DALLAS — The Boeing 737 remains the most popular aircraft in history. Since its launch in 1965, this airplane has secured more than 15,000 orders across all the variants. The most successful variant of the Boeing 737, the Next Generation, makes up more than 60% of all the delivered aircraft, earning it the title of the most common airliner in the world.

However, while not so common, there is still one country where you can find airlines today flying the 1967 Boeing 737-200 variant.

The number of 737-200s operating with Canadian registrations in 2022 is not small; a total of 19 units of the 55-year-old, fuel-inefficient airplane fly regularly for airlines within Canada.

Air Canada (AC) and WestJet (WS), which operate modern airliners like the Airbus A220 or the Boeing 787, share the domestic market with plenty of the oldest 737 aircraft flying today.

What are the reasons that encourage Canadian airlines like Air Inuit (3H), Chrono Aviation (MB), or Nolinor Aviation (N5) to still operate almost half of the total Boeing 737-200 worldwide airplanes in 2022?

Nolinor Aviation is the largest operator of the Boeing 737-200 today, with 9 units in service. Photo: Mackenzie Cole.

The Boeing 737-200


The Boeing 737 saw its preliminary design works begin in 1964 when Boeing started looking for another short-haul aircraft to complement the recently introduced Boeing 727. The North American company was looking for a small airplane able to operate short routes with thin demand.

Because of that, Boeing needed to develop an aircraft that could be adapted to the circumstances of small airports with poorer ground services. As a result, they decided to add two engines to the aircraft, which would be mounted directly beneath and across all of the wing chords.

This enabled the 737 to operate with a very low landing gear, which allowed the ground crew to have easier access to the passenger and baggage compartments of the cabin without a complex system of ground vehicles.

The Boeing 737-100, the first variant of the product, only came with 31 units built. For context, the last -100 in commercial service was retired in 2003, the Mexican Air Force retired one in 2004. The first one built, which was operated by NASA its whole life, was preserved in 2004 and is the only 737–100 still in existence.

The -100 entered service with Lufthansa (LH) in February 1968, followed by its bigger brother, the Boeing 737-200, just two months later with United Airlines (UA). These two variants make up the Boeing 737 “Original” family.

The Boeing 737-200 proved its success by delivering 1,000 units to regional customers worldwide. The last unit entered service with Xiamen Airlines (MF) in August 1988. Since then, the “Baby Boeing” has been improved in terms of its aerodynamics, fuel efficiency, and passenger comfort.

However, Boeing always maintained almost the exact flying systems and procedures, enabling most pilots to operate all variants of the type with only one certification, reducing the costs of crew training.

The first Boeing 737-200 entered service with United Airlines in 1968. Photo: Aero Icarus, Creative Commons BY 2.0

The Bypass Ratio


The engines chosen to power the Boeing 737-200 were the Pratt & Whitney JT8D-1 turbofans, and they played a vital role in influencing the evolution of the aircraft throughout history. These engines, which can provide the airplane with a force of up to 17.400 pounds, have the specific characteristic of being built with a 0.96:1 bypass ratio.

The bypass ratio (BPR) of a turbofan engine is the proportion of the air that flows through the combustion chamber to the total air mass that enters the engine core. For example, if a specific engine has an air bypass ratio of 5:1, it means that there is 5 times more air flowing around the compressor than inside the combustion chamber.

By allowing air to bypass the combustion chamber, aircraft engines are more fuel-efficient because they use less fuel to ignite the air and add thrust. This is one of the reasons engine manufacturers race to develop engines with bigger bypass ratios to reduce fuel costs.

The CFM LEAP-1B, which is used to power the brand-new Boeing 737 MAX family, has a BPR of 9:1, which allows the engine to provide 29.000 pounds-force while burning 15% less fuel than its predecessor. Of course, the diameter of the engine needs to be enlarged if the producer wants to add a greater bypass ratio, so the LEAP-1B is 30% larger than the JT8D-1, with a total diameter of 176 cm.

The LEAP-1B is the largest engine ever implemented in a Boeing 737 airplane. Photo: Casey Groulx/Airways.

Gravel Runway Operations


So why is it that 19 Boeing 737-200s still fly in such a developed and wealthy country as Canada? Enter gravel runways.

While the majority of the Canadian population lives below the 50ºN parallel, there is still a considerable portion of Canadians that live and work in the northern provinces of Yukon, Nunavut, and the Northwest Territories. These provinces are very far away from metropolitan areas of the country and tend not to be wealthy rural areas.

Some northern cities have managed to build small airports across the territory with short runways made of gravel to save on costs.

Gravel runways pose a problem for most aircraft. During operations, sand and gravel particles can be absorbed by the engines. This poses a danger to the integrity of the aircraft and the flight. To see an aircraft like the Boeing 737 MAX, with such large engines, operating on gravel runways is unimaginable.

The 176-cm LEAP-1Bs have a high probability of being damaged by the gravel lifted while landing or taking off.

