My son really wanted to go the Franklin Institute with his best friend for his 9th birthday in lieu of a party. He really wanted to see the Tesla coil and Franklin exhibits but they rotated that exhibit out. However, we managed to see tons of great exhibits one of the more interesting ones was the 1948 T-33 jet trainer. The cockpit was very spacious, from what I could tell. I took some pictures of the cockpit and the landing gear which seemed to use hydraulic disc brakes not too different from a car. They Also had a cutaway of a Curtiss-wright 3350 engine which was amazing to see the size of the valve springs, pistons and rods. If you are ever in Philly and need something to do the Franklin Institute had something for everyone. It brought back a lot of memories of when I was a kid.