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?

History

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.

The future

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.

​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.”

According to the release, the Cessna 172 was equipped with a “proprietary autonomous platform that can be applied to any fixed-wing aircraft. The platform includes avionics, software, mechanisms, a communications system, remote control interfaces, along with a backup system that has the capability to take over if needed. Following the C172 programme, it was adapted for use on the larger Cessna 208.”
 
As it happened, the first automated Cessna 208 test flight took place in June this year, with a fully automated landing taking place soon thereafter. To find out more about the technology in these aircraft, Aviation News Journal spoke with Robert Rose.
 
According to Rose, “People have been flying autonomous aircraft for some time, the military has been doing this for a while, but I think what makes our demonstration unique, is we are not a military funded programme. This is private money.
 
“We also got approval to fly over a populated area. I don’t believe that’s ever been done before through a completely privately funded programme. But more importantly, we set out from day one with certification in mind.” He mentioned that many of the components the company has developed are certifiable. “We are now working with the faa (Federal Aviation Administration) on getting this approved for use in a civilian and commercial capacity,” he added.
Do these aircraft fly with the help of artificial intelligence and machine learning? Not quite. In the words of Rose, “There is artificial intelligence in the sense that it is an intelligent system, but it is not AI in the deep learning sense by any stretch. There is no regulatory basis for flying machine learning or deep learning systems in airplanes yet. We wanted to focus on what can be done right now.”

​The North Star Practices’ (NSP) purpose is to improve safety in floatplane operations, but what exactly is it and how does it benefit the industry?
 
To find out more about the NSP, we spoke with Jim Hartwell, an experienced pilot who is currently a member of the Air Carriers Safety Working Group and Northern Air Transport Association (NATA). Hartwell, who lives in Campbell River, BC, started his career as a pilot in Saskatchewan during the 1970s, before gaining flying experience in Manitoba and the Northwest Territories. He then returned to his home province to fly floatplanes on the British Columbian coast. During the early stages of the safety programme’s development, Hartwell was serving as administrator for the Floatplane Operators’ Association, which has since been absorbed into NATA. Today, he is actively working on and promoting the North Star Practices in the aviation industry.
 
From 2000 to 2009, there were 111 fatal aviation accidents in BC, which resulted in more than 200 deaths, of which 85 were onboard commercial operators’ aircraft. In 2012, a panel of aviation experts presented a report to the Chief Coroner of BC, who then provided recommendations to Transport Canada, NavCanada, WorkSafeBC and the BC Forest Safety Council. Hoping to see a consistent set of safety practices, which could be used by operators who fly workers into work sites, the BC Forest Safety Council approached the Floatplane Operators’ Association for assistance in developing a safety programme to reduce the number of accidents in the region. As a result, the Air Carriers Safety Working Group (ACSWG) was formed. 

The ACSWG consists of Jim Hartwell, BC Forest Safety Council’s Dustin Meierhofer, experienced seaplane pilot and accident investigator Vince Crooks, as well as NATA Executive Director Glenn Priestly. The North Star Practices, as the safety programme was named, is a set of operating standards and procedures, which includes an auditing system that provides assurance to clients, regulators and the public that an operator has not only met the basic Transport Canada regulations, but operates above those regulations at a higher standard. To operators, the NSP is intended to improve business performance by enhancing safety in an efficient and effective manner. Pilots benefit from the programme, as it provides guidance on safe practices and assists them in making decisions. “We are trying to encourage operators to put this programme into their safety management systems,” said Hartwell. “It is an easy fit.”
 
For the most part, the NSP relies on self-auditing, but every third year the operator is audited by an independent auditor. That said, how would one know whether an operator is compliant throughout the three-year period? Well, the programme requires operators to make use of satellite tracking, primarily for safety reasons, but also so that, on one or two occasions during the year, an operator’s flights can be monitored by the ACSWG. This adds an element of transparency to the programme. All of the practices contained within the NSP, along with all relevant documentation and information are available on www.northstarpractices.org. An operator that meets the required level of compliance is awarded a ‘North Star’, a symbol which can be displayed to indicate that it is an approved ‘North Star’ operator. In Hartwell’s words, “If you see that logo on the side of an airplane or inside an office, it is indicative that the operator is making a concerted effort to improve safety.”
 
So far, response from the industry has been positive, as operators are keen to receive recognition for their safety standards. “There is a wanting for a consistent set of safety practices,” said Hartwell. “I think it is timely for the industry to take a closer look and see what it can do to improve safety.”
 
