I got very unfriendly replies when i dared to start up and call afterwards – like on Corfu, where i was really parked in a distant corner. So i stopped doing that :-)
Peter wrote:
I would buy a milspec hermetically sealed one off Ebay.
There was an Amsat experiment where they sent tons of relays in space to test their reliability. Guess which ones failed first?
Yes, it was the expensive space qualified ones.
I would prefer a “commercial grade” relay manufactured in the millions anytime over a hand made one in five years expensive one, because in the latter case you never get the manufacturing process stable enough.
I prefer the idea of no relay and a switch (SPDT), it sounds simpler.
On bigger aircraft they seem to use a pushbutton and a relay wired with a hold on contact and arranged so if the BATT is switched on it drops out.
AeroPlus wrote:
I think the whole startup clearance is designed primarily for larger aircraft.
Yeah, what exactly is the purpose of a start-up clearance?
I’ve never used one in the US, although I’ve noticed some airports via ATIS or the A/FD do require start-up clearances for turbine traffic.
Yeah, what exactly is the purpose of a start-up clearance?
To enable traffic flow management for instrument flights. If you start up on your own and ATC is not ready for you, you may have to hold position on the apron with the engine(s) running for a prolonged period of time. Which might be unpleasant and possibly dangerous for anybody else around you and wastes fuel better used for flying.
In my part of the world, startup clearances are only required for IFR flights, BTW.
I’ve only run into one GA airport that requires a start clearance (Oban). The fueller told me that they had heard Loganair ask for a start clearance once, so thought it must be a good idea, and mandated it for everyone!
what_next wrote:
In my part of the world, startup clearances are only required for IFR flights, BTW.
I think it’s the same in luxembourg.
If you’re VFR they have no problem making you wait a 1/2h on the ground or in the air anyway…
alioth wrote:
I’ve only run into one GA airport that requires a start clearance (Oban). The fueller told me that they had heard Loganair ask for a start clearance once, so thought it must be a good idea, and mandated it for everyone!
Depends where you are. At Kemble, for example, on the H apron they request you call for engine start and advise when you reach your parking before engine stop because they can’t physically see you from their position, elsewhere on the field they don’t really mind.
would prefer a “commercial grade” relay manufactured in the millions anytime over a hand made one in five years expensive one, because in the latter case you never get the manufacturing process stable enough.
yes, provided it is sealed.
Alioth, yes Oban chastised me one day for starting without clearance. But then everything would appear to be a problem there… 
GA, run like Heathrow. Glasgow has ground, which is not always manned, therefore you have to dial up ATIS, listen if it is ground, or tower, then call the appropriate one for start up.
My view it is generally required at the larger airports, for spacing, but at the smaller ones it would not be required.
