NWA Flight #2

http://www.reuters.com/article/newsOne/idUSTRE51J0YT20090220

What do they mean when they refer to "extreme turbulence?"

I fly twice a week, and cant image what this must be like.

What really happens?

 

probably clear air turbulence?

http://en.wikipedia.org/wiki/Clear-air_turbulence

 

I was on a flight from India back to Chicago about 12 years ago, and we were in a smaller plane, we had so much turbulence that one of the flight attendants flew from the back of the plane forward about 15 rows. It felt worse than a roller coaster.

 

Just imagine sitting in your chair at work and all of a sudden the floor drops out from under you. Or you chair shoots up and hits the ceiling while stuff falls off of shelves and hits you in the head.

 

AA definitions of turbulence intensity as follows. There are more than 3.

Light Chop. Slight, rapid, and somewhat rhythmic bumpiness without appreciable changes in altitude or attitude.

Light Turbulence. Slight, erratic changes in altitude and/or attitude. Occupants may feel a slight strain against seatbelts. Unsecured objects may be displaced slightly. Food service may be conducted and little to no difficulty is encountered in walking.

Moderate Chop. Rapid bumps or jolts without appreciable changes in aircraft altitude or attitude.

Moderate Turbulence. Changes in altitude and/or attitude occur but the aircraft remains in positive control at all times. It usually causes variations in indicated airspeed. Occupants feel definite strain against seatbelts. Unsecured objects are dislodged. Food service and walking are difficult.

Severe. Large, abrupt changes in altitude and/or attitude. Usually causes large variations in indicated airspeed. Aircraft may be momentarily out of control. Occupants are forced violently against seatbelts. Unsecured objects are tossed about. Food service and walking are impossible.

Extreme. Aircraft is violently tossed about and is practically impossible to control. May cause structural damage.

Following related FAA document dated January 2006 may be of interest:
http://www.airweb.faa.gov/Regulatory...25710000679ae0/$FILE/AC120-88A.pdf

 

My definition is: whenever the captain asks the cabin crew to cease service, put everything away, and be seated with their seatbelts on. I went through that for about 8 minutes on a 767 once descending over New Jersey, and I was digging my fingernails into the armrests. Every time there was a big jolt there was an audible gasp from various places throughout the cabin, and although the last 10 minutes of the flight thereafter were perfectly smooth, there was applause when the wheels touched down at La Guardia.

I was at least glad I was in a 767 -- I had worked on its structural design! I guess that I (and all the other engineers) did a decent job.....

 

My worst was in a small commuter plane over the Cascades during a "100 year storm"
that flared up after takeoff. Anyone not belted were thrown from their seats, several
overhead bins opened, stuff was sliding all about the cabin. All this for over 1
hour with large changes in altitude and attitude. Thought for certain we would go down.
Yikes - was very scary indeed. Horrid, nearly sideways landing topped it off. The
12 of us on the flight were silent, and all thanked the young (and clearly shaken up)
pilots with a handshake as we stepped out.

Jedi