PT6 Engine data plates recovered after 45 years

Two little pieces of history that sat in a tool box for decades have come to light – ironically, in the year the engine to which they are connected is celebrating its 50th anniversary. Tracing their story has required a little sleuthing and some excellent technical work by P&WC’s Material Investigation Test Lab.

Donald Blane, now retired and living in Florida, was running a PT6 overhaul line at Airwork in Millville, New Jersey, in the 1967−1968 time frame when a Beech King Air, owned by the U.S. Army, came in for an overhaul of its two PT6 engines. Blane, also in charge of the flight line, removed the engines. After the overhaul, while going over the rejected parts, Blane noticed that the data plates had been removed and replaced, which is standard practice with an overhaul.

“What caught my attention was that, according to the serial numbers on the data plates, these were the first two PT6 engines ever manufactured,” says Blane. “So I put them in my tool box and they stayed there all these years.” This happened at a time well before today’s protocol, which requires that data plates be returned to P&WC.

Recently, a friend of Blane’s opened an overhaul shop in Texas. “He knew people at P&WC and gave me the name of someone to contact,” says Blane. “It was just a coincidence that all this happened in the year that the engine is marking its 50th anniversary.”

The executive whom Blane contacted was Maria Della Posta, Senior Vice President, Sales & Marketing. She then asked Nivine Kallab, Business Development, General Aviation, to track down the authenticity of the plates.

“We were a bit mystified at first because we had in our possession the first PT6 engine ever built, and the data plate installed on it had PT6A-6/C20 as the engine model,” says Kallab. “As we continued to investigate, we later determined that the engines that Mr. Blane’s shop had overhauled were originally PT6A-6s that had been upgraded to PT6A-20s, so it started to make sense.”

With the help of P&WC’s configuration management team, Kallab was able to dig out the engineering drawings, which specified the dimensions, the material and the required markings on the data plates produced in the early 1960s. When she compared the drawings to the actual data plates, everything seemed visually compatible.

To help ascertain the authenticity of the plates, Kallab sought help from Denis Blanchet, manager of P&WC’s high-tech Material Investigation Test Lab, located in the Longueuil facility. The lab conducts state-of-the-art inspection and investigation of engine parts.

“Nivine made it clear that the tests we ran had to be non-destructive,” says Blanchet. “So we used a scanning electron microscope to obtain more detailed information about the sample’s surface topography. The microscope is extremely powerful; it provides up to 20,000 times magnification. It’s also able to analyze chemical elements – such as zinc, nickel, iron and aluminum – in the material it is examining without taking samples.”

Through her own research, Kallab was able to provide clear details on the type of processes used back in 1963 to inscribe the plates as well as their material composition. Blanchet’s lab expert, Pierre Leblanc, was able to use that information to further validate that the plates were, in fact, from that year.

“Using the advanced capabilities of the lab, we were able to ascertain that the plates were from 1963 and, given the numbers on them, that they were from the original number one and number two PT6A engines,” says Blanchet, who has run the lab for the past 15 years.

For his part, Blane is happy that the historic plates have found a home back with the company that makes the legendary PT6 engine. Having spent his career in aviation, Blane knows his way around aircraft engines and describes the PT6 as “a real gem of an engine with an excellent reputation. It was so easy to work on – a pleasure, really.”

P&WC plans to put these historic data plates on public display at its Longueuil facility.

  • Men from the PT6 engine shop gather around the first production PT6 being shipped to Beech on December 22, 1963. P&WC Archives (Records and Information Management).

  • Original data plate from first production engine delivered December 22, 1963.

  • Original data plate from second production engine.

COVER PHOTO: Left: Original data plate from first production engine delivered December 22, 1963. Right: Original data plate from second production engine.


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