Narrative:

Routine flight at FL210, encountered light turbulence in and out of cloud tops. Requested FL230 to get on top. Aircraft was heavily loaded and in autoplt climb mode, slowed from 190 KIAS (cruise) to 160 KIAS (climb) as we passed through FL220. ATC asked what our IAS was and I replied '160 KTS in the climb.' ATC replied 'you've got to tell me before you reduce your airspeed that much sir, break, abc XXX (company aircraft) gimme a good left turn 30 degrees and reduce your airspeed as much as practical.' then later as he handed off 'abc XXX' he said 'thanks for your help, it saved me from mounds of paper work.' when he handed us off, I apologized for the sudden loss of airspeed and told him it was a normal consequence of our heavy aircraft climbing from FL210 to FL230. He said it all worked out but that he saw a 40 KT loss of ground speed in 2 or 3 sweeps causing company aircraft to close in on us thereby reducing separation. Since it is perfectly normal for us to lose that much airspeed while climbing, I've never thought of reporting it to ATC as a change of TAS per aim 5-33, a,1(east). I wonder if you might address this issue in a future issue of callback and enlighten us all whether or not we should always report losses and/or gains of TAS in climbs and dscnts.

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Original NASA ASRS Text

Title: ACFT SLOWS WHILE CLBING FROM FL210 TO FL230, 30 KIAS. CAUSES LOSS OF SEPARATION FROM ACFT FOLLOWING.

Narrative: ROUTINE FLT AT FL210, ENCOUNTERED LIGHT TURB IN AND OUT OF CLOUD TOPS. REQUESTED FL230 TO GET ON TOP. ACFT WAS HEAVILY LOADED AND IN AUTOPLT CLB MODE, SLOWED FROM 190 KIAS (CRUISE) TO 160 KIAS (CLB) AS WE PASSED THROUGH FL220. ATC ASKED WHAT OUR IAS WAS AND I REPLIED '160 KTS IN THE CLB.' ATC REPLIED 'YOU'VE GOT TO TELL ME BEFORE YOU REDUCE YOUR AIRSPD THAT MUCH SIR, BREAK, ABC XXX (COMPANY ACFT) GIMME A GOOD L TURN 30 DEGS AND REDUCE YOUR AIRSPD AS MUCH AS PRACTICAL.' THEN LATER AS HE HANDED OFF 'ABC XXX' HE SAID 'THANKS FOR YOUR HELP, IT SAVED ME FROM MOUNDS OF PAPER WORK.' WHEN HE HANDED US OFF, I APOLOGIZED FOR THE SUDDEN LOSS OF AIRSPD AND TOLD HIM IT WAS A NORMAL CONSEQUENCE OF OUR HVY ACFT CLBING FROM FL210 TO FL230. HE SAID IT ALL WORKED OUT BUT THAT HE SAW A 40 KT LOSS OF GND SPD IN 2 OR 3 SWEEPS CAUSING COMPANY ACFT TO CLOSE IN ON US THEREBY REDUCING SEPARATION. SINCE IT IS PERFECTLY NORMAL FOR US TO LOSE THAT MUCH AIRSPD WHILE CLBING, I'VE NEVER THOUGHT OF RPTING IT TO ATC AS A CHANGE OF TAS PER AIM 5-33, A,1(E). I WONDER IF YOU MIGHT ADDRESS THIS ISSUE IN A FUTURE ISSUE OF CALLBACK AND ENLIGHTEN US ALL WHETHER OR NOT WE SHOULD ALWAYS RPT LOSSES AND/OR GAINS OF TAS IN CLBS AND DSCNTS.

Data retrieved from NASA's ASRS site as of July 2007 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.