Critics Say NDAA Could Undermine D.C. Airspace Safety

NTSB chair Jennifer Homendy has raised an alarm over language in the National Defense Authorization Act (NDAA) that critics claim would allow the military to bypass safety protocols enacted after the January 29 midair collision between a CRJ700 operating as PSA Airlines Flight 5342 and a U.S. Army UH-60 Black Hawk helicopter near Washington, D.C., in which 67 people were killed. The NDAA passed in the House on Wednesday by 312-112 and is set to go to the Senate by year-end.

According to section 373(a) of the NDAA, “Except as provided in subsection (b), the Secretary of a military department may not authorize any manned rotary wing aircraft of the Department of Defense [now the Department of War] to operate a training mission in a covered airspace unless such aircraft, while being operated, is actively providing warning of the proximity of such aircraft to nearby commercial aircraft in a manner compatible with the traffic alert and collision avoidance system [TCAS] of such commercial aircraft.”

Essentially, this was the state of affairs when the accident happened. Compatibility with TCAS means that the intruder aircraft being detected by TCAS only needs a Mode C or S transponder. While the Army Black Hawk was equipped with a transponder capable of transmitting ADS-B Out, this feature was not available. However, the Black Hawk’s transponder was detected by the CRJ700’s TCAS. Below 900 feet agl, TCAS resolution advisories are inhibited, while traffic advisory aural annunciations are inhibited below 400 feet agl. The CRJ700’s last recorded altitude was 313 feet at two seconds before the collision, while the Black Hawk’s final recorded radar altitude was 278 feet.

The NDAA language would not require the training aircraft to be equipped with and use ADS-B Out, explained a letter Homendy sent to members of the Senate Committee on Commerce, Science, and Transportation.

“Part of our focus in that investigation is on the overall limitations and gaps in the traffic awareness, alerting, and collision-avoidance technologies such as ADS-B available to both aircraft. Following the accident, the FAA and Department of Defense (DOD) entered into an agreement to require military aircraft within the D.C. airspace to broadcast their position via ADS-B Out. The NTSB has, for decades, advocated for requirements for ADS-B In and Out and its substantial contribution to safety, especially near airports.

“Section 373(a) would roll back these broadcast requirements to the very conditions that existed in the D.C. airspace at the time of the accident, by allowing military aircraft to operate without ADS-B…In fact, a TCAS alert was provided to the Flight 5342 crew nearly 20 seconds before the collision occurred—such warning system had no impact on the tragedy that unfolded. Simply stated, a requirement limited to TCAS-compatible warning systems would not ensure adequate safety for any aircraft in the D.C. airspace.”

Homendy also criticized the section 373(a) allowance for waiving the transponder requirement, which could be done by the secretary of the Department of War (DOW), a general, or flag officer, following completion of a risk assessment. “We have serious concerns that such a risk assessment would not adequately evaluate the safety of the airspace, as it is clear from our investigation thus far, that the Army and potentially other military departments within the DOW do not understand the complexities of the D.C. airspace, how to conduct a thorough safety risk assessment, or implement appropriate mitigations to ensure safety for all…In fact, the language seems to allow military departments to do what they want in the D.C. airspace, with very little input from the secretary and none from the FAA, aviation industry, and others impacted…

“This provision is an unacceptable risk to the flying public, to commercial and military aircraft crews, and to residents in the region,” Homendy concluded. “It’s also an unthinkable dismissal of our investigation and of 67 families who lost loved ones in a tragedy that was entirely preventable. I urge you to consider the consequences of this provision, and I stand ready to work with you to address these urgent safety concerns.”

Tim and Sheri Lilley, parents of Flight 5342 first officer Sam Lilley, weighed in with a LinkedIn post, also asking lawmakers to “reject this language” and to include ADS-B Out in the NDAA.

“The national security waivers allowed by this draft are also deeply concerning,” the post explained. “As highlighted in public statements by several members of Congress and administration officials, the national security waivers that operators in the D.C. area have exploited are problematic and subject to abuse. This bill addresses that with a ‘window dressing’ fix that will continue to allow for the setting aside of requirements with nothing more than a cursory risk assessment.

“Safety that depends on exemptions cannot be the foundation of a secure airspace system. The flying public and all those who utilize our airspace deserve better aviation safety policy than what this bill provides.

“The January 29 midair accident that took 67 souls, including our son, AA5342 first officer Sam Lilley, showed us exactly what is at stake,” they wrote. “Congress now has a choice: strengthen this provision and protect the traveling public or leave in place the same vulnerabilities that have already cost too many people their lives.”