This Date in Aviation History: June 17 - June 19

"ttyymmnn" (ttyymmnn) 06/19/2020 at 12:35 • Filed to: wingspan, Planelopnik, TDIAH

9

20

!!! UNKNOWN CONTENT TYPE !!!

Welcome to This Date in Aviation History , getting of you caught up on milestones, important historical events and people in aviation from June 17 through June 19.

!!! UNKNOWN CONTENT TYPE !!!

June 17, 1959 – The first flight of the Dassault Mirage IV. The world entered the atomic age in 1945 when the United States !!!error: Indecipherable SUB-paragraph formatting!!! on Hiroshima and Nagasaki in the hopes that it would hasten the end of WWII. For a time, the US had a monopoly on nuclear weapons, but it wasn’t long before the Russians fielded an operational bomb of their own in 1949. The Soviets were quickly followed by England. But in the days before the first !!!error: Indecipherable SUB-paragraph formatting!!! , the only way to deliver a nuclear bomb to an enemy target was with a deep penetration bomber, one that could fly high and fast into enemy territory in the hopes of evading enemy interceptors and antiaircraft fire.  

In 1954, French Prime Minister Pierre Mendès France decided that his country needed its own nuclear arsenal to put it on par with the United States, the Soviet Union, and Great Britain. France initiated development of a three-pronged nuclear deterrence ( Force de frappe, later called Force de dissuasion ) that would include land, sea, and air assets each capable of carrying out nuclear attacks. In 1957, work began on a supersonic bomber capable of carrying a nuclear weapon, and Dassault offered the Mirage IV, which was a substantially enlarged version of their single-engine !!!error: Indecipherable SUB-paragraph formatting!!! fighter. Where the Mirage III was powered by a single engine, the Mirage IV was powered by two !!!error: Indecipherable SUB-paragraph formatting!!! afterburning turbojets capable of pushing the bomber to a top speed of Mach 2.2. The wing surface was doubled over that of the fighter, and the wing was also made much thinner than the Mirage III for high-speed performance. It could be armed with either a single free-fall nuclear bomb, a single nuclear missile, or 16 conventional bombs. Though the Mirage IV carried three times more fuel than its predecessor, its armed range of 670 miles was still less than the Mirage III, and would have required multiple refuelings in the event that it had to reach deep inside the Soviet Union. And, if the nuclear mission had to be carried out, it would have been a one-way trip. The aircraft would not have had sufficient fuel to return, and even if it could, its home bases would likely have been annihilated.

A Mirage IV carries out a reconnaissance mission over Kuwait during the Gulf War of 1991 (US Air Force)

The Mirage IV entered service in October 1964 as the first element of France’s nuclear triad, with 36 aircraft forming nine squadrons of four aircraft each. To carry out their missions, the Mirages worked in pairs, with one aircraft carrying a nuclear weapon while the other served as a tanker to refuel the attack aircraft. At the height of operations, there were always at least 12 aircraft in the air, with 12 more on the ground ready to deploy in four minutes should the need arise. The other twelve could be readied within 45 minutes. For seven years, the Mirage IV was France’s only means of delivering a nuclear weapon, as the land and sea components of the Force de dissuassion were not available until 1971. Dassault produced a total of 62 aircraft, and the Mirage IV served in the nuclear deterrence role until it was superseded by strategic nuclear missiles. The bomber variants were retired in 1996, though the reconnaissance versions served until 2005.

!!! UNKNOWN CONTENT TYPE !!!

An F-117 drops a laser-guided bomb on a test mission over California (US Air Force)

June 18, 1981 – The first flight of the Lockheed F-117 Nighthawk. Though the Nighthawk is very much a product of 20th century technology, the radar detection it was meant to avoid traces its history back to a time 100 years earlier. In 1886, German physicist !!!error: Indecipherable SUB-paragraph formatting!!! (for whom the eponymous !!!error: Indecipherable SUB-paragraph formatting!!! is named) discovered that radio waves could be reflected back from solid objects. In 1904, another German, the inventor !!!error: Indecipherable SUB-paragraph formatting!!! , found a way to use radio waves to detect metal objects. By WWII, radar (which is actually an acronym for radio detection and ranging ) was used by the British Royal Air Force to detect incoming German bombers, and radars were installed on aircraft to direct bombers to targets and to create the first night fighters. Following the war, development of radar technology made the sets ever more powerful, with increased range and the ability to track ever smaller targets. But what if you could make an aircraft that was invisible to radar, or at least one that had a !!!error: Indecipherable SUB-paragraph formatting!!! (RCS) so small that a large aircraft appeared the size of a small bird? While not truly invisible, it would be impossible to detect the aircraft out of all the other normal clutter on a radar screen.

