Sensenich, arguably the best-known manufacturer of wooden propellers, has been around for almost 100 years. It has a fascinating history, but what does the future hold for this remarkable company?
To gain greater insight, we spoke to Sensenich’s Steve Boser, vice president, engineering. Boser has been with Sensenich from 1993, when he joined the company as a junior design engineer. At the time, rather ironically, he was a glider pilot, although he has since moved on to flying propeller-driven aircraft.
The company was incorporated in 1932, but it began in rural Pennsylvania during the 1920s, when two brothers, Harry and Martin Sensenich, who loved to tinker, procured an old World War I-era engine. According to Boser, they “proceeded to fit it to a wagon, a sled, and different contraptions they could find on their dairy farm. Their wagon worked well. It was called a ‘Wind Wagon’, but eventually they were banned from taking it into town.” The brothers then fitted the engine to a snow sled. One winter, while operating on ice, the brothers’ unique air-driven vehicle crashed, breaking its expensive propeller. At the time, it was rare for someone to be knowledgeable about propellers. Boser explained, “They were pretty good with their hands, so they thought, ‘hey, let’s make our own propeller!’”
The brothers successfully crafted a propeller for their sled. Soon, local pilots took notice and reasoned, “If you can make a propeller for that thing, you can make propellers for our aircraft.” Boser continued, “They started carving aircraft propellers, and by the beginning of World War II, they were the largest manufacturer of wooden propellers in the world. We still have that title today.” During the Second World War, which lasted from 1939 to 1945, Sensenich had more than 400 employees crafting propellers 24 hours a day to support the war effort. These propellers were primarily for liaison aircraft and trainers, as well as experimental projects.
Soon after the war, Sensenich produced a tremendous number of propellers for private light aircraft. Later, in the late 1940s, the company diversified and began making metal fixed-pitch propellers, while also servicing and maintaining other companies’ propellers, in addition to manufacturing a variety of wooden products. During the 1950s, Sensenich also began designing and manufacturing target drone propellers, as well as airboat propellers. Airboats, which have grown in popularity in places such as Florida, are essentially flat-bottom boats pushed by propellers, which are similar in appearance to those found on aircraft. Today, Sensenich produces more airboat propellers than aircraft propellers.
By the late 1980s, the company had been operating separate divisions for propellers and for wood products. The Sensenich family was forced to sell one of its divisions, either propeller manufacturing or its wood product division, which made table tops and bench seats. A Philadelphian family purchased the propeller company and continues to own Sensenich Propellers to this day. In 1994, the company’s three divisions, namely wood propellers, metal propellers and its service division, were separated. The service division had a management buyout, while the wooden propeller division was moved to Florida, the primary market for airboat propellers. The metal propeller division remained in Pennsylvania. In the late 1990s, Sensenich turned its focus to composite propellers for aircraft and airboats, while also ramping up production of unmanned aircraft propellers.
Today, Sensenich has about twenty employees in Pennsylvania, where metal propellers are produced, and about fifty employees in Florida, where the company focusses on wooden and composite propellers.
In terms of aircraft. Sensenich propellers are primarily used by experimental aircraft, trainers and vintage aircraft. Most of the company’s wooden propellers are used by vintage or antique aircraft. Sensenich produces about 4,000 wooden propellers per year, although, due to demand, its carbon fibre propeller production numbers increase significantly every year. How has covid-19 restrictions affected Sensenich? According to Boser, “Last year was probably the busiest year of the past ten years. This year is off to an even better start.” He continued, “When people are at home, they have more time on their hands. They need propellers because they are either working on kit airplanes or they are out flying.”
Sensenich currently produces about 150 to 200 composite propellers per month. Is that where the future lies? “Most of the development is on the carbon fibre product line,” explained Boser. “Wood is economical for developing a propeller in a short timeframe. It requires minimal tooling to make a wooden propeller. The engineering requirements for wooden propellers are much less than metal or carbon props, so new wood props can be made in a couple weeks. A metal prop requires vibration testing for good service life. That is an incredibly involved project and it’s a fairly mature product line. Carbon fibre offers advantages in strength, weight and configuration, with engineering demands between wood propellers and metal propellers.”
