This Date in Aviation History: August 10 - August 12

"ttyymmnn" (ttyymmnn)
08/12/2016 at 12:36 • Filed to: planelopnik, planelopnik history

Welcome to This Date in Aviation History , getting of you caught up on milestones, important historical events and people in aviation from August 10 - August 12.

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August 12, 1985 – The crash of Japan Airlines Flight 123. In our modern world of jet aviation, cabin pressurization is taken for granted. Using bleed air from the engine at the compressor stage, aircraft flying 35,000 feet above the ground are pressurized to maintain the same air pressure inside the cabin as if it were flying at no more than 8,000 feet (the FAA mandates a maximum of 8,000 feet, while most airliners maintain 6000-7000 feet, and some business jets can maintain sea-level pressure). But pumping that much air into the fuselage puts stress on the aircraft, and repeated compressions and decompressions can weaken an aircraft over time. This lesson was first learned when a series of fatal, explosive decompressions plagued the world’s first jet-powered airliner, the !!!error: Indecipherable SUB-paragraph formatting!!! , in the 1950s. For the enjoyment of the flying public, de Havilland fitted the Comet with large, rectangular windows. After the crashes, investigators discovered that the cyclical compression and decompression of the aircraft caused metal fatigue and cracks around the large windows, which then led to fatal aircraft breakups. The Comet was redesigned to use oval windows, which became an industry standard. One critical component of pressurization is the rear pressure bulkhead, a circular, dome-shaped structure that closes off the aft end tube of the passenger compartment from the rest of the !!!error: Indecipherable SUB-paragraph formatting!!! . This bulkhead must be regularly and rigorously inspected and, if damaged, must be repaired precisely to the standards set by the manufacture. But that was not the case with Japan Airlines Flight 123, a !!!error: Indecipherable SUB-paragraph formatting!!! (JA8119) that had taken off from Haneda Airport in Tokyo for a short, one-hour flight to Osaka International Airport. Twelve minutes after takeoff, the aft pressure bulkhead ruptured, leading to a rapid depressurization of the aircraft and the loss of most of the vertical stabilizer. When the stabilizer broke free, it ruptured all four hydraulic lines, leaving the plane almost completely uncontrollable. Captain Masami Takahama, a veteran 747 pilot with over 12,000 hours of flight time (4,850 in the 747), along with his flight crew, managed to regain some measure control using engine throttle inputs. Their skilled piloting kept the plane in the air for 32 minutes, long enough for many of the passengers to write farewell notes to their families. When the plane eventually crashed in the mountains near Mount Osutaka, 505 passengers and crew were killed, making it the deadliest single-aircraft accident in history. Four passengers survived, and it is surmised that more may have lived had the Japanese government acted more quickly to reach the crash site.

The cause of the bulkhead rupture was traced to an improper repair following a tail strike seven years earlier which had damaged the bulkhead. Rather than provide a redundant overlap of the bulkhead sections as dictated by Boeing, technicians in Japan instead used two separate splice plates, leaving the bulkhead dangerously weak. Even though the aircraft had gone through over 12,000 pressurization cycles before the crash, it finally burst on that fateful day. Though JAL officially admitted no liability, they agreed to pay $7.6 million to the families of the victims, and a maintenance manager committed suicide to atone for his error. JAL no longer uses the number 123 for any flight, and has changed the flight number on that particular route to 127. (747 Photo by Harcmac60 via !!!error: Indecipherable SUB-paragraph formatting!!! ; bulkhead repair illustration by Phoenix7777 via !!!error: Indecipherable SUB-paragraph formatting!!! )

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Short Takeoff

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August 10, 1949 – The first flight of the Avro Canada C102 Jetliner, the world’s second jet-powered airliner. The C102 took its first flight just 13 days after the !!!error: Indecipherable SUB-paragraph formatting!!! , and while it appeared that the Jetliner would prove to be a successful design, de Havilland Canada chose instead to focus their efforts on the production of their !!!error: Indecipherable SUB-paragraph formatting!!! interceptor. American billionaire !!!error: Indecipherable SUB-paragraph formatting!!! approached de Havilland and asked them to build 30 for him, but they refused, and they would not allow Hughes to produce the Jetliner in the US under license. A second, nearly completed prototype was scrapped, and the flying prototype was broken up in 1956. Despite a promising life cut short, the C102 did give the world one lasting legacy: the word jetliner, coined by !!!error: Indecipherable SUB-paragraph formatting!!! for the C102 and has since become the generic word for any large, jet-powered commercial transport. (Photo author unknown)

