For example: when changing from 0500 to 7000 (VFR code): you might turn the first knob to a 7 (thus 7500), and at this time the second knob still is set to 5. This would momentarily have the transponder replying the hijack code (7500), which might lead to a lot more attention than desired. I would recommend to set the transponder in 'standby mode' before changing the codes. It will cause a temporarily loss of target info on the radar screen, but it's safer than having bells going off in ATC centers and F16s scramble for you because you accidentally had 7500 displayed on the radar screen.
Mmm, nice one 500e, a direct quote from
Aircraft Transponder Codes, Ident, 1200, 7000, Squawk VFR, Emergency Code 7700, Hijack 7500, Comm Failure 7600
What you fail to notice is that a civi Gazelle squawking 0500 is in itself quite revealing!!
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UK AIP
ENR 1.6 — ATS SURVEILLANCE SERVICES AND PROCEDURES
ENR 1.6.1 — ATS SURVEILLANCE SERVICES
http://www.ead.eurocontrol.int/eadba...2012-04-05.pdf
UK SSR Code Assignment Plan
*0050 - NATO - CAOC 9 Exercises (activated by NOTAM)
Note 2. The codes or series annotated * are used for conspicuity, co-ordination or special purposes and, unless procedures have been agreed with UK CAA Directorate of Airspace Policy, the Mode A code and associated Mode C data must be considered unvalidated and unverified.
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So you might say 0500 isn't the best example. Would you rather;
1500 or 2500 or 3500 or 4500 or 5500 or 6500
Notice anything all those codes have in common?
