Category: Aircraft

World War II:

It was decided by Allied commanders that a full time strategic bombing campaign would cripple the enemy over time and allow ground troops the advantage they needed to first stop the advancing German Army and then push them back into Germany. This included the practice of daylight bombing raids on German targets. The 1st daylight bombing mission by a US unit was on 4th July, 1942. Two out of the six RAF A-20s were lost. On 17 August 1943, 60 out of 376 American bombers were lost!

Almost all the losses coming beyond the range of the bomber escort. Early escort included the RAF Spitfire and the USAAF P-47 Thunderbolt. Even with drop tanks, the range of these fighters would barely reach to the Germany border. After that, the Luftwaffe, laid in wait.

14th October of 1943, another 60 were lost in a single day, “Black Thursday”. The B-17 had a crew of 10 men. Many did not get out and if they did get out and get their chute to deploy, evading capture and returning to England was very difficult. At that loss rate, the practice of daytime bombing raids was in question. The B-17, although designed to defend itself, could not. Strategic day-time bombing was crippling both sides.

It should be noted that the concept of the P-51 Mustang began more three years before these daylight bombing missions and the heavy losses. It is often accepted that the P-51 Mustang was designed to be an escort fighter, but as you look at the timeline, it is more plausible that the Mustang, as a fighter aircraft, fit that need better than any other fighter available. NAA was building the fastest, best fighter of that time, not an escort fighter – until later when specific requirements were asked of NAA.

By the time heavy bomber losses were at hand, the P-51B and P-51C, with outstanding range, were already in production and being delivered to bases in England. The bombers of the daylight missions were taking very heavy losses each day from Luftwaffe pilots until an escort fighter could stay with them deep into enemy territory and home again on every mission. The North American P-51 Mustang was the immediate choice. The bomber crews nicknamed them their “little friends.”

North American Aviation – Key Players

James H. “Dutch” Kindelberger and Leeland J. Atwood

Dutch came to NAA from Douglas Aircraft in 1934. He was VP of Douglas and working on the DC-1 and DC-2 programs. He soon recruited Lee Atwood, also from Douglas Aircraft to be the Chief Engineer. Atwood would later became VP at NAA. Dutch was working for Douglas in Southern California, but NAA was located in Maryland. He wanted to stay in California and convinced NAA to build a new facility in Inglewood Ca not for him and other key people in the area but because there was good quality workers and the flying weather was perfect.

By the end of 1935 a new facility was built next to Mines Field in Inglewood CA. This area was later consumed into what is now LAX. In 1935 NAA responded to a USAAC Circular Proposal calling for a two-place pursuit aircraft. Atwood prepared a very detailed report for the NA-35 Model XP. This is NAA first known attempt at building a fighter. In 1936 NAA won a contract for 164 O-47A and 74 O-47B, an armed observation aircraft. Later that year, NAA was awarded a contract for 117 the BT-9B trainers.

In December 1937, the NA-40 program was started. The NA-40 evolved into the NA-62, or B-25 as we know it today, twin-engined medium bomber. The NA-40 made its first flight in January of 1939 with the B model flying in March 1939. NAA was later awarded contracts for the B-25A and B-25B bombers.

Edgar Schmued

Schmued was born in Germany, 1899. Edgar grew up in fascination of mechanical things, especially aviation. He apprenticed in a small engine factory in Germany. When he completed his apprenticeship, he began studying aeronautics on his own. When WWI started, Schmued enlisted in the Austro-Hungarian Flying Service and served as a mechanic for a short time. In the mid 20’s Schmued’s older and younger brothers immigrated to a German community in Sao Paulo Brazil, they were dentists like their father. The working conditions and prospects in Germany at that time were not the best a young man could find.

Edgar followed his brothers in 1925 with the dream of finding an aviation career – wanting to run his own enterprise. He found a job with General Motors automobile division. GM held stock in several aviation ventures, including Fokker Aircraft Corporation. GM was impressed by Schmued and sponsored him to immigrate to the U.S. in 1929. He landed his first job at Fokker Aircraft in Teterboro NJ. Fokker struck hard times and Schmued was moved to Dundalk Maryland. Schmued was now working for General Aviation, which changed names to North American Aviation in 1935. Schmued became a U.S. citizen in 1935 and later transferred to the new facility in Inglewood CA.

Now, it is late in 1939, and the British need more fighter aircraft.

Britain showed interest in the Curtiss P-40 Warhark, the Bell P-39 Aircobra and with lesser excitement, the Lockheed P-38 Lightning. None were their first choice, but that was the best that the Americans had and the British could not wait for any new designs. The Spitfire and Hurricane, Britain’s top aircraft, were superior to the American choices at that time, but the British needed more fighters and could not produce them fast enough. They decided the P-40 would be their best choice. Curtiss Aircraft was given contracts that placed their facility at full capacity. James H. “Dutch” Kindelberger, president of North American Aviation, was asked in February of 1940 to consider building P-40s for Britain.

