In Space No One Can Hear the Noise, But We Can Hear it on the Ground

The FAA’s Office of the Chief Counsel issues legal interpretations when a conflict arises between regulations or between regulations and a statute. If there truly is an irreconcilable conflict between a statute and a regulation, the statute wins, of course, because agency-issued regulations must be issued in accordance with law. We find the law in the Congressionally enacted statute.

A Launch Does not Require a Special Flight Authorization to Exceed Mach 1

In 2013, the Regulations Division of the Office of the Chief Counsel issued a legal interpretation about noise, in which it stated that SpaceShipTwo did not need to obtain a special flight authorization  to exceed Mach 1 under 14 C.F.R. § 91.817.  That aviation regulation, section 91.817 ,provides:

(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator under appendix B of this part.

Rockets are fast. Rockets can exceed Mach 1. Exceeding Mach 1 too close to houses can result in noise and even broken windows. The rocket SpaceShipTwo, like its predecessor SpaceShipOne, is carried to about 50,000 feet by a carrier aircraft called the White Knight. The carrier aircraft drops the rocket, gets out of the way, and the rocket ignites for its journey to 100 kilometers and back again. It can exceed Mach 1.

But rockets are not regulated as aircraft, even though they meet the definition of aircraft. Rather than regulating rockets or other launch vehicles under the Federal Aviation Act, the FAA regulates rockets under the Commercial Space Launch Act (CSLA), so different regulations apply. As noted in the legal interpretation, although other laws may apply to the launch of a launch vehicle, an operator need not obtain other approvals for that launch.

The Commercial Space Launch Act states in 51 U.S.C. § 50919(a)

Except as provided in this chapter, a person is not required to obtain from an executive agency a license, approval, waiver or exemption to launch a launch vehicle or operate a launch site or reentry site, or to reenter a reentry vehicle.

Because section 91.817’s requirement for a special flight authorization constitutes an approval, a person conducting a licensed launch need not obtain that additional approval for the launch.

The legal interpretation also explains that an earlier decision to require SpaceShipOne to obtain approval for an aircraft to exceed Mach 1 arose out of the legal error of applying an experimental airworthiness certificate to an activity—namely, the launch of SpaceShipOne and its carrier aircraft—that should have only been conducted under a space license. Because of the presence of the carrier aircraft, and because SpaceShipOne sometimes operated as an aircraft rather than always employing its rocket engines, the FAA had granted the rocket’s operator both a launch license and an experimental airworthiness certificate. This decision to issue dual aviation and space authorizations may have led to the decision to require the Mach 1 authorization. Regardless, in response, Congress amended the CSLA in section 50904(d) to emphasize that when operations took place under the CSLA only a single license or permit could be in effect, just as section 50919(a) already said. The legal interpretation clarifies all of this.

Don’t Break the Windows

Because the grant of a launch license is a major federal action under the National Environmental Policy Act, the FAA must conduct environmental assessments or impact statements before issuing a launch license. In these reviews the agency addresses noise issues.   One of the things I learned during my time at the FAA was that people who live close to airports care about noise.  They care a lot.  Noise can and will serve as a catalyst for the populace to rise up in indignation, march on Washington, and demand regulation. This means that escaping authorization under 91.817 does not provide carte blanche to go popping supersonic wheelies. I don’t know if Rudy Giuliani’s broken window theory applies here, but there are other regulations that may apply to supersonic activities. Be careful out there.