Drawing Lines in the Sand: Pratt & Whitney Canada’s Next One Billion Hours

Although the first mention of the Geoglyphs of Nazca, more commonly known as the Nazca Lines, dates back as far as 1553, it wasn’t until the early 20th century that pilots flying over the area in Peru saw them and made the world aware of their existence. 

Some of the geoglyphs that have been discovered are hard to decipher, but some historians argue that some point to the pre-Inca civilization that the geoglyphs tell us that people were capable of building kites that could be flown, and, most importantly, could take off and land. Historians also argue about the dates that the lines were created, although it is likely to be in the Iron Age, or perhaps one billion hours ago.

Over the course of the following one billion hours many not only perfected the design of flight, but also created powered flight and flew aircraft that could fly faster than the speed of sound.

So however you think about it, one billion hours is a very very long time. Hitting a one-billion-hour milestone is therefore a major event, especially in aviation. That one-billion-hour milestone was recently celebrated by Pratt and Whitney Canada, who’s engines have now surpassed the one billion flight hours mark.

Founded in 1928, the company has to date built more than 110,000 engines. They are fitted across various sectors, including general aviation, business aviation, helicopters and commercial aircraft. Its most popular engine, the PT6, recently celebrated its 60th anniversary.

“The PT6 really is the foundation of the company, it was our first step into the gas turbine era.”

says John Lewis, Pratt and Whitney Canada’s Senior Director, Customer Programs. “Prior to that we were making parts, but also engines in the radial world, so the air-cooled radial world. But we stepped out of that with the PT6, and I guess we haven’t looked back, even though some of those engines are still in existence today.” Originally certified in 1963, the PT6 has seen many major upgrades and features added in its 60-year history. The first aircraft that it was fitted to was a King Air, and that association has remained to this day, as King Airs still use an upgraded version of the PT6.

However, according to Lewis, the PT6 was designed for various different aircraft types, and interestingly, the first time it flew was on a helicopter, a Hiller helicopter. “They were working on various different applications at the same time, it is just that the King Air got to the finish line first,” says Lewis. “The King Air is still in production today, which is testament to the longevity of the aircraft.” 

In this day of upgrades, rebuilds and new designs, some might argue that PT6 has had its day and should be replaced by a clean sheet design. But the reality is that the current generation of PT6s have little in common with the original engine of the 1960s. “We say its venerable, yes, the basic design has been around since the ‘60s, absolutely, but have built over 66,000 PT6s over time, of which more than 25,000 are still in service,” says Lewis. “But we have also put more technology into the engine continuously over time, so that we have essentially quadrupled the power output.”

Other upgrades and changes to the PT6 over the course of the past 60 years include decreasing the engine’s fuel consumption by 20% and changing its power to weight ratio to 50%. Different versions of the PT6 fitted to different aircraft also include different features. The Pilatus PC-12NX is a great example of this, as not only the engine equipped with full FADEC (Full Engine Digital Engine Control) capabilities, but also a full prop controller. In the helicopter world, FADEC is also included on the latest versions of the PT6 that are fitted to the Airbus Helicopters ACH-175.

“So, you have an engine that bears the heritage of the PT6, and has the same basic architecture, it is none the less a modern engine.

It probably shares a few nuts and bolts I would imagine, but it doesn’t share much else apart from the concept,” says Lewis. “The advantage to that we have matured it over so many years, that it delivers benchmark reliability that it is known for.”

One new development that the company has been working on is the transition towards SAF – Sustainable Aviation Fuel (SAF), which Lewis says has been a major focus for the company for several years.

“Making aviation more sustainable is clearly very important, even though it represents a very small proportion of greenhouse gas emissions globally.”

says Lewis. “All of our engines today can run on a 50% SAF blend, and of course the interest is to go beyond that.”

One of things stopping Pratt and Whitney going further than using a 50% SAF blend is the lack of a clear definition of what 100% SAF is actually composed of, unlike 50% SAF, which already has an ASTM (American Society for Testing and Materials) definition that different SAF providers can work towards. However, Lewis says that the company is already engaging with various groups around the world to help define the chemical composition of 100% SAF.

“We know what Jet A is because it has a specification with the ASTM and we also know what 50% SAF is,” says Lewis. “Actually we know what range it can be because there are seven different ways of making SAF right now that are recognized within the ASTM spec. So we know what that is, and we know what range of chemistries that you can have, and we know that our engines can live with that range of chemistries.” 

Whilst the company is working hard to come up with that definition, it also offers a full range of carbon offsetting programs, which can be automatically tied into engine usage, which Lewis says is made easier by the way that engine utilization is automatically recorded.

“Something else we offer, which is really the most immediate thing that anybody can do at this point, is a carbon offsetting service,” says Lewis. “We work with South Pole, which is a very reputable company in this area, so that everybody on a power by the hour program, no matter what form that program takes, we already gather the amount of hours that they fly every month as part of administration those programs, and so we can relatively easily tack on the fuel burn.”

Going forward, the company is also working on hybrid electric engines, with a Dash 8 turboprop already lined up for testing. Lewis says that the program, which will see one of the Dash 8s engines replaced with a hybrid electric engine, has been partially funded by the government, and will be used to learn more about power conditioning and managing batteries. Separately, Pratt and Whitney in the U.S. is working on hydrogen engines.

A billion hours ago the Nasca civilization drew lines in the sand that hinted that man might very well have flown using primitive hand gliding kites. And now, a billion flight hours later, Pratt and Whitney is close to drawing its own line in the sand when it comes to using fossil fuel to power its engines.

“You can see that we really do have a broad gamut of lanes of attack on this particular issue,” says Lewis.