Aviation history is full of paradoxes — situations where technical change was driven not by engineering ambition, but by purely legal or economic circumstances. The creation of the Bombardier CRJ550 is one of the most instructive examples of this kind. This regional aircraft came into existence not through meticulous design work and not as the fruit of revolutionary technology — it was born from a clever response to a specific request from United Airlines in 2019.
American Scope Clauses and the Regional Aviation Market
To understand the logic behind the CRJ550, one must first grasp the peculiarities of labor relations in American commercial aviation. In the United States, major airlines — so-called mainline carriers (American, Delta, United, and others) — serve regional routes through subsidiary partner companies operating under a shared brand. Pilots at mainline carriers are organized into powerful unions, and their collective bargaining agreements tightly regulate the activities of regional partners.
This is what are known as "scope clauses." Introduced in the 1990s, they were originally designed to protect the jobs of mainline airline pilots — preventing cheap regional aviation from displacing higher-paid mainline crews from profitable routes. Scope clauses impose strict limits on regional partners across several parameters: the maximum number of passenger seats, the maximum takeoff weight of aircraft, and the total number of planes they are permitted to operate.
In the case of United Airlines, the collective bargaining agreement with pilots represented by the Air Line Pilots Association (ALPA) stipulated the following: an aircraft could be classified as regional — and thus fall under the more lenient scope clause restrictions — only if its maximum takeoff weight did not exceed 65,000 pounds (approximately 29,500 kg) and its cabin held no more than 50 seats. These two parameters became the defining constraints in the design of the CRJ550.
By 2019, however, the American regional aviation market was approaching a serious problem: the fleet of 50-seat aircraft was aging rapidly. According to the analytics firm Flight Fleets Analyzer, U.S. regional carriers were operating approximately 738 aircraft of the Bombardier CRJ100/200 and Embraer ERJ-145 types on behalf of mainline carriers. The average age of these aircraft was 16 years, with roughly 30,000 cycles on each airframe. They urgently needed replacing — yet neither Bombardier nor Embraer was producing new 50-seat aircraft anymore, having shifted focus to higher-capacity models.
To solve this problem, engineers faced an unusual challenge: transform a ready-made 70-seat aircraft into a 50-seat one, while simultaneously reducing the resulting aircraft's maximum takeoff weight. It was immediately apparent, however, that the economic losses from removing 20 seats would need to be offset somehow. The solution found was quite revolutionary. What ultimately emerged was something qualitatively different — a regional airliner capable of offering passengers a level of comfort previously unavailable on short- and medium-haul routes. The result was the CRJ550: the only 50-seat aircraft in the world equipped with three classes of service.
The Platform: The CRJ700 and Its History
To understand what exactly Bombardier modified in creating the CRJ550, a few words about the base platform — the CRJ700 — are in order.
The CRJ (Canadair Regional Jet) family traces its roots to the late 1980s, when Canadian manufacturer Canadair developed the original CRJ100 based on the Canadair Challenger 600 business jet. In 1992, Bombardier acquired Canadair and continued developing the line. The early models — the CRJ100 and CRJ200 — were designed for exactly 50 passengers, which from the outset made them compliant with scope clause requirements.
The CRJ700 program was officially launched in 1997 under the designation CRJ-X, in response to market demand for more capacious regional aircraft. The prototype's first flight took place on May 27, 1999. The CRJ700 was a substantially redesigned and stretched derivative of the CRJ200: the fuselage was lengthened, the wing enlarged, the engines replaced with more powerful General Electric CF34-8Cs, and the flight deck updated with modern Rockwell Collins Pro Line 4 avionics. The aircraft could carry up to 70 passengers over a range of 1,378 nautical miles (approximately 2,552 km), with a maximum takeoff weight of 75,000 pounds (34,000 kg).
It was precisely the CRJ700's relatively low weight compared to competitors — such as the Embraer E175 — that made it the most suitable platform for the forthcoming modification. Bombardier's Director of Marketing for the Americas, Antoine Chéreau, emphasized in 2019: "The CRJ is the lightest aircraft in its class." Reducing the MTOW from 75,000 to the required 65,000 pounds proved to be a technically feasible task, thanks in large part to this inherent structural advantage.
