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Metroliner
Perimeter Aviation C-FUZY SA226-TC Metro II over Winnipeg, Manitoba c. 2007
Type	regional airliner
Manufacturer	Fairchild
Maiden flight	26 August 1969
Introduced	1972
Status	Currently in use
Primary users	Ameriflight Bearskin Airlines Jetcraft Aviation Key Lime Air Perimeter Aviation
Produced	1968-2001
Number built	600+
Developed from	Swearingen Merlin

The Fairchild Swearingen Metroliner or the Fairchild Aerospace Metro is a 19-seat, pressurised, twin turboprop airliner first produced by Swearingen Aircraft and later by Fairchild at a plant in San Antonio, Texas.

The Metroliner was an evolution of the Swearingen Merlin turboprop-powered business aircraft. Ed Swearingen started the developments that led to the Metro through gradual modifications to the Beechcraft Twin Bonanza and Queen Air business aircraft, aircraft he dubbed Excalibur.

Then a new fuselage and vertical fin were developed, married to salvaged and rebuilt (wet) Queen Air wings and horizontal tails, and Twin Bonanza landing gear; this became the SA26 Merlin, more-or-less a pressurized Excalibur. Through successive models (the SA26-T Merlin IIA and SA26-AT Merlin IIB) the engines were changed to Pratt & Whitney Canada PT6 and then Garrett TPE331 turboprops. These were marketed as business aircraft seating eight to ten passengers.

Swearingen SA226-T Merlin III C-FAMF Perimeter Aviation c. 2007

An all-new aircraft was built and called the SA226-T Merlin III with new wings, landing gear, cruciform horizontal tail^[1] and inverted inlet Garrett engines. Ultimately a stretch of the Merlin III was designed, sized to seat 22 passengers and called the SA226-TC Metro. Because FAA regulations limited an airliner to no more than 19 seats if no flight attendant was to be carried, the aircraft was optimized for that number of passengers. The standard engines offered were two TPE331-3UW turboprops driving three-bladed propellers. A corporate version called the SA226-AT Merlin IVA was also marketed and initially sales of this version were roughly double that of the Metro^[2].

Prototype construction of the Metro began in 1968 and first flight was on 26 August 1969. Late in 1971 Swearingen was acquired by Fairchild, and the company was renamed Swearingen Aviation Corporation. It was at this point that the previously cash-strapped company was able to put the Metro into production^[3][4].

The Metroliner cabin is characterized by a long, narrow fuselage, giving rise to nicknames like the "tube" and "lawn dart".

Although Fairchild studied a version with a "stand-up" cabin (as in the Beechcraft 1900D), this was not built. At the 1987 Paris Air Show, Fairchild released details of proposed developments of the Metro designated the Metro V and Metro VI. These versions would have featured a Metro III fuselage with a redesigned, longer wing, more powerful Garrett engines moved further out on the wing from the fuselage, a "T-tail" and various system improvements. Difference in engine power was what determined if a model was a Metro V or Metro VI, the Metro VI being the more powerful aircraft.

In extreme secrecy, Swearingen Aircraft developed a prototype SA 29 T jet aircraft with modified airfoil, Friese differential ailerons, inward-retracting landing gear and other refinements. It shared the tail and cockpit with the Merlin/Metro. The engines were mounted on the aft fuselage and were to be the Garrett TFE731 turbofans that were in development. Early flights were to be undertaken with General Electric CJ610 engines fitted. When Fairchild acquired the company, this project was shut down nine weeks from first flight. It was later cut up as scrap and the fuselage used as a Metro display at trade shows.

Two of the original Metro model were delivered in 1972 to Societe Miniere de Bakwanga (MIBA) in Kinshasa, Zaire, the first customer to put the Metro into service. The first airline to put them into service was Commuter Airlines in January 1973^[3], followed shortly after by Air Wisconsin. In 1974, the original Metro models were replaced by the SA226-TC Metro II after about 20 Metros and about 30 Merlin IVAs had been built^[5]. Among the changes made were larger, squared-oval windows and optional provision for a small Rocket-Assisted Take Off (RATO) rocket in the tail cone, this being offered to improve takeoff performance out of "hot & high" airfields in the event of an engine failure.

One of the advantages of the Perimeter Aviation modifications was using a four-bladed propeller that was less susceptible to stone chips on gravel runways

The Metro and Metro II were limited to a maximum weight of 12,500 pounds (5,670 kg) in the USA and 5,700 kg in "metric" countries. When this restriction was lifted the Metro II was re-certified as the Metro IIA in 1980 with a maximum weight of 13,100 pounds (5,941 kg) and the Metro II's TPE331-3 engines replaced by -10 engines of increased horsepower. At least one Metro IIA flies in Canada with Perimeter Aviation^[6].

