1969 — Jan 18, United Flight 266 Instrument Failure/Crash, Santa Monica Bay, CA — 38

–38 Aviation Safety Network. Accident Description. United Airlines Flight 266, 18 Jan 1969.
–38 Kimura. World Commercial Aircraft Accidents 3rd Ed., 1946-1993, V.1. 4-11-1994, p. 2-10.
–38 NTSB. AAR. United Air Lines…Near Los Angeles, California, January 18, 1969.
–38 Notable California Aviation Disasters. “The 1960s.” Oct 23, 2008 update.

Narrative Information

ASN: “Boeing 727-22C N7434U operated Flight 266 from Los Angeles to Denver, CO and Milwaukee, WI. The aircraft had been operating since January 15, 1969, with the No. 3 generator inoperative. This was allowed because according to the Minimum Equipment List, the aircraft is airworthy with only two generators operable provided certain procedures are followed and electrical loads are monitored during flight.

”Flight 266 was scheduled to depart the gate at 17:55, but was delayed until 18:07 because of the inclement weather and loading problems. The flight commenced its takeoff roll on Runway 24 at approximately 18:17. At 18:18:30 the sound of an engine fire warning bell was heard in the cockpit. The crew reported a no. 1 engine fire warning and stated that they wanted to return to the airport. Shortly after shutdown of the No. 1 engine, electrical power from the remaining generator (No. 2) was lost. Following loss of all generator power, the standby electrical system either was not activated or failed to function. Electrical power at a voltage level of approximately 50 volts was restored approximately a minute and a half after loss of the No. 2 generator. The duration of this power restoration was just 9 to 15 seconds. The Boeing descended and struck the sea 11.3 miles west of the airport. The ocean depth at this point is approximately 950 feet.

“Follow-up / safety actions:

”The NTSB issued some recommendations with regards to the Boeing 727 electrical system and emergency procedures. The FAA…issued Airworthiness Directive AD 69-16-01 requiring revision of the Boeing 727 Airplane Flight Manual to provide the flight crew with more complete procedures to be followed if all generators are lost.

”The FAA also took several other actions. As a result of information developed during the early stages of the investigation, the FAA issued Airworthiness Directive AD 69-04-01 on January 31, 1969, requiring B727 operators to provide a means to prevent inadvertent operation of the battery switch in those aircraft in which the battery switch is located within 10 inches of the galley power switch.

”On August 1, 1969, the FAA proposed Airworthiness Directive 69-25-01 requiring the installation of a capacitor for the purpose of filtering out electrical interference which may be present to a sufficient extent on some B727 aircraft that, under an overloaded condition, the generator control panel may disable the generator before opening the bus tie circuit breaker.

”On September 10, 1969, the FAA proposed Airworthiness Directive 69-25-01 which required replacement of two silicon controlled switches with a transistorized amplifier and a miniature two-pole relay on B727 airplanes. As a reason for this replacement, the FAA cited failures of the generator overload protection circuit silicon controlled rectifiers, causing a single generator system lockout on B727 aircraft.” (ASN. AD. United Airlines Flight 266, 18 Jan 1969; cites NTSB/AAR-70-06, March 18, 1970.)

NTSB:
Synopsis

“United Air Lines, Inc., Flight 266, a Boeing 727-22C, N7434U, crashed into Santa Monica Bay, approximately 11.3 miles west of the Los Angeles International Airport, at 1821 P.s.t. on January 18, 1969. The plane was destroyed and the six crewmembers and 32 passengers on board were all fatally injured.

“Flight 266 departed from Los Angeles Airport at 1817 P.s.t., and 2 minutes later reported to Departure Control that they had experienced a fire-warning on the No. 1 engine and wished to return. This was the last communication with the flight. The secondary or transponder target disappeared from the radarscope immediately following the above transmission. Thereafter, movement of the primary target indicated the aircraft continued to track a straight course on the last assigned heading of 270 [degrees] for approximately a minute and a half, after which the aircraft commence a left turn. The target then disappeared from the radarscope…..

“The Board determines that the probable cause of this accident was the loss of attitude orientation during a night, instrument departure in which all attitude instruments were disabled by loss of electrical power. The Board has been unable to determine (a) why all generator power was lost or (b) why the standby electrical power system either was not activated or failed to function.

History of the Flight

“United Air Lines, Inc., (UAL), Flight 266 was a regularly scheduled passenger and cargo flight from Los Angeles, California, to Milwaukee, Wisconsin, with an en route stop at Denver, Colorado. N7434U, a Boeing 727-22C, which was utilized for this flight on January 18, 1969, arrived in Los Angeles from Denver at about 1530 on that date.