The Have Blue technology demonstrator (US Air Force)

The idea that an aircraft might be made nearly invisible to radar was first proposed by Russian mathematician !!!error: Indecipherable SUB-paragraph formatting!!! in 1964, though the shapes necessary rendered the concept impossible at the time because the aircraft would be unflyable. It wasn’t until fly-by-wire flight control computers became more sophisticated that the idea could finally become a reality. The Nighthawk program began with work led by engineer !!!error: Indecipherable SUB-paragraph formatting!!! at Lockheed’s !!!error: Indecipherable SUB-paragraph formatting!!! on a technology demonstrator known as the Hopeless Diamond, a nickname derived from the shape of the aircraft because nobody believed it would ever fly. On paper, Lockheed engineers believed that the new design would be 1,000 times less visible than any other aircraft ever created at Lockheed, and would show up on a radar screen as an object about the size of a marble. In 1976, the Air Force awarded a contract to develop the !!!error: Indecipherable SUB-paragraph formatting!!! project, the stealth demonstrator that proved the concept and eventually led to development of the F-117 Nighthawk.

The flat, angled facets which deflect radar signals are clear in this head-on view of the F-117. (US Air Force)

The Nighthawk is instantly recognizable by its faceted shape, a series of flat surfaces that never join at a right angle. This myriad of differently angled flat surfaces works to reflect radar energy away from, rather than back to, the radar receiver. Special !!!error: Indecipherable SUB-paragraph formatting!!! coatings are also used to keep the radar signals from bouncing off the aircraft. But radar isn’t the only way to track an aircraft. The heat signature from jet engines is also easily detectable, so the Nighthawk’s engines are buried deep within the aircraft. This placement, however, ruled out the use of afterburners and limited the Nighthhawk to subsonic speeds. The F-117 also relied on redundant, fly-by-wire flight controls that make thousands of corrections per second. Without this system, the aircraft would simply tumble out of control.

Though given the “F” designation for fighter, the Nighthawk was strictly an attack platform for dropping guided bombs or missiles, and has no gun, either internal or external. After being revealed to the public in 1988, the F-117 made its combat debut in 1989 during the US !!!error: Indecipherable SUB-paragraph formatting!!! . Nighthawks saw extensive action in the 1991 !!!error: Indecipherable SUB-paragraph formatting!!! , where they flew the first missions of the war to knock out Iraqi radar sites and eventually took part in nearly 1,400 sorties. Though a number of Nighthawks have been lost to accidents, only one was ever lost in combat when it was !!!error: Indecipherable SUB-paragraph formatting!!! in 1999 during NATO operations over Serbia. Despite the F-117's stealthy design, Russian radar operators, using modified radars, discovered they could detect the Nighthawk when its landing gear or bomb bay doors were open. The plane came down relatively intact, and the Serbians invited the Russians and Chinese to inspect the wreckage and gain valuable information on American stealth technology.

Four Nighthawks from the 410th Flight Test Squadron fly in formation in 2007. One of these aircraft is on display, and another was broken up in 2008. The other two were placed in storage, and may well still be flying to this day. (US Air Force)

Lockheed produced a total of 64 Nighthawks, and the F-117 was officially retired in 2008. However, observers have reported continuing flights of F-117s over the US Air Force’s super-secret testing site at Groom Lake in Nevada, popularly known as !!!error: Indecipherable SUB-paragraph formatting!!! , and even more !!!error: Indecipherable SUB-paragraph formatting!!! have occurred over the West Coast of the US. No official explanation has been given for the flights, but it is likely that the Nighthawks are playing the role of stealthy adversaries for Air Force and/or Navy flight training.

!!! UNKNOWN CONTENT TYPE !!!