VH-EEO, a purpose-built SA227-AT Expediter freighter (without cabin windows) in service with Pel-Air c. 2007

Jetcraft Aviation SA227-AT Merlin IVC freighter conversion VH-UZA in service, Australia c. 2007

In service with Perimeter Aviation in Canada, this long-term operator of the Metro II made a number of modifications to suit its use in northern and remote Canadian sites where rudimentary gravel "strips" were common. Some of the many innovative changes to the design of the Metro allowed the aircraft to fly more efficiently as well as cutting down on the "noise factor" that was attributed to the early models. The airline installed Garrett engines with quieter and more efficient four-bladed Hartzell propellers. Their Metros are also all equipped with modern avionics suites including certified AlliedSignal KLN 90B GPS.

The SA227-AC Metro III was next, also initially certified in 1980 at up to 14,000 pounds (6,350 kg) this increasing to 14,500 pounds (6,577 kg) as engines and structures were upgraded. An option to go as high as 16,000 pounds (7,257 kg) was offered. Other improvements incorporated into the Metro III were a 10 ft (3.05 m) increase in wing span, four-bladed props, redesigned "quick-access" engine cowlings and numerous drag-reducing airframe modifications, including landing gear doors that close after the gear is extended.

Once again a corporate version was offered as the Merlin IVC (the model name was chosen to align with the contemporaneous short-fuselage Merlin IIIC). A version with strengthened floors and the high gross weight option was offered as a cargo aircraft known as the Expediter. Both the Expediter and the Merlin IVC were designated the SA227-AT. Finally, the Metro IIIA was offered with two Pratt & Whitney Canada PT6A-45R turboprops in place of the Garrett units. A special model was the SA227-BC Metro III built for Mexican airline AeroLitoral, which took delivery of 15 of the 18 of this model that were produced.

Bearskin Airlines C-FXUS SA227-CC model, Winnipeg c.2007

Improvements beyond the Metro III provided better systems, more power and a further increase in takeoff weight. This design effort resulted in the SA227-CC (for Commuter Category) and SA227-DC models, both called the Metro 23; so named as they were designed for certification under FAR Part 23 (Amendment 34) standards. A Metro 23 EF with an external pod under the lower fuselage for greater baggage capacity was also offered as well as an Expediter 23 and Merlin 23. The SA227-CC was an interim model and only three were built, two of these are today registered with Canadian operator Bearskin Lake Air Service Ltd.^[4][7] The third also flew with Bearskin Airlines but was destroyed in a mid-air collision in 1995^[8].

Many of the improvements resulting in the Metro 23 came about during work to produce the military C-26B model. The USAF had previously bought eleven C-26A aircraft based on the SA227-AC^[9][4], two of these being supplied to the Venezuelan Air Force^[10][11]. The first three C-26Bs were procured later in the 1980s, two for the US Army and one for the USAF. These three had been built as SA227-BC models. Later C-26Bs were the military equivalent of the Metro 23 and the USAF took delivery of 37 examples. Some of these were transferred to the Peruvian Air Force and the US Army, while six were transferred to the US Navy as C-26Ds^[4][12][13]. The US Army also took a second-hand Merlin IVC and operated it as the solitary UC-26C^[14].

A Metro III, c/n AC-614, was modified as the Fairchild Aircraft/Lockheed Multi Mission Surveillance Aircraft, featuring a Lockheed phased array radar in a long pod under the fuselage^[15]. The MMSA was restored to its original configuration and now flies in Australia as a freighter with Pel-Air. However several aspects of the modifications were incorporated on some USAF C-26s as the RC-26B for use in the War on Drugs^[16]. Another aircraft was modified for the Colombian Air Force for the same purpose.

In civilian service the type has proved to be very popular, with sales in the 19-seat airliner market rivalled only by the Beech 1900^[17]. It is especially popular in Australia. Since the first example (a Merlin IVA) arrived in 1975 almost 20% of the fleet has operated in that country. Currently 62 Metros and Expediters are registered in Australia, more than all of its market rivals combined^[18].

Metro production ended in 1998, however by this time Regional Jets were in vogue and turboprop types were out of favour with airlines, and several airframes remained unsold at the factory. The final aircraft, Metro 23 c/n DC-904B, was not delivered (to air charter company National Jet Aviation Services of Zelienople, Pennsylvania) until 2001^[3]. A total of 703 Metro, Expediter, Merlin IV series and C-26 series aircraft were built^[4]. The production numbers for the confusion^[19] of various model names and model designations are:

Perimeter Aviation C-FTNV SA226-TC Metro II landing at Tadoule Lake, Manitoba c.2006

• 198 SA226-TC Metro and Metro II
• 56 SA226-AT Merlin IVA

• 291 Metro III
  • 273 SA227-AC (11 to US Armed Forces as C-26As)
  • 18 SA227-BC (3 to US Armed Forces as C-26Bs)
• 43 SA227-AT
  • 21 Merlin IVC
  • 22 Expediter
• 115 Metro 23
  • 3 SA227-CC
  • 112 SA227-DC (37 to U.S. Armed Forces as C-26Bs)

VH-KDO, a Metro 23 of Australian regional airline Rex. The Rex Metros have since been sold or transferred to subsidiary company Pel-Air.

