To confirm the CAA starter warning light was always a red warning light.
The LAA do consider the starter waning light warning light mandatory on LAA administered Permit to Fly aircraft.
To quote LAA Technical Leaflet TL 3.26 paragraph 3.8:
‘A starter-engaged warning light is considered mandatory by the LAA, in order to warn the pilot of a failure of the starter motor to disengage.
The starter-engaged warning light used to be mandated by the CAA on most certified aircraft by way of an Airworthiness Notice which has since been withdrawn. This is not because CAA no longer considers these devices important but rather that where necessary they are nowadays specified by way of the basic design certification codes.’
http://www.lightaircraftassociation.co. ... sytems.pdfA point to note is that although it is often termed (and placarded) as a ‘starter engaged’ warning light, normally they were wired up to the starter contactor (solenoid) so are in actual fact a ‘starter energised’ warning light.
Some 20+ years ago, the flying club that I worked for had a Cessna 172 and I had a note on the Monday morning to say that the starter motor had failed the day before. As it was at the back of the hangar, I removed said starter and it was obviously an ex-starter motor as it had failed internally.
On went the new starter motor and I took the aircraft outside to test it. I got in, turned the battery master switch on and instantly, the new starter did its thing and the propeller spun. No key in the ignition switch – all I’d done was but the battery master on. If anyone had been within the arc of the propeller it may well have killed them.
Obviously, what had happened was on the last flight, the starter contactor had failed and stayed in the energised position. The starter motor remained engaged for the hour long flight which took its toll on the innocent starter motor. The highly experienced instructor/examiner hadn’t noticed the ‘starter energised’ warning light was illuminated from their side of the cockpit.
From that moment on, I have never applied power to an aircraft without ensuring no one was near the propeller and a warning call made of ‘power going on’. I taught new engineers this and aircraft owners and pilots whenever I got the chance.
PS With aerobatic aircraft, it might be considered wise to mount battery and starter contactors horizontally rather than in the more common vertical position to ensure G loads can’t affect the contactors’ required position.