During that time, North American Aviation was producing NA-16 training aircraft for the British and meeting all expectations. They had also built their first fighter, the NA-50 and exported it to Peru. Edgar Schmued, now Chief Designer at NAA had been sketching designs of a fighter aircraft he envisioned for some time now. In March, Kindelberger was talking to Schmued and asked him if (NAA) wanted to build P-40s. The question was already answered by the tone from Kindelberger. Schmued had been waiting for a question like that – his answer was easy – no, we can design and build a better fighter.

March 15, 1940

Kindelberger and Atwood were planning to meet with the British Purchasing Commission in a few weeks and Kindelberger wanted some drawings and data on their proposed new fighter. That was Schmued’s first order to work on the future P-51 Mustang. Although Kindelberger and Atwood returned without any contract or promise, the British were looking over the proposal from NAA and soon decided based on the past performance of NAA that they would grant them a contract.

The Britain Purchasing Commission was formed in January 1940, headed by Sir Henry Self and had an official office in New York City. It is not clear, as some papers/books state Kindelberger and Atwood went to England, others just say they met with the British Purchasing Commission – which could have been in NY.

Kindelberger had convinced Britain’s Sir Henry Self of the British Purchasing Commission that North American Aviation could design and build a new fighter that was better than the P-40 in the time it would take to tool up to build P-40s. British approval by letter of intent was given on 10th April 1940. Shortly after, 23 May (NAA doc shows 9-29-40), a contract order was placed by the British for the first 320 aircraft designated by North American Aviation as NA-73. These Mustang Is would be serialed AG345 – AG664 for Britain. By the time the official contract was received, NAA was already deep into the design of NA-73.

One requirement from Britain was to obtain the wind tunnel data from Curtiss Aircraft for the XP-46 – a fighter concept with similar requirements to the P-51. NAA vice-president Lee Atwood was sent to Curtiss Aircraft to get this data. NAA purchased the data for $56,000 in May 1939. It has been reported that the data was received too late – the main design of the P-51 was already finished. Although sources at NAA stated that the XP-46 design was not used in the development of NA-73, you cannot help to notice some basic similarities. The prototype XP-46 flew a top speed of only 355 mph at 12,000 feet. The XP-46 was never put into production but the Allison used on the XP-46 was incorporated in the next P-40, the P-40D.

Kindelberger put Edgar Schmued in charge of the new P-51 prototype design, NA-73X. Others who worked with Schmued included Ed Horkey, Raymond Rice , Larry Waite and Art Chester. Their work week was not typical of our work week today.

They worked late into each night, only going home “early” on Sunday at 6pm. After 78,000 man hours and 102 days later, on Sep 9 1940, the prototype, NA-73X, rolled out of the hangar – without an engine. Eighteen days later, the Allison V-1710-39 was ready but was delivered with changes unknown to NAA engineers. The existing motor mount conflicted with the new engine’s electrical system. A new motor mount had to be built and quick. On October 26 1940, NX19998 took to the skies for its maiden flight with test pilot Vance Breese at the controls. After several test flights with Breese as test pilot, he totaled a bit over 3 hours and had very favorable remarks about the P-51.

Test pilot Paul Balfour got a chance to fly her early in the morning of Nov 20 1940. It’s reported that he had a very relaxed approach to this flight and dismissed an offer to go through flight procedures before the flight. During the test flight, the Allison quit, turning the XP-51 into a very poor glider. Balfour could not make the airport, so he landing, gear-down, in a plowed field. The main gear dug into the soft soil and the aircraft flipped over causing much damage. Balfour was able to get out with little or no injury. Repairs were started right away and the aircraft was ready for engine runs in about 30 days – but it did not fly again until Jan 13 1941. There are articles that state that “not wanting to wait, the first production aircraft, AG345, was prepared for test flights ” but the timeline does not support this statement. AG345 was first test flown in April 1941. Even though this would be considered a huge setback on a normal test flight program, the test flights so far have been so good that the team at NAA was comfortable moving forward with production.

There are varying accounts about why the engine quit. It is mostly stated that Balfour missed a fuel selector change and starved the engine of fuel. Some dismiss this saying that Balfour was a seasoned test pilot and would not make such a rookie mistake. Then, why did the engine quit? There was a real defect on NA-73X with regards to the air-inlet-scoop being too far behind the nose of the aircraft – at high angles of attack the airflow is cut-off, thus starving the engine of air. NAA later moved the inlet as far forward as possible solving that problem. Is it possible that NAA didn’t want to blame the crash on their design and found it convenient to use Balfour as the reason? It is reported that an eye witness to the crash (an NAA employee) stated that the crash happened shortly after take-off and upon examination of the fuel tanks, fuel was in the auxiliary and right tank, but no fuel in the left tank. If that is true and the crash happened shortly after take-off, the aircraft was given to Balfour with little fuel in the left tank – that was burned up during taxi, run-up and take-off (Either he wasn’t told correctly about the fuel status, he selected the wrong tank or ground personnel did not fill as instructed. Balfour was transferred to the B-25 flight test program after the accident. Balfour was later killed (Nov 10, 1951) in a crash during a test flight of a modified CB-25J for NAA.

