Misplaced Pages

#346653

85-463: The Cirrus SR20 is an American piston-engined , four- or five-seat composite monoplane built since 1999 by Cirrus Aircraft of Duluth, Minnesota . The aircraft is the company's earliest type-certified model, earning certification in 1998. It was the first production general aviation (GA) aircraft equipped with a parachute to lower the airplane safely to the ground after a loss of control, structural failure, or midair collision. The SR series

170-441: A crankshaft or by a swashplate or other suitable mechanism. A flywheel is often used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle. The more cylinders a reciprocating engine has, generally, the more vibration-free (smoothly) it can operate. The power of a reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between

255-459: A flywheel , the power from other pistons connected to the same shaft or (in a double acting cylinder ) by the same process acting on the other side of the piston. This is where the piston forms the smallest volume in the cylinder. In most types the expanded or " exhausted " gases are removed from the cylinder by this stroke . The exception is the Stirling engine , which repeatedly heats and cools

340-501: A ski-jump on take-off is subjected to loads of 0.5g which also last for much longer than a landing impact. Helicopters may have a deck-lock harpoon to anchor them to the deck. Some aircraft have a requirement to use the landing-gear as a speed brake. Flexible mounting of the stowed main landing-gear bogies on the Tupolev Tu-22 R raised the aircraft flutter speed to 550 kn (1,020 km/h). The bogies oscillated within

425-414: A "boat" hull/floats and retractable wheels, which allow it to operate from land or water. Beaching gear is detachable wheeled landing gear that allows a non-amphibious floatplane or flying boat to be maneuvered on land. It is used for aircraft maintenance and storage and is either carried in the aircraft or kept at a slipway. Beaching gear may consist of individual detachable wheels or a cradle that supports

510-473: A 10" MFD. In July 2003, Cirrus made Avidyne Entegra PFDs standard on the SR20 and faster SR22 , pioneering the use of glass cockpits in the light aircraft GA industry. The SR-series remains the only airplane in its class to include side-stick flight controls that combine aspects of a traditional yoke handle (this has been referred to in the industry as a "side yoke"). The SR20 and SR22 are equipped with

595-442: A 10 in (25 cm) thick flexible asphalt pavement . The 210,000 lb (95 t) Boeing 727 -200 with four tires on two legs main landing gears required a 20 in (51 cm) thick pavement. The thickness rose to 25 in (64 cm) for a McDonnell Douglas DC-10 -10 with 443,000 lb (201 t) supported on eight wheels on two legs. The heavier, 558,000 lb (253 t), DC-10-30/40 were able to operate from

680-462: A 2014 fatal rate of 0.42 per 100,000 flight hours, making it one of the best safety records in the industry. This marked the fewest fatalities in a single year for Cirrus since 2001, and the first year where the number of CAPS deployments (12) exceeded the number of fatal accidents (3). As of September 2018, the SR-series has had its parachute system deployed 79 times, with 163 survivors. The SR20

765-474: A 90° angle during the rearwards-retraction sequence to allow the main wheel to rest "flat" above the lower end of the main gear strut, or flush within the wing or engine nacelles, when fully retracted. Examples are the Curtiss P-40 , Vought F4U Corsair , Grumman F6F Hellcat , Messerschmitt Me 210 and Junkers Ju 88 . The Aero Commander family of twin-engined business aircraft also shares this feature on

850-597: A capacity of 1,820 L (64 cu ft), making a total capacity of 25,480 L (900 cu ft) for the largest versions. For piston engines, an engine's capacity is the engine displacement , in other words the volume swept by all the pistons of an engine in a single movement. It is generally measured in litres (l) or cubic inches (c.i.d., cu in, or in ) for larger engines, and cubic centimetres (abbreviated cc) for smaller engines. All else being equal, engines with greater capacities are more powerful and consumption of fuel increases accordingly (although this

