Notso Fantastic,
Your comment,
"A strong updraft will pitch an aeroplane nose down."
Unless the resultant angle of the aircraft's forward momentum and the vertical component of the updraft increases the lift and moves the center of lift forward on the swept wing. pulling the nose up.
The vertical updraft component of the relative wind was so strong that NW 705 was unable to return to a level flight attitude even with a full forward pitch control input. Full nose down trim on the horizontal stabilizer was also ineffective, until the aircraft returned to a normal relative wind direction, and then it was drastically effective!
AirQuake,
Your comment,
"Didn't the Co-Pilot on that Northwest flight survive an almost identical 'upset' some months earlier?"
I believe you are referring to the Eastern Co-pilot that shoved the nose over into a steep dive attitude in an Eastern DC-8, when his airdpeed indicator went to zero!
The Captain put the DC-8 engines into reverse and recovered. (The DC-8 was the only aircraft that you could reverse the engines in flight.)
As an aside, the same co-pilot was aboard another Eastern DC-8 that disapeared over Lake Ponchetain in Lousiana, (no spelling checker!), a year later.
Last edited by wsherif1; 7th Jan 2005 at 21:31.