June 19-20, 1944 –   The Battle of the Philippine Sea. The use of the airplane in warfare began in WWI, and by WWII it had become a formidable weapon. The Japanese demonstrated the enormous power of carrier-based warplanes with the surprise !!!error: Indecipherable SUB-paragraph formatting!!! , and the ensuing !!!error: Indecipherable SUB-paragraph formatting!!! and !!!error: Indecipherable SUB-paragraph formatting!!! showed that the airplane had replaced the battleship as the center of power in the modern naval battle group. In both battles, no two surface ships ever fired a shot at each other, and Midway proved to be a turning point in the Pacific War, with a decisive American victory finally putting the brakes on what had been a relentless Japanese advance. Though they lost four carriers at Midway, Japanese naval aviation wasn’t utterly destroyed, though it was severely hobbled. There remained one more epic carrier battle to be fought. Coming two years after the pivotal Battle of Midway, the Battle of the Philippine Sea, the largest carrier battle in history, proved to be the last gasp for Japanese naval air power in WWII.

In the summer of 1944, American forces launched their !!!error: Indecipherable SUB-paragraph formatting!!! campaign to take the Japanese-held islands of Tinian, Saipan, and Guam in the !!!error: Indecipherable SUB-paragraph formatting!!! . The Japanese, despite their losses at Midway, were still able to assemble a fleet that included five heavy carriers, four light carriers, five battleships, 11 heavy cruisers, two light cruisers, and 28 destroyers to contest the American advance toward the Japanese homeland. To counter the Japanese fleet, the Americans had !!!error: Indecipherable SUB-paragraph formatting!!! , one of the most powerful armadas ever assembled. Under the command of Admiral !!!error: Indecipherable SUB-paragraph formatting!!! , TF 58 included seven heavy carriers, eight escort carriers, seven battleships, eight heavy cruisers, 13 light cruisers and 69 destroyers. On June 16, a US submarine discovered the Japanese fleet off the coast of the Philippines as they turned to face the Americans. Mitscher divided his fleet into four carrier task groups and one battleship task group, while the Japanese divided their fleet into four groups based around their carriers.

Japanese scout planes spotted the American fleet on the morning of June 19 and launched the first attack. However, American radar detected the planes 50 miles away from the fleet, and American fighters were waiting for them when they arrived. In the ensuing battle, more than 200 Japanese planes were shot down against the loss of only 23 US aircraft. Meanwhile, US submarines had located the main body of the Japanese fleet. First, the carrier !!!error: Indecipherable SUB-paragraph formatting!!! was struck with torpedoes, and then the carrier !!!error: Indecipherable SUB-paragraph formatting!!! , which sank four hours later. The Japanese attacked again, but the planes flew in the wrong direction. Nevertheless, the attackers were detected and annihilated by American fighters.

By the end of the battle on June 20, roughly 600 Japanese aircraft had been destroyed, earning the battle the nickname “The Great Marianas Turkey Shoot.” Along with the huge loss of aircraft, the Japanese Navy lost three carriers and an estimated 3,000 dead. The Americans suffered one damaged battleship, 123 aircraft lost, and 109 dead. Though it might have been possible for the Japanese to replace their aircraft, the losses in experienced pilots was a blow from which they would never recover. Even though Japan still had carriers, they no longer had the men or planes to operate effectively from their decks, and the once-proud ships were reduced to the role of a diversionary force four months later in the !!!error: Indecipherable SUB-paragraph formatting!!! , which resulted in another decisive victory for the US and her allies.

!!! UNKNOWN CONTENT TYPE !!!

Short Takeoff

!!! UNKNOWN CONTENT TYPE !!!

(US Air Force)

June 17, 1986 – The final flight of the Boeing B-47 Stratojet. When   the final !!!error: Indecipherable SUB-paragraph formatting!!! (52-0166) was restored to flying status for a one-time ferry flight from Naval Weapons Center China Lake to Castle Air Force Base in California for museum display, it marked the end of one of the most influential designs of the early jet era. Following a 1944 US Air Force request for a new jet-powered bomber, the B-47 entered service with the !!!error: Indecipherable SUB-paragraph formatting!!! in 1951. By 1956, there were 28 wings of B-47 bombers and five wings of RB-47 reconnaissance variants, with many staged at forward bases as part of America’s nuclear deterrence policy. Though the Stratojet never saw combat, it remained the mainstay of SAC’s bomber force into the 1960s. Over 2,000 were produced, and the EB-47E electronic countermeasures variant served until 1977.

