| F-86 Sabre | |
|---|---|
| A North American F-86 during the Oshkosh Air Show | |
| Role | Fighter aircraft |
| National origin | United States |
| Manufacturer | North American Aviation |
| First flight | 1 October 1947 |
| Introduction | 1949, with USAF |
| Retired | 1994, with Bolivia |
| Primary users | United States Air Force Japan Air Self-Defense Force Spanish Air Force Republic of Korea Air Force |
| Number built | 9,860[1] |
| Unit cost | US$219,457 (F-86E)[2] |
| Developed from | North American FJ-1 Fury |
| Variants | North American F-86D Sabre Canadair Sabre CAC Sabre North American FJ-2/-3 Fury North American FJ-4 Fury |
| Developed into | North American YF-93 |
The North American F-86 Sabre (sometimes called the Sabrejet) was a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as America's first swept wing fighter which could counter the similarly-winged Soviet MiG-15 in high speed dogfights over the skies of the Korean War. Considered one of the best and most important fighter aircraft in the Korean War, the F-86 is also rated highly in comparison with fighters of other eras.[3] Although it was developed in the late 1940s and was outdated by the end of the 1950s, the Sabre proved versatile and adaptable, and continued as a front-line fighter in numerous air forces until the last active operational examples were retired by the Bolivian Air Force in 1994.
Its success led to an extended production run of more than 7,800 aircraft between 1949 and 1956, in the United States, Japan and Italy. Variants were built in Canada and Australia. The Canadair Sabre added another 1,815 airframes, and the significantly redesigned CAC Sabre (sometimes known as the Avon Sabre or CAC CA-27), had a production run of 112. It was by far the most-produced Western jet fighter, with total production of all variants at 9,860 units.[1]
Contents |
North American had produced the highly successful propeller-powered P-51 Mustang in WWII which saw combat against some of the first operational jet fighters. By late 1944, North American proposed its first jet fighter to the US Navy which became the FJ-1 Fury. It was an unexceptional transitional jet fighter which had a straight wing derived from the P-51.[4][5] Initial proposals to meet a United States Army Air Forces (USAAF) requirement for a medium-range, single-seat, high-altitude jet-powered day escort fighter/fighter bomber were drafted in mid-1944.[6] In early 1945, North American Aviation submitted four designs.[6] The USAAF selected one design over the others, and granted North American a contract to build three examples of the XP-86 (eXperimental Pursuit), By deleting specific requirements from the FJ-1 Fury, coupled with other modifications, this allowed the XP-86 to be lighter and considerably faster than the Fury, with an estimated top speed of 582 mph (937 km/h), versus the Fury's 547 mph (880 km/h).[6] Despite the gain in speed, early studies revealed the XP-86 would have the same performance as its rivals, the XP-80 and XP-84. It was also feared that, because these designs were more advanced in their development stages, the XP-86 would be canceled.
Crucially, the XP-86 would not be able to meet the required top-speed of 600 mph (970 km/h);[7] North American had to quickly come up with a radical change that could leapfrog over its rivals. The North American F-86 Sabre was the first American aircraft to take advantage of flight research data seized from the German aerodynamicists at the end of the war.[8] This data showed that a thin swept wing could greatly reduce drag and delay compressibility problems which had bedeviled even prop-powered fighters such as the Lockheed P-38 Lightning as fighter speeds approached the speed of sound. By 1944, German engineers and designers had established the benefits of swept wings based on experimental designs dating back to 1940. Study of the data showed that a swept wing would solve their speed problem, while a slat on the wing's leading edge which extended at low speeds would enhance low-speed stability.