That’s where the Boeing 737-200 comes into play. The small JT8D-1 engines have such a tiny diameter that it is difficult for particles to enter the engine core and cause damage. By chance, it is an aircraft that is ideal for these types of operations.

Today, 19 Boeing 737-200s are still in service for the following Canadian carriers: one for Canadian North (5T), two for Glencore Corporation, three for Chrono Aviation, four for Air Inuit (3H), and nine for Nolinor Aviation (N5).

Nolinor Aviation operates some of its 737-200s in a COMBI configuration. Photo: Nolinor Aviation

Designed for Gravel Runways


Even though the Boeing 737-200 is suited for gravel runway operations thanks to its low-bypass engines, this doesn’t mean that it is entirely safe to fly the type into the harsh conditions of airports in Northern Canada. The aforementioned airlines, in collaboration with Boeing, have designed a series of specific complements to the 737-200 that ensure a 100% safe landing and takeoff from gravel runways.

Among the 10 total modifications, the most important are the gravel deflectors placed around the engines and landing gear, which help to dissipate the lifted-up gravel during operations to avoid any damage caused to the inner core of the engine and the belly of the aircraft.

Most of them function by expelling compressed air from the turbine to blow off any particle of gravel that may hit the airplane during takeoff or landing.

Furthermore, the vast majority of the Canadian Boeing 737-200 fleet is equipped with a COMBI variant of the aircraft. This means that the cabin of the Boeing 737-200 can be divided into two sections, one for large cargo and the other for passengers.

Demand for passenger flights to Northern Canada, while existing, is very low. On the other hand, air cargo demand is strong, as it is a quick and efficient way to transport goods to the isolated towns of the north from the main southern cities of Canada.

One of the gravel diffusers is located just in front of the engine of a 737-200. Photo: Ted Brown Creative Commons BY 2.0

The Future Replacement of the Boeing 737-200


The main problem for Canadian Boeing 737-200 operators is not the very low fuel efficiency of their aircraft, as the fuel cost is usually covered by subsidies from the Canadian Government. The real problem, however, is that the average age of these aircraft is 41,3 years. Some of them, like C-GNLK, have been operating for airlines constantly since 1974. These airplanes are very close to reaching their physical operational death by cycles, so airlines need a replacement.

Chrono Aviation (MB) did actually receive last year two newer Boeing 737-800 aircraft, but these feature large CFM-56 engines and do not include any gravel kit, eliminating them completely from most of the northern Canadian route network of MB.

Air Inuit (3H), though, has been taking delivery since 2008 of second-hand Bombardier Q300 from Europe, and today operates a fleet of 12 total aircraft, in addition to 3 separate Q100s. Canadian North (5T) and Summit Air, on the other hand, opted for the purchase of ATR42 and ATR72 airplanes, different types of turboprop airliners.

Turboprop aircraft have the pros against the 737 of having higher turbo propeller engines that stay further away from gravel and do not have to deal with the issue of having their inner core damaged by particles, as there isn’t any inner engine core.

However, these aircraft usually tend to have very short ranges and their maximum payload is a lot smaller than a conventional jet airliner, so it would be less rentable for Air Inuit to operate the Q300 in the long term than to stay with the 737-200s.

Summit Air operates a discrete fleet of five ATR72 aircraft to small gravel airports in Northern Canada. Photo: Liam Funnell/Airways

A Boeing 737-200 With Glass Cockpit?


Nolinor Aviation, on the other hand, has come up with a completely different approach to this issue. Knowing that the Boeing 737-200 is a critical piece in their plans for the future, they decided to stay with the aircraft to the end of its operational life and to invest in its modernization to stay as safe and efficient as possible. Because of that, the airline announced in 2018 a complete cockpit refurbishment for their fleet of nine aircraft, valued at US$7.5m.

Now, most of this Canadian airline’s fleet of Boeing 737-200 is equipped with a nice glass cockpit with up-to-date avionics and navigation systems, similar to the Boeing Next Generation’s aircraft cabins. If the airline has decided to make such an investment in these 40-year-old aircraft, it means that they want to keep them until their final days.

Additionally, Nolinor has shown that the only replacement for a Boeing 737-200 is another 737-200. The company acquired two second-hand 737-200s from African carrier Angola Airlines (DT) in 2019 to support its operations.

Another airline that puts its trust in the Boeing 737-200 is Glencore Corporation, which in 2014 stated that its two remaining units, C-FFAL and C-GXNR, would remain in operation with the airline for another 15 years.

The first ever Boeing 737-200 fitted with a glass cockpit was C-GTUK, a 39.8-year-old airplane. Photo: Nolinor Aviation

Modern Problems, Old Solutions


The Boeing 737-200, which made its first flight in 1967, has completely proved that sometimes the most modern and efficient airliners aren’t the solution every airline needs.

In a complex and unusual situation such as the one occurring on gravel runways in Northern Canada, the golden Boeing 737 “original” family is thriving and will continue to do so in the coming years, allowing isolated communities to stay connected to the rest of the world.


Featured image: Miles Aronovitz/Airways

Source: airwaysmag.com

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