Calling mayday and transponder codes
Continuing in the recent vein of 'what if...?' scenarios posted here recently....
In May, at an uncontrolled a/f in Florida, I had to make a forced landing because of an engine that was about to die on me (and it did die, when taxying off the runway). Confident that I would make the runway I did not call mayday but instead made an 'air to ground' call advising all traffic on the aerodrome frequency (a Unicom freq) that I was making an immediate forced landing on the non-active runway as I had no time or power to join the circuit and get around to the active.
Not wanting to create havoc with local ATC I did not squawk 7700. But this has led me to think... what if?
Let's say I'm currently on a A/G frequency (and need to declare an emergency). I understand that the general rule is make a mayday/pan call on the frequency already in use, and then only switch to 121.5 if you cannot raise anyone.
So now I'm talking to a local airfield about my emergency and then set the transponder to 7700; I gather that claxons will sound and alarm bells ring at ATC stations. But since I'm not talking to ATC/LARS, they're only going to know that someone has an emergency and roughly where the emergency is (from SSR). They won't know who I am or what the problem is, or what my intentions are (or whether they need to send help/fire brigade/local clergy...).
So if I squawk a 7--- emergency code, should I also switch to 121.5 to make the mayday so they know what's going on? In a real emergency there would be precious little time to make TWO mayday calls, so who am I better off talking to?
Your words of advice and wisdom for a newly qualified PPL are appreciated....
Thanks!