What about unmanned aircraft? “We do see a lot of potential with UAVs (Unmanned Aerial Vehicles) in the future, but our sales are fairly steady.” Sensenich develops propellers specifically for mid-size, or tactical-size, UAVs. “We are doing product development across the board with all our products,” said Boser. “We have just received an stc (Supplemental Type Certificate) from the FAA for installation of one of our composite two-bladed propellers on STOL (Short Take-Off and Landing) aircraft. We plan on doing a further STC for lower horsepower SuperCubs. Then we will be looking very closely at the market before we decide on follow-on STCs. The light sport market is very active too. We recently released a number of new prop designs for the light sport and experimental market.” Intriguingly, Boser also mentioned, “We have some pretty exciting things coming up. I don’t want to give out too much about that, but it’s a very new area for us.”
“The recently released STOL propeller for bush planes is very exciting for us,” Boser added. “We are preparing to apply for a Canadian STC.”
Of course, the development of the eVTOL (Electric Vertical Take-Off and Landing) industry is quite exciting. “We have been remarkably busy prototyping for that market, and we have become one of the top fabricators for prototypes and test articles for the eVTOL market.” He added that, “we deal with mature but innovative programmes. There is a whole range of projects out there, so we focus on the ones where we can have the most impact and provide the most value.
On 20 May 1945, shortly after the Second World War had come to an end in Europe, a group of military veteran pilots came together to form the Christian Airmen’s Missionary Fellowship (CAMF), now known around the world as Mission Aviation Fellowship (MAF). Over the course of the past 75 years, MAF has become quite famous for its advances in improving the lives of isolated people around the world, but what is it like to serve as an MAF pilot?
To answer this question, Aviation News Journal interviewed experienced Canadian MAF pilot Nick Frey. He has spent the past nine years flying in central Africa and has just recently returned to Canada.
Nick was born and raised in Ontario, where he earned his commercial pilot’s licence. He moved to Alberta and began his career in aviation in a regional airline’s operations department. Nick’s first job as a pilot was to fly Dornier 228s and Navajo Chieftains for Edmonton-based charter airline Alta Flights. One of the company’s pilots told Nick about how he had gained flying experience in Botswana with MAF.
Nick was intrigued. “I was looking to do something more meaningful with my life,” he recalled. “I had everything I wanted, and it still didn’t seem enough.”
Nick asked his colleague to tell him more about MAF and what it was like flying in Africa. “He explained MAF and their mission and values, and that seemed to align with what I wanted to do: to serve and help people.” Nick then contacted MAF and studied theology in Ontario for one year. MAF’s pilots are missionaries, so official theological training is a prerequisite. After that, he briefly returned to Edmonton to fly skydivers in Cessna 182s and 206s, which turned out to be a great way to build experience to fly MAF’s aircraft types. As it happened, while flying skydivers, Nick met his future wife, who was willing to travel and work with him in remote parts of the world.
A Canadian Pilot in Central Africa
After a technical flight evaluation at Prairie Aviation Training Centre at Three Hills, AB, it was decided that Nick’s skills, IFR experience and the ability to speak French, for example, would be best suited for operations in the Democratic Republic of the Congo (DRC). Nick did not mind being sent to the DRC. “I was ready and willing to go to any of the thirty countries where MAF serves, but that’s where we ended up.”
Nick and his wife Jocelyn arrived in Kinshasa, the DRC’s capital city, in 2011. “At the time, MAF had about six or seven families living there, all of which were American,” remembered Nick.
“I started flying 206s to some of the easier mission airstrips. After a while, I started flying the SMA diesel Cessna 182. I gradually flew to more and more difficult airstrips.”
Meanwhile, Nick helped out with technical work, such as setting up solar panels and battery systems, as well as in information technology. “Power cuts and water cuts happen all the time, so we had to have our own backup systems.”
Nick also took on the role of programme manager in 2014. Around that time, MAF’s fleet in Kinshasa changed to what it is now. The diesel 182, for example, was transferred to Madagascar. Nick flew the aircraft all the way from Kinshasa to the island country. “It was one of the most amazing flights I had ever done – flying all the way across Africa,” said Nick. As for the rest of MAF’s Kinshasa fleet, its 206 and Cessna Caravan were complemented with a second Caravan and a Pilatus PC-12. In the east of the DRC, MAF had two Caravans and a 206. The PC-12, which happens to be the only one of its kind in MAF’s global fleet, might seem like an odd choice for the DRC’s rugged environment, but according to Nick, “it was perfect for Congo. It is a versatile and utility-capable aircraft. We would not take it into all of our airstrips, especially not the ones that were undulating and had bumps, because the propeller clearance was quite low and also it had low wings. The country is so large; from Kinshasa to Goma on the other side of the country is almost 1,000 miles (1,600 km) and the PC-12 can do it in four hours. We would go to Goma and back in the same day, which you would never do in a Caravan. The huge cargo door on the PC-12 was perfect as well. We could fit caskets, generators, solar panels, large vaccine boxes, and all kinds of large items that you would never think you could fit into a Pilatus. It was my favourite plane to fly, for sure. It is just an amazing, versatile machine.”
