1971 — June 6, Hughes Air 706 (49) & USMC Phantom II jet (1) collide, ~Duarte, CA– 50

–50 Airdisaster.com. Accident Database. “Accident Synopsis 06061971.”
–50 Aviation Safety Network. Hughes Airwest Flight 706, N of Duarte, CA, 6 Jun 1971.
–50 Baugher. US Navy…Marine Corps BuNos Third Series (150139 to 156169). 10-29-2011.
–50 Kimura. World Commercial Aircraft Accidents 3rd Ed., 1946-1993, V.1. 4-11-1994, p. 2-12.
–50 NationMaster.com, Encyclopedia. “List of Notable Accidents and Incidents Com. Aircraft.”
–50 NTSB. Hughes Air West…and U.S. Marine Corps F-4B…Duarte, CA, June 6, 1971. 1972.
–50 Notable California Aviation Disasters. “The 1970s.” Oct 23, 2008 update.

Narrative Information

Baugher: “151458 collided in midair with DC-9 N9345 of Hughes Air West near Duarte, CA Jun 6, 1971. Both aircraft crashed, killing all 49 occupants of the DC-9 and pilot of F-4 (whose canopy would not jettison). Navigator of F-4 ejected safely.” (Baugher. US Navy…Marine Corps BuNos Third Series (150139 to 156169). 10-29-2011.)

NTSB: “Synopsis A Hughes Air West DC-9, N9345, and a U. S. Marine Corps F-4B, Bureau No. 151458. collided in flight near Duarte, California, at approximately 1811 P.d.t.. June 6, 1971. All 49 occupants, 44 passengers and five crewmembers, aboard the DC-9, and the pilot of the F-4E were fatally injured. The radar intercept officer, the only other occupant in the F-4B, ejected from the aircraft after the collision and parachuted to the ground. He was not injured. Both aircraft were destroyed by the collision. ground impact, and fire.

“The Hughes Air West DC-9 was under radar control of the Los Angeles Air Route Traffic Control Center, climbing to Flight Level 330. The F-4B was being flown at approximately 15,500 feet. in accordance with Visual Flight Rules, en route to the Marine Corps Air Station, El Toro, California. The collision occurred at an altitude of approximately 15,150 feet

“The visibility in the area. at the time of the accident, was good and there were no clouds between the two aircraft during the final minutes of flight.” (NTSB. Hughes, 1972, p. 1.)

“The National Transportation safety Board determines that the probable cause of this accident was the failure of both crews to see and avoid each other but recognizes that they had only marginal capability to detect, assess, and avoid the collision. Other causal factors include a very high closure rate, commingling of IFR and VFR traffic in an area where the limitation of the ATC system precludes effective separation of such traffic, and failure of the crew of BuNo458 [Marine jet] to request radar advisory service, particularly considering the fact that they had an inoperable transponder.

“….The Safety Board…recommended that the Federal Aviation Administration and the Department of Defense cooperatively develop a program to inform all airspace users of the heaviest traffic areas. In addition, it was recommended that the Department of Defense: (1) restrict high-speed, low-level operations to designated areas and routes; (2) delineate explicit circumstances where the 10,000 feet/250 knots limitation may be exceeded; (3) consider using air intercept radar for collision avoidance purposes; and (4) publicize the availability of the FAA
Radar Advisory Service and consider making the use of this service mandatory.” (NTSB. p. 2.)

“History of the Flight Hughes Air West Flight 706 (RW706) was a regularly scheduled flight from Los Angeles, California, to Seattle, Washington, with intermediate stops at Salt Lake City, Utah, Boise and Lewiston, Idaho, and Pasco and Yakima, Washington. The flight departed Los Angeles International Airport at 1802 and. following radar vectors from Los Angeles Departure Control, contacted the Los Angeles Air Route Traffic Control Center (ARTCC) at 1806. In accordance with a request, the flight reported leaving 12,000 feet at 1809, and the controller advised, ‘Air West seven zero six red, turn left heading zero four zero until receiving Daggett proceed direct.’ RW706 acknowledged. ‘OK, zero four zero direct to Daggett.’ This was the last recorded transmission from the flight. (NTSB. p. 3.)

“…During most of this period [El Toro approach] period, he [radar intercept officer] was operating the radar in the mapping mode, but, due to the extremely degraded air-to-air detection capability, no airborne targets were seen. Since the radarscope was in the stowed position, the RIO was leaning forward, and his line of sight was directed downward at approximately a 450 angle while using the radarscope. Approximately 3 to 10 seconds prior to collision. the RIO raised his head, observed the DC-9 in his peripheral vision approximately 50 [degrees] to the right and slightly beneath his aircraft. He shouted to the pilot, but the pilot had initiated an evasive roll before the RIO finished the warning. He did not see RW706 take any evasive action.

