Officials investigating why a panel on a Boeing 737 Max 9 opened during an Alaska Airlines flight last week say they are struggling to piece together exactly what happened because the plane's cockpit voice recorder was overwritten before it could be recorded. recovered.
This is not a new problem. The National Transportation Safety Board, which is leading the investigation, has for years recommended that recorders be programmed to capture up to 25 hours of audio before automatically restarting, but the Federal Aviation Administration has been reluctant to require longer recordings. .
Last month, the FAA proposed 25-hour recorders on new planes, but argued that adding them to the existing fleet of U.S. planes would be too costly. Additionally, a pilots union has opposed the change to 25-hour recordings unless Congress establishes protections prohibiting their release to the public.
Safety board chair Jennifer Homendy said agency investigators had conducted 10 investigations since 2018 in which the cockpit voice recorder had been erased and critical recordings were lost forever. Voice recorders are among the key evidence investigators use to reconstruct the events leading up to the accidents as they work to establish a cause.
Ms. Homendy said a recording of the Alaska Airlines flight would have contained a lot of important information, including the bang the crew described hearing shortly after the plane took off Friday from Portland, Oregon. She said the recording would have allowed investigators to listen to communications between the crew during the incident and identify any communication problems, including audible alerts in the cockpit.
“There is so much information we can get from the CVR that goes beyond communication between the flight crew,” Ms. Homendy said. “That is a key test to improve security. Without that, we are piecing things together from the interviews and losing a lot.”
Members of the flight crew told federal investigators that they had been so focused on going through their emergency checklist, communicating with air traffic control and landing the plane on the ground that they had not heard any alerts. Federal investigators have not suggested any errors were made by the pilots or flight crew.
“So now that's what they don't remember, and we have no evidence that it was happening,” Ms. Homendy said. “So if there was some kind of failure in any kind of oral alert, we wouldn't know about it.”
Alaska Airlines said in a statement Wednesday that because of the active investigation, it could not comment on why audio from the cockpit recorder was not recovered in time. But the airline added that it welcomed the FAA's proposal to lengthen the recording time.
“We support this effort, which would bring the US airline industry more in line with international regulations,” the airline said.
The United States had lagged behind much of the world in requiring the use of longer voice recordings on commercial airplanes. In 2016, the International Civil Aviation Organization, a branch of the United Nations, adopted a standard requiring recorders capable of capturing the last 25 hours of audio on all new aircraft starting in 2021. The Agency's 25-hour mandate of Aviation Safety of the European Union was fulfilled. will come into effect in January 2021 for new aircraft.
Cockpit voice recordings begin the moment the pilots start the plane. This allows the recording to capture pilots' pre-flight checks, passenger boarding and other activities as the crew prepares for takeoff.
The two-hour limit means the recorder can be quickly overwritten even on short flights, especially if there are delays on the runway. Once the two-hour limit is reached, recording starts again automatically.
The recorders are designed to automatically stop when there is an accident, but they do not stop in incidents like the Alaska Airlines 737 Max 9. In such cases, someone would have to remove a circuit breaker from the plane to prevent the device from stopping. start again. That didn't happen in this case.
The safety board began recommending increasing the recording time after a horrific incident in 2017 at San Francisco International Airport when an Air Canada plane nearly landed on a taxiway instead of a nearby runway. Four planes loaded with passengers were waiting on the taxiway. The incident could have been one of the worst aviation disasters in history, but federal investigators still have no idea what was happening in the cockpit because the recording automatically started over before it could be recovered.
Robert Sumwalt, who was the safety board's chairman at the time, said recordings of major aviation incidents could give federal investigators a more complete picture of what happened and how to prevent it from happening again.
“It gives you a pretty much first-hand view of what conversations and what sounds are going on in the cabin,” he said. “People may think they remember things clearly, but sometimes our memory fails us.”
In December, the FAA proposed a rule that would require new airplanes to be equipped with 25-hour voice recorders, but stopped short of requiring commercial airlines to install the recorders on all airplanes, as the NTSB recommended.
The FAA estimated that upgrading each plane would cost $741 million. Installing the new recorders on new planes alone would cost $196 million.
“Our proposed rule aligns with regulations established by the International Civil Aviation Organization and the European Union Aviation Safety Agency,” the agency said in a statement.
Homendy said saving lives should outweigh any financial concerns. He also noted that the lasting impact of a catastrophic plane crash would be far greater than the immediate cost of improved safety that would be borne by airlines and, ultimately, travelers.
“The cost would be substantial, not only in financial terms but also in terms of the reputation of the company, in terms of the reputation of the manufacturer and the suppliers and everyone else involved, and the cost of public confidence in the system.” of American aviation. ”Ms. Homendy said. “That's what would be lost immediately.”
Congress has also taken note of the issue. Bills pending in the House and Senate to reauthorize the FAA would extend the recording duration to 25 hours on all aircraft within four years.
Since the incident in San Francisco in 2017, Rep. Mark DeSaulnier, a California Democrat on the House Transportation and Infrastructure Committee, said he supported the safety board's recommendation on voice recorders because they are often They were losing critical data because researchers couldn't recover it quickly enough.
“Moving to 25-hour cockpit voice recorders is an essential component of advancing air travel safety that has already been adopted as an international standard,” said Mr. DeSaulnier.
But the Air Line Pilots Association, which represents Alaska pilots, Delta Air Lines, United Airlines and other companies, has long opposed the adoption of a 25-hour voice recorder, citing privacy concerns. . In a statement, the union said that while voice and flight data recorders provided critical information, the group wanted lawmakers to ensure that researchers used the recordings only to improve the aviation system.
Federal law prohibits the safety board from releasing copies of the cockpit voice recorders under freedom of information laws. But the law does not prevent the FAA or airlines from publishing copies.
“Unfortunately, the legal statute protecting the privacy of the cockpit voice recorder only applies to the NTSB,” the statement said. “In addition to the NTSB, the protections contained in that statute should be strengthened and applied to airlines, as well as the FAA, before considering extending the duration.”
Sen. Ted Cruz, R-Texas, said that despite pushback from the pilots' union, he and other members of Congress planned to advance legislation to increase recording time.
“Without access to cockpit voice recordings, investigators lack essential information about any concerning incident, whether a near miss, an equipment failure or the recent Alaska Airlines flight,” Cruz said in an interview.
Niraj Chokshi contributed reports.
