The Swearingen Merlin or the Fairchild Aerospace Merlin is a pressurized, twin turboprop business aircraft first produced by Swearingen Aircraft , and later by Fairchild at a plant in San Antonio , Texas .
31-561: Merlin II or Merlin 2 may refer to: Swearingen Merlin II , an airplane Merlin II, an aeroengine in the Rolls-Royce Merlin line Merlin II, a telephone system in the AT&;T Merlin line Merlin 2, a rocket engine concept by SpaceX Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
62-402: A defining feature of all subsequent production models), new landing gear with two wheels on each leg, a redesigned horizontal tail mounted on the vertical fin instead of on the fuselage as in earlier models (This and subsequent Merlin and Metro models have a trimmable horizontal stabilizer (THS) usually used on jet aircraft, one of only two turboprop aircraft types to have this design feature). and
93-527: A redesigned longer nose with room for a baggage compartment as well as the avionics found in the noses of Merlin II series aircraft. All of these design changes came from the Metro design, which was undergoing development in the late 1960s. The SA226-TC Metro was more-or-less a new design, conceptually a stretch of the Merlin II (which it superficially resembled) sized to seat 22 passengers. Prototype construction of
124-485: Is a generally circular window used on the hull of ships to admit light and air. Though the term is of maritime origin, it is also used to describe round windows on armored vehicles , aircraft , automobiles (the Ford Thunderbird a notable example) and even spacecraft . On a ship, the function of a porthole, when open, is to permit light and fresh air to enter the dark and often damp below- deck quarters of
155-500: Is also used in related rules and regulations for the construction of ships. The use of the word "sidescuttle" instead of "porthole" is meant to be broad, including any covered or uncovered hole in the side of the vessel. A deadlight is a hinged metal cover which can be clamped over the porthole to secure it in heavy weather. According to the Navy Department Library, the word "porthole" has nothing to do with its location on
186-429: Is primarily a circular glass disk, known as a 'portlight', encased in a metal frame that is bolted securely into the side of a ship's hull. Sometimes the glass disk of a porthole is encased in a separate frame which is hinged onto the base frame so that it can be opened and closed. In addition, many portholes also have metal storm covers that can be securely fastened against the window when necessary. The main purpose of
217-427: The port side of a ship, but originated during the reign of Henry VII of England (1485). The king insisted on mounting guns too large for his ships and therefore the conventional methods of securing the weapons on the forecastle and aftcastle could not be used. A French shipbuilder named James Baker was commissioned to solve the problem, which he did by piercing the ship's sides so the cannon could be mounted inside
248-745: The Excalibur Queen Airs; the airstair in the same place and of the same general design as the Queen Air; and the nose being especially similar, of the same general shape with access panels the same size, shape and location as those of the Queen Air. The Australian Department of Civil Aviation (now the Civil Aviation Safety Authority ) took delivery of four Merlin IIBs in 1969 and operated them for almost fifteen years. As of May 2021 there have been 63 documented incidents and 96 deaths involving
279-911: The Merlin III was replaced by the SA226-T Merlin IIIA , with an extra window on the right side of the cabin and a small window aft of the airstair on each side of the fuselage. Customers for the Merlin IIIA included the Argentinian Air Force , the Argentine Army and the Belgian Air Force . In January 1979 production of the Merlin IIIA ended in favour of the SA226-T(B) Merlin IIIB . The IIIB differed mainly by TPE331-10U engines of increased power driving four-bladed propellers turning in
310-609: The Merlin IIIB, and other drag-reducing airframe modifications including landing gear doors that close after the gear is extended. The US Army bought a second-hand Merlin IVC and operated it as the solitary UC-26C. Towards the end of production of the short-fuselage variants of the Merlin, optional winglets were offered. Ten of the last 25 SA227-TTs were built with the winglets as Merlin 300s . Production of short-fuselage Merlins ended in 1983 with