By investing in safety, especially in this case in the west coast, where flying conditions can be challenging, an operator can expect to not only improve business performance, but earn favour from their clients, peers and the public. For further information, please visit www.northstarpractices.org​.

Draganfly
 
To find out more about these developments and their impact on the North American market, we spoke to Camaron Chell, CEO of Draganfly Inc, the oldest operating commercial drone company in the world. Over the years, it has established a reputation of being a pioneering company in the field of unmanned aircraft. Founded in 1998, Draganfly made its mark in history by being the first company to commercialize a quadcopter. In 2013, the RCMP used a Draganflyer X4-ES quadcopter to locate an injured man in a remote part of Saskatchewan. It was the first time in history that a drone had been used to save someone’s life. Draganfly holds 26 patents and is the first company to have a drone inducted into the Smithsonian Museum.
 
Chell, who has a background in machine vision-based ‘follow me’ technology for drones, has been with Draganfly since 2014. The company currently has offices in California and a manufacturing plant in Saskatchewan, but will be expanding over the next few months. Over the course of its existence, Draganfly has sold more than 9,500 drones, and will more than likely sell its 10,000th product this year.
 
The company conducts advanced research and development, producing fixed-wing and rotary wing drones, as well as unmanned ground vehicles or robots. The Draganflyer Commander, for example, is a comparatively small UAV, a quadcopter, which can fly at speeds of up to 50 km/h, in winds as strong as 35 km/h. It can carry a payload of 1 kg and operate in temperatures from -24°C to 38°C. Equipped with infra-red and electro-optical cameras, the Commander can be used for digital surface monitoring, search and rescue, tactical overwatch or firefighting missions. With a multispectral kit, the same quadcopter could be used by farmers for crop health assessments or by researchers to determine a normalized difference vegetation index (NVDI). If the Commander is equipped with a QX100 camera, it could be used for 3D modelling and mapping, or by law enforcement officers for accident reconstruction.
 
These are just a few examples of the versatility of one small remotely piloted quadcopter. The number of tasks which can be accomplished by drones in general, is simply incredible, and technology is advancing rapidly. According to Chell, “We are now getting to a point where there is enough data for machine learning and artificial intelligence (ai) are becoming practical and useful. Twenty-four months from now, I don’t think there will be a drone out there that does not utilize ai or machine vision.” Chell continued that with the advent of 5G, cloud computing will make drones even more versatile and capable. “It will help the whole drone market realize
its potential.”
 
A Time of Opportunity
 
In addition to addressing a national security concern, the US government’s ban on imported drones for government use seems to be targeting foreign policy, in which foreign authoritarian governments are able to obtain data from its drone manufacturers. According to Chell, “The amount of data collected by drones is off the charts.” He continued, “Incredible amounts of data is collected, which along with other data points and ai, can paint some pretty impressive security pictures.”
 
As a result of the ban, North American drone manufacturers now have access to a market which had until recently been dominated by Chinese manufacturers. “There is somewhere between $600 million and $1 billion of yearly revenue that is attributable to commercial drones that are on government projects, whether that is military, industrial, infrastructure, commercial, etc.,” said Chell. That revenue is now available to North American drone manufacturers who demonstrate and meet the security criteria of the US government.
 
With their biggest competitors banned from supplying unmanned aircraft to a major market, this is certainly an exciting time, filled with opportunity, for North American manufacturers.

The Canadian Museum of Flight is home to an impressive collection of static and flying aircraft. One of the most interesting of these is a Handley Page Hampden Second World War bomber, which happens to be one of three surviving examples in the world. This particular aircraft crashed into the ocean during a torpedo training flight in 1942. After a lengthy and challenging process, the Hampden’s restoration to static display condition was completed in 1998.
 
Visitors are allowed to climb into the cockpits of some of the museum’s aircraft, such as its Sikorsky S-55 helicopter, Beechcraft Expeditor transport aircraft, as well as its
ever-popular Lockheed CF-104 Starfighter.
 
Other non-flying aircraft range from a Canadair CT-114 Tutor to a Conair Firecat and Douglas DC-3. Also, the Museum’s hangar is packed with fascinating artifacts, engines and beautifully restored aircraft.
 