The Birth of the CRJ550: Announcement and Certification
On February 6, 2019, Bombardier and United Airlines jointly announced the launch of a new variant — the CRJ550. The news was received by the industry with interest, but also with a degree of skepticism: how viable was the concept of a deliberately downsized aircraft in an industry that traditionally pursues maximum seat capacity?
From a technical standpoint, the process of creating the CRJ550 was unconventional. This was neither a clean-sheet aircraft design nor a classic upgrade program: Bombardier took existing CRJ700 airframes already in service and carried out conversions under a specially developed program. Changes were limited exclusively to the cabin layout and the certified MTOW value — the airframe structure, powerplant, avionics, and all other systems remained unchanged. This approach significantly reduced the cost of the program and accelerated the certification process.
The first converted aircraft was registered as N504GJ — an airframe originally built in 2002. This veteran, having spent 17 years in the GoJet Airlines fleet, became the pioneer of the 550 series.
The certification process concluded as expected in 2019. Mid-year, Transport Canada Civil Aviation (TCCA) assigned the aircraft the type designation CL-600-2C11 — a derivative of the CL-600-2C10 designation assigned to the CRJ700. On September 26, 2019, GoJet Airlines officially announced receipt of FAA type certification. Notably, EASA (the European Union Aviation Safety Agency) never pursued certification of the CRJ550 — the aircraft was conceived exclusively for the American market.
An important operational consequence of the shared type certificate was that pilots already qualified on the CRJ700 could fly the CRJ550 without recurrent training or a new type rating — a significant operational advantage for airlines.
On August 7, 2019, GoJet Airlines operated the first familiarization flight along the Montreal–Chicago route. Commercial operations under the United Express brand commenced in November 2019, though some sources cite October as the start of scheduled passenger service.
The Cabin: A Revolution in the Regional Segment
The central innovation of the CRJ550 was a fundamentally different cabin concept. By removing 20 seats, Bombardier and United Airlines transformed the freed-up space into a competitive advantage.
First Class (10 seats, rows 1–5) is located in the forward section of the aircraft in a 1+2 configuration. The seat pitch is 42 inches (107 cm) — a figure with no equivalent among regional aircraft. Recline is 5 inches, and seat width ranges from 19¾ to 20 inches. All seats are equipped with AC power outlets and USB ports.
Economy Plus (20 seats, rows 6–15) is positioned behind First Class in a 2+2 configuration. Seat pitch is 34–36 inches, with 3 inches of recline. On a number of routes, this space is comparable to the business class offered by many Russian airlines on short-haul flights.
Economy (20 seats, rows 16–25) is a standard economy cabin in a 2+2 configuration with 30-inch seat pitch.
Since U.S. regulations permit a single flight attendant on aircraft carrying 50 or fewer passengers — rather than two — United Airlines adopted an unconventional solution for First Class service: a self-service galley is installed in the forward section, equipped with a refrigerator stocked with non-alcoholic beverages and a selection of snacks. This allows First Class passengers to help themselves while the flight attendant is occupied serving the economy cabin.
Solving the Carry-On Baggage Problem
Historically, one of the most persistent passenger complaints about regional aircraft in the CRJ family was the severely limited overhead bin space: the narrow fuselage meant that a standard carry-on bag often would not fit in the overhead compartments, and passengers were routinely forced to gate-check their luggage.
In developing the CRJ550, this shortcoming was addressed in a radical manner. A portion of the space freed up by the removal of seats was used to install four large floor-level carry-on storage closets — two on each side of the aisle. Each closet accommodates 12 bags (6 per shelf). Individual shelf dimensions are: width 32 inches, depth 28 inches, height 22 inches. This allows standard carry-on bags to be stowed without restriction.
Operations: From Niche Product to Fleet Expansion
At the time of the announcement in February 2019, United Airlines placed an order for the conversion of 50 CRJ700 aircraft to the CRJ550 standard. All of them were operated by GoJet Airlines under the United Express system — a regional partnership arrangement in which the partner carrier operates flights under contract and under the United brand, using its own fleet. The busiest route for the CRJ550 proved to be Washington–Newark, which during certain periods was operated up to nine times daily.
