49 U.S.C. § 1112

1. (a)If an accident involves a substantial question about public safety in air transportation, the National Transportation Safety Board may establish a special board of inquiry composed of—
   1. (1)one member of the Board acting as chairman; and
   2. (2)2 members representing the public, appointed by the President on notification of the establishment of the special board of inquiry.
2. (b)The public members of a special board of inquiry must be qualified by training and experience to participate in the inquiry and may not have a pecuniary interest in an aviation enterprise involved in the accident to be investigated.
3. (c)A special board of inquiry has the same authority that the Board has under this chapter.