Because development of the XP-86 had reached an advanced stage, the idea of changing the sweep of the wing was met with resistance from some senior North American staff. Despite stiff opposition, after good test results were obtained in wind tunnel tests, the swept-wing concept was eventually adopted. Performance requirements were met by incorporating a 35° swept-back wing, using NACA 4-digit modified airfoils, using NACA 0009.5-64 at the root and NACA 0008.5-64 at the tip.[9] with an automatic slat design based on that of the Me 262 and an adjustable stabilizer.[10][11][12] It should be noted that many Sabres had the "6-3 wing" (a fixed-leading edge with 6 inches extended chord at the root and 3 inches extended chord at the tip) retrofitted after combat experience was gained in Korea.[10][13] This modification changed the wing airfoils to the NACA 0009-64 mod at the root and the NACA 0008.1-64 mod at the tip.[9]
Delays caused by the major redesign meant that manufacturing did not begin until after World War II. The XP-86 prototype, which would lead to the F-86 Sabre, was rolled out on 8 August 1947.[14] At the controls of George Welch, the maiden flight occurred on 1 October 1947[15] from Muroc Dry Lake (now Edwards AFB), California.[8][14]
The United States Air Force's Strategic Air Command had F-86 Sabres in service from 1949 through 1950. The F-86s were assigned to the 22nd Bomb Wing, the 1st Fighter Wing and the 1st Fighter Interceptor Wing.[16] The F-86 was the primary U.S. air combat fighter during the Korean War, with significant numbers of the first three production models seeing combat.
The F-86 Sabre was also produced under license by Canadair, Ltd., in the Province of Quebec as the Canadair Sabre. The final variant of the Canadian Sabre, the Mark 6, is generally rated as having the highest capabilities of any Sabre version made anywhere.[17][N 1] The last Sabre to be manufactured by Canadair (Sabre #1815) is now kept in the Western Canada Aviation Museum's (WCAM) permanent collection in Winnipeg, Manitoba, after being donated by the Pakistan Air Force.[18]
The F-86A set its first official world speed record of 670 miles per hour (1,080 km/h) in September 1948.[19]
Several people involved with the development of the F-86, including the chief aerodynamicist for the project and one of its other test pilots, claimed that North American test pilot George Welch had unofficially broken the sound barrier in a dive with the XP-86 while on a test flight on 1 October 1947.[20] Chuck Yeager broke the sound barrier on 14 October 1947 in the rocket-propelled Bell X-1 during level flight, making it the first true supersonic aircraft.[21] Five years later, on 18 May 1953, Jacqueline Cochran became the first woman to break the sound barrier, flying a "one-off" Canadian-built F-86 Sabre Mk 3, alongside Chuck Yeager.[2]
The F-86 was produced as both a fighter-interceptor and fighter-bomber. Several variants were introduced over its production life, with improvements and different armament implemented (see below). The XP-86 was fitted with a General Electric J35-C-3 jet engine that produced 4,000 lbf (18 kN) of thrust. This engine was built by GM's Chevrolet division until production was turned over to Allison.[22] The General Electric J47-GE-7 engine was used in the F-86A-1 producing a thrust of 5,200 lbf (23 kN) while the General Electric J73-GE-3 engine of the F-86H produced 9,250 lbf (41 kN) of thrust.[23] The fighter-bomber version (F-86H) could carry up to 2,000 lb (907 kg) of bombs, including an external fuel-type tank that could carry napalm.[24] Unguided 2.75 in (70 mm) rockets were used on some of the fighters on training missions, but 5 inch (127 mm) rockets were later carried on combat operations. The F-86 could also be fitted with a pair of external jettisonable jet fuel tanks (four on the F-86F beginning in 1953) that extended the range of the aircraft. Both the interceptor and fighter-bomber versions carried six 0.50 in (12.7 mm) M3 Browning machine guns with electrically-boosted feed in the nose (later versions of the F-86H carried four 20 mm (0.79 in) cannons instead of machine guns). Firing at a rate of 1,200 rounds per minute,[25] the .50 in (12.7 mm) guns were harmonized to converge at 1,000 ft (300 m) in front of the aircraft, using armor-piercing (AP) and armor-piercing incendiary (API) rounds, with one armor-piercing incendiary tracer (APIT) for every five AP or API rounds. The API rounds used during the Korean War contained magnesium, which were designed to ignite upon impact but burned poorly above 35,000 ft (11,000 m) as oxygen levels were insufficient to sustain combustion at that height. Initial planes were fitted with the Mark 18 manual-ranging computing gun sight. The last 24 F-86A-5-Nas and F-86E were equipped with the A-1CM gunsight-AN/APG-30 radar which used radar to automatically compute the range of a target. This would later prove to be a significant advantage against MiG opponents over Korea.