Tooling Up For Production

Back in 1938, Kindelberger had visited the German aircraft factories of Heinkel and Messerschmitt and used what notes he took to help in setting up an extremely efficient production line. At peak times NAA produced 857 P-51s in one month! Production was so good that there were rows of completed P-51Ds at the NAA factory in Inglewood, CA just waiting for delivery pilots.

The first production P-51 designated “Mustang I” with serial# AG345 for Britain, was test flown by Louis Waite on April 23 1941. Bob Chilton test flew AG345 several times in May 1941. Chilton also test flew the 4th production model XP-51 41-038 that was to be delivered to the US Army Air Corps for evaluation. By August, Chilton had test flown the 2nd production aircraft AG346, and it was the first P-51 ready for delivery to Britain. By the end of 1941, the RAF accepted 138 Mustangs with more coming each month. The RAF pilots reported favorably after flying their new fighter. To understand the quick work of NAA in developing the P-51, lets look back a little to the Curtiss XP-46 which was well underway well before the P-51 idea was born. The XP-46 finally test flew four and a half months after the XP-51.

Conditions of the US approval for export to Britain included that 2 examples of the Mustang would be turned over to the USAAF for evaluation at no cost. The US was very slow to evaluate the new fighter designated XP-51. They were busy with the P-38, P-39, P-40 and the P-47. When Chilton went to Wright field in October of 1941, he saw the XP-51 sitting on the ramp but noticed only 1 hour had been added since it was delivered. After the attack on Pearl Harbor, Dec 7 1941, the USAAC interest in the P-51 did increase as the immediate need for fighters in the Pacific was being filled by the fighters already in production. US contracts for fighter aircraft were near full at that time, but there was room and need of attack aircraft. NAA seized on the opportunity and the A-36 was created to fill that need. The A-36 was a P-51A set up for dive-bombing ground attack. On April 16 1942, NAA received a contract for 500 A-36s for USAAC.

Then in June of 1942, US placed an order for 310 P-51As. The P-51A was a very capable aircraft but did lack in high-altitude performance because the Allison V-1710-39 lost considerable horse power above 20,000 feet. It didn’t take long for smart minds on both sides of the pond to consider using the Rolls Royce Merlin V-12 that was in use in the Spitfire and other RAF aircraft. Ron Harker, test pilot for Rolls Royce is credited with the idea after test flying the Mustang I. In June of 1942, work began in Britain on converting a Mustang I to use a Merlin 61 engine. The Merlin incorporated a two-stage supercharger that kept horsepower up to over 30,000 feet. The US then followed.

NAA submitted model specs for NAA-101 in July of 42. In august, two P-51 airframes were designated XP-78 and later designated XP-51B in September. Bob Chilton test flew the first XP-51B on November 30 1942. Orders where actually placed before the XP-51B flew as NAA and the USAAF were both excited about the new design. General Hap Arnold was a loud proponent of the escort fighter. He insisted that the bombers must have fighter escort deep into Germany. It took another 10 months to deliver the P-51B/C to Europe. They arrived in England in September 1943. General Arnold later wrote that it was the USAAF’s own fault that they did not have the Mustangs earlier. Remember above, when the USAAF sat on the evaluation of the P-51 for some time. That delay seems costly for many B-17 crews shot down over Germany in 1943 with no fighter escort, however, NAA later stated they had needed that time for the mustang design to evolve.

As production increased, NAA needed to expand – their Inglewood CA plant was at max capacity. NAA moved the B-25 line form Inglewood to Kansas, freeing up some much needed space. They built the P-51C at the Dallas plant in Texas. The P-51C was identical to the P-51B. P-51 models built in Inglewood held the suffix -NA, in Dallas it was -NT, so a P-51C dash 5 built in Dallas was designated P-51C-5-NT. Production increased as the war was in full bloom.

The P-51B was an excellent aircraft, very fast and capable. The main complaints were lack of rearward and downward visibility, gun jamming of the 4 .50 Browning machine guns (which were mounted at an angle because they were too tall for the P-51B wing thickness) and not enough guns. The RAF invented the Malcolm hood, that was a bubble type that replaced the center flat section of the canopy. The new canopy was a huge improvement. The firepower of the P-51B/C was minimal with only 4 guns as compared to the P-47 which used 8.

During the construction of the B/C, the allied bombers were taking very heavy casualties on daylight raids into Germany. In July of 1943, the USAAF needed to act on the heavy bomber losses over Germany. They sent a directive to NAA to provide maximum range to the P-51B for fighter escort at the earliest possible date. The P-51 already had the longest range of any Allied fighter. An 87 gallon fuselage fuel tank behind the pilot was added to some of the B/C models and all of the D/K models to fulfill this directive. This fuel tank when fully loaded produced an aircraft that was a handful to control on take-off and climb at full load. Pilots soon adapted by practice and by selecting the fuselage tank first to burn off half the fuel behind the pilot before switching to drop-tanks.

