Section 417.121 - Safety critical preflight operations(a)General. A launch operator must perform safety critical preflight operations that protect the public from the adverse effects of hazards associated with launch processing and flight of a launch vehicle. The launch operator must identify all safety critical preflight operations in the launch schedule required by § 417.17(b)(1) . Safety critical preflight operations must include those defined in this section.(b)Countdown. A launch operator must implement its countdown plan, of § 417.111(l) , for each launch. A launch operator must disseminate a countdown plan to all personnel responsible for the countdown and flight of a launch vehicle, and each person must follow that plan.(d)Meteorological data. A launch operator must conduct operations and coordinate with weather organizations, as needed, to obtain accurate meteorological data to support the flight safety analysis required by subpart C of this part and to ensure compliance with the flight commit criteria required by § 417.113 .(e)Local notification. A launch operator must implement its local agreements and public coordination plan of § 417.111(i) .(f)Hazard area surveillance. A launch operator must implement its hazard area surveillance and clearance plan, of § 417.111(j) , to meet the public safety criteria of § 417.107(b) for each launch.(g)Flight safety system preflight tests. A launch operator must conduct preflight tests of any flight safety system as required by section E417.41 of appendix E of this part.(h)Launch vehicle tracking data verification. For each launch, a launch operator must implement written procedures for verifying the accuracy of any launch vehicle tracking data provided. For a launch vehicle flown with a flight safety system, any source of tracking data must satisfy the requirements of § 417.307(b) .(i)Unguided suborbital rocket preflight operations. For the launch of an unguided suborbital rocket, in addition to meeting the other requirements of this section, a launch operator must perform the preflight wind weighting and other preflight safety operations required by §§ 417.125 , 417.233 , and appendix C of this part.Docket No. FAA-2000-7953, 71 FR 50537, Aug. 25, 2006, as amended by Amdt. No. 417-5, 81 FR 59439, Aug. 30, 2016; Doc. No. FAA-2019-0229, Amdt. 417-6, 85 FR 79716, Dec. 10, 2020