341-564: The Merlin. The prototype IIA took to the air for the first time on 13 April 1965, about fifteen months after the competing Beech Model 65-90 King Air (which was also derived from the Model 65 Queen Air). 36 Merlin IIA models were built before a follow-on model with Garrett AiResearch TPE-331 -1 engines called the SA26-AT Merlin IIB entered production after AiResearch was appointed as distributor for
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#1732854680888372-440: The Merlin. Listed below are a select few of the most notable ones. Data from Jane's All The World's Aircraft 1982–83. General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists [REDACTED] Media related to Swearingen Merlin at Wikimedia Commons Porthole A porthole , sometimes called bull's-eye window or bull's-eye ,
403-460: The Metro began in 1968 and first flight was on 26 August 1969. The standard engines offered were two TPE331-3UW turboprops driving three-bladed propellers. A corporate version called the SA226-AT Merlin IV was also marketed and initially sales of this version were roughly double that of the Metro. These sales were not immediately forthcoming however, as the company was financially stretched by
434-416: The astronauts used at the beginning and end of each flight. Portholes on submarines are generally made of acrylic plastic. In the case of deep diving submarines, the portholes can be several inches thick. The edge of the acrylic is usually conically tapered such that the external pressure forces the acrylic window against the seat. Usually such windows are flat rather than spherically dished. This decreases
465-568: The building of Merlin IIIC c/n TT-541. The last Merlin IVC (c/n AT-695B) was built in 1987 and Metro production ended in 1998. The SA26 Merlin is a pressurized Excalibur fitted with a different Lycoming TIGO-540 6-cylinder geared piston engine. The TIGO 540 was used despite the fact that one of the reasons the IO-720 was used in the Excalibur was that the Queen Air series' IGSO-480 and IGSO-540 engines from
496-523: The cracking that can result from thermal shock . Those on the International Space Station were made from quartz glass mounted on titanium frames, covered with enamel. These were designed to be opened though no returning astronaut has done so. The windows also have shrouds or doors to protect them from micro-meteorites. On the Apollo space capsules a porthole was located in the hatch that
527-508: The development of the Metro prototype and lacked the funds to gear up for production. This situation was rectified in late 1971 when Ed Swearingen agreed to sell 90% of the company to Fairchild; the company was then renamed Swearingen Aviation Corporation. By the end of 1972 six Merlin IVs had been built and production gradually built up alongside the concurrently produced short-fuselage Merlin III. In 1974,
558-538: The fore and aft castles. For heavy weather and when the cannons were not in use, the openings were fitted with covers, that were called porte in French, meaning " door ". " Porte " was Anglicized to "port" and later corrupted to porthole. Eventually, it came to mean any opening in a ship's side whether for cannon or not. A porthole consists of at least two structural components and is, in its simplest form, similar to any other type of window in design and purpose. The porthole
589-775: The integrity of the ship's hull. The porthole's thick glass and rugged construction, tightly spaced fasteners, indeed even its round shape, all contribute to its purpose of maintaining hull strength and withstanding the pressure of storm waves crashing against it. Recently there has been a decline in the number of portholes on larger ships. Cruise liners have higher superstructures with more upper deck cabins which can have large windows and balconies. Most warships no longer have portholes on their main hulls as they could weaken them and modern vessels have air conditioning and strong lighting below decks meaning that they are no longer necessary. Portholes on spacecraft must be made from glass that can survive rapid temperature changes, without suffering
620-627: The opposite direction to those of earlier models. The SA227-TT Merlin IIIC was next, introduced concurrently with the SA227-AC Metro III (the first Metro III was Fairchild c/n AC-420 and the first Merlin IIIC was c/n TT-421, Metro and Merlin aircraft at this stage being numbered consecutively with different prefixes to denote the different types), and the SA227-AT Merlin IVC version of the Metro III followed shortly after (the first Merlin IVC
