A few days ago, former Air Combat Command leader Mike Loh, who now consults for Pratt & Whitney, wrote an op-ed for the Fort Worth Star-Telegram advocating the cancellation of the F136 alternate engine for the JSF. That inspired a response to Ares from Desert Storm air commander Gen. Chuck Horner, consulting for rival General Electric. Some of Horner’s comments:
I have a personal reason to argue for competing F-35 engines. I was the Wing Commander at Luke AFB in 1979, and we flew F100-powered F-15 aircraft. There was no second engine source at that time. Due to engine design flaws and a lack of spare parts, I had 103 engines stored in a warehouse awaiting parts and a total of 35 holes in aircraft parked on the ramp without engines. Flying our daily schedule was a struggle, with our maintenance folks having to work overtime due to the inexcusable lack of serviceable engines. Also, one of the fixes was to reduce thrust to reduce heat stress on the engines, which reduced F-15 performance - another inexcusable action if we sent those jets into combat. I know firsthand why we needed the so-called Great Engine War that led to the F100/F110 engine competition that served the Air Force and the taxpayers so well.
Neither P&W nor the GE-Rolls-Royce team can assure us that they will not encounter problems with their engines. To have two competing engines for the same aircraft is merely prudent. This was the case recently with the Royal Saudi Air Force.
I was at King Khalid AFB and the RSAF commander AB took me to his engine shop. It was as well run as any I had seen before, with Saudi airmen in white uniforms and a few American tech reps there to help as needed. The F100 engines being repaired were everywhere, and there was a big table with hot section parts on display that looked like someone had taken a blow torch to them: melted metal, warped, twisted, really ugly.
The Saudi major-general asked what I could do. His pleas to P&W had fallen on deaf ears as they were telling others that it was a Saudi maintenance problem. The USAF training team consisted of aircrews, and they had told him the depot was the place to make his case. I told him to talk to GE since that engine was now qualified for the F-15, which was not the case when they bought their jets.
It turned out that the F100-PW-229s were ingesting the fine sand in the air and it melted going through the hot section. When the engine cooled, the molten sand solidified into glass on the thermal barrier coatings in the hot section, and eroded the coating, not unlike what ice does to concrete surfaces. The F110-GE-129 does not use this coating and most of the sand is routed away from the hot section.
When P&W heard the RSAF was looking at the GE engine they sent former defense secretary Bill Cohen and retired Gen. Joe Ralston (Joe works for the Cohen group) over to Riyadh. They met with Prince Khaled, deputy minister of defense and aviation (his dad is the Minister and also the Crown Prince, and Khaled was Schwarzkopf's counterpart in 1990-91) and told him the solution was to reduce the thrust a bit and have a cooler running engine. I have been told Prince Khaled replied: "I did not buy the F-15 to have it fly like a F-5."
The RSAF changed all of its F100s over to F110-GE-129s. P&W bought the used engines rather than have GE dump them on the market. The whole deal will be paid for in less than ten years (the number six years sticks in my mind but I am not sure) due to the decreased need to replace modules and hot section parts and to borescope the engines.