A new model, the NAA-106, P-51D was created to solve these problems. A new full bubble canopy was developed. The wing section was increased to house the Brownings fully upright, eliminating the jamming – they also added 2 more of the .50 Brownings to a total of six. The P-51D was produced in Inglewood. The P-51K and the P-51D were both produced in Dallas. The P-51K was identical to the P-51D except for a different propeller and slightly different shape canopy – not by design, but more by variances in suppliers. The gross weight increased and after losing the razorback of the B/C pilots reported more stability problems. NAA solved this by adding the dorsal fin that connects the top of the fuselage with the vertical tail adding more vertical area.

The P-51D was the most produced model and was favored among most pilots even though the P-51B/C was a little faster. The D model provided excellent visibility and the extra fire-power was needed. The P-51H was a redesigned lighter-weight version but entered service to late to make an impact on WWII. The P-51H is noticeably different in design and uses less than ten percent of the parts from the P-51D. Another light-weight, the P-51G prototypes were produced and tested. Other models, like the P-51L, P-51M never made it to production because the war ended.

Why was the P-51 so fast? Even the creators could not agree. During the 1960’s and beyond, there became a disagreement between Lee Atwood and Ed Horkey – maybe it started long before. Lee being a firm believer that the laminar flow wing did not produce the results Ed Horkey had stated and that the P-51 was fast and efficient because of the Meredith effect of the the belly scoop, radiator and oil cooler design. Horkey believed the P-51 was so good because of the wing design and aerodynamic design of the fuselage and tail surfaces and that the Meredith effect and scoop design could only cancel out drag added by the frontal area not add propulsion. Who’s right? Who cares? Certainly the scoop design of the P-51 is far superior to the slower P-40 and Spitfire – each with different approaches to the design. This author does not believe that any one item led to the design efficiency and low drag of the Mustang. But all things put together, stealing and shaving drag anywhere they could is why the P-51 Mustang was so effective in WWII – and luckily it was not only efficient but the most beautifully designed fighter of WWII.

During the United States Air Force’s jet era, the A-1 Skyraider may have been a tortoise among hares, but true to the fable’s ending, the venerable “Spad’s” slow and steady delivery won the race every time.

Manufactured by Douglas Aircraft in the late 1940s to 1950s, the A-1 Skyraider’s smart combination of long loiter times and sheer size made it the perfect aircraft for dangerous delivery missions and bombings. It was most well-known for its ability to withstand enemy fire and return in one piece.  As one of the few propeller aircraft still used in the Korean and Vietnam Wars, A-1 Skyraiders were a key element of the USAF’s Combat Search and Rescue (CSAR) mission as close air support of the CSAR helicopters.

The Air Force Heritage Flight Foundation is fortunate to have two A-1 Skyraiders within the program: Wiley Coyote and Heritage Flight Museum’s The Proud American.

“With a big motor, big wings, big airframe, she’s the biggest, baddest fighter on the ramp,” said Air Force Heritage Flight pilot Greg “B.A.” Anders.

The airframe that would eventually become the museum’s “The Proud American” was a Naval AD-4 model officially cataloged as BuNo 126965. It was deployed to Korea with the U.S. Navy after the cease-fire had been called, so it never saw combat. However, as a part of the Naval attack squadron VA-115, the aircraft was then tasked with patrolling the DMZ for the duration of their mission.

Once it returned stateside the aircraft traveled across the United States, with stops at both Alameda and then Norfolk, Virginia with the “FAETULANT” unit, and was eventually stored and stricken from the Navy list in July 1958.

Two years later, the Skyraider was purchased by the French Air Force (officially known as l’Armee de l’Air) and was based in Chateaudun with tours in Algeria, Djibouti, Madagascar, and Chad throughout the ‘60s and ‘70s.

Ultimately, the aircraft was acquired by Greg Anders and the Heritage Flight Museum in 2005 from a private owner in Belgium. Anders’ brother, Alan, had been especially passionate about adding a Skyraider to the museum following his work with the Commemorative Air Force and the Ravens, a renowned group of pilots that flew covert missions across Laos and Cambodia during the Vietnam War.

However, getting a 6-ton “Spad” across the Atlantic to Washington state proved a feat of its own.

“Getting it home was pretty interesting,” Anders said. “Once it was purchased in Belgium, it was sent to France where it got on a ‘Roll-On-Roll-Off’ boat to come across the Atlantic and be delivered to Charleston [South Carolina].

“They had to lift the aircraft off the boat and tow it through the streets to the nearby airport. You can imagine how large this plane was, even with the wings folded up, being towed through the narrow streets, and at one point, they literally had to build ramps to get the wings over the cars because they couldn’t get all the cars out of the street.”

When the Skyraider arrived in Charleston, the next task was flying the plane from the Southeast to the Pacific Northwest with a little help from Greg’s brother and a Grumman Tiger.

“The guy that we bought it from flew from Charleston to up to the Pacific Northwest – Bellingham at the time. His English was poor, so my brother had to chase him in a Grumman Tiger and do all the talking on the radio,” said Anders.