A pivotal moment in the CRJ550's history came in 2024, when a second major operator joined the program — SkyWest Airlines. In July 2024, SkyWest began operating the CRJ550 on behalf of Delta Air Lines under the Delta Connection brand, thereby moving beyond its exclusive relationship with United for the first time. The Delta configuration differs in a couple of details: First Class seats have a smaller pitch (36 inches versus 42 on United), but every seat on the aircraft is equipped with AC and USB power.
In October 2024, SkyWest announced plans to operate an additional 40 CRJ550s under the United Express brand, including 11 aircraft previously belonging to GoJet. In November 2024, SkyWest placed an order for 60 conversion kits to bring CRJ700s up to CRJ550 standard. According to the analytics firm Cirium, by the end of 2024, more than 8,000 CRJ550 flights were being operated monthly in the United States, of which approximately 6,400 were GoJet flights under the United Express brand.
Economic and Industry Assessments
The professional aviation community's reaction to the CRJ550 was mixed. The ALPA union broadly supported the program, acknowledging that the CRJ550 was a worthwhile replacement for the 50-seat aircraft that passengers had long grown to resent for their cramped interiors. Nevertheless, ALPA raised serious questions: "The verdict on whether this product is a short-term stopgap or a long-term solution will depend on the ability of the company to offset the revenue lost from removing 20 seats."
Indeed, the economics of the CRJ550 required unconventional thinking. Airlines traditionally seek to maximize seat count, and the CRJ550 ran directly counter to that logic. However, United Airlines bet that the premium revenue generated by 10 First Class seats and 20 Economy Plus seats would more than compensate for the lost revenue from the 20 economy seats removed. In essence, the CRJ550 had the potential to transform an unprofitable or marginally profitable regional route into a viable premium product.
Embraer, for its part, entered the debate by pointing out that a 50-seat variant of the E170, with MTOW limited to 65,000 pounds, would have retained a wider fuselage and could potentially have competed with the CRJ550. The Brazilian manufacturer, however, did not pursue the concept to fruition.
Bombardier Commercial Aircraft President Fred Cromer presented the CRJ550 in 2019 as "the only solution in North America" capable of replacing more than 700 aging 50-seat aircraft. This claim was largely accurate: there were simply no competing offerings in the market.
The Fate of the CRJ Program and the Role of Mitsubishi
The story of the CRJ550 is inseparable from the broader fate of the entire CRJ program. In 2020, Bombardier made the decision to exit the commercial aircraft market entirely, refocusing on business jet manufacturing. The CRJ program — including production, maintenance, and fleet support — was transferred to Japanese conglomerate Mitsubishi Heavy Industries, which established a dedicated subsidiary, Mitsubishi Aircraft Corporation, for this purpose.
Mitsubishi ceased new production of the CRJ family but continued to provide technical support to the existing fleet and, crucially, retained the capability to carry out CRJ700-to-CRJ550 conversions using the accumulated documentation. It was this continuity that allowed SkyWest Airlines to place an order for 60 conversion kits in 2024 — well after formal production of new airframes had ended.
Conclusion
The Bombardier CRJ550 is an aircraft that came into existence in defiance of conventional aviation logic. Its story is a vivid demonstration of how legal restrictions and union stipulations can serve as a catalyst for genuine innovation in the passenger experience. The engineers involved did not develop fundamentally new technologies — they reimagined what a regional flight could be.
The paradox of the CRJ550 is this: an aircraft with fewer seats turned out to be a more attractive product than its full-capacity counterpart. Passengers on regional routes, previously forced to endure the discomfort of standard 50-seat jets, gained access to a cabin experience comparable to long-haul aircraft.
The program's commercial expansion in 2024 — with the addition of SkyWest and Delta Connection — demonstrates that the CRJ550 has moved well beyond a single exclusive United Airlines order and evolved into a self-sustaining niche product with genuine market potential. The model's success has dismantled the skeptics' arguments about the economic non-viability of deliberately downsized aircraft.
In the broader context of aviation history, the CRJ550 will be remembered as an example of unconventional problem-solving — one in which regulatory and contractual constraints were not merely complied with, but transformed into a competitive advantage, to the obvious benefit of passengers.