First OfficerPerhaps this is somehow related to the Indicated Airspeed issue brought up in another thread.
I was flying a CRJ-700 from TJSJ to KMIA in fair weather, calandar month January, mid-AM departure. I'm climbng from 20,000 feet to 30,00 on autopilot, speed set to 280kts, and I go to look at my GPS or something, taking my attention away from the gauges.
I'm snapped back to attention by my stall alarm and I get back to the controls to see the aircraft in a handsome nose-up stall, around 28,000 feet. I snap off the auto pilot, nose it down, get up some airspeed and flatten out at about 22,000 feet. I check for symptoms of de-icing (OK, OK, I'm just GUESSING that maybe something iced up). I throw every de-icing switch to on, and put the autopilot back on but hold it at 22K for a while. After a few minutes I initiate a climb (ATC: "Please expedite your ascent to FL 300" Me: Yaaah, c'mon!!! Can't you see I'm cheatin' DEATH here???!!!")
Well , lo and behold, it happens AGAIN!!!!. Same outcome, this time when I climb a third time I run the climb rate waaay down, maybe 500-700 ft/min. I get up in the air fine and have no problems later on in climbing and mainteining altitude in the 40's.
At some point after this, ATC notifies me that my IFR flight plan has been cancelled. But that's beside the point.
Whenever ATC gnaws on my rear about expeditiing my ascent, I always run the climb rate up, 2200-2700 ft/min. Sometimes I do that even without waiting for being harangued by ATC.
Is that excessive??? Or, more exactly, does an aggressive climb rate have to be cut back as you go up in altitude, as the air thins out, with an explanation being based on the same principles to those of why IAS differs more from true airspeed the higher you go?
It seems that climb "rates" inherently "flatten out "in a way, in that if you're maintaining a constant IAS as you go higher, the true air speed is going up, therefore although you might be climbing at the same rate with respect to TIME, you're traveling more horizontal DISTANCE the thigher you go (at a given IAS). Time rate of ascent remains the same, but angle of ascent decrease because you're going faster.
If the climb rate being too high is not the answer, is it somehow an icing matter? I've taken the CRJ-700 to higher altitudes in other flights without incident, in the same general locales, but in spring/summer months.
Or, since I was flying near Cuba, was ol' Fidel trying to go out with a bang and put the whammy on me?
mdaskalos
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Chief Captain