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August 1o, 1896 – The death of Otto Lilienthal, an early and influential pioneer of manned flight who was known as the Glider King for his experiments with, and development of, unpowered glider flight. Born on May 23, 1848, Lillienthal worked closely with his brother Gustav and made over 2,000 flights beginning in 1891, some of which covered distances of over 800 feet. While all those flights only accounted for five hours of actual flying, Lillienthal’s influence on the history of manned aviation far outstripped his hours in the air, and the notoriety he garnered not only popularized the idea of future powered flight, but also influenced the early work of the !!!error: Indecipherable SUB-paragraph formatting!!! and other aviation pioneers. Lillenthal was killed in the crash of one of his gliders when he entered an unrecoverable stall at an altitude of about 50 feet and suffered a broken neck in the subsequent crash. (Lillienthal portrait via !!!error: Indecipherable SUB-paragraph formatting!!! ; Glider photo via US Library of Congress)

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August 11, 1995 – The first flight of the Embraer ERJ-145, the largest of a family of commuter airliners that includes the ERJ 140, which seats 44 passengers, and the ERJ 135, which seats 37 passengers. With accommodation for 50 passengers, the ERJ 145 was developed as a faster and more comfortable alternative to the turboprop regional airliners in service at the time. Powered by a pair of !!!error: Indecipherable SUB-paragraph formatting!!! high bypass turbofan engines, the ERJ 145 has a maximum cruising speed of about 515 mph, and the XR long-range variant can travel up to 2,000 nautical miles. More than 900 have been produced since 1989, and it remains in production today. (Photo by the author)

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August 11, 1972 – The first flight of the Northrop F-5E Tiger II. an upgraded version of the Northrop F-5A and winner of the International Fighter Aircraft competition in 1970. In an effort to make the F-5A more competitive with the Soviet !!!error: Indecipherable SUB-paragraph formatting!!! , Northrop lengthened and enlarged the F-5A to provide room for more fuel and improved avionics, and fitted more powerful !!!error: Indecipherable SUB-paragraph formatting!!! engines. The wing area was increased with the addition of larger leading edge extensions for better maneuverability. Northrop also equipped the F-5E with an !!!error: Indecipherable SUB-paragraph formatting!!! radar, where the F-5A/B had none. Almost 1,400 F-5E/Fs were built, and they saw extensive service with American allies. Though tested in combat by the US Air Force in 1965 during Operation Skoshi Tiger , where the F-5E received its nickname, the Tiger II never entered regular service with the USAF, though it does serve in the aggressor role for US combat flight training. (US Air Force photo)

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August 11, 1955 – The first flight of the Bell XV-3. Though not the first !!!error: Indecipherable SUB-paragraph formatting!!! aircraft, the Bell XV-3 verified the tiltrotor concept and eventually completed 110 successful transitions from vertical to horizontal and back to vertical flight. The XV-3 was powered by a single !!!error: Indecipherable SUB-paragraph formatting!!! radial engine located in the fuselage which turned a pair of two-bladed rotors (the prototype had a three-bladed rotor) through a drive assembly that could rotate through 90 degrees. While only two aircraft were built, data from the XV-3 program was used to develop the !!!error: Indecipherable SUB-paragraph formatting!!! , which then paved the way for the !!!error: Indecipherable SUB-paragraph formatting!!! tiltrotor in service today. (US Air Force photo)

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August 11, 1937 – The first flight of the Boulton Paul Defiant, a “turret fighter” interceptor developed for the RAF just before WWII. At the time, the RAF envisioned waves of unescorted German bombers flying over England, and the turret fighter concept would allow the pilot to focus on flying below or alongside the bomber while the gunner, along with other Defiants, concentrated the firepower of four !!!error: Indecipherable SUB-paragraph formatting!!! .303 caliber machine guns on the bomber. However, the Defiant proved to be vulnerable to more maneuverable escort fighters such as the !!!error: Indecipherable SUB-paragraph formatting!!! , and it was eventually converted to a night fighter before being replaced in the interceptor role by the !!!error: Indecipherable SUB-paragraph formatting!!! . The Defiant was then used for gunnery practice and as a target tug. Just over 1,000 were built, and it was retired at the end of the war. (British Government photo)