935-469: A cylinder to drive a reciprocating engine in a local-pollution-free urban vehicle. Torpedoes may use a working gas produced by high test peroxide or Otto fuel II , which pressurize without combustion. The 230 kg (510 lb) Mark 46 torpedo , for example, can travel 11 km (6.8 mi) underwater at 74 km/h (46 mph) fuelled by Otto fuel without oxidant . Quantum heat engines are devices that generate power from heat that flows from

SECTION 10

#1732776707347

1020-418: A dozen cylinders or more. Cylinder capacities may range from 10 cm or less in model engines up to thousands of liters in ships' engines. The compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The bore/stroke ratio

1105-476: A forward and aft position. The forward position was used for take-off to give a longer lever-arm for pitch control and greater nose-up attitude. The aft position was used to reduce landing bounce and reduce risk of tip-back during ground handling. The tandem or bicycle layout is used on the Hawker Siddeley Harrier, which has two main-wheels behind a single nose-wheel under the fuselage and

1190-585: A higher sink-rate requirement because the aircraft are flown onto the deck with no landing flare . Other features are related to catapult take-off requirements for specific aircraft. For example, the Blackburn Buccaneer was pulled down onto its tail-skid to set the required nose-up attitude. The naval McDonnell Douglas F-4 Phantom II in UK service needed an extending nosewheel leg to set the wing attitude at launch. The landing gear for an aircraft using

1275-474: A higher sink-rate requirement if a carrier-type, no-flare landing technique has to be adopted to reduce touchdown scatter. For example, the Saab 37 Viggen , with landing gear designed for a 5m/sec impact, could use a carrier-type landing and HUD to reduce its scatter from 300 m to 100m. The de Havilland Canada DHC-4 Caribou used long-stroke legs to land from a steep approach with no float. A flying boat has

1360-406: A hot to a cold reservoir. The mechanism of operation of the engine can be described by the laws of quantum mechanics . Quantum refrigerators are devices that consume power with the purpose to pump heat from a cold to a hot reservoir. In a reciprocating quantum heat engine, the working medium is a quantum system such as spin systems or a harmonic oscillator. The Carnot cycle and Otto cycle are

1445-439: A large number of unusual varieties of piston engines that have various claimed advantages, many of which see little if any current use: Landing gear#Retractable gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing , takeoff or landing . For aircraft, it is generally needed for all three of these. It was also formerly called alighting gear by some manufacturers, such as

1530-489: A light aircraft, an emergency extension system is always available. This may be a manually operated crank or pump, or a mechanical free-fall mechanism which disengages the uplocks and allows the landing gear to fall under gravity. Aircraft landing gear includes wheels equipped with solid shock absorbers on light planes, and air/oil oleo struts on larger aircraft. As aircraft weights have increased more wheels have been added and runway thickness has increased to keep within

1615-403: A lower fuselage with the shape of a boat hull giving it buoyancy. Wing-mounted floats or stubby wing-like sponsons are added for stability. Sponsons are attached to the lower sides of the fuselage. A floatplane has two or three streamlined floats. Amphibious floats have retractable wheels for land operation. An amphibious aircraft or amphibian usually has two distinct landing gears, namely

1700-537: A nosewheel) chassis. Landing is done on skids or similar simple devices (fixed or retractable). The SNCASE Baroudeur used this arrangement. Historical examples include the "dolly"-using Messerschmitt Me 163 Komet rocket fighter, the Messerschmitt Me 321 Gigant troop glider, and the first eight "trolley"-using prototypes of the Arado Ar 234 jet reconnaissance bomber. The main disadvantage to using

1785-572: A seal, and more heavily when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders usually measured in cubic centimetres (cm or cc) or litres (l) or (L) (US: liter). For example, for internal combustion engines, single and two-cylinder designs are common in smaller vehicles such as motorcycles , while automobiles typically have between four and eight, and locomotives and ships may have

SECTION 20

#1732776707347

1870-484: A sequence of strokes that admit and remove gases to and from the cylinder. These operations are repeated cyclically and an engine is said to be 2-stroke , 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. The most common type is 4-stroke, which has following cycles. The reciprocating engine developed in Europe during the 18th century, first as the atmospheric engine then later as