Regular airshow-goers in BC will be familiar with the museum’s flying aircraft, which include replicas of Sopwith Pup and SE.5A World War I-era fighters, a Fleet 16B
Finch Mk.II trainer, Fleet 80 Canuck light aircraft, as well
as a stunning 1937 Waco Cabin.
 
A few years ago, the museum was tasked with building two Sopwith Pup replicas to participate in commemorations of the 100th anniversary of the Battle of Vimy Ridge in France, held in April 2017. In addition to these two aircraft, the museum’s SE.5A was transported to France to participate in the ceremonies. While the Pups were used in static displays, the SE.5A  completed a flypast of the Canadian National Vimy Memorial in northern France. Having completed their mission, the three aircraft were returned to the museum’s facilities in BC.
 
There is quite a bit more to the Canadian Museum of Flight than has been briefly covered in this article. The museum is certainly worth a visit, and so is its website, www.canadianflight.org, which has a wealth of information on all its aircraft and engines, not to mention news on its restoration projects.

​Challenger
 
The improved construction method of Challenger’s airframe made it considerably lighter than Columbia, resulting in its capacity to carry heavier payloads. Astronauts preferred flying in Challenger as its flight deck was much more spacious and its instrument panels were not as cluttered as those of Columbia. In fact, Challenger was the first Space Shuttle to be equipped with HUDs (Head Up Displays) and became the first shuttle to carry a crew of five. As a matter of interest, Challenger was also the first Shuttle to have a female crew member as well as the first to have an African American as part of the crew.
 
Later on, it became normal practice to have a crew of seven onboard the craft, while the maximum number of the crew was eight. However, in an emergency there would be sufficient space for ten people. In theory, it would be possible for a two-man crew to fly a shuttle into orbit, in order to rescue eight crew members of a stranded orbiter.
 
Programme managers used Challenger more often than other shuttles, as it could be prepared for the next flight in less time than other orbiters. This was mainly due to its incredible reliability. The first spacewalk of the Space Shuttle programme took place during Challenger’s maiden flight. During its third mission, it became the first orbiter to launch and land at night. Challenger was also the first Space Shuttle to land at Kennedy Space Centre. In short, every Challenger mission became a groundbreaking flight.
 
A typical mission
 
A typical Space Shuttle flight began with the STS (Space Transportation System) resting on a launch platform. The biggest component was the external fuel tank, to which the orbiter (Space Shuttle) was attached. The external tank provided fuel (liquid hydrogen and liquid oxygen) to the Space Shuttle’s three main engines. Two white SRBs (Solid Rocket Boosters) were responsible for the Shuttle’s initial acceleration and could be seen on either side of the external tank. At the end of the launch countdown, the Space Shuttle’s three main engines would ignite. 2.64 seconds later, the two SRBs would ignite, providing more thrust for the next two minutes than 140 Boeing 747 engines.

As the shuttle left the launch platform in its wake, it would roll 120° to the right, while accelerating at 3 Gs. 124 seconds after lift off, the Shuttle would be 45 km above the ground with explosive bolts separating the SRBs from the external tank. At 129 km altitude, the shuttle exceeded Mach 15. Just less than nine minutes after lift off, the external tank was released from the shuttle and disintegrated as it fell back to Earth. The two SRBs descended to the Atlantic Ocean with parachutes and would be refurbished and reused in future STS missions. Once in orbit, the Shuttle used orbital maneuvering systems and reaction control systems to alter its attitude.
 
At 300 km altitude, the shuttle orbited the Earth once every hour and a half at a speed of 15,200 kts. This is where mission specialists started completing the mission’s objectives. These objectives ranged from launching, repairing or retrieving satellites to conducting Spacelab experiments and providing a ‘shuttle service’ to the International Space Station. The shuttle’s most important tool was its Remote Manipulator System (RMS). A highly trained RMS operator used this robotic arm to store or unload cargo and to assist astronauts in conducting ‘extra vehicular activities’ (space walking). On Earth, the RMS arm weighed just over 400 kg, but in space it could move large objects weighing as much as 30 tons. ‘Manned Maneuvering Units’ with vectoring thrusters allowed astronauts to move around outside the orbiter, without the need to be tethered to the spacecraft. Astronauts could literally spacewalk up to a distance of 90 metres away from the shuttle, to retrieve an object.
 
Interestingly, in order to finance the Space Shuttle programme, NASA continuously had to prove that it was a good investment to keep these spacecraft operational. Fees charged for placing, repairing and retrieving commercial satellites, as well as maintaining military satellites with strategic importance, helped to make the programme financially viable. NASA claimed that each dollar they spent returned at least $2 in benefits.
 