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August 12, 1960 – The launch of Echo 1A, an experimental passive communications satellite and the first of two enormous, metal-coated balloons placed into low Earth orbit. The balloons acted as passive reflectors of microwave signals that could be bounced off the balloon and back to Earth. The launch of Echo 1 on May 13, 1960 fell into the Atlantic Ocean when a stage of the newly-designed !!!error: Indecipherable SUB-paragraph formatting!!! launch system failed, but the launch of Echo 1A was successful, and a microwave transmission from the !!!error: Indecipherable SUB-paragraph formatting!!! in California was received at !!!error: Indecipherable SUB-paragraph formatting!!! in New Jersey. Echo 1 was followed four years later by Echo 2, which was 35 feet larger, and was placed in a polar orbit that was visible from Earth with the naked eye. Echo 1A burned up in Earth’s atmosphere in 1968, followed by Echo 2 a year later. (NASA photo)

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DISCUSSION (11)

MonkeePuzzle > ttyymmnn
08/12/2016 at 12:42

Using bleed air from the engine at the compressor stage, aircraft flying 35,000 feet above the ground are pressurized to maintain the same air pressure inside the cabin as if it were flying at no more than 8,000 feet

I had simply never thought about how it is done... why had I never put thought to that?

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > ttyymmnn
08/12/2016 at 13:18

If the JAL flight was in the air 35min, they couldn’t get a bit left and out to sea? Probably a better chance. I’ve seen pictures of the crash in Japan. Aren’t the new composite monster jets closer to sea level, I heard they give you less jet lag because of that too. I want to fly on one of them but for some reason ANA only flies the new planes out of San Jose around here and I’m not driving an hour south from SFO.

BringBackTheCommodore > MonkeePuzzle
08/12/2016 at 13:18

For me, I don’t think about it, I just valsalva as the aircraft climbs/descends.

BringBackTheCommodore > ttyymmnn
08/12/2016 at 13:19

Great article, and a few milestones I had not realized before. Amazing the advances we’ve seen in aviation in the past 150 years - from hot air balloons to tiltrotor aircraft.

facw > ttyymmnn
08/12/2016 at 13:44

The Japanese response to JAL 123 was so horrifically bad. Who responds to a crash by saying “everyone’s probably dead, so we’ll deal with it in the morning”? Even if they were so consumed by national pride as to not let the Americans help out, surely they could have gotten Japanese personnel on site via helicopter sometime during the night if they had tried.

someassemblyrequired > ttyymmnn
08/12/2016 at 14:30

JAL has a Safety Promotion Center with a display of wreckage (including the bulkhead) and personal effects from 123. Almost all new staff are required to visit the center with the idea being that it will help them understand the importance of safety. Some photos and details here:

http://www.jal.com/en/flight/safe…

It is open to the public as well, but you need to make an appointment in advance.

ttyymmnn > someassemblyrequired
08/12/2016 at 23:28

That’s called taking it seriously.

ttyymmnn > BringBackTheCommodore
08/12/2016 at 23:32

The pace of aviation development has been noting short of remarkable. From the First Flight in 1903, it was just 44 years until Chuck Yeager broke the sound barrier, then only 22 more years until Neil Armstrong stepped on the moon.

ttyymmnn > 415s30 W123TSXWaggoIIIIIIo ( •_•))°)
08/12/2016 at 23:42

I doubt they had that much control. The 787 gives passengers a 6,000 foot altitude, as far as I can find out. I think the A380 is similar. That’s an improvement over the regular 8,000 feet. As for jet lag, no idea.

ttyymmnn > MonkeePuzzle
08/12/2016 at 23:44

The air is pumped into the cabin, then exits through a release valve that maintains the desired pressure in the cabin. So the air inside the cabin is constantly cycled through, and people who say that being inside an aircraft means sitting in a can of stagnant air are just wrong. If you get sick on an airplane, it’s simply because of the close proximity of humanity, not stale air.

BringBackTheCommodore > ttyymmnn
08/13/2016 at 09:47

Now we have aircraft that are both V/STOL capable and capable of supersonic flight, and twin-engine airliners that exceed the capabilities that were previously relegated to 4-engine airliners.

Milestones like the ones you mentioned as well, they show the pinnacle of advancement in technology and I can only wonder what will happen when commercial ( commercial! ) spaceflight takes center stage.