1955-457: A similar arrangement, except that the fore and aft gears each have two twin-wheel units side by side. Quadricycle gear is similar to bicycle but with two sets of wheels displaced laterally in the fore and aft positions. Raymer classifies the B-52 gear as quadricycle. The experimental Fairchild XC-120 Packplane had quadricycle gear located in the engine nacelles to allow unrestricted access beneath

2040-520: A smaller wheel near the tip of each wing. On second generation Harriers, the wing is extended past the outrigger wheels to allow greater wing-mounted munition loads to be carried, or to permit wing-tip extensions to be bolted on for ferry flights. A tandem layout was evaluated by Martin using a specially-modified Martin B-26 Marauder (the XB-26H) to evaluate its use on Martin's first jet bomber,

2125-557: A tricycle undercarriage to prevent damage to the underside of the fuselage if over-rotation occurs on take-off leading to a tail strike . Aircraft with tail-strike protection include the B-29 Superfortress , Boeing 727 trijet and Concorde . Some aircraft with retractable conventional landing gear have a fixed tailwheel. Hoerner estimated the drag of the Bf 109 fixed tailwheel and compared it with that of other protrusions such as

2210-412: Is also unique in that all four pairs of main wheels can be steered. This allows the landing gear to line up with the runway and thus makes crosswind landings easier (using a technique called crab landing ). Since tandem aircraft cannot rotate for takeoff, the forward gear must be long enough to give the wings the correct angle of attack during takeoff. During landing, the forward gear must not touch

2295-586: Is not to be confused with fuel efficiency , since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of 75 kW/L (1.65 hp/in ). Reciprocating engines that are powered by compressed air, steam or other hot gases are still used in some applications such as to drive many modern torpedoes or as pollution-free motive power. Most steam-driven applications use steam turbines , which are more efficient than piston engines. The French-designed FlowAIR vehicles use compressed air stored in

2380-412: Is not true of every reciprocating engine), although power and fuel consumption are affected by many factors outside of engine displacement. Reciprocating engines can be characterized by their specific power , which is typically given in kilowatts per litre of engine displacement (in the U.S. also horsepower per cubic inch). The result offers an approximation of the peak power output of an engine. This

2465-463: Is popular with many flying schools and is operated by private individuals and companies. The largest operators are Civil Aviation Flight University of China with 40 aircraft, Aerosim Flight Academy with 34, Western Michigan University with 29, Lufthansa Flight Training and United Aviate Academy both with 25, and Purdue University with 16. Between 1999 and September 2022, the SR20 was involved in 40 known fatal accidents. Listed below are some of

2550-465: Is required to reduce the impact with the surface of the water. A vee bottom parts the water and chines deflect the spray to prevent it damaging vulnerable parts of the aircraft. Additional spray control may be needed using spray strips or inverted gutters. A step is added to the hull, just behind the center of gravity, to stop water clinging to the afterbody so the aircraft can accelerate to flying speed. The step allows air, known as ventilation air, to break

2635-394: Is the fictitious pressure which would produce the same amount of net work that was produced during the power stroke cycle. This is shown by: where A p {\displaystyle A_{p}} is the total piston area of the engine, S {\displaystyle S} is the stroke length of the pistons, and V d {\displaystyle V_{d}}

Cirrus SR20 - Misplaced Pages Continue

2720-459: Is the ratio of the diameter of the piston, or " bore ", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square". If it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line , in a V configuration , horizontally opposite each other, or radially around

2805-425: Is the total displacement volume of the engine. Therefore: Whichever engine with the larger value of MEP produces more net work per cycle and performs more efficiently. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle. These are worked by cams, eccentrics or cranks driven by the shaft of the engine. Early designs used