In the end, the Skyraider arrived in Washington, and then the restoration work began. The size of the aircraft played a role in this process as well, with the Skyraider boasting a 50-foot wingspan, 39-foot length, and weighing almost 12,000 pounds.

“It’s newer technology than seen in a typical P-51 Mustang, but it’s a somewhat complicated airplane because it’s so robust. Thankfully, it had been flying in France for many years, and it been kept in great condition. The aircraft restoration was challenging, but most of the parts we really needed were there or could be fabricated very easily.”

When it came time to decide on the paint scheme and name for the museum’s Skyraider, Anders — who served with the USAF for over 23 years — felt it was only fitting to have it dressed in official Air Force colors as an homage to the Skyraider pilots from the Vietnam War.

The name The Proud American pays tribute to Vietnam veteran Lieutenant Colonel William Jones, one of two USAF Skyraider pilots who received the Medal of Honor. Lt. Jones’ Skyraider was also the last USAF aircraft shot down in the Vietnam War.

“Everyone knows the story of Maj. Bernie Fisher, so we really wanted to pay homage to the lesser-known Medal of Honor recipient,” said Anders. “And with Lt. Jones’ aircraft being the last Skyraider shot down in the Vietnam War, it felt serendipitous.”

The size of the aircraft would have made a professional paint job extremely expensive for the small family museum, so Anders and a team of museum volunteers painted the entire exterior, just as troops would have done in the rivets of Vietnam.

“We’ve gotten a lot of compliments from people about how authentic the paint scheme looks, as opposed to some Skyraiders today which have a high-gloss finish,” said Anders.

The Proud American has since become a staple fixture for both the Heritage Flight Museum and the Air Force Heritage Flight program. The passion and enthusiasm for the “Spad” is incomparable, especially from many Vietnam veterans. The A-1 Skyraider was instrumental in their missions, and more importantly, their survival.

“I was at the Luke Air Show [in Glendale, Arizona] one Saturday morning to prep The Proud American for the show quite early in the morning and this guy was standing about 30 feet away just standing and looking at it,” said Anders.

“I knew it was a very private moment for him, so I continued my walk around without bothering him.  I eventually approached him and said, ‘Hey, how are you? I see you have an interest in our Skyraider. Can I answer any questions for you?’ And he goes, ‘Nope. I was lying in a ditch in Vietnam getting shot at, and I would be dead now if it wasn’t for this airplane.’”

“It’s incredible to get those stories of feedback, as there’s a lot of passion there. I still get emotional just telling that story. What the Skyraider did was extremely impactful, and that’s why it’s so important to continue telling those stories,” said Anders.

For Anders and his team, there are still plenty of challenges in maintaining this rare piece of history. His team is already on their third engine for The Proud American and has an equally difficult airframe to maintain. Nonetheless, The Proud American is emblematic of the sacrifice and service of so many Americans and another way to pay tribute to their service then and now.

• Wanna know what’s behind the trademark BRTTTTT noise of the A-10 Warthog’s GAU-8/A Avenger Gatling Gun?
• The video below, produced by the 3D Mil-Tech YouTube channel, shows in extensive detail how the Avenger works.

Dubbed Warthog, Hog or just Hawg, the A-10 Thunderbolt II is, basically, an airplane built around the GAU-8 Avenger 30-mm hydraulically driven seven-barrel Gatling-type cannon.

The Avenger cannon is the Hog primary weapon and is able to fire 3,900 bullets per minute.

“It’s a highly-accurate point-and-shoot weapon that grants our pilots superior firepower and flexibility in a close-combat ground fight,” a Warthog pilot once told us. The GAU-8 is rated at “5 mil, 80%,” meaning that 80% of rounds will hit within a 5-mil circle, with mils being milliradiants (at 1,000 feet five mils would be 5 m hence 80% of rounds would hit within a 5-m circle and that’s at 70 rounds a second).

Everything in the A-10 is designed to “make room” to the gun, including the nose landing gear, offset to the right of the aircraft so that the firing barrel lines up along the center of the airframe.

More in detail, as the gun’s recoil forces could push the entire plane off target during strafes, the gun itself is mounted laterally off-center, slightly to the port side of the fuselage centerline, with the actively “firing” barrel in the nine o’clock position (when viewed from the front of the aircraft), so that the firing barrel lies directly on the aircraft’s centerline.

The firing barrel also lies just below the aircraft’s center of gravity, being bore-sighted along a line 2 degrees below the aircraft’s line of flight. This arrangement accurately centers the recoil forces, preventing changes in aircraft pitch or yaw when fired.

Each of its seven barrels has an internal riffling groove which passes through the whole length of the barrel so that a spin on each round can be induced.

The 1,150 30-mm rounds of bullets stored in the drum weigh about 4,000 pounds: this means that the weight of the rounds and their shells has to be taken in consideration to position of the center of gravity of the aircraft. Without the rounds, you would actually have to put ballast in the nose on an empty gun to balance the airplane!

Other design features of the Warthog support the operation of the Avenger.