The F-86 entered service with the United States Air Force in 1949, joining the 1st Fighter Wing's 94th Fighter Squadron "Hat-in-the-Ring" and became the primary air-to-air jet fighter used by the Americans in the Korean War. While earlier straight-winged jets such as the F-80 and F-84 initially achieved air victories, when the swept wing Soviet Mikoyan-Gurevich MiG-15 was introduced in November 1950, it immediately outperformed all UN-based aircraft. In response, three squadrons of F-86s were rushed to the Far East in December.[26] Early variants of the F-86 could not outturn, but they could outdive the MiG-15, and the MiG-15 was superior to the early F-86 models in ceiling, acceleration, rate of climb, and zoom. With the introduction of the F-86F in 1953, the two aircraft were more closely matched, with many combat-experienced pilots claiming a marginal superiority for the F-86F. MiGs flown from bases in Manchuria by Red Chinese, North Korean, and Soviet VVS pilots were pitted against two squadrons of the 4th Fighter-Interceptor Wing forward-based at K-14, Kimpo, Korea.[26]
Many of the American pilots were experienced World War II veterans, while the North Koreans and the Chinese lacked combat experience, thus accounting for much of the F-86's success.[27] However, United Nations pilots suspected many of the MiG-15s were being flown by experienced Soviet pilots who also had combat experience in World War II. Former Communist sources now acknowledge Soviet pilots initially flew the majority of MiG-15s that fought in Korea, and dispute that more MiG-15s than F-86s were shot down in air combat. Later in the war, North Korean and Chinese pilots increased their participation as combat flyers.[28][29] The North Koreans and their allies periodically contested air superiority in MiG Alley, an area near the mouth of the Yalu River (the boundary between Korea and China) over which the most intense air-to-air combat took place. The F-86E's all-moving tailplane was more effective at speeds near or exceeding the speed of sound, so the plane could safely recover from a sonic dive, where the MiG-15 could not safely exceed Mach 0.92, an important advantage in near-sonic air combat. Far greater emphasis has been given to the training, aggressiveness and experience of the F-86 pilots.[27] American Sabre pilots were trained at Nellis, where the casualty rate of their training was so high they were told, "If you ever see the flag at full staff, take a picture." Despite rules-of-engagement to the contrary, F-86 units frequently initiated combat over MiG bases in the Manchurian "sanctuary."[28] The hunting of MiGs in Manchuria would lead to many reels of gun camera footage being 'lost' if the reel revealed the pilot had violated Chinese airspace.
The needs of combat operation balanced against the need to maintain an adequate force structure in Western Europe led to the conversion of the 51st Fighter-Interceptor Wing from the F-80 to the F-86 in December 1951. Two fighter-bomber wings, the 8th and 18th, converted to the F-86F in the spring of 1953.[30] No. 2 Squadron, South African Air Force also distinguished itself flying F-86s in Korea as part of the 18 FBW.[31]
By the end of hostilities, F-86 pilots were credited with shooting down 792 MiGs for a loss of only 78 Sabres, a victory ratio of 10:1.[32] More recent research by Dorr, Lake and Thompson has claimed the actual ratio is closer to 2:1.[33] The Soviets claimed to have downed over 600 Sabres,[34] together with the Chinese claims, although these are thought by some to be an overcount as they cannot be reconciled with the 78 Sabres recorded as lost by the US.[35] A recent RAND report[36] made reference to "recent scholarship" of F-86 v MiG-15 combat over Korea and concluded that the actual kill: loss ratio for the F-86 was 1.8:1 overall, and likely closer 1.3:1 against MiGs flown by Soviet pilots. Of the 41 American pilots who earned the designation of ace during the Korean war, all but one flew the F-86 Sabre, the exception being a Navy Vought F4U Corsair night fighter pilot.
In addition to its distinguished service in Korea, USAF F-86s also served in various stateside and overseas roles throughout the early part of the Cold War. As newer Century Series fighters came on line, F-86s were transferred to Air National Guard (ANG) units or the air forces of allied nations. The last ANG F-86s continued in US service until 1970.
The Republic of China Air Force of Taiwan was an early recipient of surplus USAF Sabres. From December 1954 to June 1956, the ROC Air Force received 160 ex-USAF F-86F-1-NA through F-86F-30-NA fighters. By June 1958, the Nationalist Chinese had built up an impressive fighter force, with 320 F-86Fs and seven RF-86Fs having been delivered.