Having completed orbital operations, the shuttle had to slow down in order to quite literally ‘fall’ out of orbit. Once the cargo bay’s doors had been shut, the Shuttle maneuvered into a tail-first attitude – flying backwards. The Shuttle’s orbital maneuvering engines then fired a three minute burst, slowing the Space Shuttle down, to the extent that it started to descend. The commander quickly had to correct the orbiter’s attitude to a nose-first 30° angle of attack. The thermal protection tiles would then start to heat up as the Shuttle entered the Earth’s atmosphere at a speed of 14,000 kts. The heat would cause surrounding air to ionize (become electrically charged), causing a communications blackout that lasted up to the point where the orbiter slowed down to Mach 6. At 200,000 ft the Shuttle’s aerodynamic control surfaces became more effective. Finally, after gliding the spacecraft to the landing strip or runway, the Shuttle would touch down at about 190 kts.

When determining the when a propeller, or related components, need to be overhauled, flight time or calendar dates are not the only factors one should consider. It is important to take operating conditions and the environment into consideration.

​That said, what does an overhaul entail? The first step is to mount the propeller and visually inspect it. The paint is removed and blades are examined to see if they had been damaged in any way, and to measure dimensions to determine whether they can be overhauled. Once the propeller has been taken apart, the basic components are cleaned and degreased. The next step is to repair the damage and ensure that the components are within the manufacturer’s dimensional limits. All major components are then sent to a certified workshop for non-destructive inspection. Next, components are polished and dipped in a solution for corrosion protection, before being painted and receiving a durable polyurethane coating. Finally, the propeller is reassembled and set according to the manufacturer’s overhaul manual.
 
Internal corrosion is extremely dangerous and can only be detected when all the components have been taken a part and cleaned in a workshop. The importance of propeller inspections and overhauls cannot be overstated. When experiencing an engine failure, for the most part, the aircraft can glide and complete a safe forced landing. If, on the other hand, a propeller blade separates, the remainder of the flight can be considerably more eventful, if not catastrophic.
 
For further information on propeller maintenance, or advice regarding purchasing or owning a propeller, please contact Aero Propeller of Calgary at 403-291-9400.
 
Information on how frequently propellers need to be overhauled can be found on Transport Canada’s website, www.tc.gc.ca, in the Canadian Aviation Regulations (CARs) section.

​Analyzing or monitoring flight data is not a new concept, but it is surprising just how many misconceptions and myths there are regarding this remarkably important tool, especially now that modern technology has made it more accessible to smaller aircraft operators.

​​Dispelling Myths
 
What exactly is Flight Data Monitoring (FDM) and how does it benefit operators? To find out, we contacted Dion Bozec of Scaled Analytics, based in Ottawa, on, who is passionate about developing modern FDM programmes.
 
In a nutshell, FDM, also commonly known as Flight Operations Quality Assurance (FOQA) or Flight Data Analysis (FDA), is a programme in which flight data is recorded and analyzed, with the goal of improving operating procedures and safety. With the right FDM system in place, operators benefit from increased operational efficiency and profitability.
 
According to Bozec, one of the biggest myths or assumptions is that FDM is a punitive programme, intended to evaluate pilots. Instead, FDM programmes are designed to look at trends, rather than individual performance, benefiting the entire company, including its pilots.
 
Many operators also erroneously believe that FDM is expensive, difficult to implement and only useful for airlines. In the past, FDM or FOQA systems were complex, requiring expensive hardware, highly specialized software and a host of engineers and it experts to manage the programme. Thankfully, technology has progressed to the point where this is no longer the case. Today, FDM is accessible and beneficial to any operator, regardless of the size of its fleet, even if it has only one light aircraft or helicopter.

Advantages
 
FDM was originally developed to enhance safety and it continues to serve as a valuable component of safety management systems, but there is considerably more to the story than that. “A programme that involves reviewing flight data can benefit many departments within an organization, besides the safety department,” said Bozec. “An FDM programme can be extended to improving operational efficiency, monitoring maintenance events, monitoring or improving fuel efficiency, improving training programmes and reducing maintenance trouble shooting times, among other uses.”
 
As an example, with the use of FDM, an operator with only one aircraft in its fleet was able to detect a recurring problem with unstable approaches. A trend was discovered, measures were put in place and the number of unstable approaches was dramatically reduced.
 
