Cracked

A week ago, I attended the United Airlines Family Day at its maintenance base at San Francisco International Airport. Besides getting close-up views of the Blue Angels and a few United aircraft, I also was able to walk through the airline's engine repair show where mechanics maintain engines for United's Boeing 747, 757, 767, and 777 aircraft. The tour offered an intriguing glimpse into not only what jet engines look like from the inside, but also what all the parts cost.
This Pratt & Whitney PW4090 powers United's Boeing 777 aircraft. It can offer up to 91,790 pounds of thrust.