Sabres and MiGs were shortly to battle each other in the skies of Asia once again in the Second Taiwan Strait Crisis. In August 1958, the Chinese Communists of the People's Republic of China attempted to force the Nationalists off of the islands of Quemoy and Matsu by shelling and blockade. Nationalist F-86Fs flying CAP over the islands found themselves confronted by Communist MiG-15s and MiG-17s, and there were numerous dogfights.
During these battles, the Nationalist Sabres introduced a new element into aerial warfare. Under a secret effort designated Operation Black Magic, the US Navy had provided the ROC with the AIM-9 Sidewinder, its first infrared-homing air-to-air missile, which was just entering service with the United States. A small team from VMF-323, a Marine FJ-4 Fury squadron with later assistance from China Lake and North American Aviation, initially modified 20 of the F-86 Sabres to carry a pair of Sidewinders on underwing launch rails and instructed the ROC pilots in their use flying profiles with USAF F-100s simulating the MiG-17. The MiGs enjoyed an altitude advantage over the Sabres, as they had in Korea, and Communist Chinese MiGs routinely cruised over the Nationalist Sabres, only engaging when they had a favorable position. The Sidewinder took away that advantage and proved to be devastatingly effective against the MiGs.[37]
The combat introduction of the Sidewinder took place in a battle on 24 September 1958 when ROC Sabres succeeded in destroying 10 MiGs and scoring two probables without loss to themselves. In one month of air battles over Quemoy and Matsu, Nationalist pilots tallied a score of no less than 31 MiGs destroyed and eight probables, against a loss of two F-84Gs and no Sabres. The data comes from Nationalist Air Force filmed data.
In 1954, Pakistan began receiving the first of a total of 120 F-86F Sabres. Many of these aircraft were the F-86F-35 from USAF stocks, but some were from the later F-86F-40-NA production block, made specifically for export. Many of the −35s were brought up to −40 standards before they were delivered to Pakistan, but a few remained −35s. The F-86 was operated by nine PAF squadrons at various times: Nos. 5, 11, 14, 15, 16, 17, 18, 19 and 26 Squadrons.
During the 22-day Indo-Pakistani War of 1965 the F-86 became the mainstay of the PAF, although the Sabre was no longer a world-class fighter, since fighters with Mach 2 performance were now in service. Many sources state the F-86 gave the PAF a technological advantage. PAF scored 91 air kills in 1965 which were primarily due to this aircraft.[38][39]
During the war, the United States barred sales of military equipment to Pakistan and the F-86 fleet was almost grounded due to lack of spare parts. Pakistan managed to procure around 90 Canadair CL-13 Sabre Mk 6 illegally from West Germany through Iran, these formed the backbone of the operations during the 1971 Indo-Pakistani War. The F-86 proved vulnerable to the diminutive Folland Gnat, which proved to be fast, nimble and hard to see. The IAF Gnats, given the nickname "Sabre Slayer," claimed to have downed seven PAF Sabres.[40][41][N 2]
In the air-to-air combat of the Indo-Pakistani War of 1965, the PAF Sabres claimed to have shot down 15 IAF aircraft, comprising nine Hunters, four Vampires and two Gnats.[40] India, however, admitted a loss of 14 combat aircraft to the PAF's F-86s.[42] The F-86s of the PAF had the advantage of being armed with AIM-9B/GAR-8 Sidewinder missiles whereas none of its Indian adversaries had this capability. Despite this, the IAF claimed to have shot down four PAF Sabres in air-to-air combat.[41] This claim is disputed by the PAF who admit to having lost seven F-86 Sabres during the whole 23 days but only three of them during air-to-air battles.[40]
The top Pakistani ace of the conflict was Sqn Ldr Muhammad Mahmood Alam, who ended the conflict claiming 11 kills. In air-to-air combat Pakistan Air Force F-86 Flying Ace Sqn Ldr Muhammad Mahmood Alam shot down five Indian Aircraft in less than a minute.[43][44][45] These five kills were all against Indian Air Force (IAF) Hawker Hunter Mk.56 fighters, which were export versions of the Hunter Mk.6 of the Royal Air Force.