Another operator had occasional overtemp problems with a turboprop engine on one of its aircraft. Each time an overtemp was indicated, the aircraft was grounded and its flight data recorder sent to the recorder’s manufacturer, which would download the data file and send it to the operator. On each occasion, the process would take five days, before the decision on whether the aircraft could fly was made. Now, with more modern techniques, retrieving the same information would take mere minutes, dramatically reducing the aircraft’s time on the ground.
 
Understanding the process
 
How exactly does FDM work? The first step is to record flight data. Most transport aircraft and helicopters have crash resistant Flight Data Recorders (FDR), called ‘black boxes’ by the media. These data recorders serve as hard drives, storing all the information sent to it by the aircraft’s Flight Data Acquisition Unit (FDAU).
 
Data can be recovered with a download unit and used for FDM, but there are disadvantages to using an FDR for this purpose. FDRs are only required to record 25 hours of data, download units are expensive and, depending on the aircraft, it might be difficult to access.
 
As a result, it might make more sense to use a Quick Access Recorder (QAR). This device is effectively a flight data recorder that is not crash survivable. Compared with an FDR, a QAR is small, light, easily accessible, more affordable and able to record more than 400 hours of information.
 
That said, these data recorders may not even be necessary. If the aircraft has modern avionics, such as the Garmin G1000, data can simply be saved on a memory card and used as part of an FDM programme. This can be particularly useful to smaller commercial operators or flying schools, as glass cockpits have become increasingly popular in even light general aviation aircraft.
 
Once the data has been downloaded, it needs to be processed by specialized software, which converts raw binary data into meaningful information. The software also looks for ‘events’ or situations where predefined limits were exceeded.
 
The resulting statistics and ‘events’ are then reviewed by a flight data analyst, who is able to identify unsafe or inefficient trends in flight operations. These steps can be accomplished with the help of a service provider. This would be particularly useful to smaller operators, which would otherwise need to employ a data analyst.
 
Once the information has been reviewed and examined, an analyst presents it to the operator’s decisionmakers in the form of charts or flight animations. Actionable, informed decisions can then be made to improve safety, efficiency and profitability. By continuously monitoring flight data, the impact and value of those decisions can be measured as the organization keeps working toward perfection.
 
In recent years, the cost of technology has become more affordable, creating real opportunities for smaller operators to benefit from FDM. With solutions provided by the likes of Scaled Analytics, decisionmakers and maintenance engineers are now able to access vital flight data and statistics online from anywhere in the world, quicker than ever.
 
For further information on how to benefit from the latest technology in Flight Data Monitoring, visit www.scaledanalytics.com

The sound barrier was broken for the first time, in level flight, 71 years ago, but who was the first person to fly faster than the speed of sound?

The official answer
 
Chuck Yeager is arguably one of the most famous pilots of all time. He became a P-51 Mustang ace during World War II by shooting down 17 Axis aircraft – an impressive tally that includes an Me-262 kill. His first five kills were achieved in one mission, making him the first usaaf pilot to become an ace during a single mission. Of course, Chuck Yeager didn’t become famous by shooting down enemy aircraft; his fame came with a much more significant event that only came after the war.
 
On 14 October 1947, Chuck Yeager broke the sound barrier in level flight in a Bell X-1 called ‘Glamorous Glennis’. The X-1 didn’t have enough endurance to take off under its own power, so instead it was carried under the bomb bay of a B-29 Superfortress. Similar to other X-1 test flights, the B-29 climbed to an altitude of 25 000 ft, before starting a shallow dive. Once 240 mph had been reached, the X-1 was released from the B-29’s underside. Chuck Yeager then ignited the liquid oxygen and alcohol powered rockets and accelerated to a speed that exceeded Mach 1. However, the question remains: was he the first man to fly faster than the speed of sound?

The other side of the story
 
The following account is mildly controversial and the accuracy of the sequence of events is still debatable. Our story begins with another World War II ace, albeit from a different theatre of the war. George Welch was one of four P-40 pilots who managed to fight against Japanese forces (and claim four kills) on the day that Pearl Harbour was attacked. After a successful wartime fighter pilot career, George Welch became a test pilot with North American Aviation. On 1 October 1947, (two weeks before the Bell X-1’s attempt) Welch conducted high speed dives while test flying the XP-86 – the prototype Sabre. During one of these dives he experienced all the telltale signs that he was passing through the transonic speed range. In fact, he even caused a sonic boom. Welch reportedly repeated the feat seconds before Chuck Yeager’s official attempt. Naturally, this would be quite embarrassing for those who had spent huge amounts of money on an aircraft that was designed solely for the purpose of ‘breaking the sound barrier’. It would therefore make sense to cover up the fact that the same could be accomplished sooner by a conventional, affordable aircraft, which could actually be used in a time of war.