The Frey family resided in Kinshasa, from where most of Nick’s flying took place, but what kind of missions did he fly? “It was really anything and everything. Basically, all of the NGOs (non-governmental organizations) and humanitarian groups that are in the Congo and need to get into the interior Congo have to use un (United Nations) or MAF aircraft. Those are the only options to get around. We flew for groups like World Vision, Doctors Without Borders, World Wildlife Fund, and anybody who wanted to have an impact on the interior of the country. There are no roads, no railways, the rivers take weeks, so planes are basically the only option. The roads that did exist were alright for shipping items that were not fragile, such as mosquito nets.”
MAF aircraft were utilized to transport people, fragile medical equipment, or items such as medicine or vaccines which had to be kept cold for a certain amount of time. Vaccines, for example, had to be delivered within 48 hours. “I once flew six dirt bikes for the World Wildlife Fund. We fit all six of them into a Caravan – that was a tight squeeze!”
Nick explained that “we were essentially an on-call, on-demand charter company, but specifically for NGOs and humanitarian groups, as well as church mission groups and mission hospitals.”
During deadly Ebola virus outbreaks, Nick flew journalists, aid workers, doctors, the DRC’s minister of health, and other delegates, such at the Anglican Church’s Archbishop of Canterbury, to Ebola sites. Of course, there have also been other situations where MAF’s crews and aircraft have proved to be incredibly useful, such as directly helping people affected by cholera outbreaks and the constant threat of malaria. Nick himself has had malaria at least ten times.
“Sometimes we would fly medevac flights to Kinshasa,” said Nick. “I remember one where a village chief passed away. They called him the king of a tribe near the Angolan border. He was sick so we picked him up and took him to Kinshasa for medical attention, but he didn’t make it. We flew his body back in a Casket. We ended up making four or five flights with passengers, who wanted to attend the funeral, to this small village airstrip. We had the only aircraft in that half of the country that could physically land at that airstrip.” He explained, “It is very important in Congolese culture to be buried in your home village.”
Naturally, there are risks associated with flying in the DRC, which is known for having the highest frequency of thunderstorms in the world, as well as having the second largest rainforest in the world, after the Amazon. According to Nick, “Weather can be a problem. Typically, we would see thundershower cells in Congo. Usually you could fly around them, even if it meant flying thirty or forty miles to the left or right. We never had to deal with snow or icing, so that was a blessing for a Canadian pilot to never have to deal with that!”
What about conflict in the region? “For our base in the east, near Nyankunde, it is quite often a problem. If the rebel groups come near one of the trigger points we have in our security protocols, MAF personnel would typically get in the aircraft, evacuate and wait in Uganda for the situation to calm down. In Kinshasa, the tension was from political drama. There would often be protests for one political party or another. They would impede our operations because we couldn’t physically reach the hangar from our houses and our kids couldn’t get to school, and schools would be closed. Instead of ‘snow days’, our kids would have ‘political unrest days’. These protests would typically happen every four to six months.”
As for living in the DRC, life for pilots’ families can be somewhat isolating, due to security measures in residential areas, such as tall walls, razor wire and security guards. That said, there are several high-quality international schools for MAF crews’ children to attend.
Now that they are back in Canada, does the Frey family miss the DRC? “Most certainly! We all do, but there are certain things were really enjoy here in Canada. I bike to work and I would never do that in Kinshasa. We go to the park and we don’t have ten-foot walls around our home. We have so much freedom. What we miss most about the DRC is the people – friends and coworkers. I miss flying out in the jungle and spending the night in the middle of nowhere.”
All MAF pilots are missionaries, which affects the way the organization builds relationships with the local population. Most aid groups and humanitarian organizations tend to stay in a country for about two years, whereas missionary pilots and their families will stay in a country for ten years, or sometimes even for several decades. “We stay for long-term relationship building and to really become a part of the community in the countries where we serve.” MAF personnel also have side projects, such as mini fundraisers. For example, “we once had a fundraiser to buy mattresses for a village hospital,” Nick mentioned. “From a financial point of view, every MAF pilot and mechanic is self-supported.” This makes it more affordable for humanitarian organizations to make use of MAF aircraft.
For further information on MAF, please visit www.maf.ca