The PAF Sabres performed well in ground attack with claims of destroying around 36 aircraft on the ground at Indian airfields at Halwara, Kalaikunda, Baghdogra, Srinagar and Pathankot.[40][46][47][48] India only acknowledges 22 aircraft lost on the ground to strikes partly attributed to the PAF's F-86s and its bomber Martin B-57 Canberra.[42]
Pakistani F-86s were also used against advancing columns of the Indian army when No. 19 Squadron Sabres engaged the Indian Army using 5 in (127 mm) rockets along with their six .50 in (12.7 mm) M3 Browning machine guns. According to Pakistan reports, Indian armor bore the brunt of this particular attack at Wagah.[48] The Number 14 PAF Squadron earned the nickname "Tailchoppers" in PAF for their F-86 operations and actions during the 1965 war.[47]
The Canadair Sabres (Mark 6), acquired from ex-Luftwaffe stocks via Iran, were the mainstay of the PAF's day fighter operations during the Bangladesh Liberation War 1971, and had the challenge of dealing with the threat from IAF. Despite having acquired newer fighter types such as the Mirage III and the Shenyang F-6, the Sabre Mark 6 (widely regarded as the best "dog-fighter" of its era[49]) along with the older PAF F-86Fs, were tasked with the majority of operations during the war, due to the small numbers of the Mirages and combat unreadiness of the Shenyang F-6.[18] In East Pakistan only one PAF F-86 squadron (14th Squadron) was deployed to face the formidable IAF Soviet MiG-21s and the Sukhoi Su-7 and the numerical superiority of the IAF. At the beginning of the war, PAF had eight squadrons of F-86 Sabres.[50]
Despite these challenges, the PAF F-86s performed well with Pakistani claims of downing 31 Indian aircraft in air-to-air combat including 17 Hawker Hunters, eight Sukhoi Su-7 "Fitters", one MiG 21, and three Gnats[51] while losing seven F-86s.[52] India however claims to have shot down 11 PAF Sabres for the loss of 11 combat aircraft to the PAF F-86s.[53] The IAF numerical superiority overwhelmed the sole East Pakistan Sabres squadron (and other military aircraft)[54][55] which were either shot down, or grounded by Pakistani Fratricide as they could not hold out, enabling complete Air superiority for the Indian Air Force.[56]
In the Battle of Boyra, the first notable air engagement over East Pakistan (Bangladesh), India claimed four Gnats downed three Sabres while Pakistan acknowledges only two Sabres were lost while one Gnat was shot down.[18] As per official Pakistan accounts, 24 Sabres were lost in the war: 13 due to enemy action and 11 disabled by PAF forces to keep them out of enemy hands,[52] while 28 Sabres were lost per Indian accounts: 17 due to IAF action and 11 disabled by the PAF on the ground to keep them out of enemy hands.[57] Five of these Sabres, however, were recovered in working condition and flown again by the Bangladesh Air Force.[57][58][59]
After this war, Pakistan slowly phased out its F-86 Sabres and replaced them with Chinese F-6 (Russian MiG-19 based) fighters. The last of the Sabres were withdrawn from service in PAF in 1980.[18] F-86 Sabres nevertheless remain a legend in Pakistan and are seen as a symbol of pride. They are now displayed in Pakistan Air Force Museum and in the cities in which their pilots lived.
Based at AB2-Bissau/Bissalanca in 1961–1964, some F-86Fs were deployed in Guinea in 1961 where they were used in ground attack and close support operations. These aircraft formed “Detachment 52”, equipped with eight F-86Fs (serials: 5307, 5314, 5322, 5326, 5354, 5356, 5361 and 5362) of the Esquadra 51, based at the Base Aérea 5, in Monte Real, Portugal. In August 1962, 5314 overshot the runway during emergency landing with bombs still attached on underwing hardpoints and burned out. F-86 5322 was shot down by enemy ground fire on 31 May 1963; the pilot ejected safely and was recovered. Several other aircraft suffered combat damage, but were repaired.
In 1964, 16 F-86Fs based at Bissalanca returned to mainland due to U.S. pressure. They had flown 577 combat sorties, of which 430 were ground attack and close air support missions. During these operations, one FAP Sabre was shot down and another crashed.
