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Statisticians ONLY: What is the probability of this being a jet stream?

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* The captain apologized for the inconvenience and the horrific events of earlier in the evening.

* He went on to say that he has flown all over the world for United and has never experienced anything like we did that night.

Flight 1028 passenger: I thought we would crash

By Carter Robertson Special to The Denver Post

Article Last Updated: 01/24/2008 04:16:48 PM MST

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Editor's note: Carter Robertson was on United Flight 1028 with his wife, daughter and future son-in-law on Monday. They had been in Hawaii on vacation and were returning to Virginia. The plane encountered turbulence and was diverted to Denver at 2:55 a.m. Eight passengers and two flight attendants were injured.

The plane was close to being full — 187 counting crew — and it was approaching the time for take-off. Everyone was getting settled in for the relatively short flight to Chicago. As we rolled down the runway, I'm sure no one had any idea of what was to come.

As we approached the 37,000-foot mark, the captain turned off the seat belt light. The flight attendants were handing out drinks to passengers some 3 to 4 rows in front of me. The flight thus far, again, was so remarkably smooth that I would say it felt as if we were floating on clouds.

I had decided I would pass on a drink and start with my nap. I had not yet closed my eyes when without any warning — not even the slightest hint of what was about to happen — it happened.

* In a split-second some indescribable force violently sucked the plane 700-vertical feet up and in another split second pushed it down the same 700 feet. ( Care to look up the probability of survival in a physics book')

* How did he know it was 700 feet up & down?

* What does the radar for the weather report say about this?

* Is there any recorded incident in aviation history that even resembles this?

* Satellite imagery readings?

People who weren't buckled in were thrown up, hitting the bulkhead. I was buckled in tight but was suspended above my seat during the roller-coaster ride.

* The flight attendants were also launched up into the plane's ceiling, bouncing off and returning to the cabin floor.

The drink cart was lifted off the floor and landed at an angle against a passenger. One female flight attendant was injured while pulling the cart off the passenger. Pillows, blankets, ice, drink cups and drink cans flew across the plane in every direction. Women and children (and, I'm sure, even some men) screamed.

* The force wasn't just a smooth up-and-down movement.

* The plane was in a constant state of vibrating, shuddering and rolling during this unexpected vertical ride.

* There is no way I can do justice in describing the violent nature of this unprovoked attack upon the aircraft.

I can only say that in the 5-10 seconds this event occurred that many things raced through my mind. In an instant I knew we were all dead, that the plane could not possibly withstand the violent forces attacking it at from every angle.

* As the thoughts continued to race, seconds ticked by, and the plane was now in a 6,000 foot nose dive.

* I quickly realized that the plane had actually survived one of nature's most wicked forces, and now we were racing toward the Rocky Mountains at 400 mph. Probability of survival from this incident? +700 to -7-- ft. and then a 6,000 ft, 'dive'.

Just like in the movies, the noise from the jet engines was increasing in decibels and in pitch. My attention now shifted to the dive of the plane and what was taking place in the cockpit. Was the captain in control?

I don't know how long the dive lasted, but slowly the plane leveled, and the engine noise subsided.

The captain did have control of the plane.

I looked to my right at my wife. We could only shake our heads. It was moments latter before anyone could say anything.

Once the plane was in control, the flight attendants went about the job of assessing the injuries to the passengers. I can't begin to express my sincere gratitude for the clam, professional and courageous manner in which the flight crew handled the aftermath of the event.

It was probably five minutes later when the captain came over the intercom and informed us that due to injuries and possible damage to the plane that we would stop at Denver, and that paramedics would be on hand to treat the injured.

We were in the terminal for about 45-60 minutes when the captain came out and addressed the passengers. The captain apologized for the inconvenience and the horrific events of earlier in the evening. He went on to say that he has flown all over the world for United and has never experienced anything like we did that night.

He assured us that the rest of the flight to Chicago would be uneventful, and he was right.

My everlasting praise goes out to the crew of United Flight 1028. Outstanding job. Outstanding job.

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4 ANSWERS


  1. Zero %

    This was CAT ( clear air turbulence)


  2. I am not a statistician just a retired flight engineer. Ever heard of clear air turbulence?

    Why would you rely on what a statistician says?

    "There are lies, bloody lies and then there are statistics"

  3. Post it under Mathematics.

  4. I don't think I could give you an actual statistical answer, but I'd say it is very UN-likely.  What you most likely experienced is known as Clear Air Turbulence (CAT).  It is hard to see and difficult to predict, however it tends to exist most often in the area just north of the jet stream in a trough (thats what we call it when the jet stream loops down to the south and forms kind of a "U" shape).  RADAR does not see CAT, as there is no water associated with it, and thats all weather RADAR can see.

    It may also have been (since you were in the vicinity of Denver) severe mountain wave turbulence.  Mountain waves happen when air blows over the mountains and gets disturbed.  They form a type of wave that moves up and down just like the waves on the surface of water.  They can extend from the surface to 50,000' and go hundreds of miles downwind of the mountains.  Typically, mountain waves are not that violent, but extreme instances have been recorded.  You *might* have gotten caught underneath the "peak" of one of those waves where the rotational force can actually form a rotor, which is kind of like a sideways tornado.  That would be very violent and would probably produce the kind of turbulence you encountered.  They are also nearly impossible to see or predict, though most pilots tend to avoid places where rotors can form just out of habit and respect for them.

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