For instance, as explained by Maj. Cody “ShIV” Wilton, the commander of the A-10 Demo Team, in a pretty epic walkaround video we have published last year, the slat on each wing — that are not slats in the traditional airplane sense as they do not generate lift nor help the pilot land any slower it, but they smooth the airflow off the wing in the engine and prevent stalls when the aircraft flies at high AOA (Angle Of Attack) — also helps diverting the gun gas underneath the wing so it doesn’t suffocate the engine (as the gun gas does not have oxygen) when the aircraft uses the gun.

There’s also a wind fence that, when the gun is shooting, diverts the gas down the fuselage.

The stunning video below, produced by the 3D Mil-Tech YouTube channel, shows with unprecedented details, how the GAU-8 Avenger works: It gives an idea of the seven-barrel carriage assembly including the double-ended feed system which allows the spent casings to be returned to the ammunition drum.

What a fine piece of machinery!

One of the most famous aircraft ever built and an icon of the Battle of Britain, the Spitfire had a long and varied history during its operational service with the Royal Air Force, which it still flies with today as part of the Battle of Britain Memorial Flight. Find out 25 Spitfire facts about the aircraft and the people behind it.

Design Team Led by Reginald Joseph Mitchell

Born in Talke, Staffordshire on the 20th May 1895, Reginald Joseph Mitchell joined Supermarine in 1916. During his time at Supermarine, many as chief designer, Mitchell would be involved in the design of twenty four aircraft. Although it is the Spitfire he is most remembered for he also played a role in the Walrus and Stranraer flying boats. Both of these aircraft would also serve during the Second World War (1939 – 1945). Reginald Joseph Mitchell died of cancer, at the age of 42, on the 11th June 1937.

Supermarine Type 224

The Type 224 was designed in response to Specification F.7/30 which had been issued by the Air Ministry in October 1931. Featuring fixed undercarriage and gull wings the aircraft flew for the first time on the 19th February 1934. It proved unsuccessful and only one example was built, but the data and experience gained during the development of the aircraft helped in the design of the Spitfire.

First Flight

The 5th March 1936 saw the Spitfire prototype (K5054), still known then as the Supermarine Type 300, fly for the first time. With a 900-hp Rolls-Royce Merlin ‘C’ engine powering the aircraft as it flew from what was then RAF Eastleigh , now Southampton Airport, with Vickers Supermarine test pilot Captain Joseph Summers at the controls for the eight minute flight.

Don’t Touch Myth

“Don’t touch anything” was said by Captain Joseph Summers at the end of the prototype’s first flight. This was not because the Spitfire was perfect but because he was to fly the prototype again later and it was set up how he wanted it.

Joseph Smith

After the death of Reginald Joseph Mitchell, development of the Spitfire would be headed up by Joseph Smith. Born on the 25th May 1897, Smith, who had been working under Mitchell, would be involved with all variants of the type. Joseph Smith died on the 20th February 1956 aged 58.

Entered Service

The Spitfire began to enter Royal Air Force service on the 4th August 1938 when No. 19 Squadron, RAF Duxford took delivery of the first Mk IA (K9789). These would be a fry cry from the Gloster Gauntlet biplanes they were using at the time.

High Speed Spitfire

A converted Mk I (K9834) fitted with a 2,160-hp Rolls-Royce Merlin 3M engine was to try and beat the air speed record of 440.68 mph set on the 23rd October 1934 by Francesco Agello in a Macchi M.C. 72. Known as the High Speed Spitfire (N.17) it would never make an attempt as before it was ready the Heinkel He 100 V8 reached 463.91 mph (30th March 1939) and then the Messerschmitt Me 209 V1 achieved a speed of 469.22 mph (28th April 1939) and put the record out of its reach. It would be converted to a PR Mk I then a PR Mk II serving in the photo reconnaissance role for the duration of the Second World War.

First Aerial Victory Over Britain of the Second World War

No. 602 Squadron Spitfires flown by Flight Lieutenant George Pinkerton and Flying Officer Archie McKellar intercepted a Junkers Ju 88 over the Firth of Forth on the 16th October 1939 and although both pilots attacked the aircraft the victory was given to Flight Lieutenant Pinkerton. Nearby that same day a Spitfire of No. 603 Squadron flown by Flight Lieutenant Pat Gifford also shot down a Ju 88. These would be the first German aircraft shot down during the Second World War over Britain and to be shot down by the Spitfire.

Spitfires in France During 1939

One Spitfire PR Mk IA would be sent to France during November 1939, followed by a Spitfire PR Mk IB. Both would only be used for reconnaissance duties as part of the ‘Special Survey Flight’. They undertook their first successful operational sortie on the 22nd November 1939, when the Spitfire PR Mk IA, flown by Flight Lieutenant Maurice Longbottom, flying from Coulommiers, France, photographs Eupen-Elsenborn, Belgium. These would have the distinction of being the first Spitfires to serve overseas.

