From the unique and fascinating world of aviation patents, provided by Aeropatent.com, it appears that UTC (parent of Pratt & Whitney) is offering a path to convert engines to a geared fan configuration.
As Aeropatent observes: “We’ve seen a batch of new patent applications publish from United Technologies Corporation over the past week for geared turbofan engine systems. This particular concept involves a rather neat process to convert a conventional gas turbine engine from direct drive to geared drive, allowing for a wider fan rotor and greater bypass ratio. The low spool (low pressure compressor rotor and low pressure turbine rotor) is modified in the conversion process. Gear reduction is introduced between the fan rotor and low pressure turbine rotor shaft. One or more stages of the high pressure compressor rotor may be eliminated, with the remaining stages re-engineered.“
But the conversion process should be a boon to MRO shops worldwide. We suspect many airlines and lessors would consider converting older engines to benefit from this idea. After all, why wait for the latest re-engined models that cost a lot more? There is no information on what this conversion costs. But it has to be priced at way below new engine prices.
Moreover, engines outside their warranty are fair game, because the OEM cannot threaten voiding a warranty. Recall how Pratt & Whitney disrupted the CFM56 repair business when they started making parts for it. We suspect that, given is huge footprint, the CFM56 is a target again. Perhaps not on the 737 given its limited ground clearance and the need for the geared engine to use a larger fan. But on the A320 family, it must be a target. No doubt UTC (and by extension Pratt) will collect a license fee from every conversion, if they don’t do the conversion themselves.
Another target comes to mind: the USAF and its hundreds of KC135 tankers. The replacement tankers (KC46) are going to take a long time to take over. Which means the KC135s with CFM56s are also fair game.
But let’s not stop there. What about bigger turbofans? What might this technology do for Rolls-Royce engines, or CF6s, on A330s? How about on the 767s that will be serving the likes of FedEx and UPS for decades yet? If GTF technology can offer 15% fuel burn savings and lower maintenance costs, it is, as they say in racing, a runner.
The GTF has proved itself disruptive already. Now the GTF idea has moved to another disruptive stage.