Why do they have the registration numbers on and under the wings of some aircraft?
Example- members.shaw.ca/teddy.salad/JAL_Airliner_04.jpg
Thanks for any help.
It’s just the way their aviation regulations want it. Once upon a time in the USA the registration was also under the wing in addition to the tail.
Didn’t say American aircraft don’t have it under the wing. Just saying it’s no longer required, although, as a spotter, I would love to see it required! 
Because planes at really high altitudes, for us plane spotters would be able to get these registrations with our cameras.
In my case it would be great because I work under the approach to OAK. Right under! I can only see the bottom of the aircraft.
Amazing, hope you keep a camera with you! 
Would like to but as I said all I see is the bottom of the aircraft. Occasionally I get to see portion of the front side.
I’m getting really good at telling which airline it is by looking at the bottom!
Makes sense ex: if it has a blue bottom it either delta or jetblue if its white its either frontier or alaska!
I’ll try to take some pictures when I get a chance. Oakland being Oakland, the majority of the aircraft are Southwest. The next biggest operator is Alaska. The only other aircraft I’ve seen are Allegiant, UPS, and Spirit. My break times just don’t line up with the other airlines.
The Alaska B738s I’ve seen, and they have only been coming to KSAT a couple weeks now, are gray on the bottom.
More white than gray, with blue on the tail section.
My bad about Alaska guys, don’t see it to often, I go off of what I saw. 
Must be the viewing condition I view the Alaska 737’s under. I am literally directly under the aircraft. The bright blue sky around the aircraft evidently causes the gray to look more white.
Thanks for the posting.
No problemo, that is pretty damn cool you work right under a flight path! For some reason it seems almost every job I’ve ever had I’ve been able to see aircraft at a short distance.
If you work at an airport you pretty much have access to everything, correct me if im wrong, I will be working for LSG Sky Chefs next year.
I actually work in between 2 airports - HWD and OAK. I have no problems seeing the general aviation aircraft departing HWD because they need to make an immediate turn after takeoff due to the fact that OAK is only 5 miles away from HWD.
You’re wrong. Consider yourself corrected.
In Canada and most ICAO countries, if the Reg is under 12" on the tail or body you had to have the large letters under the left wing. That was the case on my Meridian were we had 7" on the rudder for looks.