Press Stylebook for Alaska (Revised 2nd ed.). 2000.
–104 passengers.
— 7 crew.
–111 Haine, Edgar A. Disaster in the Air. New York: Cornwall Books, 2000, p. 124.
–111 Liefer, G. P. Broken Wings: Tragedy & Disaster in Alaska Civil Aviation. 2003, p. 121.
–111 NTSB. AAR. Alaska Airlines…Juneau, Alaska, September 4, 1971 (NTSB-AAR-72-28).
–109 Emergency-Management.net. “Airplane Accidents 1969-1979.”
Narrative Information
NTSB: “Synopsis Alaska Airlines Flight 1866, a Boeing 727, N2969G, crashed during an instrument approach to Juneau Municipal Airport. Juneau. Alaska, at approximately 1215 P.d.t. [Pacific Daily Time], on September 4, 1971.
“The flight had been cleared for a Localizer Directional Aid (LDA) approach to Runway 8 and had reported passing the final approach fix (Barlow Intersection). This intersection is located 10.2 nautical miles west of the airport. No further communications were heard from the flight.
“The aircraft struck a slope in the Chilkat Mountain range at about the 2,500-foot level, 18.5 miles west of the airport, and approximately on the inbound localizer course. All 104 passengers and the seven crewmembers were injured fatally. The aircraft was destroyed by impact and isolated postcrash fires.
“The National Transportation Safety Board determines that the probable cause of this accident was a display of misleading navigational information concerning the flight’s progress along the localizer course which resulted in a premature descent below obstacle clearance altitude. The origin or nature of the misleading navigational information could not be determined. The Board further concludes that the crew did not use all available navigational aids to check the flight’s progress along the localizer nor were these aids required to be used. The crew also did not perform the required audio identification of the pertinent navigational facilities.” (NTSB 1972, 1)
“History of the Flight Alaska Airlines, Flight 1866 (AS66) of September 4, 1971, a Boeing 727. N2969G, was a regularly scheduled passenger flight from Anchorage, Alaska, to Seattle, Washington, with intermediate stops a t Cordova, Yakutat, Juneau, and Sitka, Alaska. The flight, operating under instrument flight rules (IFR), departed Anchorage at 0913 and landed at Cordova at 0942. AS66 departed Cordova at 1034…The flight landed at Yakutat at 1107….The flight departed Yakutat at 1135, with 104 passengers and seven crewmembers on board….” (NTSB. 3)
“….Search and rescue facilities were alerted at approximately 1223. several hours later, the aircraft’s wreckage was located 18.5 NM west of the airport at about the 2,500- foot level in the Chilkat Mountain Range.” (NTSB. 4)
“….Two…witnesses, who were located about 1½ miles west of the accident site and at the approximate 2,500-foot elevation of the Chilkat Range, heard a low flying jet aircraft pass approximately overhead proceeding in an easterly direction. They stated that they were unable to see the aircraft because of the restricted visibility, which was estimated at 60 to 70 yards in fog and light rain. They further stated that the engines sounded normal and that there was no change in the engine sounds from the time they first heard the aircraft until the sound of explosions was heard approximately 1 minute later. They estimated the time of the accident as approximately 1215….” (NTSB. 5)
“….Juneau Municipal Airport, published elevation of 18 feet m.s.1., is surrounded on three sides by mountainous terrain and opens to a bay on the southwest…..” (NTSB. 9)
“….The aircraft crashed on the easterly slope of a canyon in the Chilkat Range of the Tsongas National Forest. The impact occurred at the 2,475-foot level, in near-alignment with the Juneau localizer course, and at a distance of approximately 18.5 nautical miles from the airport. The aircraft disintegrated on impact, and the wreckage covered an area approximately 800 feet long and 600 feet wide. The major portion of the wreckage came to rest on the slope of the canyon. The cockpit and various portions of the forward fuselage were found on the ridge of the canyon and farther along the projected flightpath…. No evidence of in-flight structural failure, fire or explosion was found.” (NTSB. 11)
“….Based on all available evidence, it appears that Alaska Airlines Flight 1866 was operating routinely as it progressed over its route of flight from Yakutat to the Pleasant Intersection in the Juneau area. The aircraft was airworthy, maintained properly, and capable of normal operation in the existing weather conditions with regard to powerplants, flight controls, altimetry system, and communications equipment. The crew was certificated and qualified for the operation involved. There was no crew incapacitation, nor were there any other factors that might have interfered with the crew’s physical ability to perform their tasks.[1] The CVR readout revealed no evidence of crew suspicion or concern about aircraft performance.
