The F135 is the heaviest high-performance fighter engine ever built, weighing 70% more than the P&W F100 and measuring 24% larger in diameter, with consequently larger inertial and gyroscopic forces.
Therein the problem lies. Somehow, during the initial conceptual design, this observation wasn't sorted out properly. Although the engine is a heavy weight, the parts that need to be heavy don't seem to be heavy enough. The stator vanes are locked into the engine casing. IMHO, the integral bladed rotor and their seal teeth, being the best true diameter achievable, seem to be snagged by the stator vane seal grooves, not the other way around. Must have something to do with the engine casing true roundness in the air when the aircraft is maneuvering.
Bennett's dissertation can be condensed: We're good guys, thought we did everything right, didn't work out, don't know the root cause of the problem yet, working the issue, only 60% of the way to the end of development, not to worry, we will eat the added costs for this mishap…
Wonder what the future costs of spare parts will be?