!!! UNKNOWN CONTENT TYPE !!!

(Author unknown)

June 17, 1961 – The first flight of the HAL HF-24 Marut ( Spirit of the Tempest ), a twin-engine fighter bomber designed by former Focke-Wulf designer !!!error: Indecipherable SUB-paragraph formatting!!! and the first jet aircraft developed and built in India. Though designed for Mach 2 flight, the lack of a sufficiently powerful engine meant that the Marut could barely reach Mach 1, and following the successful detonation of India’s !!!error: Indecipherable SUB-paragraph formatting!!! , import restrictions prevented more powerful engines from being fitted. The Marut did see some action as a ground attack aircraft, and during the !!!error: Indecipherable SUB-paragraph formatting!!! , an Indian pilot flying an HF-24 claimed a victory over a Pakistani !!!error: Indecipherable SUB-paragraph formatting!!! . A total of 147 Maruts were built, and the type was retired in 1985.

!!! UNKNOWN CONTENT TYPE !!!

June 17, 1955 – The first flight of the Tupolev Tu-104, (NATO reporting name Camel ), the world’s first successful jet-powered airliner. Though the !!!error: Indecipherable SUB-paragraph formatting!!! had flown first, the Comet was withdrawn from service in 1954 due to a series of fatal crashes and did not return to service until 1958. !!!error: Indecipherable SUB-paragraph formatting!!! based the Tu-1o4 on the !!!error: Indecipherable SUB-paragraph formatting!!! bomber, and when the Tu-104 arrived in London in 1956 it caused much consternation in the West because nobody believed that the Soviets had the technology to produce a modern airliner. The Tu-104 entered service with Czechoslovak Airlines in 1957, and while it had a safety record comparable to other airliners of the time, a series of crashes led to its retirement on commercial routes in 1979, and it was removed from military service the following year .

!!! UNKNOWN CONTENT TYPE !!!

June 17, 1928 – Amelia Earhart becomes the first woman to cross the Atlantic Ocean in an airplane. Though best known for her !!!error: Indecipherable SUB-paragraph formatting!!! while attempting a circumnavigation of the globe in 1937, Earhart made headlines in 1928 as the first woman to cross the Atlantic Ocean in an airplane, though she did so as a passenger. In response to !!!error: Indecipherable SUB-paragraph formatting!!! famous crossing the previous year, Earhart accompanied pilot !!!error: Indecipherable SUB-paragraph formatting!!! and copilot/mechanic Louis Gordon on a 22-hour flight from Newfoundland eastward to Wales flying a !!!error: Indecipherable SUB-paragraph formatting!!! trimotor. Since the flight was made on instruments, Earhart never did any flying during the trip, though on landing, she did tell an interviewer, “...maybe someday I’ll try it alone.” Earhart made her own solo Atlantic crossing in 1932.

!!! UNKNOWN CONTENT TYPE !!!

(NASA)

June 18, 1983 – Sally Ride becomes the first American woman to fly in space. Ride joined NASA in 1978 and went to space in 1983 as a Mission Specialist on board Space Shuttle !!!error: Indecipherable SUB-paragraph formatting!!! on !!!error: Indecipherable SUB-paragraph formatting!!! , 20 years after the first woman in space, cosmonaut !!!error: Indecipherable SUB-paragraph formatting!!! . At age 32, Ride was also the youngest American and the first LGBT astronaut to fly in space. She went to space a second time the following year, again on Challenger , as a Mission Specialist on !!!error: Indecipherable SUB-paragraph formatting!!! . Ride left NASA in 1987, but served on the investigation committees into the !!!error: Indecipherable SUB-paragraph formatting!!! and !!!error: Indecipherable SUB-paragraph formatting!!!   disasters. After teaching physics at the University of California, San Diego, Ride died of pancreatic cancer in 2012 at age 61.

!!! UNKNOWN CONTENT TYPE !!!

June 18, 1928 – Explorer Roald Amundsen and his crew disappear in the Arctic. !!!error: Indecipherable SUB-paragraph formatting!!! was a famed explorer of the Earth’s polar regions and became the first to reach the South Pole in 1911. On May 25, 1928 the airship !!!error: Indecipherable SUB-paragraph formatting!!!   crashed in the Arctic Ocean while flying around the North Pole, and Amundsen and his crew of five left Tromsø, Norway in a !!!error: Indecipherable SUB-paragraph formatting!!! floatplane to search for survivors. Flying across the Barents Sea, the aircraft disappeared without a trace. Two months later a piece of a float was found washed ashore, then three months later a gas tank washed ashore. The bodies of Amundsen and his crew were never found.

