Why can NTSB reports not be admitted as evidence?

Question

According to 49 U.S. code § 1154, part (b),

No part of a report of the Board, related to an accident or an investigation of an accident, may be admitted into evidence or used in a civil action for damages resulting from a matter mentioned in the report.

That is to say, an NTSB report may not be used as evidence in a civil action for damages, resulting from an aviation incident. This is re-iterated at the end of most final NTSB reports.

My question is what is the motivation and reasoning behind this legislation? While some of the elements of the report may be of a subjective nature, there is a specific section detailing factual information.

Could the motivation be to force admittance of the original evidence, rather than the NTSB report which would potentially secondary source?

A more interesting aside is also, can it be admitted into evidence if the civil action is not for damages from the incident in question? What if a report has tangential relevance in a potentially non-civil, say, criminal action?

Answer 1

"The purpose of the statute making the NTSB's reports of accidents inadmissible in actions arising out of such accidents is to exclude reports that express agency views as to the probable cause of the accident because that is a finding in the province of the jury or fact finder." Britton v. Dall. Airmotive, Inc., No. 1:07-cv-00547-EJL, 2011 U.S. Dist. LEXIS 163211, at *5-6 (D. Idaho May 20, 2011) (citations omitted). "The legislative history of this statute demonstrates that the purpose of this exclusionary rule is to prevent a usurpation of the jury's role as fact finder." McLeod v. ERA Aviation, No. 93-294, 1996 U.S. Dist. LEXIS 3204, at *3 (E.D. La. Mar. 12, 1996) (citations omitted).

"This limitation on the admissibility of the NTSB report, however, applies to the official conclusions of the NTSB, not to the factual accident reports of the investigators." Britton, 2011 U.S. Dist. LEXIS 163211, at *6 (citation omitted); accord 49 C.F.R. § 835.2.

By its terms, the statute applies only to civil actions, but the report would be subject to the ordinary hearsay rules if offered in a criminal case. See Fed. R. Evid. 801; United States v. PG&E, 178 F. Supp. 3d 927, 946 (N.D. Cal. 2016).