augustus Posted February 6, 2010 Share Posted February 6, 2010 why there's no modex number like X08 and X09 in US navy? I never found any A/C pic with those modex number. Any guru can help? Thanks Anthony Quote Link to post Share on other sites
GreyGhost Posted February 6, 2010 Share Posted February 6, 2010 I believe it's due to radio communications ... Gregg Quote Link to post Share on other sites
Tailspin Turtle Posted February 6, 2010 Share Posted February 6, 2010 You mean now or then: Quote Link to post Share on other sites
GreyGhost Posted February 6, 2010 Share Posted February 6, 2010 I'm believe it was during the F-4 Phantom era that the discontinuation of X08 and X09 was implemented ... Gregg Quote Link to post Share on other sites
Tailspin Turtle Posted February 6, 2010 Share Posted February 6, 2010 GreyGhost said: I'm believe it was during the F-4 Phantom era that the discontinuation of X08 and X09 was implemented ... Gregg Yes and no - there are pictures of F-4Bs with X08 and X09 but they do seem to disappear after that. See Baugher for a couple of possible explanations: http://home.att.net/~jbaugher/navyserials.html Quote Link to post Share on other sites
Superheat Posted February 6, 2010 Share Posted February 6, 2010 Hi Anthony, When the Navy began computerizing maintenance records at the squadron level in the mid sixties, the system used was octal, not decimal, so the number series looked like this: Standard decmal: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 .......... -------------Octal: 0 1 2 3 4 5 6 7 10 11 12 13 14 15 16 17 20 21 22 23 24 .......... Since the records were kept at squadron level, only the last two digits were "octalised" , which is no problem for modexs x00 through x07, but x08 would be 10, x09, 11, x10, 12 and so on. A bit confusing when x10 was actually on deck, so the modexs x08 and x09 were dropped to make the decimal numbering system painted on the aircraft conform to the octal based accounting system. For maintenance records purposes the aircraft were in numerical sequence, but on deck they weren't, no big deal. Since there were rarely more than 12 aircraft in a squadron, it was convenient and it worked. Why it persists to this day is a good question, though it would not surprise me to learn that the Navy still uses the same octal based system. Interestingly, in the Training Command, those digits were not dropped. As an instructor in VT-21 one of the two aircraft that ended up with my name on them was 3E 108. I suspect, since the squadron had about 60 aircraft, that all three digits were octalized so the maintenance numbers did not correspond to the aircraft numbers at all, but I don't know for sure. Also the Marines, who as far as I know used the same octal-based accounting system and had as many as 20 aircraft to a squadron with two digit modexes , never dropped those digits, either. Go figure Hope this helps, Tom Quote Link to post Share on other sites
Fuji Posted February 6, 2010 Share Posted February 6, 2010 Superheat said: Hi Anthony,When the Navy began computerizing maintenance records at the squadron level in the mid sixties, the system used was octal, not decimal, so the number series looked like this: Standard decmal: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 .......... -------------Octal: 0 1 2 3 4 5 6 7 10 11 12 13 14 15 16 17 20 21 22 23 24 .......... Since the records were kept at squadron level, only the last two digits were "octalised" , which is no problem for modexs x00 through x07, but x08 would be 10, x09, 11, x10, 12 and so on. A bit confusing when x10 was actually on deck, so the modexs x08 and x09 were dropped to make the decimal numbering system painted on the aircraft conform to the octal based accounting system. For maintenance records purposes the aircraft were in numerical sequence, but on deck they weren't, no big deal. Since there were rarely more than 12 aircraft in a squadron, it was convenient and it worked. Why it persists to this day is a good question, though it would not surprise me to learn that the Navy still uses the same octal based system. Interestingly, in the Training Command, those digits were not dropped. As an instructor in VT-21 one of the two aircraft that ended up with my name on them was 3E 108. I suspect, since the squadron had about 60 aircraft, that all three digits were octalized so the maintenance numbers did not correspond to the aircraft numbers at all, but I don't know for sure. Also the Marines, who as far as I know used the same octal-based accounting system and had as many as 20 aircraft to a squadron with two digit modexes , never dropped those digits, either. Go figure Hope this helps, Tom Still in use today - These three F-5Ns were in numerical order on the VFC-13 det Key West line up. There was no 48 or 49 in the squadron for the reasons listed above. Quote Link to post Share on other sites
Spongebob Posted February 8, 2010 Share Posted February 8, 2010 Today it's because of transponder codes. Mode 2 is normally set to the aircraft side number. Mode 2, like Mode 3 (normal ATC codes) is a 4 digit octal code (4096 possible combinations, no 8's or 9's). Optimized NALCOMIS (aka "OOMA"; the current maintenance management software for the Navy/USMC) uses BuNo to elimnate problems when swapping aircraft between squadrons. Spongebob Quote Link to post Share on other sites
Jinxter13 Posted February 9, 2010 Share Posted February 9, 2010 Fuji said: Still in use today - These three F-5Ns were in numerical order on the VFC-13 det Key West line up. There was no 48 or 49 in the squadron for the reasons listed above. Now doesn't that just remind you of the MiG-28's lining up to jump Ice and Slider, Hollywood and Wolfman.....ain't they purrrrrrrrrrty!!!!!. I mean they got the red star and everthang Quote Link to post Share on other sites
augustus Posted February 11, 2010 Author Share Posted February 11, 2010 Thanks guys, that helps a lot. But i found another pic that make me confuse again...... Quote Link to post Share on other sites
Neeko Posted February 12, 2010 Share Posted February 12, 2010 augustus said: Thanks guys, that helps a lot.But i found another pic that make me confuse again...... Seems you answered your original question then! There was an answer above that covered the reason as to 99.9% of how things are with reference to Modexes, and you found and posted the .1% that is the exception... Quote Link to post Share on other sites
Sabre Freak Posted February 12, 2010 Share Posted February 12, 2010 (edited) .. Edited February 26, 2010 by Sabre Freak Quote Link to post Share on other sites
Tailspin Turtle Posted February 12, 2010 Share Posted February 12, 2010 (edited) Sabre Freak said: On the subject of modex (or unit side number as the Baugher article describes)Do these get recorded anywhere? For example, if I know a BuNo, a time frame (mid 50s) and a squadron, is there anyway to find out what the side number would have been (other than a picture)? Its a question I've been meaning to ask... Some enthusiasts have collected that data for some deployments, but even then it is only a snapshot. See http://www.gonavy.jp/CVW-AGf.html and click on the BuNo button for the Sept/Oct 1969 exercise http://www.gonavy.jp/CVW7-AG1969.html or the Oct 75/May 76 cruise. Edited February 12, 2010 by Tailspin Turtle Quote Link to post Share on other sites
Sig Saur & Son Posted February 13, 2010 Share Posted February 13, 2010 (edited) This is a great site I sue for tracking down BuNos and Modex information. http://www.scramble.nl/databases.htm Edited February 13, 2010 by Sig Saur & Son Quote Link to post Share on other sites
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