14 CFR §417.119

1. (a)General. A launch operator must rehearse its launch crew and systems to identify corrective actions needed to ensure public safety. The launch operator must conduct all rehearsals as follows:
   1. (1)A launch operator must assess any anomalies identified by a rehearsal, and must incorporate any changes to launch processing and flight needed to correct any anomaly that is material to public safety.
   2. (2)A launch operator must inform the FAA of any public safety related anomalies and related changes in operations performed during launch processing or flight resulting from a rehearsal.
   3. (3)For each launch, each person with a public safety critical role who will participate in the launch processing or flight of a launch vehicle must participate in at least one related rehearsal that exercises his or her role during nominal and non-nominal conditions so that the launch vehicle will not harm the public.
   4. (4)A launch operator must conduct the rehearsals identified in this section for each launch.
   5. (5)At least one rehearsal must simulate normal and abnormal preflight and flight conditions to exercise the launch operator's launch plans.
   6. (6)A launch operator may conduct rehearsals at the same time if joint rehearsals do not create hazardous conditions, such as changing a hardware configuration that affects public safety, during the rehearsal.
2. (b)Countdown rehearsal. A launch operator must conduct a rehearsal using the countdown plan, procedures, and checklist required by § 417.111(l). A countdown rehearsal must familiarize launch personnel with all countdown activities, demonstrate that the planned sequence of events is correct, and demonstrate that there is adequate time allotted for each event. A launch operator must hold a countdown rehearsal after the assembly of the launch vehicle and any launch support systems into their final configuration for flight and before the launch readiness review required by § 417.117.
3. (c)Emergency response rehearsal. A launch operator must conduct a rehearsal of the emergency response section of the accident investigation plan required by § 417.111(h)(2). A launch operator must conduct an emergency response rehearsal for a first launch of a new vehicle, for any additional launch that involves a new safety hazard, or for any launch where more than a year has passed since the last rehearsal.
4. (d)Communications rehearsal. A launch operator must rehearse each part of the communications plan required by § 417.111(k), either as part of another rehearsal or during a communications rehearsal.