Hello, I was looking for some covers today and I found this. Nice stamp. I have a feeling I have written about this before but am not sure. Anyway  this was issued in 1985 to commemorate the 50th Anniversary of the first trans pacific  airmail service which was operated by a Martin  M-130 flying boat.    Have a look at the video.   just click the start button and you should see a minute of footage.. be patient  and you will see the plane.

I am not the first to write about this or show this stamp. Have a look at for more if this interests you.  This is a very good blog by the way. enjoy.