2890-423: Is then fed through one or more, increasingly larger bore cylinders successively, to extract power from the steam at increasingly lower pressures. These engines are called compound engines . Aside from looking at the power that the engine can produce, the mean effective pressure (MEP), can also be used in comparing the power output and performance of reciprocating engines of the same size. The mean effective pressure

2975-705: The Beriev A-40 Hydro flaps were used on the Martin Marlin and Martin SeaMaster . Hydroflaps, submerged at the rear of the afterbody, act as a speed brake or differentially as a rudder. A fixed fin, known as a skeg , has been used for directional stability. A skeg, was added to the second step on the Kawanishi H8K flying boat hull. High speed impacts in rough water between the hull and wave flanks may be reduced using hydro-skis which hold

3060-807: The Cirrus Airframe Parachute System (CAPS), a large parachute that can be deployed in an emergency to lower the entire aircraft to the ground safely. On 1 June 2004, the SR20 became the first aircraft to achieve the new European Aviation Safety Agency certificate for aircraft imported into the European Union . In 2004, Cirrus introduced the SR20 G2 (Generation 2) and in 2008, the SR20 G3 (Generation 3). Both were defined by airframe modifications, G2 by fuselage and G3 by wing/landing gear changes. In 2012, "60/40 flex seating"

3145-452: The D slide valve but this has been largely superseded by piston valve or poppet valve designs. In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can often be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder . Internal combustion engines operate through

3230-670: The Glenn L. Martin Company . For aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US) . For aircraft, the landing gear supports the craft when it is not flying, allowing it to take off, land, and taxi without damage. Wheeled landing gear is the most common, with skis or floats needed to operate from snow/ice/water and skids for vertical operation on land. Retractable undercarriages fold away during flight, which reduces drag , allowing for faster airspeeds . Landing gear must be strong enough to support

3315-561: The Martin Marlin , the Martin M-270, was tested with a new hull with a greater length/beam ratio of 15 obtained by adding 6 feet to both the nose and tail. Rough-sea capability can be improved with lower take-off and landing speeds because impacts with waves are reduced. The Shin Meiwa US-1A is a STOL amphibian with blown flaps and all control surfaces. The ability to land and take-off at relatively low speeds of about 45 knots and

3400-702: The Martin XB-48 . This configuration proved so manoeuvrable that it was also selected for the B-47 Stratojet . It was also used on the U-2, Myasishchev M-4 , Yakovlev Yak-25 , Yak-28 and Sud Aviation Vautour . A variation of the multi tandem layout is also used on the B-52 Stratofortress which has four main wheel bogies (two forward and two aft) underneath the fuselage and a small outrigger wheel supporting each wing-tip. The B-52's landing gear

3485-470: The maximum takeoff weight (MTOW) and 1.5 to 1.75% of the aircraft cost, but 20% of the airframe direct maintenance cost. A suitably-designed wheel can support 30 t (66,000 lb), tolerate a ground speed of 300 km/h and roll a distance of 500,000 km (310,000 mi) ; it has a 20,000 hours time between overhaul and a 60,000 hours or 20 year life time. Wheeled undercarriages normally come in two types: The taildragger arrangement

Cirrus SR20 - Misplaced Pages Continue

3570-420: The steam engine . These were followed by the Stirling engine and internal combustion engine in the 19th century. Today the most common form of reciprocating engine is the internal combustion engine running on the combustion of petrol , diesel , liquefied petroleum gas (LPG) or compressed natural gas (CNG) and used to power motor vehicles and engine power plants . One notable reciprocating engine from

3655-536: The Diamond DA40 (0.35), Cessna 172 (0.45), Diamond DA42 (0.54), Cessna 182 (0.69), and Cessna 400 (1.0), despite the Cirrus's CAPS. By 2014, the accident rate had been dramatically reduced, with a 2013 fatal rate of 1.01 per 100,000 flight hours. This was attributed to better training, particularly in when to deploy the ballistic parachute system. By 2015, the accident rate had continued to decrease, with

