Ejection seat question
 

If an aircraft has a command ejection system, would safety pins in the 'other' seat prevent it being ejected? The safety pins I've seen just prevent the handle being used but I wondered if command ejection mechanisms work differently.

With the Hawk, command eject is selected to rear seat unless the instructor occupies the front seat. On my one Hawk flight, one of the 'strappers in' called out 'command eject off' to the front seater meaning if I went accidentally, the front seater wouldn't be ejected too.
I can't speak for other aircraft seats.
The seat pins are stowed along the right hand side of the canopy and if any of the stowages are empty when the canopy is shut, the flight line mechanic will not allow engine start.

Sorry to be a little pedantic Chevvron but historically the Hawk see off man would be on the port side for engine start,there is a stowage block for 8 pins on the port side between the cockpits (at the rear of the front cockpit),originally the other 2 pins per cockpit were stowed on the port canopy rail but that was modified in the 1980's (?) to have a flip up stowage on the port instrument panel glare shield (when pins not stowed the bright yellow stowage flipped 'up' to be highly visible to ground crew).
Red Arrows I believe retained the original canopy rail stowages because the glare shield had smoke lights mounted - also XX341 (Astra) at ETPS retained the original canopy rail stowage due to modified cockpits.

My flight was in '77 and I'm positive the pins were on the stbd side adjacent to my right shoulder (definitely none on the glareshield) so maybe they were 'modded' after my flight.

Hi Chevvron
The pin stowages were always on the left side - there were of course 2 x pins fitted on the RH side (MDC Handle at the front + the MDC sear by your right shoulder) - the MDC sear pin being removed before strap in and the MDC pin removed before engine start.
The original final 2 pin stowage (Seat Pan Pin and MDC Handle Pin) was on the LH Canopy Rail (as I posted above) but was modded to the glare shield in the 1980's to be more visible to the ground crew (as I mentioned above).
Originally the start crew would always be on the left because the steps were on the left (both built in steps + ground equip steps) and the canopy hinged to the right (hinges on the right) - we normally did single man starts at Brawdy when I was there 1977-80 and I continued doing single man starts on and off until well into the 2000's (note - I never was based at Valley ;)) - I know Valley did 2 man starts !

Well it was 47 odd years ago and I only ever did it once apart from in the sim beforehand; that's my excuse.:{

Hey it's a very fair excuse :) - we used to attend seat training every 12 months - in fact I still have my 2 company seat training booklets (covering Harrier all marks and Hawk) from when I was at Dunsfold :)