The coolest? Apart from falling down the stairs while my eyes were in the direction of a very pretty lady was... doing a trial photoshoot for Kartika Airlines at CGK.
Arrived at CGK one late afternoon, sat in their small ops room, then received a pass. Took the crew car, went through the security checkpoint, and we were at the apron of terminal 1. Sat underneath the airbridge, took photos and had close ups on other planes on adjacent gates or passing our stand. (poor light though).
The jet we were waiting for arrived. Walked up across the apron, and start taking photos as I walked backwards. No earplugs, I ended up 2 meters in front of a running JT8D-9A engine. Did a walk around of the airplane during the turn around, at that point, the captain said, "let's take a ride" Took a j/s ride to Semarang and back, never left the plane (coz security in SRG would arrest me without a boarding pass and the pass I have was for CGK). Back at CGK, j/s ride all the way, spent an hour at the aircraft after arrival, taking night inside shots.
Had a nice chat with the cabin crew, then went home...
My best day ever at an airport