The Philippine Air Force first received the Sabres in the form of F-86Fs in 1957. Replacing the North American P-51 Mustang as the Philippine Air Force's primary interceptor. F-86s first operated from Basa Air Base, known infamously as the Nest of Vipers where the 5th Fighter Wing of the PAF was based. Later on, in 1960, the PAF acquired the F-86D as the first all weather interceptor of the PAF. The most notable use of the F-86 Sabres was in the Blue Diamonds aerobatic display team which operated eight Sabres until the arrival of the newer, supersonic Northrop F-5. The F-86s were subsequently phased out of service in the 1970s as the F-5 Freedom Fighter and Vought F-8 Crusaders became the primary fighters and interceptors of the Philippine Air Force.
The most notable F-86 pilot of the PAF is Antonio Bautista who was a Blue Diamonds pilot and a decorated officer for his actions on 11 January 1974.
During the Korean War, the Soviets were searching for an intact US F-86 Sabre for evaluation/study purposes. Their search was frustrated, largely due to the US military's policy of destroying their weapons and equipment once they had been disabled or abandoned; and in the case of US aircraft, USAF pilots destroyed most of their downed Sabres by strafing or bombing them. However, on one occasion an F-86 was downed in the tidal area of a beach and subsequently was submerged, preventing its destruction. The aircraft was ferried to Moscow and a new OKB was established to study the F-86, which later became part of the Sukhoi OKB. The Soviets studied and copied the optical gunsight and radar from the captured aircraft to produce the ASP-4N gunsight and SRC-3 radar. Installed in the MiG-17, the gunsight system would later be used against American fighters in the Vietnam war. [N 3]The F-86 studies also contributed to the development of aircraft aluminum alloys (V-95 etc.).[61]
The old but nimble MiG-17 had become such a serious threat against the Republic F-105 Thunderchief over Vietnam that the Air Force created project "Feather Duster" to test tactics supersonic American fighters could use against fighters like the MiG-17. Air National Guard F-86H units proved to be an ideal stand-in for the Soviet jets. One pilot remarked that "In any envelope except nose down and full throttle", either the F-100 or F-105 was inferior to the F-86H in a dogfight.[62] [63]
Two types based on the US F-86F were built under licence by the Commonwealth Aircraft Corporation (CAC) in Australia, for the Royal Australian Air Force as the CA-26 (one prototype) and CA-27 (production variant). The RAAF operated the CA-27 from 1956 to 1971.[66] Ex-RAAF Avon Sabres were operated by the Royal Malaysian Air Force (TUDM) between 1969 and 1972. From 1973 to 1975, 23 Avon Sabres were donated to the Indonesian Air Force (TNI-AU); five of these were ex-Malaysian aircraft.
The CAC Sabres included a 60% fuselage redesign, to accommodate the Rolls-Royce Avon Mk 26 engine, which had roughly 50% more thrust than the J47, as well as 30 mm Aden cannons and AIM-9 Sidewinder missiles. As a consequence of its powerplant, the Australian-built Sabres are commonly referred to as the Avon Sabre. CAC manufactured 112 of these aircraft.
CA-27 marques:
The F-86 was also manufactured by Canadair in Canada as the CL-13 Sabre to replace its de Havilland Vampires, with the following production models:
| F-86A | F-86D | F-86E | F-86F | F-86H | F-86K | F-86L | |
|---|---|---|---|---|---|---|---|
| Program R&D cost | 4,707,802 | ||||||
| Airframe | 101,528 | 191,313 | 145,326 | 140,082 | 316,360 | 334,633 | |
| Engine | 52,971 | 75,036 | 39,990 | 44,664 | 214,612 | 71,474 | |
| Electronics | 7,576 | 7,058 | 6,358 | 5,649 | 6,831 | 10,354 | |
| Armament | 16,333 | 69,986 | 23,645 | 17,669 | 27,573 | 20,135 | |
| Ordnance | 419 | 4,138 | 3,047 | 17,117 | 4,761 | ||
| Flyaway cost | 178,408 | 343,839 | 219,457 | 211,111 | 582,493 | 441,357 | 343,839 |
| Maintenance cost per flying hour | 135 | 451 | 187 |
Note: The costs are in approximately 1950 United States dollars and have not been adjusted for inflation.[2]
According to the FAA there are 50 privately owned and registered F-86s in the US, including Canadair F-86 Sabres.[69][N 5]
Data from The North American Sabre[72]
General characteristics
Performance
Armament
'before we had completed more than of about 270 degree of the turn, at around 12 degree per second, all four hunters had been shot down.'
|
||||||||||||||
|
||||||||||||||