I was at my local airport and noticed a few jets that caught my eye. I have the callsign and reg. of one (N576QS/EJA576) but only the callsign of the other two: OPT913 and EJA351.
How do I find out the reg. of the last two?
EJA is NetJets. IIRC all of their tail numbers end in QS and their call sign is EJA + the three digits of their tail number. So EJA351 would be N351QS.
Sorry - can’t help you with OPT…
From “what I remember” OPT does the same thing. Accuracy of that information isn’t guaranteed. Been a while since I’ve serviced an OPT a/c.
I do know for sure NASA does the same thing at least for most of their flights… N926NA would fly as NASA926.
OPT913 was probably N913LX, a Embraer 135.
The Options fleet uses CW (Cleveland Wings) and LX (Luxury) as the last two characters, so you can usually just add one of those suffixs to the flight # to come up with the tail #.
OPT913 - N913LX is an Embraer Legacy 600 operated by Flight Options.
Wow, I could have sworn that’s what I posted.
Sorry about the incorrect “135” desigination instead of the “Legacy 600”. 
You screw up just this much, you’ll both be flying a cargo plane full of dog **** out of Hong Kong! 
Better than your @$$ on the couch without a job…
RUBBER dog Sh*t 
I should be ashamed. 
RUBBER dog Sh*t
HAHAHAHA!!!
The callsign/n-number correlation works almost all the time, but it’s not foolproof. I could file for any Avantair number that I felt like (VNR007!), but it’s just easier to file the number of the airplane I’m in, that way I know there’s no one else using that same number. Some companies have a number for each pilot, so the pilot files using their own number regardless of what aircraft they’re flying.
thanks for your help.