Flight crew of a cpr jet failed to maintain descent speed assigned by ATC due to moderate turbulence...

Attributes
ACN	316608
Time
Date	199509
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mpw airport : mdw
State Reference	IL
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	general aviation : corporate
Make Model Name	BAe 125 Series 800
Operating Under FAR Part	Part 91
Flight Phase	cruise other descent : approach
Route In Use	enroute other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 125 flight time total : 5000 flight time type : 1400
ASRS Report	316608
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : clearance other anomaly other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

On the above date while talking to chicago approach control, we were instructed to maintain 250 KTS. Due to moderate turbulence, the captain slowed to 220 KTS. We did not have time to notify the controller of this. Shortly afterward the controller asked our speed. I advised him that it was 220 KTS, due to moderate turbulence. He did not care about the turbulence, all he was concerned about was our speed. He proceeded to tell us never to deviate from an assigned speed without notifying ATC of the intent. Upon advising him that the frequency was busy and we had been unable to advise him prior to him calling us. The controller became irate and stated 'look I don't care if it is busy, you advise me prior to changes.' I think this entire thing could be avoided if controllers will admit to their own faults and not feel that pilots don't listen to them. The turbulent air penetration speed of our aircraft is 220 KTS not 250 KTS. I would have advised him if I could have gotten through. Controllers need to understand this and allow some leeway.

Original NASA ASRS Text

Title: FLC OF A CPR JET FAILED TO MAINTAIN DSCNT SPD ASSIGNED BY ATC DUE TO MODERATE TURB.

Narrative: ON THE ABOVE DATE WHILE TALKING TO CHICAGO APCH CTL, WE WERE INSTRUCTED TO MAINTAIN 250 KTS. DUE TO MODERATE TURB, THE CAPT SLOWED TO 220 KTS. WE DID NOT HAVE TIME TO NOTIFY THE CTLR OF THIS. SHORTLY AFTERWARD THE CTLR ASKED OUR SPD. I ADVISED HIM THAT IT WAS 220 KTS, DUE TO MODERATE TURB. HE DID NOT CARE ABOUT THE TURB, ALL HE WAS CONCERNED ABOUT WAS OUR SPD. HE PROCEEDED TO TELL US NEVER TO DEVIATE FROM AN ASSIGNED SPD WITHOUT NOTIFYING ATC OF THE INTENT. UPON ADVISING HIM THAT THE FREQ WAS BUSY AND WE HAD BEEN UNABLE TO ADVISE HIM PRIOR TO HIM CALLING US. THE CTLR BECAME IRATE AND STATED 'LOOK I DON'T CARE IF IT IS BUSY, YOU ADVISE ME PRIOR TO CHANGES.' I THINK THIS ENTIRE THING COULD BE AVOIDED IF CTLRS WILL ADMIT TO THEIR OWN FAULTS AND NOT FEEL THAT PLTS DON'T LISTEN TO THEM. THE TURBULENT AIR PENETRATION SPD OF OUR ACFT IS 220 KTS NOT 250 KTS. I WOULD HAVE ADVISED HIM IF I COULD HAVE GOTTEN THROUGH. CTLRS NEED TO UNDERSTAND THIS AND ALLOW SOME LEEWAY.

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.