Narrative:

On climb out somewhere between 15000 - 18700 ft; chinese ATC quickly told us to 260 and climb to 25000 ft. As the flying pilot I should've immediately said unable; but many of us are used to accommodating ATC so I opened the speed window to slow down. I think ATC had a slower aircraft in front of us and I suspect he wanted us to slow our closing rate and climb us faster over the top at the same time. We were very heavy and climb out speed was like 281 knots below 10000 ft; which is why I should've said 'unable.' I opened the speed window first and then began to roll the speed back. The speed began to slow towards the yellow band and at the same time the ca suddenly calls flaps and moved the lever to flaps 1. Immediately the speed tape band narrowed and I realized my focus needed to be zeroed in on the speed and pitch to avoid stick shaker or worse; stall the inboard section of wing. I firmly stated I didn't like this situation and told the captain to say unable and request something higher than 290; which was our max angle speed. The ca initially hesitated trying to say 260 knots would be fine; but by then we were so far behind the power curve. I fought the VNAV forces; especially with thrust levers wanting to come way back but elected not to disconnect the autopilot because I thought it safer to act quickly with better observation using the autopilot rather than being off of it and the ca doing other strange things like selecting flaps again on climb out. I had the thrust fire walled for quite some time to prevent worse. I also shallowed the rate of climb. Myself and the 3rd pilot convinced the ca to join the plan in asking for a higher speed and pulling the flaps back up. We were still prior to 20000 ft but in my focus on speed and pitch I forgot to reset the altitude to 250 and it began to level off. I realized it then and pressed the button for higher so it was not much an issue on altitude. I think we got very close to stick shaker though and possibly a critical inboard wing stall with the flaps out and slow airspeed. I definitely think the chinese ATC didn't handle this well. I imagine someone told him 'hey; you know how to really get someone to climb fast if they're getting jammed up behind other traffic?... Slow their speed significantly and give them an higher altitude!!' I don't think this was done well on their part but again; I never should've accepted this speed of 260 knots from ATC. I'm trying to think what else could help in this scenario... We brief the climb speed below 10000 ft but from 10-20k; we don't have anything. And where's the cutoff? We could fly a 250 knot restriction below 10k say out of ZZZ with heavy aircraft; but then how high can we keep that speed through 20k? After this; I would prefer to brief whatever speed below 10k and then say we can't accept anything below 280 from 10-20 so there's no risk of thought for flaps which can immediately aggravate the situation. As far as I remember; if given speed and altitude restrictions at the same time; it doesn't seem to say which one to move first. I moved the speed window and knob first but I think it may have helped keep us from getting so significantly behind the power curve.

Related reports:

Google
 

Original NASA ASRS Text

Title: B747 First Officer reported experiencing airspeed control problems attempting to comply with ATC speed reduction clearance during climb out.

Narrative: On climb out somewhere between 15000 - 18700 ft; Chinese ATC quickly told us to 260 and climb to 25000 ft. As the flying pilot I should've immediately said unable; but many of us are used to accommodating ATC so I opened the speed window to slow down. I think ATC had a slower aircraft in front of us and I suspect he wanted us to slow our closing rate and climb us faster over the top at the same time. We were very heavy and climb out speed was like 281 knots below 10000 ft; which is why I should've said 'unable.' I opened the speed window first and then began to roll the speed back. The speed began to slow towards the yellow band and at the same time the CA suddenly calls flaps and moved the lever to flaps 1. Immediately the speed tape band narrowed and I realized my focus needed to be zeroed in on the speed and pitch to avoid stick shaker or worse; stall the inboard section of wing. I firmly stated I didn't like this situation and told the Captain to say unable and request something higher than 290; which was our max angle speed. The CA initially hesitated trying to say 260 knots would be fine; but by then we were so far behind the power curve. I fought the VNAV forces; especially with thrust levers wanting to come way back but elected not to disconnect the autopilot because I thought it safer to act quickly with better observation using the autopilot rather than being off of it and the CA doing other strange things like selecting flaps again on climb out. I had the thrust fire walled for quite some time to prevent worse. I also shallowed the rate of climb. Myself and the 3rd pilot convinced the CA to join the plan in asking for a higher speed and pulling the flaps back up. We were still prior to 20000 ft but in my focus on speed and pitch I forgot to reset the altitude to 250 and it began to level off. I realized it then and pressed the button for higher so it was not much an issue on altitude. I think we got very close to stick shaker though and possibly a critical inboard wing stall with the flaps out and slow airspeed. I definitely think the Chinese ATC didn't handle this well. I imagine someone told him 'Hey; you know how to really get someone to climb fast if they're getting jammed up behind other traffic?... slow their speed significantly and give them an higher altitude!!' I don't think this was done well on their part but again; I never should've accepted this speed of 260 knots from ATC. I'm trying to think what else could help in this scenario... we brief the climb speed below 10000 ft but from 10-20k; we don't have anything. And where's the cutoff? We could fly a 250 knot restriction below 10k say out of ZZZ with heavy aircraft; but then how high can we keep that speed through 20k? After this; I would prefer to brief whatever speed below 10k and then say we can't accept anything below 280 from 10-20 so there's no risk of thought for flaps which can immediately aggravate the situation. As far as I remember; if given speed and altitude restrictions at the same time; it doesn't seem to say which one to move first. I moved the speed window and knob first but I think it may have helped keep us from getting so significantly behind the power curve.

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.