Aero Commander 1121 Jet Commander – N400CP

Incident Overview

Date: Wednesday 27 January 1971

Aircraft Type: Aero Commander 1121 Jet Commander

Owner/operator: Cousin Properties

Registration Number: N400CP

Location: Lake Champlain, VT – ÿ United States of America

Phase of Flight: En route

Status: Destroyed

Casualties: Fatalities: 5 / Occupants: 5

Component Affected: Aero Commander 1121 AirplaneAero Commander 1121 Airplane

Investigating Agency: NTSBNTSB

Category: Accident

On January 27, 1971, an Aero Commander 1121 airplane, N400CP, crashed into Lake Champlain, Vermont, resulting in the presumed deaths of two pilots and three passengers. The flight departed from Burlington International Airport (BTV) under an instrument flight rules flight plan, heading to Providence Airport (PVD) in Rhode Island. Radar contact was lost approximately 1952 hours after departure over Lake Champlain, Vermont, and subsequent searches yielded no significant wreckage discoveries. A subsequent search in the spring of 1971 failed to locate additional wreckage. The NTSB concluded the wreckage was likely located near the Four Brothers Islands in Lake Champlain. In May 2024, multiple private organizations utilized EdgeTech 4125-P sonar to locate potential wreckage fragments. Analysis of the underwater video revealed numerous components consistent with the Aero Commander 1121, indicating a significant impact. The investigation remains at a probable cause stage, with the exact cause of the crash currently undetermined.On January 27, 1971, an Aero Commander 1121 airplane, N400CP, crashed into Lake Champlain, Vermont, resulting in the presumed deaths of two pilots and three passengers. The flight departed from Burlington International Airport (BTV) under an instrument flight rules flight plan, heading to Providence Airport (PVD) in Rhode Island. Radar contact was lost approximately 1952 hours after departure over Lake Champlain, Vermont, and subsequent searches yielded no significant wreckage discoveries. A subsequent search in the spring of 1971 failed to locate additional wreckage. The NTSB concluded the wreckage was likely located near the Four Brothers Islands in Lake Champlain. In May 2024, multiple private organizations utilized EdgeTech 4125-P sonar to locate potential wreckage fragments. Analysis of the underwater video revealed numerous components consistent with the Aero Commander 1121, indicating a significant impact. The investigation remains at a probable cause stage, with the exact cause of the crash currently undetermined.

Description

On January 27, 1971, about 1955 eastern standard time, an Aero Commander 1121 airplane, N400CP, was destroyed when it impacted Lake Champlain, Vermont. The two pilots and 3 passengers were presumed fatally injured. The airplane was operated by Cousins Property as business/executive flight. The airplane departed under an instrument flight rules flight plan from the Burlington International Airport (BTV), Burlington, Vermont, from runway 33 about 1952 local. The destination was Providence Airport (PVD), Providence, Rhode Island. According to air traffic controller recollection, the airplane climbed on runway heading, turned left to the west, then south. Radar contact was lost a few minutes after departure over Lake Champlain, Vermont. Following the accident, no significant portions of the wreckage were located despite an 8-day search. The search was suspended due to the winter weather conditions. An additional search in the spring of 1971 was commenced, however, this search also discovered no significant portions of the wreckage. The original NTSB report concluded that the wreckage was likely located in Lake Champlain near the Four Brothers Islands. On May 19, 2024, multiple private organizations located a target with a high resolution EdgeTech 4125-P side scan sonar system. On May 25, 2024, an underwater submersible recorded video images of what appeared to be several large fragments of aircraft wreckage. The footage was provided to the investigation by GK Consulting. Review of the underwater drone video found multiple components that were consistent with fragments and parts from an Aero Commander 1121. The wreckage was destroyed and observed in the video in a highly fragmented condition. As part of this investigation, the NTSB was not provided physical wreckage to examine nor is the investigation aware of activities to surface the wreckage at the time of this writing. PROBABLE CAUSE: “Undetermined.”

Source of Information

https://data.ntsb.gov/Docket?ProjectID=132624, https://news.google.com/newspapers?id=Chk0AAAAIBAJ&sjid=x-AIAAAAIBAJ&dq=lake%20champlain%20jet%20missing%201971&pg=3287%2C3624989, https://www.necn.com/news/local/lake-champlain-plane-wreck/3244839/, https://eu.burlingtonfreepress.com/story/news/2017/11/18/history-space-mystery-missing-jet/107822054/https://data.ntsb.gov/Docket?ProjectID=132624, https://news.google.com/newspapers?id=Chk0AAAAIBAJ&sjid=x-AIAAAAIBAJ&dq=lake%20champlain%20jet%20missing%201971&pg=3287%2C3624989, https://www.necn.com/news/local/lake-champlain-plane-wreck/3244839/, https://eu.burlingtonfreepress.com/story/news/2017/11/18/history-space-mystery-missing-jet/107822054/