earth science

United Airlines Flight 826

United Airlines Flight 826 is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand United Airlines Flight 826 rather than just read about it. In short: On December 28, 1997, United Airlines Flight 826 was operated by a Boeing 747-100 flying from New Tokyo International Airport (Narita), Japan to Honolulu International Airport, Hawaii. Two hours into the flight, at an altitude of 31,000 feet (9,400 m), the plane received reports of severe clear-air turbulence in the area and the seat belt sign was turned on.

Key takeaways

United Airlines Flight 826 belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect United Airlines Flight 826 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of United Airlines Flight 826 from memory before moving on to harder problems.

Reference excerpt

On December 28, 1997, United Airlines Flight 826 was operated by a Boeing 747-100 flying from New Tokyo International Airport (Narita), Japan to Honolulu International Airport, Hawaii. Two hours into the flight, at an altitude of 31,000 feet (9,400 m), the plane received reports of severe clear-air turbulence in the area and the seat belt sign was turned on. Moments later, the aircraft suddenly dropped around 100 feet (30 m), seriously injuring 15 passengers and 3 crew members. The plane turned around and landed safely back in Tokyo, but one passenger, a 32-year-old Japanese woman, died.

Background

Aircraft The aircraft involved, manufactured in 1971, was a Boeing 747-122 registered as N4723U. It was powered by four Pratt & Whitney JT9D-7A engines.

Crew Flight 826 was piloted by an experienced cockpit crew. The captain had around 15,000 flight hours, including 1,100 hours on the Boeing 747. The first officer had around 10,000 hours, including 1,500 hours on the Boeing 747, and the flight engineer had around 3,500 hours of flight time, including 850 hours in the Boeing 747. The cabin crew ranged from 8 to 34 years in seniority.

Flight details Flight 826 departed Tokyo's Narita airport on December 28, 1997, at 20:30 local time. It reached a cruising altitude of 31,000 feet (9,400 m) just under a half-hour later. The flight was originally planned to cruise at 35,000 feet (11,000 m), but air traffic control (ATC) only cleared to cruise at the lower altitude due to air traffic. The captain chose the only authorized route at the time on which severe turbulence or thunderstorms were not forecast to occur. At cruising altitude, the flight initially encountered enough turbulence for the captain to turn on the "fasten seat belt" sign. Fifteen minutes later, the turbulence subsided and the fasten seatbelt sign was switched off. At the time the captain announced to the passengers that turbulence was still a possibility and that the seat belts should be fastened when seated. A flight attendant made the same announcement in Japanese. About an hour later, after calm conditions, the "fasten seat belt sign" came on again without any announcement. After about two minutes of not very strong turbulence, suddenly the 747 dropped slightly then shot back up and then back down at such a velocity that a purser, who was hanging on to a fixed countertop, found himself hanging upside down holding the countertop with his feet in the air. The airplane then pitched up and steeply climbed before heavily falling again, this occurring when the right wing dropped sharply. After another moderate climb, the flight returned to normal. After the accident, a Japanese woman who had her belt unfastened was found lying unconscious and bleeding heavily in the aisle. Despite quick resuscitation efforts by injured flight attendants and a passenger doctor, she was soon pronounced dead. Fifteen passengers and three flight attendants had spine and neck fractures. Another 87 other passengers had bruises, sprains and other minor injuries. While Henderson Field on Midway Atoll was the closest airport, the captain opted to return to Tokyo after assessing the aircraft was still flightworthy, and Tokyo had medical facilities judged better to handle the injuries. Three hours later, the aircraft landed safely at Narita Airport.

NTSB investigation and aftermath The flight data recorder, as analyzed by the National Transportation Safety Board (NTSB), found that the sensors had initially recorded a peak normal acceleration of 1.814g in the first sharp ascent. Then the data showed that the aircraft had an out of control roll by 18° and then plunged to an extreme negative G of -0.824g. The NTSB investigation found a potential issue that could have prevented the death and many injuries. Nobody could remember hearing the typical "fasten seat belt" chime when the fasten seat belt light came on about two minutes before the turbulence event and no announcements of the "fasten seat belt" light being on were made in either English or Japanese. As a result of the accident, United Airlines released a bulletin entitled Turbulence Encounter and Passenger Fatality which went into detail on the events of Flight 826 and emphasized the importance of effective communication. The airline also took measures to enforce its policy of encouraging passengers to keep their seat belts fastened even if the seat belt sign is off. United Airlines had previously intended to sell the aging aircraft to a salvage company in early 1998. After this accident, the airline opted to retire the aircraft soon afterwards with Flight 826 being its last revenue flight. It was ferried to Las Vegas McCarran International Airport in January 1998 and scrapped later that year.

See also TWA Flight 742 Singapore Airlines Flight 321

References

External links

"Accident description". Aviation Safety Network.

Illustrations

Worked examples

Example 1 — a first encounter with United Airlines Flight 826

Start with the simplest possible case. Write down what United Airlines Flight 826 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to United Airlines Flight 826 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about United Airlines Flight 826 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of United Airlines Flight 826

In research: United Airlines Flight 826 appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses United Airlines Flight 826 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: United Airlines Flight 826 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1997 disasters in Oceania, Aviation accidents and incidents caused by clear air turbulence, Aviation accidents and incidents in 1997, so understanding it makes those chapters shorter.
In everyday life: Look for United Airlines Flight 826 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “United Airlines Flight 826” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study United Airlines Flight 826 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what United Airlines Flight 826 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain United Airlines Flight 826 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is United Airlines Flight 826 in simple terms?

Why does United Airlines Flight 826 matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study United Airlines Flight 826?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on United Airlines Flight 826.