Tamarack Files Petition for Reconsideration of NTSB Report of 2018 CitationJet Mishap Near Memphis, Indiana

(Sandpoint, ID) – Tamarack’s concern for aviation safety and evidence-based conclusions triggered its formal request today that the NTSB reconsider its determination that the Active Winglets played a role in the Cessna Citation mishap in Memphis, Indiana. The Tamarack Petition for Reconsideration provides evidence to show that the Active Winglets installed on the CitationJet did not cause or contribute to the accident, and demonstrates that the autopilot disconnected for unknown reasons prior to reaching its internal disconnect criteria.  Tamarack will provide further updates as the reconsideration process develops.

Tamarack Aerospace Group (Tamarack) hereby petitions the National Transportation
Safety Board (NTSB) pursuant to 49 CFR § 845.32, to reconsider and modify its
findings and determination of probable cause in the above-referenced matter. The
basis of this petition is that the NTSB has made erroneous findings that are
unsupported by the factual record, inconsistent with engineering principles, or
proven to be physically impossible.
This petition also points out that significant factual information provided by Tamarack
as a party of this accident investigation and included in the public docket for this
accident (https://data.ntsb.gov/Docket?ProjctID=98710) was not analyzed or properly
considered by the NTSB. The investigation and resulting NTSB Factual Reports
(Systems, Aircraft Performance, Cockpit Voice Recorder, Computed Tomography) also
failed to address additional issues raised by Tamarack in its Supplemental Submission
(Docket Item # 25). These issues include the relationship of the Attitude Heading
Reference System (AHRS) to the autopilot system and the Primary Flight Display
(PFD), whether an AHRS anomaly or failure contributed or caused the autopilot to
disconnect, the lack of specificity regarding the pilot’s experience in the accident
aircraft and training to obtain his type rating, and the possibility that the pilot was
experiencing spatial disorientation during the accident sequence.
Overall, the errors and gaps in the factual record are so fundamental that the NTSB
must reconsider and modify its determination of probable cause of the accident. As
but one example of the NTSB’s failure to properly consider key information provided

by Tamarack, note that Tamarack, with the approval of the accident Investigator-in-
Charge, provided a supplemental party submission to the NTSB on October 26, 2021.

That supplemental submission provided important new information concerning a
system anomaly or failure that could bear significantly on the accident’s probable

Please read the full petition here.

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