3740-546: The G6 SR-series, with a 9 knots (17 km/h) increased cruise speed, upgrades to the mobile IQ app, USB-A and USB-C charging ports and more. In January 2024, the company announced the SR20 G7 (Generation 7), with a major overhaul to the interior and avionics, making it more comparable to the cockpit of a Cirrus Vision Jet , as well as safety and engine-start improvements and an automatic fuel selection system. In 2011,

3825-686: The SR20 is its Garmin Cirrus Perspective avionics suite with dual 10-inch (250 mm) or 12-inch (300 mm) screens: one primary flight display (PFD) and one multifunction display (MFD), first introduced by the company in May 2008. This provides all standard communication , navigation ( GPS and conventional VHF), and surveillance ( Mode S transponder ) functions. Other avionics features include in-flight weather information and TCAS -like traffic information. SR20s made from 1999 to 2003 were equipped with traditional analog instruments and

3910-489: The World War II era was the 28-cylinder, 3,500  hp (2,600 kW) Pratt & Whitney R-4360 Wasp Major radial engine. It powered the last generation of large piston-engined planes before jet engines and turboprops took over from 1944 onward. It had a total engine capacity of 71.5 L (4,360 cu in), and a high power-to-weight ratio . The largest reciprocating engine in production at present, but not

3995-486: The accident records of the SR20 and -22 were the subject of a detailed examination by Aviation Consumer magazine. The review concluded that the series has an overall accident record that is better than average for light aircraft, exceeded only by the Diamond DA40 and DA42 . However, its fatal accident rate is much worse at 1.6/100,000 hours, placing it higher than the U.S. general aviation rate of 1.2 and higher than

4080-518: The aircraft and its design affects the weight, balance and performance. It often comprises three wheels, or wheel-sets, giving a tripod effect. Some unusual landing gear have been evaluated experimentally. These include: no landing gear (to save weight), made possible by operating from a catapult cradle and flexible landing deck: air cushion (to enable operation over a wide range of ground obstacles and water/snow/ice); tracked (to reduce runway loading). For launch vehicles and spacecraft landers ,

4165-416: The aircraft can be landed in a satisfactory manner in a range of failure scenarios. The Boeing 747 was given four separate and independent hydraulic systems (when previous airliners had two) and four main landing gear posts (when previous airliners had two). Safe landing would be possible if two main gear legs were torn off provided they were on opposite sides of the fuselage. In the case of power failure in

4250-520: The airplane's release, the GA industry was struggling; the SR20 was one of the first of its kind to earn FAA Part 23 certification in several years. Over a thousand SR20s have been sold since deliveries began in July 1999. From 1999 to 2015, more than 6,000 SR-series aircraft had been delivered, something that no other aviation company had accomplished for the last half-century. One of the major selling points for

4335-470: The airstream, it is called a semi-retractable gear. Most retractable gear is hydraulically operated, though some is electrically operated or even manually operated on very light aircraft. The landing gear is stowed in a compartment called a wheel well. Pilots confirming that their landing gear is down and locked refer to "three greens" or "three in the green.", a reference to the electrical indicator lights (or painted panels of mechanical indicator units) from

SECTION 50

#1732776707347

4420-482: The company introduced a new mobile application for the SR series, called "Cirrus IQ", which enables remote aircraft communication including access to preflight status information such as fuel and oxygen levels, battery voltage, oil temperature, aircraft location, and flight hours. Upgrades also included a new stabilized approach-advisory system for the flight deck. In January 2022, speed and aesthetic improvements were added to

4505-845: The company introduced the SR20 G6 (Generation 6), with several upgrades to the avionics, new navigation lights , and an increased useful load. In September 2019, Cirrus unveiled the TRAC, a training-oriented version of the SR20, with a simplified interior, more durable seat material, backseat radio transmit switch to allow an observer to communicate with air traffic control , electronic stability and protection system, integrated engine indication and crew alerting/warning systems, and simulated retractable landing gear controls and position lights to allow cadets and instructors to feign landing-gear operation and failures during instructional flights (the actual landing gear remains permanently fixed). In January 2020,