Spitfire vs Messerschmitt Bf 109

The Spitfire Mk I and Bf 109E had their first combat engagement on the 23rd May 1940. This saw Nos. 54 and 74 Squadron engage Messerschmitt Bf 109Es of I./JG 27.

Presentation Spitfires

As the aircraft began to enter public consciousness, May 1940 saw the creation of ‘Spitfire Funds’. From a single rivet costing sixpence to a whole aircraft at £5,000, although the true cost of a Spitfire was more. Everyone from the public to businesses could donate, and if you could afford a whole Spitfire, you could dedicate it, such as Lloyds Bank, who named theirs ‘The Black Horse’. In total, around 13 million pounds was raised at the time.

Highest Aerial Battle of the Second World War

Taking-off from RAF Northholt on the 12th September 1942 a Special Service (High Altitude) Flight Spitfire Mk IX (BS273) was vectored to the skies above Southampton. It would end up in an engagement with a Junkers Ju 86R at 43,000 ft, the highest aerial battle of the war.

First Jet Aircraft Victory

When the Messerschmitt Me 262 entered service with the Luftwaffe during 1944 it was the first jet fighter to enter operational service. When a Spitfire Mk IX of No. 401 Squadron, Royal Canadian Air Force shot one down on the 5th October that same year it was the first aerial victory by an Allied piston-engined aircraft over a Luftwaffe jet aircraft.

Top British RAF Ace of the Second World War

With 34 victories, 14 Messerschmitt Bf 109s and 20 Focke-Wulf Fw 190s, James Edgar ‘Johnnie’ Johnson would end the war as the Royal Air Force’s top scoring British pilot. He would score all his victories in four different Spitfire variants. Mk I, Mk II, Mk V and Mk IX.

Pink Spitfires

During the Second World War a number of photo reconnaissance Spitfires were painted in light pink. These would operate mainly at dawn and dusk to blend in with the clouds at this time, flying just underneath them. This colour made the aircraft harder to spot from the ground but had the opposite effect when looking down on the Spitfire from above, making it easier for enemy aircraft to spot it.

Beer Delivery

After the invasion of France during June 1944 it was difficult for Allied service personnel to get hold of luxuries such as beer. As a result some Spitfires were modified to hold beer kegs in their underwing pylons, normally used for bombs, or had their external fuel tanks converted to hold beer, and unofficially known as the Spitfire Mk XXX. Due to the cold air at altitude if the pilot flew high enough the beer was ready to serve on landing.

Naval Spitfire

Entering service with the Royal Navy’s Fleet Air Arm on the 15th June 1942, the Supermarine Seafire, as the naval version was known, would remain in service with the Fleet Air Arm until the 23rd November 1954, when No. 764 Naval Air Squadron, who were using the type, disbanded. During its time in service, the Seafire would take part in one of the last dogfights of the Second World War on the 15th August 1945 and would see combat during the Korean War (1950 – 1953).

Supermarine Spiteful

During June 1944 a Spitfire Mk XIV fitted with a laminar flow wing made its first flight. This new aircraft, to be known as the Spiteful, was intended as a successor for the Spitfire. However the advent of the jet age and the aircraft’s less than expected performance meant it would never enter operational service.

Spitfire Users

A total of 33 air forces would use the aircraft, this included the United States, who received approximately 600 Spitfires, and the Soviet Air Force, who had 1,331 delivered to them, who used them during the Second World War. Post-war a small number were used for photo reconnaissance and as fighters by the Royal Danish Air Force and the Swedish Air Force used them only in the photo reconnaissance role.

MesserSpit

After making a forced landing in Jersey Spitfire Mk VB (EN830) flown by Pilot Officer Bernard Scheidhauer, No. 131 Squadron was repaired and fitted with a Daimler-Benz DB 605A engine by the Luftwaffe. It would then undergo comparison tests against a Bf 109G which was powered by the same engine. No details of the tests are known.

Total Built

20,334 Spitfires would be built. The first was a Spitfire Mk IA (K9787) which made its maiden flight on the 14th May 1938 fitted with a 1,030-hp Rolls-Royce Merlin II engine. This was serving with a Photographic Reconnaissance Unit when it was lost on an operation on the 30th June 1941. The last production version would be a Spitfire F.24 (VN496) and this made its first flight on the 24th February 1948 and was powered by a Rolls-Royce Griffon engine, this would be struck off charge on the 15th December 1950.

Highest Spitfire Flight

On the 5th February 1952 a No. 81 Squadron Spitfire Mk XIX piloted by Flight Lieutenant Edward Powles was undertaking metrological reconnaissance when it reached a height of 51,550 ft whilst over Hong Kong.

Last Operational Sortie

The last operational sortie by a Spitfire was made by a No. 81 Squadron, RAF Seletar Spitfire PR XIX (PS888) on the 1st April 1954, with ‘The Last’ painted on one side of the engine cover. This aircraft was then sold to the Royal Thai Air Force two months later.

Last RAF Spitfire Flight

Serving with the Temperature and Humidity Flight, RAF Woodvale it would be Spitfire Mk XIX (PS915) that made the last flight by a Spitfire whilst in active service with the Royal Air Force when it performed its last sortie on the 10th June 1957. This aircraft is still flying today with the RAF Battle of Britain Memorial Flight.