651-667: The original Merlin IV and Metro models were replaced by the SA226-AT Merlin IVA and the SA226-TC Metro II after about 30 Merlin IVs and about 20 Metros had been built. Among the changes made were larger, ovalised rectangular windows replacing the circular porthole -style windows of the early aircraft, 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. The same year
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#1732854680888682-442: The porthole's weight comes from its glass, which, on ships, can be as much as two inches thick. Metal components of a porthole are also typically very heavy; they are usually sand-cast and made of bronze , brass , steel , iron , or aluminium . Bronze and brass are most commonly used, favoured for their resistance to saltwater corrosion . The design of the porthole is such that it achieves its humble purposes without sacrificing
713-526: The same manufacturer were so troublesome. The decision was soon made to offer increased engine power, which was achieved through installing two Pratt & Whitney Canada PT6 A-20 turboprop engines, resulting in the SA26-T Merlin IIA . The Merlin IIAs and IIBs were visually still obviously derivatives of the Queen Air, featuring as they did Queen Air tailplanes and wings with the same flat-top engine nacelles as
744-465: The ship's hull, and are typically fastened to their closed positions by hand tightening several pivoting, threaded devices, commonly referred to as "dogs". Older portholes can be identified by the protruding collar of their base plate which may be up to several inches deep, thus accommodating the thickness of a wooden hull. Portholes range in diameter from several inches to more than two feet, and weigh from several pounds to over one hundred pounds. Much of
775-475: The storm cover is, as its name implies, to protect the window from heavy seas. It is also used to block light from entering lower berths when darkness is preferred. The storm cover is referred to as a deadlight in maritime parlance. Storm covers are also used on navy and merchant marine ships to prevent interior light from escaping the ship's lower berths, and to provide protection from hostile fire. Hinged porthole windows and storm covers are accessible from inside
806-524: The title Merlin II . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Merlin_II&oldid=1216068937 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Swearingen Merlin II The Merlin
837-511: The type. The TPE-331 became the definitive engine of all subsequent production Merlins and the longer-fuselage Metros that were to follow. These visual similarities ended with the next model, the SA226-T Merlin III , which was placed in production in February 1972 after 87 Merlin IIBs were built. This had new wings and engine nacelles with inverted inlet Garrett engines (this again becoming
868-548: The vessel. It also affords below-deck occupants a limited view to the outside world. When closed, the porthole provides a strong water-tight, weather-tight and sometimes light-tight barrier. A porthole on a ship may also be called a sidescuttle or side scuttle (side hole), as officially termed in the International Convention for the Safety of Life at Sea . This term is used in the U.S. Code of Federal Regulations . It
899-572: Was an evolution of earlier modification programs performed by Swearingen Aircraft. Ed Swearingen started the developments that led to the Merlin through gradual modifications to the Beechcraft Twin Bonanza and Queen Air business aircraft which he dubbed Excalibur . Then a hybrid aircraft was developed, with a new fuselage and vertical fin, mated to salvaged and modified (wet) Queen Air wings and horizontal tails, and Twin Bonanza landing gear:
930-492: Was c/n AT-423). The Merlin IIIC was a redesign to incorporate structural and other changes but was visually the same as the Merlin IIIB, the redesign taking place to make the aircraft compliant with Special Federal Aviation Regulation 41 (SFAR-41). The Merlin IVC version was initially certified in 1980 at up to 14,000 pounds (6,400 kg) this increasing to 14,500 pounds (6,600 kg) as engines and structures were upgraded. An option to go as high as 16,000 pounds (7,300 kg)
961-512: Was offered. Other improvements incorporated into the Merlin IVC were a 10 ft (3.0 m) increase in wing span (achieved by the simple expedient of removing the wingtips from the Metro II wing, bolting an extension to the end of each wing, and fitting a new wingtip, redesigned to reduce drag), TPE331-11U engines with redesigned "quick-access" engine cowlings and driving four-bladed propellers as on