4590-477: The crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic . Some designs have set the cylinders in motion around the shaft, such as the rotary engine . In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam. This

4675-430: The cylinder either by ignition of a fuel air mixture ( internal combustion engine ) or by contact with a hot heat exchanger in the cylinder ( Stirling engine ). The hot gases expand, pushing the piston to the bottom of the cylinder. This position is also known as the bottom dead center (BDC), or where the piston forms the largest volume in the cylinder. The piston is returned to the cylinder top (top dead center) (TDC) by

4760-410: The entire aircraft. In the former case, the beaching gear is manually attached or detached with the aircraft in the water; in the latter case, the aircraft is maneuvered onto the cradle. Helicopters are able to land on water using floats or a hull and floats. For take-off a step and planing bottom are required to lift from the floating position to planing on the surface. For landing a cleaving action

4845-418: The fuselage for attaching a large freight container. Helicopters use skids, pontoons or wheels depending on their size and role. To decrease drag in flight, undercarriages retract into the wings and/or fuselage with wheels flush with the surrounding surface, or concealed behind flush-mounted doors; this is called retractable gear. If the wheels do not retract completely but protrude partially exposed to

4930-424: The fuselage lower sides as retractable main gear units on modern designs—were first seen during World War II, on the experimental German Arado Ar 232 cargo aircraft, which used a row of eleven "twinned" fixed wheel sets directly under the fuselage centerline to handle heavier loads while on the ground. Many of today's large cargo aircraft use this arrangement for their retractable main gear setups, usually mounted on

5015-438: The fuselage. The 640 t (1,410,000 lb) Antonov An-225 , the largest cargo aircraft, had 4 wheels on the twin-strut nose gear units like the smaller Antonov An-124 , and 28 main gear wheels. The 97 t (214,000 lb) A321neo has a twin-wheel main gear inflated to 15.7 bar (228 psi), while the 280 t (620,000 lb) A350 -900 has a four-wheel main gear inflated to 17.1 bar (248 psi). STOL aircraft have

5100-603: The hull out of the water at higher speeds. Hydro skis replace the need for a boat hull and only require a plain fuselage which planes at the rear. Alternatively skis with wheels can be used for land-based aircraft which start and end their flight from a beach or floating barge. Hydro-skis with wheels were demonstrated as an all-purpose landing gear conversion of the Fairchild C-123 , known as the Panto-base Stroukoff YC-134 . A seaplane designed from

5185-471: The hydrodynamic features of the hull, long length/beam ratio and inverted spray gutter for example, allow operation in wave heights of 15 feet. The inverted gutters channel spray to the rear of the propeller discs. Low speed maneuvring is necessary between slipways and buoys and take-off and landing areas. Water rudders are used on seaplanes ranging in size from the Republic RC-3 Seabee to

SECTION 60

#1732776707347

5270-402: The landing gear usually consists of skis or a combination of wheels and skis. Some aircraft use wheels for takeoff and jettison them when airborne for improved streamlining without the complexity, weight and space requirements of a retraction mechanism. The wheels are sometimes mounted onto axles that are part of a separate "dolly" (for main wheels only) or "trolley" (for a three-wheel set with

5355-405: The landing gear usually only supports the vehicle on landing and during subsequent surface movement, and is not used for takeoff. Given their varied designs and applications, there exist dozens of specialized landing gear manufacturers. The three largest are Safran Landing Systems , Collins Aerospace (part of Raytheon Technologies ) and Héroux-Devtek . The landing gear represents 2.5 to 5% of

5440-604: The largest ever built, is the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine of 2006 built by Wärtsilä . It is used to power the largest modern container ships such as the Emma Mærsk . It is five stories high (13.5 m or 44 ft), 27 m (89 ft) long, and weighs over 2,300 metric tons (2,535 short tons ; 2,264 long tons ) in its largest 14 cylinders version producing more than 84.42 MW (113,209 bhp). Each cylinder has