!!! UNKNOWN CONTENT TYPE !!!

(Authors unknown)

June 18, 1916 – The death of Max Immelmann. Immelmann was the first German ace of WWI, and the first to be awarded the !!!error: Indecipherable SUB-paragraph formatting!!! , one of the highest awards of the !!!error: Indecipherable SUB-paragraph formatting!!! . He is credited with the creation of the !!!error: Indecipherable SUB-paragraph formatting!!! that bears his name, and had scored 15 victories by the time of his death. Immelmann was one of the first to make use of the !!!error: Indecipherable SUB-paragraph formatting!!! developed by !!!error: Indecipherable SUB-paragraph formatting!!! which allowed the pilot to fire directly through the arc of the fighter’s propeller. Ironically, Immelmann’s death resulted from a malfunction of the device, when he shot away the propeller of his !!!error: Indecipherable SUB-paragraph formatting!!!   Eindecker monoplane and crashed.

!!! UNKNOWN CONTENT TYPE !!!

June 19, 2002 – Adventurer Steve Fossett takes off on the first solo balloon circumnavigation of the Earth. !!!error: Indecipherable SUB-paragraph formatting!!! departed from Northam, Western Australia on June 19 in a balloon named Spirit of Freedom , and flew eastward across the Pacific Ocean, over Chile and Argentina, then across the southern Atlantic Ocean to South Africa and then across the southern Indian Ocean, arriving back in Australia on July 4. The flight covered 20,626 miles and set numerous distance and flight longevity records. Fossett made other world record flights, including the first solo, nonstop circumnavigation of the Earth in the !!!error: Indecipherable SUB-paragraph formatting!!! . Fossett died in the crash of his private plane on September 3, 2007.

!!! UNKNOWN CONTENT TYPE !!!

Connecting Flights

!!! UNKNOWN CONTENT TYPE !!!

!!! UNKNOWN CONTENT TYPE !!!

!!! UNKNOWN CONTENT TYPE !!!

!!! UNKNOWN CONTENT TYPE !!!

!!! UNKNOWN CONTENT TYPE !!!

If you enjoy these Aviation History posts, please let me know in the comments. You can find more posts about aviation history, aviators, and aviation oddities at !!!error: Indecipherable SUB-paragraph formatting!!! .

!!! UNKNOWN CONTENT TYPE !!!

SBA Thanks You For All The Fish > ttyymmnn 06/19/2020 at 12:42

2

As usual, great piece!  I STILL have to make it up to Castle AFB’s Museum-- it’s supposed to be phenomenal.  

WasGTIthenGTOthenNOVAnowbacktoGTI > ttyymmnn 06/19/2020 at 12:44

2

If anyone is reading this post and hasn’t read Skunkworks , you’re missing out.

ttyymmnn > SBA Thanks You For All The Fish 06/19/2020 at 12:47

1

I’ve got a long list of museums I want to go to. The US Navy museum is perhaps on the top. I really want to go back and spend a few hours at Udvar-Hazy. Last time I only had about an hour. 

SBA Thanks You For All The Fish > ttyymmnn 06/19/2020 at 12:52

1

I “think” the new Silver Line Extension, which is proceeding pretty well, will make it a lot easier to get out to U/H. I got half a day last time I was out there and it wasn’t nearly enough. Plus, they have the AFM issue that so much great stock is not on display, either...

Hey! I drove from Texarkana to Dallas on I-30 the other day, during my coast to coast drive... and some “aircraft surplus guy” out there has an F-111 on display. I was shocked to see one in private hands. Have you been up there?  It’s right next to the freeway

user314 > ttyymmnn 06/19/2020 at 13:02

1

Dear God, the crash of the Italia   and the attempted rescues were a nightmare:

It crashed in 1928, with one confirmed fatality from the crash, one fatality from exposure while awaiting rescue, and the death of six crew members who were trapped in the still-airborne envelope. At the end of the rescue operations there were 17 dead (crew and rescuers).