Spitfire vs Lightning

During 1963 a Spitfire PR XIX would be used in trials against the English Electric Lightning to help Lightning pilots develop combat tactics against piston-engined aircraft. This was because the Lightning may have been involved in combat against Indonesian Air Force North American P-51 Mustangs during the Indonesia – Malaysia Confrontation (1963 – 1966).

The aircraft was painted black, and soon earned its name: “Blackbird.”

At Lockheed’s advanced development group, the legendary Skunk Works in Burbank, work on a revolutionary intelligence aircraft had already begun before the shooting down of Gary Power’s U-2. This innovative aircraft had to fly faster than any aircraft before or since, at greater altitude, and with a minimal radar cross section (RCS).

President Eisenhower deeply valued the strategic benefits of the U-2’s airborne reconnaissance during these tense Cold War times. And now the call came from Lockheed’s customer in Washington to build the impossible – an aircraft that can’t be shot down – and do it fast.

As explained in the article Creating The Blackbird appeared on Lockheed Martin website, Kelly Johnson, one of the preeminent aircraft designers of the twentieth century, and his Skunk Works team had a track record of delivering “impossible” technologies on incredibly short, strategically critical deadlines.

However according to Johnson this new aircraft was in a different category from anything that had come before. “Everything had to be invented. Everything,” he said. He committed Skunk Works to succeed in its toughest assignment to date: to have the innovative, challenging, envelope-bursting aircraft flying in a mere twenty months.

The speed of the new aircraft was to exceed 2,000 mph. Even if other planes of the era could approximate that speed but only in short, after-burner-driven bursts, this new plane needed to maintain a record-setting speed for hours at a time. At such velocity, friction with the atmosphere generates temperatures that would melt the conventional airframe.

With anticipated temperatures on the aircraft’s leading edges exceeding 1,000 degrees Fahrenheit, dealing with the heat raised a host of seemingly insurmountable design and material challenges. The only option to overcome these problems was to use titanium alloy which would have provided the strength of stainless steel, a relatively light weight, and durability at the excessive temperatures.

Titanium, however, proved to be a particularly sensitive material from which to build an airplane. The brittle alloy shattered if mishandled, which meant great frustration on the Skunk Works assembly line, and new training classes for Lockheed’s machinists.

Furthermore while friction would generate incredible heat at the leading edges of the aircraft, the ambient temperature outside the cockpit window would be -60 degrees Fahrenheit. Skunk Works’ Ben Rich spent untold hours tackling the problem of how heat could be dissipated across the entire airframe. Then he recalled a simple lesson from one of his university courses: Black paint both emits and absorbs heat. The aircraft was painted black, and soon earned its name: “Blackbird.”

The original Blackbird was designated the A-12 and made its first flight on Apr. 30, 1962. The single-seat A-12 soon evolved into the larger SR-71, which added a second seat for a Reconnaissance Systems Officer and carried more fuel than the A-12. The SR-71’s first flight was on Dec. 22, 1964.

Reducing the size of the Blackbird’s radar image meant an even further reduction in the likelihood that the plane would be perceived and shot down. Even though the initial test results were good, rumors of Soviet radar advances led the U.S. government to ask for an even smaller radar profile.

Surfaces had to be redesigned to avoid reflecting radar signals, the engines moved to a subtler mid-wing position, and a radar-absorbing element was added to the paint. Then a full-scale model of the Blackbird was hoisted on a pylon for radar testing at a Skunk Works’ secret location in the Nevada desert. With tests carefully scheduled to avoid Soviet satellite observations, the results were impressive: The Blackbird model, more than 100 feet in length, would appear on Soviet radar as bigger than a bird but smaller than a man. The team had succeeded in reducing radar cross section by 90 percent.

The pressure mounted to deliver the Blackbird to service on Oct. 27, 1962 when, at the height of the Cuban missile crisis, Air Force Major Rudolph Anderson was piloting a U-2 reconnaissance mission over Cuba and suffered a fatal injury from a Soviet surface-to-air strike.

Skunk Works responded, diligently and creatively persisting through the many problems that arose as flight testing pushed the envelope. Breaking records nearly every time it flew, the Blackbird achieved a sustained speed above Mach 3 on July 20, 1963, at an astounding altitude of 78,000 feet. The challenges kept coming: Zipping across the sky at 3,000 feet per second, the rules of navigation needed be rewritten. Visual references for conventional flying—highways, rivers, and metropolitan areas—were rendered obsolete, giving way to mountain ranges, coast lines, and large bodies of water.

Piloting the Blackbird was an unforgiving endeavor, demanding total concentration. But pilots were giddy with their complex, adrenaline-fueled responsibilities. “At 85,000 feet and Mach 3, it was almost a religious experience,” said Air Force Colonel Jim Wadkins. “Nothing had prepared me to fly that fast… My God, even now, I get goose bumps remembering. ”