5525-417: The lower corners of the central fuselage structure. The prototype Convair XB-36 had most of its weight on two main wheels, which needed runways at least 22 in (56 cm) thick. Production aircraft used two four-wheel bogies, allowing the aircraft to use any airfield suitable for a B-29. A relatively light Lockheed JetStar business jet, with four wheels supporting 44,000 lb (20 t), needed

5610-504: The main gear struts lengthened as they were extended to give sufficient ground clearance for their large four-bladed propellers. One exception to the need for this complexity in many WW II fighter aircraft was Japan's famous Zero fighter, whose main gear stayed at a perpendicular angle to the centerline of the aircraft when extended, as seen from the side. The main wheels on the Vought F7U Cutlass could move 20 inches between

5695-489: The main gears, which retract aft into the ends of the engine nacelles . The rearward-retracting nosewheel strut on the Heinkel He 219 and the forward-retracting nose gear strut on the later Cessna Skymaster similarly rotated 90 degrees as they retracted. On most World War II single-engined fighter aircraft (and even one German heavy bomber design ) with sideways retracting main gear, the main gear that retracted into

5780-419: The most notable ones. Data from Cirrus SR20 Specifications Webpage General characteristics Performance Avionics Related development Aircraft of comparable role, configuration, and era Piston-engine There may be one or more pistons. Each piston is inside a cylinder , into which a gas is introduced, either already under pressure (e.g. steam engine ), or heated inside

5865-611: The nacelle under the control of dampers and springs as an anti-flutter device. Some experimental aircraft have used gear from existing aircraft to reduce program costs. The Martin-Marietta X-24 lifting body used the nose/main gear from the North American T-39 / Northrop T-38 and the Grumman X-29 from the Northrop F-5 / General Dynamics F-16 . When an airplane needs to land on surfaces covered by snow,

5950-444: The nosewheel/tailwheel and the two main gears. Blinking green lights or red lights indicate the gear is in transit and neither up and locked or down and locked. When the gear is fully stowed up with the up-locks secure, the lights often extinguish to follow the dark cockpit philosophy; some airplanes have gear up indicator lights. Redundant systems are used to operate the landing gear and redundant main gear legs may also be provided so

6035-410: The ones most studied. The quantum versions obey the laws of thermodynamics . In addition, these models can justify the assumptions of endoreversible thermodynamics . A theoretical study has shown that it is possible and practical to build a reciprocating engine that is composed of a single oscillating atom. This is an area for future research and could have applications in nanotechnology . There are

6120-722: The outset with hydro-skis was the Convair F2Y Sea Dart prototype fighter. The skis incorporated small wheels, with a third wheel on the fuselage, for ground handling. In the 1950s hydro-skis were envisaged as a ditching aid for large piston-engined aircraft. Water-tank tests done using models of the Lockheed Constellation , Douglas DC-4 and Lockheed Neptune concluded that chances of survival and rescue would be greatly enhanced by preventing critical damage associated with ditching. The landing gear on fixed-wing aircraft that land on aircraft carriers have

6205-556: The pilot's canopy. A third arrangement (known as tandem or bicycle) has the main and nose gear located fore and aft of the center of gravity (CG) under the fuselage with outriggers on the wings. This is used when there is no convenient location on either side of the fuselage to attach the main undercarriage or to store it when retracted. Examples include the Lockheed U-2 spy plane and the Harrier jump jet . The Boeing B-52 uses

6290-513: The runway loading limit . The Zeppelin-Staaken R.VI , a large German World War I long-range bomber of 1916, used eighteen wheels for its undercarriage, split between two wheels on its nose gear struts, and sixteen wheels on its main gear units—split into four side-by-side quartets each, two quartets of wheels per side—under each tandem engine nacelle, to support its loaded weight of almost 12 t (26,000 lb). Multiple "tandem wheels" on an aircraft—particularly for cargo aircraft , mounted to