• Metro
• Metro II
• Merlin IVA
• Metro III
• Merlin IVC
• Metro 23
• Metro 23EF

C-26 is the designation of the United States military for the Metroliner series. It was not officially named by the US Armed Forces.

• C-26A - military version of the Metro III (Model SA227-AC).
• C-26B - military version of the Metro III (Model SA227-BC) and Metro 23 (Model SA227-DC).
• RC-26B - C-26B modified with electronic surveillance equipment for drug interdiction missions (USAF operates 11)^[20].
• UC-26C - this was a second-hand 1983-built Merlin IVC operated for several years as 89-1471^[14].
• C-26D - C-26Bs transferred from USAF inventory to the US Navy.
• Tp88 - Metro III (one aircraft) delivered to the Swedish Air Force for use as a VIP transport.

Bearskin Airlines C-FFZN SA227-AC Metroliner operating out of Red Lake, Ontario, c. 2007

In August 2007 a total of 366 Fairchild Metro/Merlin aircraft (all variants) remain in airline service. Major operators include: Aeronaves TSM (18), Aeronova (5), Air Cerberus (7), Alta Flights (5), Ameriflight (44), Baires Fly (6), Bearskin Airlines (12), Berry Aviation (8), Business Aviation Courier (9), Carson Air (12), IBC Airways (8), Jetcraft Aviation (12), Key Lime Air (18), Merlin Airways (8), Pel-Air (14), Peninsula Airways (5), Perimeter Aviation (20), Skippers Aviation (6), Sunwest Aviation (6) and Western Air (10). Some 72 other airlines also operate smaller numbers of the type^[21].

•  Argentina
•  Australia^[22].
•  Belgium
•  Colombia
•  El Salvador
•  Mexico
•  Peru
•  Sweden
•  Thailand
  • Royal Thai Air Force
•  Trinidad and Tobago
•  United States
  • US Navy
  • US Air Force (Air National Guard)
  • US Army (National Guard)
•  Venezuela

Data from The Encyclopedia of World Aircraft ^[23]

General characteristics

• Crew: Two (pilot & first officer), 1 pilot in cargo only configuration
• Capacity: 19 passengers
• Length: 59 ft 4 in (18.09 m)
• Wingspan: 57 ft 0 in (17.37 m)
• Height: 16 ft 8 in (5.08 m)
• Wing area: 309 ft² (28.71 m²)
• Empty weight: 8,737 lb (3963 kg)
• Max takeoff weight: 14,500 lb or 16,000 lb, depending on model (6,577 kg or 7,257 kg)
• Powerplant: 2× Garrett AiResearch TPE-331 (either -11U-601G, -611G or -612G depending on propeller fitted) turboprops with continuous alcohol-water injection (AWI); and equipped with four-bladed McCauley 4HFR34C652 or Dowty Rotol R.321/4-82-F/8 propellers^[24], 1,000 shp (dry), 1,100 shp (with AWI) (745.5 kW, 820 kW) each
• * Cargo Volume: 143.5 ft³ (4.06 m³)

Performance

• Maximum speed: 311 knots (355 mph, 576 km/h)
• Cruise speed: 278 knots (318 mph, 515 km/h)
• Range: 575 nm or 1,150 nm (1,065 km or 2,131 km)

General characteristics

• Crew: 2
• Capacity: 22/14 passengers
• Length: 42 ft 2 in (12.85 m)
• Wingspan: 46 ft 3 in (14.01 m)
• Height: 16.83 ft (5.13 m)
• Max takeoff weight: 14,000 lb (6,400 kg
• Fuel: 625 gal (2,370 L))
• Powerplant: 2× Allied Signal Garrett TPE-331-IIUG-601G turboprops, 1,100 hp (820 kW) each

Performance

• Maximum speed: 248 knots (285 mph, 460 km/h)
• Range: 2,025 nm (2,331 mi, 3,750 km)
• Service ceiling: 31,000 ft (9,500 m)
• Power/mass: 0.08 hp/lb (130 W/kg)

Notes

Bibliography

• Fairchild Metro
• Virtual Museum; Fairchild

Designation sequence

• C-23 - C-24 - VC-25 - C-26 - C-27 - C-28 - C-29

• List of military aircraft of the United States