The Crosscheck: The CVR is for Accident Investigation

Cockpit voice recorder. Photo credit: Adobe Stock/alswart

Cockpit voice recorders (CVRs) have proven invaluable to accident investigations in the U.S. since they were first required in 1967. To the trained ear, crew remarks and sounds picked up by cockpit area microphones can provide essential clues that help explain the accident sequence of events, the crew’s concerns and focus, the conduct of checklists and nuances of cockpit activity that are not available any other way.

To protect privacy and to avoid feeding media sensationalism, the NTSB never releases the actual recordings to the public. Most other countries follow the same practice. Unlike many investigative agencies, the NTSB does produce a transcript--a precise written record of every sound and statement that can be understood by skilled auditioners--and releases that transcript at the time of a public hearing, if one is held, or when the majority of other factual reports are placed in the public docket. 

Being able to read a CVR transcript often gives the informed observer a good idea of why the investigators drew some of their conclusions. This is in keeping with the NTSB’s focus on clarity and transparency of factual information.

In the 2010 board meeting to consider the facts, circumstances and causes of the Colgan 3407 accident, board members ventured onto dangerous ground. They brought up the idea of using CVR recordings to monitor crew performance as part of flight operational quality assurance (FOQA) programs. The way that the Colgan crew had allowed their personal conversation to distract them undoubtedly affected the board members’ judgment on this recommendation. The Board’s debate about the three proposed FOQA recommendations went on at great length. The meeting, which started at 9:30am, went past 6pm before concluding.

The idea of using CVRs in FOQA was first raised by Harry Mitchel, Colgan’s VP of Flight Operations. In a letter to Colgan’s newly formed unit of the Air Line Pilots Association (ALPA), Mitchel suggested that CVR data should be added to their FOQA program. At the time, three months after the accident, the NTSB was heavily scrutinizing Colgan’s safety management practices. Colgan was only in the preliminary stages of FOQA and had no actual program under way, and the idea of such use of CVRs had not been broached by any other airline. Mitchel made sure that NTSB investigators got a copy of the letter. In my view, it was a red herring.

When the final report was presented to the NTSB, board members bit on Mitchell’s ploy. The FOQA recommendations, which had originally been drafted only to require Part 121,135 and 91k operations to adopt FOQA, was modified to include “all available sources of safety information.” It was a way to recommend CVR use in FOQA without using the actual term, and it marred an otherwise good recommendation.

It is ironic that the board fell prey to this use of the CVR. The CVR has long been sacrosanct at the NTSB. Staff members could be, and have been, fired for leaking or even speaking about CVR information outside an investigation. The NTSB has a strict chain of custody procedure for handling even the transcript before it is officially released. Having operators routinely peruse voice recordings violates the spirit of the board’s own rules.

The FAA Administrator, Randy Babbitt, immediately replied to these recommendations but ignored the CVR idea, saying the FAA agreed FOQA programs were a good idea but they would remain voluntary. In a 2015 letter to the FAA regarding FOQA, the NTSB again raised the argument of using the CVR for “safety improvement” purposes. The FAA disagreed in 2016 and again in 2020. Administrator Steve Dickson finally closed the door on this argument in March of 2020, saying the FAA considered their actions on the matter complete. 

Demonstrating a genuine tin ear, the board once again wrote a lengthy letter to the FAA arguing in favor of using the CVR for FOQA. Rather than just closing out their final FOQA recommendation, A-10-29, they left it “open--unacceptable response.” When it will be closed is anybody’s guess, but CVRs will not be a part of FAA approved FOQA programs.

The recording of cockpit conversations has been a hot button item for pilots since CVRs were first introduced. Pilot groups, including ALPA, have long accepted CVRs as a proper tool for accident investigation, but they are absolutely opposed to having their discussions routinely monitored. Why antagonize a key group and jeopardize a successful safety program? CVRs have earned a rightful place in the accident investigator’s toolbox. Thanks to the FAA, we’ll be leaving it that way.

Editor's Note: Roger Cox's BCA safety column called The Crosscheck explores the interaction between regulators/investigators and pilots/operators. Send comments to

Roger Cox

A former military, corporate and airline pilot, Roger Cox was also a senior investigator at the NTSB. He writes about aviation safety issues.