6375-505: The same sealed quantity of gas. The stroke is simply the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting . In most types, the linear movement of the piston is converted to a rotating movement via a connecting rod and

6460-538: The same thickness pavements with a third main leg for ten wheels, like the first Boeing 747 -100, weighing 700,000 lb (320 t) on four legs and 16 wheels. The similar-weight Lockheed C-5 , with 24 wheels, needs an 18 in (46 cm) pavement. The twin-wheel unit on the fuselage centerline of the McDonnell Douglas DC-10 -30/40 was retained on the MD-11 airliner and the same configuration

6545-407: The sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine. This seal is usually provided by one or more piston rings . These are rings made of a hard metal, and are sprung into a circular groove in the piston head. The rings fit closely in the groove and press lightly against the cylinder wall to form

6630-508: The takeoff dolly/trolley and landing skid(s) system on German World War II aircraft—intended for a sizable number of late-war German jet and rocket-powered military aircraft designs—was that aircraft would likely be scattered all over a military airfield after they had landed from a mission, and would be unable to taxi on their own to an appropriately hidden "dispersal" location, which could easily leave them vulnerable to being shot up by attacking Allied fighters. A related contemporary example are

6715-685: The water suction on the afterbody. Two steps were used on the Kawanishi H8K . A step increases the drag in flight. The drag contribution from the step can be reduced with a fairing. A faired step was introduced on the Short Sunderland III. One goal of seaplane designers was the development of an open ocean seaplane capable of routine operation from very rough water. This led to changes in seaplane hull configuration. High length/beam ratio hulls and extended afterbodies improved rough water capabilities. A hull much longer than its width also reduced drag in flight. An experimental development of

6800-499: The wings was raked forward in the "down" position for better ground handling, with a retracted position that placed the main wheels at some distance aft of their position when downairframe—this led to a complex angular geometry for setting up the "pintle" angles at the top ends of the struts for the retraction mechanism's axis of rotation. with some aircraft, like the P-47 Thunderbolt and Grumman Bearcat , even mandating that

6885-424: The wingtip support wheels ("pogos") on the Lockheed U-2 reconnaissance aircraft, which fall away after take-off and drop to earth; the aircraft then relies on titanium skids on the wingtips for landing. Some main landing gear struts on World War II aircraft, in order to allow a single-leg main gear to more efficiently store the wheel within either the wing or an engine nacelle, rotated the single gear strut through

6970-463: Was also the first mass-manufactured light aircraft with all-composite construction and flat-panel avionics . The SR20 was developed into the Cirrus SR22 , which was introduced in 2001 and is the most-produced GA aircraft of the 21st century. The SR20 mock-up was unveiled in 1994. The aircraft first flew on 21 March 1995 and FAA certification was achieved on 23 October 1998. At the time of

7055-445: Was common during the early propeller era, as it allows more room for propeller clearance. Most modern aircraft have tricycle undercarriages. Taildraggers are considered harder to land and take off (because the arrangement is usually unstable , that is, a small deviation from straight-line travel will tend to increase rather than correct itself), and usually require special pilot training. A small tail wheel or skid/bumper may be added to

7140-456: Was introduced, allowing up to three passengers in the rear with a split fold-down seat arrangement. This five-seat configuration was optional in 2012, but became standard equipment for 2013 SR20 models. In 2016, Cirrus introduced enhancements to the SR series, including Bluetooth wireless connectivity, a remote keyless entry, a convenience lighting system, and a new easy-access door latch, among other interior and exterior improvements. In 2017,

7225-467: Was used on the initial 275 t (606,000 lb) Airbus A340 -200/300, which evolved in a complete four-wheel undercarriage bogie for the heavier 380 t (840,000 lb) Airbus A340-500/-600. The up to 775,000 lb (352 t) Boeing 777 has twelve main wheels on two three-axles bogies, like the later Airbus A350 . The 575 t (1,268,000 lb) Airbus A380 has a four-wheel bogie under each wing with two sets of six-wheel bogies under

#346653