“After takeoff from Los Angeles, RW706 was given two radar traffic advisories by departure control, and control was subsequently transferred to the R-18 sector of Los Angeles ARTCC. The data and radar positions of this sector were manned by developmental controllers, each of whom was being supervised by a journeyman controller. Consequently, four individuals were observing the radarscope at the R-18 position prior to the collision. They all agreed that no primary targets were observed in proximity to RW706 at any time. Five traffic advisories were given to other aircraft in the R-18 sector in the 6-minute time span prior to the collision.

“After the collision, BuNo458 began to tumble violently about the lateral axis. The RIO waited about 5 seconds, and, after seeing numerous warning lights in the cockpit, he ejected from the aircraft. The ejection was successful, and he parachuted to the ground without injury….” (NTSB. p. 5.)

“Wreckage. The main wreckage of the two aircraft was scattered over approximately 2 square miles. The DC-9 crashed in a canyon… One piece of P-4E aft fuselage structure was also found at the DC-9 crash site. This piece of the F-4E had become entangled in electrical wiring…of the DC-9.” (NTSB. p. 9.)

NationMaster.com: “June 6 – Following a mid-air collision with a United States Marine Corps F-4B Phantom II jet fighter, Hughes Airwest Flight 706, a DC-9, crashes into the San Gabriel Mountains near Duarte, California, killing all 49 people aboard. The pilot of the Phantom also dies. The radar intercept officer on the Phantom successfully bails out.” (NationMaster.com, Encyclopedia, List of Notable Accidents and Incidents of Commercial Aircraft)

Notable California Aviation Disasters:
Number 5 (tie) of California’s “10 Worst Crashes
Date / Time: Sunday, June 6, 1971 / 6:11 p.m.
Operator / Flight No.: Hughes Airwest / Flight 706
Location: San Gabriel Mountains, north of Duarte, Calif.

“Details and Probable Cause: Midair collision. The Hughes Airwest DC-9-31 (N9345) departed Los Angeles International Airport at 6:02 p.m. on a flight to Salt Lake City, Utah, the first destination on an itinerary that also was to include stops at Boise and Lewiston, Idaho, and Pasco, Yakima and Seattle, Washington.

“Nine minutes later the DC-9 was climbing over the San Gabriel Mountains to its assigned altitude of 33,000 feet when it was struck at 15,150 feet by a two-man U.S. Marine Corps McDonnell Douglas F-4B Phantom jet fighter (151458) that was en route from Fallon Naval Air Station near Reno, Nevada, to El Toro Marine Corps Air Station in Orange County.

“The pilot aboard the F-4B was killed; the radar interception officer ejected and parachuted to safety, drifting to earth in Azusa.

“All 44 passengers and five crew members were killed aboard the DC-9, which plunged out of control into a remote canyon of the San Gabriel Mountains approximately three miles north of the city of Duarte. The wreckage of the F-4B fighter landed in another canyon approximately 3/4 of a mile southeast of the DC-9’s impact site.

“Although visibility was good, with no clouds, both crews failed to see and avoid each other. The Airwest DC-9 jetliner was under radar control, but the F-4B fighter was flying with an inoperable transponder that made it invisible on air traffic control radar screens.

“Allegations also surfaced that the F-4B was performing an aerobatics maneuver shortly before the collision.

“Fatalities: 50 — all 49 aboard the Airwest DC-9; 1 of 2 crew aboard the F-4B fighter.” (Notable California Aviation Disasters. “The 1970s.” Oct 23, 2008 update.)

Sources

Airdisaster.com. Accident Database. “Accident Synopsis 06061971.” Accessed at: http://www.airdisaster.com/cgi-bin/view_details.cgi?date=06061971&reg=N9345&airline=Hughes+Airwest

Aviation Safety Network. Accident Description. Hughes Airwest Flight 706, N of Duarte, CA, 6 Jun 1971. Accessed 8-1-2009 at: http://aviation-safety.net/database/record.php?id=19710606-0

Baugher, Joseph F. US Navy and US Marine Corps BuNos Third Series (150139 to 156169). Oct 29, 2011 revision. Accessed at: http://www.joebaugher.com/navy_serials/thirdseries19.html

Kimura, Chris Y. World Commercial Aircraft Accidents 3rd Edition, 1946-1993, Volume 1: Jet and Turboprop Aircrafts. Livermore, CA: Lawrence Livermore National Laboratory, Risk Assessment and Nuclear Engineering Group. 4-11-1994.

National Transportation Safety Board. Aircraft Accident Report. Hughes Air West DC-9, N9345 and U.S. Marine Corps F-4B, 151458 Near Duarte, California, June 6, 1971 (SA-426; File No. 1-0005; NTSB-AAR-72-26). Washington, DC: NTSB, adopted August 30, 1972, 50 p. At: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR72-26.pdf

NationMaster.com. Encyclopedia. “List of Notable Accidents and Incidents on Commercial Aircraft.” Accessed 12-15-2008 at: http://www.nationmaster.com/encyclopedia/List-of-notable-accidents-and-incidents-on-commercial-aircraft

Notable California Aviation Disasters. “The 1970s.” Oct 23, 2008 update. Accessed 10-18-2009 at: http://www.jaydeebee1.com/crash70s.html