The DoD Safety Privilege: A Powerful Tool with an Interesting History


The national security of the United States is dependent on the efficient operation of weapon systems such as Air Force aircraft, missiles, space satellites, and nuclear weapon systems. When mishaps occur, commands operating these systems must be able to quickly obtain candid, complete, and accurate information to find and correct, or rule out, systemwide defects. To do this, commands must be free to deliberate confidentially and to exchange information without fear of repercussion, a privilege that was born in the early days of flight and has progressed up to modern times.

The U.S. military has been investigating military airplane crashes since 1908, when Orville Wright, flying a Wright Flyer III, crashed during a demonstration flight at Fort Myer, Virginia, killing 1st Lt Thomas Selfridge. The military produced an investigation report in response that was not privileged, but was classified, meaning exempt from public disclosure. Department of Defense (DoD) classification criteria changed in the mid-1950s to the standards we are familiar with now, i.e., information that could seriously damage national security if disclosed in an unauthorized manner.

Following the Wright incident, the DoD recognized the effectiveness of mishap investigations in reducing the number and severity of mishaps, and it noticed the direct correlation between reduced injury, death, damage, and mission readiness and combat capability to the United States’ national security. The Department created the limited-use Safety Investigation and declared that this type of report would be for the exclusive purpose of preventing mishaps, and would not be available for other aims including public release or disciplinary action. For reference, DoDI 6055.07 describes the specific justification and the limited use of this type of report.

The common-law recognition of the limited-use Safety Investigation and the concept of safety privilege was shaped in a 1963 federal court decision, Machin v. Zuckert, and affirmed by the United States Supreme Court in United States v. Weber Aircraft Corp. in 1984.

Machin v. Zuckert was the first formal recognition of the “military safety privilege” and is still used by the DoD today. In 1956, a B-25 bomber crashed shortly after takeoff, leaving one survivor, Lt Jack Machin. After his recovery, Lt Machin sued the manufacturer of the aircraft propeller assemblies and requested to use the safety investigation report as evidence. A notable point of discussion was that safety investigators, lacking the power to compel legal testimony, encouraged frank and full cooperation by means of promises that the witnesses’ testimony would be used solely for the purposes of flight safety. The Inspector General of the Air Force in 1961 stated, “… if investigators were unable to give such assurances, testimony in many instances would be less than fully factual and the determination of the exact causative factors would be jeopardized, thus seriously hindering the accomplishment of prompt corrective action designed to preclude recurrences of similar accidents.”

The Machin court partially denied the Lt’s request, holding that confidential statements of private parties made to investigators of an Air Force accident were privileged when disclosure would hamper the efficient operation of an important government program. The court also held that the military safety privilege extended to any conclusions that might be based on such privileged information. In conclusion to the case of Machin v. Zuckert, “the court held that the military safety privilege attached to any portions of the investigative report, reflecting military deliberations or recommendations as to policies, should be pursued.” However, the court also found that certain portions of the investigative report—specifically, the factual findings of Air Force mechanics who provided technical assistance—were not privileged.

In 1984, the U.S. Supreme Court stated in United States v. Weber Aircraft Corp. that the so-called Machin privilege was a “well-recognized” judicial privilege and was protected from disclosure under the Freedom of Information Act, affirming its use in the safety reporting process until the present day.

The mishap investigation process has matured over the course of history. Courts have confirmed that the portions of a safety report that reflect the investigators’ analysis, including its findings, factors, causes, and recommendations, were properly privileged because releasing them could stifle the candor of the investigators, and statements taken under a promise of confidentiality were properly privileged, for the same reason. The courts recognized that regardless of the specific harm in a case, the loss of that blunt and frank honesty would not only take away a valuable tool for commands, but would detract from the confidence of operators and other military personnel in the safety investigation process, which would further erode the candor of all parties.

Meanwhile, non-confidential information gathered by a safety investigation is generally not privileged and may be publicly released, subject to appropriate classification and Privacy Act and Freedom of Information Act restrictions. Those non-privileged materials may also be used by other investigations, such as those performed by an Accident Investigation Board (AIB).

Unlike Air Force Safety Investigation Boards (SIBs), AIBs obtain and preserve evidence for all other purposes, including public disclosure, claims, litigation, administrative actions, and even disciplinary action. The AIB president must provide the public a statement of opinion to include the cause or substantially contributing factors, if supported by a preponderance of evidence.

The AIB report is not privileged and is fully releasable. A copy is provided and briefed to the next of kin of military and civilians killed and to individuals seriously injured in the accident. The AIB report is important because it fulfills these and other needs for information after a mishap, including public release and any litigation requirements.

The DoD’s efforts to protect and use privileged safety information are critical to mishap prevention and combat readiness.

When confidential witnesses and investigators doubt that SIBs are being used only for those purposes, witnesses are likely to stop providing complete and candid statements, and investigators are likely to dilute hard-hitting recommendations. In short, the whole enterprise falls apart.

The next time you are completing your annual training, remember that safety privilege has nearly six decades of legal history, and that protecting limited-use SIB reports requires the consistent demonstration of intent and practice not to release them outside the Air Force safety community. Safety privilege is a powerful tool that can be lost through the lack of vigilance. Routine use of safety information must be in strict accordance with DAFI 91-204, Safety Investigations and Reports.