The lack of co-ordination meant that it took more than 48 days before all of the crash survivors (and the stranded would-be rescuers) were retrieved. 

ttyymmnn > SBA Thanks You For All The Fish 06/19/2020 at 13:02

0

We have driven past that a/c (and seen it) a couple of times on road trips out of Austin.

We did drive past this a couple of weeks ago. It’s outside the gate at the Burnet Municipal Airport. Sadly, this is the airport where the C-47 Bluebonnet Belle crashed last year. I have a lot of photos of the Belle from her airshow days. She was a beauty.

ttyymmnn > user314 06/19/2020 at 13:06

1

Reminds me of the 13 men lost while searching for Flight 19.

SBA Thanks You For All The Fish > ttyymmnn 06/19/2020 at 13:07

0

Shame about the C-47.

I guess the F111 is a landmark...

http://www.f-16.net/forum/viewtopic.php?f=46&t=25220

user314 > ttyymmnn 06/19/2020 at 13:15

1

I mean, it’s easier to lose 13 people when they’re on the same plane. Curious how the loss of Flight 19 has basically been explained, but 59225 is just assumed to be the result of a mid-air explosion with no further explanation .  

ttyymmnn > SBA Thanks You For All The Fish 06/19/2020 at 13:15

0

As long as we’re talking about stray F-111s, there’s this one at the airport in Brownwood, TX along US 183.

I drove past these two planes for 23 years on my way to and from Abilene (I used to play in the orchestra up there) but I never stopped to check them out. 

ttyymmnn > user314 06/19/2020 at 13:22

0

Did those PB Ms have a tendency to go full Curtiss Commando and just blow up randomly in midair?

SBA Thanks You For All The Fish > ttyymmnn 06/19/2020 at 13:35

0

Dyess AFB!!   Just drove past Abilene on the way west myself...

TheRealBicycleBuck > ttyymmnn 06/19/2020 at 13:47

2

It’s hard to see the 117 and not think of the “bird” story. They say that in the initial radar tests the return signature was so low that the radar operator thought the model fell off the pole. When someone opened the bunker door to check, a bird landed on the model and the radar operator said, “never mind, I’ve got it!”

I ’ve seen several variations of that tale, but they all have one common thread - that aircraft is really hard to see on radar.

ttyymmnn > SBA Thanks You For All The Fish 06/19/2020 at 14:01

0

When I would go to Abilene (seven times a year), I spent all my free time out by the base. T here is a road, appropriately numbered TX 707, that runs along the west side of the base, and there is a public park, Rister Park, that is right near the north end of the runway. My leisure time was spent there, smoking cigars, doing crossword puzzles, and watching the planes. Not surprisingly, it was a steady stream of Bones and Herks, but there were occasional surprises. Saw my one and only EA-6B take off from there—it was loud as hell. My most interesting catch was this E-4B , and I also got some really nice shots of a US Navy P-8.

https://tshaff.smugmug.com/Aviation/Dyess-Air-Force-Base/

https://tshaff.smugmug.com/Aviation/P-8A-Poseidon/

user314 > ttyymmnn 06/19/2020 at 14:02

1

Not that I can see. It was under-powered , with a nasty habit of submarining during landings, but I’m not seeing a lot of them lost due to explosion. 

John Norris (AngryDrifter) > ttyymmnn 06/19/2020 at 14:26

1

Of course the Im melman had to be named after a guy named Im melman, but I didn’t  put it together that he was  WWI era. Amazing. Thanks. As always, great post.

John Norris (AngryDrifter) > ttyymmnn 06/19/2020 at 14:35

0

John Norris (AngryDrifter) > WasGTIthenGTOthenNOVAnowbacktoGTI 06/19/2020 at 14:41

1

Ball bearing.

ttyymmnn > John Norris (AngryDrifter) 06/19/2020 at 14:43

0

Perhaps you edited, but your comment showed up on my dashboard, but not here. Regardless, I would be one of those people sitting in the cockpit and making helicopter noises. 

John Norris (AngryDrifter) > ttyymmnn 06/19/2020 at 15:23

1

Entering it on the phone it looked like it posted in the wrong spot. I think I got Ki nj a’d. Glad y ou got the message.

I’m certain I performed at least one Immelmann in one of those cockpits with full engine and guns audio. The n casually walked back over by the other adults and watched the kids play.