Before the first 747 was put together, parts and systems were being tested. In one important test, 560 volunteers evacuated a replica of a 747 cabin using the emergency chutes. The first evacuation took two and a half minutes. However, the FAA says that the maximum time for an evacuation is 90 seconds. Many of the volunteers were hurt. More evacuations happened, and they eventually reached the 90 seconds. However, they also caused a lot of injuries. Evacuating from the top deck of the plane was difficult. Instead of using the usual slides, the volunteers had to leave the plane using a harness. The plane's taxiing also had to be tested. Boeing made "Waddell's Wagon" (named after a 747 test pilot, Jack Waddell) to train the pilots. "Waddell's Wagon" was a replica of a 747 cockpit which was put on the roof of a truck. This helped pilots to learn how to taxi the plane.