Found this at
http://www.gregdonner.org/blue_thunder/bt_misc.html
History of the production helicopters used in Blue Thunder
Data provided by Stipe Zivaljic:
SA.341G; S/N 1066; Prod. Yr. 1973; temporary regd. F-WKQD to SNIAS; regd. 31/7/74 N57936 to Vought Helicopter Co.; regd. 2/10/74 N37LR to L.T. Ruth Coal Co.; sold to Kentucky Gem Coal Co. Inc. 10/10/74; purchased to Continental Flying Service, Inc. 19/11/76; regd. 17/12/76 same reg. to Continental Flying Service Inc.; 20/12/76 purchased to L.T. Ruth Coal Co.; reg. N37LR reserved 10/76; regd. 11/1/77 N37LR to L.T. Ruth Coal Co.; purchased 19/8/81 to Columbia Pictures Industries, Inc.; allocated experimental reg. 28/11/83 N51BT to Columbia Pictures; purchased 25/10/84 to Mr. Michael E. Grube; w/o 23/6/94; dismantled for parts; NOTES: a) during 1981 modified for movie requirements on 1704.7 total hours done by R.W. Martin, Inc. (Cinema Air); b) used as mod for film "Blue Thunder" and "Amerika" TV miniserial (pilot: Jim Gavin)
SA.341G; S/N 1075; Prod. Yr. 1973; regd. 7/8/73 N94494 to G. D. Turner (Vought Helicopters Co.); re-regd. 25/9/73 N94494 to N777GH Holley & Beck; regd. 2/3/77 to F.R.B.C. Leasing Co.; leased 14/3/77 to Mocomb Contracting Corp.; leased 29/9/80 to P. Bosco & Sons, Inc. (fmr. Mocomb Contr.); 17/8/81 purchased by F.R.B.C. Leasing Co. to Moceri Management Co.; purchased 19/8/81 to Columbia Pictures Industries, Inc.; allocated experimental reg. 16/11/81 N52BT to Columbia Pictures Inc.; regd. 21/3/86 same reg. to Mr. Michael E. Grube; Cof Reg. cancelled 16/8/88; dismantled (scrapped) for parts, w/o; NOTE: a) during 1981 modified as movie requirements by R.W. Martin, Inc. (Cinema Air)
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Hopefully this is not your site. Jon