JS1452: ICAO Acoustic Test Analysis and Results for the Schweizer Model 269D Helicopter, 1992-11-19, Box: 17, Folder: 5. Shannon Engineering, Inc., records, 8746. Division of Rare and Manuscript Collections. https://aspace3-test.library.cornell.edu/repositories/2/archival_objects/766975 Accessed June 14, 2026.