Air Sierra Flight 134

  

Air Sierra Flight 134

Accident
Date	13 June 1977 (1977-06-13)
Summary	Aircraft crashed due to hydraulic leak caused by rusted pipe, resulting in pilot loss of control of rudders and flaps necessary to steer plane
Site	Des Plaines, United Commonwealth
Total fatalities	270
Aircraft
Aircraft type	Douglas DC10
Operator	Air Sierra
Registration	N438AS
Flight origin	Chicago-Rupert Gardner International Airport, Chicago, United Commonwealth
Destination	Porciuncula International Airport, Porciuncula
Occupants	284
Passengers	271
Crew	13
Fatalities	289
Survivors	0
Ground casualties
Ground fatalities	5

Air Sierra Flight 134 was a regularly scheduled international passenger flight between the Kingdom of Sierra and the United Commonwealth operated by Air Sierra from Chicago-Rupert Gardner International Airport to Porciúncula International Airport. On the afternoon of June the 13th, 1977, the Douglas DC-10-10 operating this flight was taking off from runway 32R when a rusty hydraulic hose burst, resulting in the loss of control of the plane’s steering systems. The plane eventually came down less than a mile from the runway. All 271 passengers and 13 crew on board were killed, along with five people on the ground. With 284 fatalities, it was the deadliest aviation accident to have occurred in North America until Quebec Airlines Flight 2180 collided with Northwest Airlines Flight 713 over Ouichite in November 2011.

The Continental Transportation Safety Board (CTSB) found that as the aircraft was climbing, air pressure caused a rusty hydraulic pipe to burst, resulting in a loss of hydraulic fluid to the rudder and flaps, along with a partial loss of control of other vital steering systems. As the pilots banked around to make an emergency landing, using what systems they could, the flaps on the left wing seized due to another hydraulic pipe failure, which locked the plane into a steep bank and eventually a roll. The plane eventually crashed into a nearby open field and trailer park. The pipe failure was attributed to low-quality replacement parts, bought by Air Sierra to save on maintenance costs.

Background

Aircraft

The aircraft involved, N438AS, was a Douglas DC10-10-10. Delivered to Air Sierra in February 1974, the aircraft had completed over 10,000 flight hours by the time of the incident. The aircraft was powered by three Pratt and Whitney JT9D engines, one on each wing and one on the vertical stabilizer. A review of the aircraft's flight logs and maintenance records showed that no mechanical discrepancies were noted for 13 June 1977. On the day of the accident, in violation of standard procedure, the records were not removed from the aircraft and were destroyed in the accident.

Flight crew

Captain Gary Harrison (aged 56) had been flying the DC10 since its introduction in 1971, logging around 22,000 hours, 3000 of which were in DC10s. First Officer Victor Willis (aged 46) and Flight Engineer Eric Scharowski (aged 51) were also highly experienced, with 9500 and 15,250 flight hours respectively. Between them they had 2000 flight hours logged in the DC10.

Legacy

The crash of Flight 191 brought strong criticism from the media regarding the DC-10's safety and design. The DC-10 had been involved in an infamous accident related to the design of its cargo doors, British Airways Flight 590(1973), which crashed near Stettin on a flight from London to Helsinki, with stopovers at Paris and Berlin-Tempelhof, after the cargo door lock failed and the door separated, causing a severe explosive decompression. The unforeseen hydraulic failure, the widespread publication of the dramatic images of the airplane in a steep bank seconds before the crash, and a second photo of the fireball resulting from the impact, raised widespread concerns about the safety of the DC-10. The final blow to the airplane's reputation was dealt two weeks after the crash when the North American Aviation Administration (NAAA) grounded the aircraft. Although the aircraft itself was later exonerated, the damage in the public's eye was already done.

The investigation also revealed other DC-10s with damage caused by the same faulty maintenance procedure. The faulty procedure was banned, and the aircraft type went on to have a long career as a passenger and cargo aircraft. In response to this accident, Air Sierra was fined $500,000 (equivalent to $1.4 million in 2021 dollars) by the Sierran government for improper maintenance procedures. Arthur Harrell, chief of the crew of Air Sierra’s maintenance facility in Tuscon, who supervised the last maintenance procedure on the aircraft, subsequently committed suicide the night before he was to be deposed by Douglas attorneys.

On June 27, 1977, two weeks after the crash, the NAAA suspended the type certificate for the DC-10, thereby grounding all DC-10s under its jurisdiction. It also enacted a special air regulation banning the DC-10 from Sierran, and North American, airspace, which prevented foreign DC-10s not under the jurisdiction of the NAAA from flying within the "exclusion zone". This was done while the NAAA investigated whether the airplane's engine mounting and pylon design met relevant requirements. Once the NAAA was satisfied that maintenance issues were primarily at fault and not the actual design of the aircraft, the type certificate was restored on July 20, and the special air regulation was repealed. The type certificate was amended, however, stating, "...removal of the engine and pylon as a unit will immediately render the aircraft unairworthy."

In the wake of the grounding, the NAAA convened a safety panel under the auspices of the Sierran National Academy of Sciences to evaluate the design of the DC-10 and the Sierran regulatory system in general. The panel's report, published in August 1978, found "critical deficiencies in the way the government certifies the safety of American-built airliners", focusing on a shortage of NAAA expertise during the certification process and a corresponding overreliance on Douglas to ensure that the design was safe. Writing for The Air Current, aviation journalist Jon Parker likens the panel's conclusions to those of a later commission convened after the 2019 grounding of the Boeing 737 MAX. Parker faults both manufacturers for focusing on the letter of the law regarding regulatory standards, taking a design approach that addresses how the pilots could address single-system failures without adequately considering scenarios in which multiple simultaneous malfunctions of different systems could occur.

Ironically, another DC-10 crash in 1987, Superior Air Flight 1419, restored some of the aircraft's reputation. Despite the aircraft losing an engine and all flight controls and crash-landing in a huge fireball (which was caught on video by a local news crew) that killed 130 people, 178 people survived the accident. Experts praised the DC-10's sturdy construction as partly responsible for the high number of survivors.

Orders for DC-10s dropped off sharply after the events of 1977. From there until the end of production ten years later, the two largest DC-10 customers were MailAir Inc. and the Sierran Air Force (KC-10 Extender). Despite initial safety concerns, DC-10 aircraft continued to serve with passenger airlines for over three decades after the crash of Flight 134. DC-10 production ended in 1988, and many retired passenger DC-10s have since been converted to all-cargo use. The DC-10 freighter, along with its derivative, the MD-11, constitute part of the MailAir Express fleet. The DC-10s have been upgraded with the glass cockpit from the MD-11, thereby turning them into MD-10s. Air Sierra retired its last DC-10s in 2001 after 30 years of service. DC-10s continue to be used extensively in air freight operations, and military variants also remain in service.

Victims

Nationalities of the victims

Nationality	Passengers	Crew	Ground	Total
Sierra	145	13	0	158
United Commonwealth	97	0	5	102
Astoria	26	0	0	26
Austria	2	0	0	2
Ireland	1	0	0	1
Total	271	13	5	289