Narrative:

Our flight was [known] to be going through a SIGMET area calling for several aircraft reporting severe turbulence from FL240 to FL380. I have flown this trip many; many times in fact just a week prior to this event and noticed the routing to be fairly east of our usual filed flight plan. I saw on our release a 4 around the about mid flight indicating moderate turbulence. I advised the flight attendants (all) to remain seated until I called them. On our climb out passing through FL220 we started encountering moderate turbulence with the winds from the north quickly escalating from 40 knots to at one time 152 knots just in a few thousand feet of climb. We were filed for FL390. Being light the performance page (FMC) indicated our max cruise of 39;800. Of course we are limited to FL390 per sops. We were asked if we wanted direct. Since our dispatch and questioned the ride to ATC indicated smooth at FL390 we accepted. The winds aloft at FL390 were approx. 330 at 60 knots. I noticed a little light turb with an occasional moderate 'bump.' the static air temperature (sat) temp would change from minus 53 to minus 48 and you could feel the aircraft 'swelling' like riding up then down but only about 200 (continued below).my first officer had downloaded the winds aloft chart on his ipad prior to launch and it showed the jetstream really pouring down the middle of the western us then a surge looping up to the northeast. We had been originally filed east of this surge and now were in the eastern edge of this loop. I asked my first officer if we might head east toward our original filed route since it appeared bumpy. ATC said it should be smooth at FL390 with some light chop. We discussed it further amongst ourselves when we entered an area of moderate turbulence and the aircraft was trending a climb in excess of 1;500 feet per minute and then 1;500 descent per minute. I immediately got on the PA and said [flight attendants] take your seats as I didn't know if they stayed seated. I earlier told them to use their discretion on service that it was told to us by ATC light turb. The aircraft altitude alert was going off and on as we went through these gyrations of climb and descent through our assigned altitude. I asked ATC for a lower altitude and a turn to the east but was told unable. We started down and turned east at which time the ATC controller obliged our request giving us a block altitude of 390 to 370. We began our turn and descent and were still in this severe 'mountain wave' as we continued turning east bound. Finally after what seemed forever the aircraft became stable in a constant rate descent of about 1;500 feet to FL370. I asked for direct a fix on our original flight plan. Believe it or not the rest of the flight was very smooth. I contacted the flight attendants to see how things were in the back. They never got up out of their seats and I never turned off the seat belt sign so everything was tidy in the back.in my aviation career which spans over 40 years I have never seen anything like that incident before and pray it doesn't happen again as it was a very sobering experience.in the future I will be more in line with what routing the dispatcher has for us as he has more information at his than I do at mine even though it was [thought] to be a smooth ride.

Google
 

Original NASA ASRS Text

Title: An Airbus flight crew encountered extreme Rocky Mountain wave activity at FL390 with climbs and descents in excess of 1;500 feet.

Narrative: Our flight was [known] to be going through a SIGMET Area calling for several aircraft reporting severe turbulence from FL240 to FL380. I have flown this trip many; many times in fact just a week prior to this event and noticed the routing to be fairly East of our usual filed flight plan. I saw on our release a 4 around the about mid flight indicating moderate turbulence. I advised the flight attendants (all) to remain seated until I called them. On our climb out passing through FL220 we started encountering moderate turbulence with the winds from the north quickly escalating from 40 knots to at one time 152 knots just in a few thousand feet of climb. We were filed for FL390. Being light the performance page (FMC) indicated our max cruise of 39;800. Of course we are limited to FL390 per SOPs. We were asked if we wanted direct. Since our dispatch and questioned the ride to ATC indicated smooth at FL390 we accepted. The winds aloft at FL390 were approx. 330 at 60 knots. I noticed a little light turb with an occasional moderate 'bump.' The Static Air Temperature (SAT) temp would change from minus 53 to minus 48 and you could feel the aircraft 'swelling' like riding up then down but only about 200 (continued below).My first officer had downloaded the winds aloft chart on his iPad prior to launch and it showed the jetstream really pouring down the middle of the western U.S. then a surge looping up to the Northeast. We had been originally filed east of this surge and now were in the eastern edge of this loop. I asked my First Officer if we might head east toward our original filed route since it appeared bumpy. ATC said it should be smooth at FL390 with some light chop. We discussed it further amongst ourselves when we entered an area of moderate turbulence and the aircraft was trending a climb in excess of 1;500 feet per minute and then 1;500 descent per minute. I immediately got on the PA and said [flight attendants] take your seats as I didn't know if they stayed seated. I earlier told them to use their discretion on service that it was told to us by ATC light turb. The aircraft altitude alert was going off and on as we went through these gyrations of climb and descent through our assigned altitude. I asked ATC for a lower altitude and a turn to the east but was told unable. We started down and turned east at which time the ATC controller obliged our request giving us a block altitude of 390 to 370. We began our turn and descent and were still in this severe 'mountain wave' as we continued turning east bound. Finally after what seemed forever the aircraft became stable in a constant rate descent of about 1;500 feet to FL370. I asked for direct a fix on our original flight plan. Believe it or not the rest of the flight was very smooth. I contacted the flight attendants to see how things were in the back. They never got up out of their seats and I never turned off the seat belt sign so everything was tidy in the back.In my aviation career which spans over 40 years I have never seen anything like that incident before and pray it doesn't happen again as it was a very sobering experience.In the future I will be more in line with what routing the dispatcher has for us as he has more information at his than I do at mine even though it was [thought] to be a smooth ride.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.