“Correlation between the CVR readout and the approximate flightpath derived from the flight data recorder traces shows that the first, unmistakable abnormality in the flight’s progress occurred at 1201:03 when the captain told the first officer; “Okay, you’re Howard,” although the aircraft was actually about 9 NM west of Howard. Since prior cockpit conversation indicates that the captain had set the 3530 radial (Howard Intersection) into his CDI, it appears that the crew depended on a display of navigational information that seemed to be correct, but was in error by about 45 [degrees]. Similar erroneous indications of progress along the localizer course are evident in subsequent intracockpit conversation dealing with the passing of Rockledge and Barlow Intersections, although the aircraft, in fact, never progressed as far as Howard.” (NTSB, 21)
“….The weather in the vicinity of the accident site was characterized by multilayered cloud coverage with the bases between 1,000 and 1,500 feet m.s.1. These conditions would have obscured the terrain below the aircraft’s flightpath, as well as the mountain peaks above the lower cloud layer, thereby preventing any visual discovery of the misleading navigational display which resulted in the premature descent below obstacle-clearance altitude. Neither the CVR nor the FDR showed any evidence of a last-second awareness on the part of the crew that a mishap was imminent.” (NTSB, 22)
Haine: “….At this time in 1971, Juneau did not have an instrument landing system with both a glide slope and a localizer to line up with the incoming plane with the center of the runway. FAA officials said Juneau had not installed such an ILS system because of the peculiar geography that forces approaching planes to follow a dogleg course.[2] The airport did have a localizer type of device that lined up an approaching aircraft with a cut in the peninsula. Once through the cut, a lighting system was used to guide the pilot visually to the runway; altitudes were of course taken from the plane’s own altimeters. Officials said the Alaska Airlines flight did not make it through the cut….
“The crash was caused by flying too low. Why the plane was at such a dangerous altitude was possibly due to some equipment malfunction or pilot error…. [ p. 125]
“Shortly after this accident, the FAA installed Distance Measuring Equipment (DME) at the Juneau Airport. Following the commissioning of this equipment the Board recommended that the F.A.A. ‘Amend the public instrument approach procedure for the LDA approach to Juneau, Alaska, Airport to reflect the addition of the DME as a means of determining the location of fixes on the final approach course of the localizer.’ This action…[was] approved by the FA Administrator, and the appropriate charts now incorporate data concerning the DME distances associated with the localizer….” [p. 127] (Haine. Disaster in the Air. 2000.)
Liefer: “….By the evening of the third day following the tragedy, fifty-six of the 111 bodies and both cockpit recorders had been recovered. Bad weather continued to hinder much of the recovery process with persistent rain and high winds. By September 8, almost all the bodies had been found at the crash site, but only eighty-nine had been removed from the mountain. Of those, only seventeen were positively identified by an FBI disaster team working out of a temporary morgue in Juneau. It would be several more days before all the bodies could be transported to Juneau and identified, and months before aircraft components from the wreckage could be tested and analyzed….” (p. 125)
“Human error could not be identified with any certainty as the cause of the accident, but several factors could have contributed to the misinterpretation of navigational information by the crew. Once the flight neared Pleasant Intersection, the first officer changed his navigation receiver to the localizer frequency at Juneau for tracking the inbound course. The captain was requested to tune the other navigation receiver to the Sisters Island VHF omni-directional range in order to fix the correct step-down points along the approach. From post-crash analysis of the cockpit voice recordings, it seems likely the captain did not comply with the request and instead left his navigation receiver tuned to the same localizer frequency as the first officer.
“Proper execution of the approach required that two components be used in conjunction with each other to identify correct intersection radials along the inbound course. First, the VHY omni-directional range navigation receiver had to be tuned to the correct station, and second, the course indicator had to be set on the correct radial from the station. If this was not done correctly, intersection fixes along the approach course would be inaccurate. During the time the first officer initially requested the VHF omni-directional range be tuned and identified to Sisters Island, the captain was involved in a three-way conversation between the Piper Apache and air traffic control….” (pp. 127-128.)
“A few years after the crash of AS66 [flight 1866], the Federal Aviation Administration accepted partial blame for the navigational error when it was determined that the VHF omni-directional range signal had malfunctioned by transmitting a directional error of 35° to 40°. In a court settlement, the Federal Aviation Administration agreed to pay $4.5 million of the $15 million damage claim awarded to plaintiffs in the case. As part of the settlement, new navigation facilities were installed at Juneau….” (Liefer. Broken Wings: Tragedy & Disaster in Alaska Civil Aviation, 2003, p. 145.)
Sources
Emergency-Management.net. “Airplane Accidents 1969-1979.” Accessed at: http://www.emergency-management.net/avi_acc_1969_1979.htm (No longer operational.)
Gottehrer, Dean M. The Associated Press Stylebook for Alaska (Revised and 2nd edition). Fairbanks, Alaska: Epicenter Press, 2000. Partially digitized by Google at: http://books.google.com/books?id=O53zwdFYTGEC&printsec=frontcover#v=onepage&q&f=false
Haine, Edgar A. Disaster in the Air. New York: Cornwall Books, 2000, 394 pages.
Liefer, G. P. Broken Wings: Tragedy & Disaster in Alaska Civil Aviation. Blaine, WA: Hancock House, 2003.
National Transportation Safety Board. Aircraft Accident Report. Alaska Airlines, Inc. Boeing 727, N2969G, Near Juneau, Alaska, September 4, 1971 (SA-429; File No. 1-0008; NTSB-AAR-72-28). Washington, DC: NTSB, adopted October 13, 1972, 86 pages. Accessed 12-29-2017 at: https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7228.pdf
[1] Liefer writes that “the crew seemed to be distracted at that time [11:58 when entering a holding pattern over the Pleasant Intersection] by…[a] Piper Apache’s ongoing situatin with air traffic control. The captain voiced obvious concern about the other aircraft to the first officer and spent several minutes acting as a radio relay between the smaller aircraft and air traffic control….Continued concern over the Piper Apache’s location distracted the cockpit crew until at least 1205.” (p. 123)
[2] Liefer notes “The mountains around Juneau required an approaching aircraft to make a final turn to the runway only three miles from the airport.” (p. 122)