Ha, I can claim to have done this too :-)

Between 1988 and 1994 I was licensed on avionics for the BAC 1-11 as I worked for a TPM based at BOH. I flew with Dan-Air to ARN from LGW on a 1-11 in the early 90's and on the return there was a problem at the gate announced after we had boarded - a technical fault. A long delay was announced (pilot stated including possibility of a Dan-Air Engineer having to be flown out) so I identified myself to one of the FA's - more just to see if I could assist in any way at this stage.

So I was taken up to the cockpit (this was way pre-9-11) and chatted to the pilots and after listening to them felt the problem was a well known one with an avionic LRU that was normally just connector related requiring removal, relalignment and a system test. I told him I was qualified to do that, showed him my license and off he went to make a phone call.

So the pilot spoke to Dan-Air Engineering, came back and formally asked if I could assist. I went and spoke to my employer and then Dan-Air Engineering and got them to fax me over the relevant test spec which was about 8-pages long. I removed the LRU, aligned the connector and retested the system and this took about 40 minutes, documented it as per regs and cleared the system as fit for flight.

We departed after about a 90-120 minute delay in the end. Interestingly my employer seriously considered billing Dan-Air but in the end didn't. It was announced on the flight that I had assisted and they thanked me whilst being at pains to point out that I was licensed on the 1-11 - as opposed to just some pax who knew a bit about aircraft. Nothing further resulted, no letter of thanks to me or my company and no complimentary flights. Shame, was looking forward to a free weekend in Stockholm or something....

Nor did I get any publicity like this chap mentioned by the OP who helped out.....can't understand what the news angle on his (or mine) is anyway?