“While N7434U was on the ground at Los Angeles, a routine en route inspection was performed by UAL mechanic who found the aircraft to be serviceable and noticed nothing unusual. This check consists basically of an interior and exterior visual inspection of the aircraft for any condition that might require corrective action. During the period the aircraft was on the ground, rain was falling intermittently. However, the aircraft was equipped with a protective canvas shroud designed to prevent water from dripping into the electrical bay area….

“Two ground witnesses observed an aircraft taking off from Runway 24 at a time corresponding to the departure of Flight 266. One of these witnesses, who identified the aircraft as a E727 based on the engine arrangement, noticed nothing unusual about the aircraft as it flew directly over his car. The other witness’ attention was attracted by many sparks, reddish in color, coming from the right side and rear engine of the aircraft. She observed the aircraft when it was about 1,000 feet high and climbing gradually at what appeared to be normal speed.

“Another ground witness, who was located on a hill above Paradise Cove (northwest of the impact point), observed an aircraft over the water, turn to its left, and head east back toward the airport. As the plane descended into a thick fog bank, he heard an explosion and saw a flash of light. A fourth ground witness was driving along Malibu Beach i n an easterly direction when his son exclaimed “Look, Dad, fire.” The man stopped the car, got out and saw an aircraft “on fire”, which seemed to be coming from the front of the plane. The aircraft was descending, heading toward the airport and then it plunged straight down into the ocean. This witness also heard several “firecracker” or “backfire” sounds while the plane was still in the air….

Survival Aspects

“The complete destruction and extreme degree of fragmentation of the aircraft, particularly the occupiable area, are indicative of impact forces far exceeding human tolerance. Apart from one severely mutilated body, only body fragments were recovered and only two identifications (both of which were passengers) could be made….

Analysis

“On the basis of the evidence adduced from the wreckage, and the recorded crew conversation in the final moments of flight, it is apparent that the aircraft was in an abnormal attitude when it struck the water. The limited scatter of the wreckage is indicative of a steep impact angle, while the fragmentation pattern indicates that the aircraft impacted at a relatively high rate of speed in a right wing low, nose low attitude. The exclamations of the first officer during the final seconds (“Keep it going up – you’re a thousand feet – pull it up”) further demonstrate that loss of attitude orientation was experienced prior to striking the water.” (NTSB. AAR. United Air Lines…Near Los Angeles, California, January 18, 1969.)

Notable California Aviation Disasters:

“Number 10 of California’s “10 Worst Crashes”
Date / Time: Saturday, January 18, 1969 / 6:21 p.m.
Operator / Flight No.: United Air Lines / Flight 266
Location: Pacific Ocean, near Los Angeles International Airport

“Details and Probable Cause: A second commercial jetliner crash into Santa Monica Bay near Los Angeles International Airport occurred just five days after an SAS DC-8 accident (see above) killed 15 persons.

“In the second offshore accident, a United Air Lines Boeing B727-22QC (N7434U) tri-jet, bound for Denver, Colorado, and Milwaukee, Wisconsin, crashed at high speed into the Pacific Ocean 11.5 miles west of the airport shortly after takeoff.

“Two minutes into its flight, the plane’s crew reported a fire warning in the No. 1 engine and shut it down. The aircraft had departed LAX with its No. 3 generator inoperable, and shutting down the suspect engine now took a second generator offline. The remaining No. 2 generator became overloaded and shut down, resulting in the loss of all electrical power aboard the 727.

“Flying in darkness and rain, with no lights or instruments, the cockpit crew became disoriented and the jetliner crashed into the ocean, killing all 32 passengers and six crew members on board.
At the time, a battery powered back-up source for instruments was not required on commercial aircraft. The disaster prompted the Federal Aviation Administration (FAA) to require all transport category aircraft to have new back-up instrumentation installed, and powered by a source independent of the generators.

“Fatalities: 38 — all 32 passengers and 6 crew members.” (Notable California Aviation Disasters. “The 1960s.” Oct 23, 2008 update.)

Sources

Aviation Safety Network. Accident Description. United Air Lines Flight 266, 18 Jan 1969. Accessed 3/2/2009 at: http://aviation-safety.net/database/record.php?id=19690118-0

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. United Air Lines, Inc., Boeing 727-22C, N7434U, Near Los Angeles, California, January 18, 1969 (SA-413; File No. 1-0004; NTSB-AAR-70-6). Washington, DC: NTSB, Adopted March 18, 1970, 43 pages. Accessed at: http://www.airdisaster.com/reports/ntsb/AAR70-06.pdf

Notable California Aviation Disasters. “The 1960s.” Oct 23, 2008 update. Accessed 10/17/2009 at: http://www.jaydeebee1.com/crash60s.html