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Were there any other candidates?
 
There have been many tales of World War II fighters breaking the sound barrier, while diving to escape enemy aircraft.  One fact that we have to bear in mind is that one could not rely on air speed indicators to be accurate when approaching transonic speeds. For example, P-38 Lightning pilots have claimed on several occasions that they broke the sound barrier while referring to their asi readings as proof, even though Lightnings had very low Mach limits when compared to contemporary fighters. Mustangs and Thunderbolts had better initial dive speeds than Spitfires, but because of their thin wings, Spitfires could reach superior Mach speeds. During flight trials at the Royal Aircraft Establishment, a Spitfire Mk XI reached a speed of Mach 0.92 during a dive from high altitude. Perhaps we shouldn’t ask whether these propeller driven aircraft could dive at supersonic speeds, but rather whether the pilots survived to tell their stories.
 
The most credible account from the Second World War is the one of Hans Guido Mutke, an Me-262 pilot. In an effort to intercept a Mustang, Mutke initiated a 40 degree full-power dive from an altitude of 36 000 ft. The German pilot experienced a sequence of events very similar to those experienced by Chuck Yeager. Even so, the air speed indicator’s needle stopped at the end of its range and the aircraft obviously didn’t have any testing equipment installed.  Therefore we can’t be absolutely sure – let alone prove - that Mutke did fly supersonic. Messerschmitt did conduct high speed dive tests and reached the conclusion that one would lose control over the Me-262 at Mach 0.86. In theory, if one would exceed that Mach number, the aircraft’s nose would pitch down, with the resulting negative G-forces severely compromising the fighter’s structural integrity. Some variants of the Me-262 were estimated to have Mach limits as high as Mach 0.96 at cooler air temperatures, but these were never confirmed by official tests. The bottom line is that it is quite possible that World War II aircraft exceeded Mach 1, while diving toward or away from enemy aircraft – shortly before disintegrating or hitting the ground.
 
Arguably, the least credible claims of early supersonic aircraft are probably those that involve the German designer, Alexander Martin Lippisch. He was responsible for a number of fascinating aircraft designs and is said to have successfully built supersonic, rocket engined gliders. Some conspiracy theorists claim that he designed fighters resembling ‘flying saucers’ (also known as ‘Foo Fighters’), before retreating to a secret Antarctic base.
 
What about the Russians?
 
The Bell X-1’s historic flight took place during the Cold War; therefore news of this accomplishment was kept secret for a while after the actual event. Could the same scenario have taken place on the other side of the Iron Curtain? At the end of the Second World War, an uncompleted German prototype was evaluated by the Soviet Union. This aircraft, a rocket-powered DFS 346, was intended to serve as a supersonic reconnaissance plane. The Soviets, assisted by German engineers, developed further examples of the concept, which were eventually, and ironically, launched from a captured B-29. Interestingly, pilots had to lie on their stomachs while flying a DFS. Although theoretically capable of transonic speeds, it cannot be confirmed that any of these aircraft actually broke the sound barrier. In the end, the first Soviet aircraft to officially fly supersonic was the Lavochkin La-176 – an aircraft similar in appearance to the legendary MiG-15. This was accomplished in 1948, while diving at full power.

 
What is the final verdict?
 
The fact that Chuck Yeager flew faster than the speed of sound on 14 October 1947 cannot be disputed. The event was well documented and the flight was monitored by accurate equipment. George Welch’s claims of reaching Mach 1 before Yeager are without substantial proof, however, shortly after Yeager’s flight, it was established that the XP-86 was capable of reaching supersonic speeds during a dive. In fact, the first female pilot to fly supersonic did so while piloting a Sabre. Then there were other fighter pilots, who fought in World War II, who claimed to have broken the sound barrier long before Chuck Yeager and George Welch.
 
Who was the first person to accomplish this feat? Until sufficient proof has been accumulated to change history as we know it – you’ll have to be the judge.