On July 22, 2014, the Federal Aviation Administration (FAA) issued a supplemental notice of proposed rulemaking (SNPRM), to amend an August 23, 2013 notice of proposed rulemaking (August NPRM) to ensure that tethered launches using propellants that cause serious injury to the public would not be eligible for exclusion from existing safety regulations.
The August NPRM (77 FR 50956) proposed to exclude certain tethered launches from the FAA’s licensing and permitting requirements under chapter III of title 14, Code of Federal Regulations. The FAA included criteria to determine whether the tethered launches had a sufficient level of safety to merit exclusion. These criteria included minimum safety factors for yield stress and ultimate stress, a maximum launch height of 75 feet above ground level, and insulation or location such that the launch vehicle would not experience thermal damage from the launch vehicle exhaust. A commenter on the NPRM raised an issue regarding toxic propellants that was not discussed in the NPRM, and the FAA felt that this issue needed to be addressed.
In response to the concerns raised by the commentator, PHMSA, in the July 22 SNPRM, clarified the exclusion and proposed that if an operator chooses to use any of the toxic propellants identified in Tables I417-2 and I417-3 in Appendix I of part 417 that launch must meet chapter III licensing, permitting, and waiver requirements.
The SNPRM also included two revisions to the language in the original NPRM based on recommendations from commenters from the August NPRM. First, the agency removed the term “established strength properties” from proposed Section 400.2(c)(2)(i) to better clarify the proposed requirement andpreserve the original intent, which is to ensure that the tether system can withstand the maximum dynamic load placed upon it. Second, the FAA revised proposed Section 400.2(c)(2)(iii) to clarify that the maximum flight limit of 75 feet for a tethered launch vehicle would be measured from the ground to a fully-extended tether’s attachment point to a vertically-oriented vehicle.
The FAA SNPRM can be foundhere.
For further information regarding the proposed rulemaking, please contact Glenn Wicks, Ronce Almond, or Arielle Pacer at (202) 457-7790.