Speed deviation from clearance when the flight crew of a CE560 allows the speed to drop off while us...

Attributes
ACN	574115
Time
Date	200302
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iad.airport
Altitude	msl bound lower : 18000 msl bound upper : 26000
Environment
Flight Conditions	IMC
Weather Elements	Ice
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	Other
Make Model Name	Citation V
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 80 flight time total : 5700 flight time type : 3000
ASRS Report	574115
Person 2
Affiliation	Other
Function	flight crew : first officer
Events
Anomaly	inflight encounter : weather non adherence : clearance
Independent Detector	other controllera
Resolutory Action	aircraft : automation overrode flight crew controller : issued advisory flight crew : exited adverse environment flight crew : overrode automation flight crew : returned to original clearance flight crew : became reoriented
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Airspace Structure Flight Crew Human Performance Weather ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On climb out from iad, I was given an altitude assignment of approximately FL270. Soon after, I was given '280 KTS or better.' at about 16000 ft, the wing/engine anti-ice system were activated which reduced my airplane performance. In addition, we were required to reduce power slightly to stay within engine limitations when the anti-ice system is active. At about FL180, I realized that our speed had decayed to 265 KTS. I reduced the climb rate to regain 280 KTS. At FL220, the controller queried us. He asked if we were still keeping 280 KTS. We responded that we were back up to 270 KTS and accelerating, but would have a very low climb rate. The controller reminded us that 280 KTS was our assigned speed and that he needed that speed. He also reminded us that there was traffic behind us. I quickly regained my airspeed. We exited icing/IMC at approximately FL260. To my knowledge, no other aircraft had to maneuver or be vectored for my error. This was a fairly busy day which contributed to my being distraction. The main action that could have prevented this situation altogether would have been to climb using the 'speed mode' on the autoplt instead of the 'vertical speed' mode. This is a common practice among pilots of this type of airplane as 'vertical speed mode' seems to be smoother and 'speed' of 'indicated speed mode' tends to 'hunt' for the speed while oscillating slightly in pitch. I should have also anticipated the reduced airplane performance from activating the anti-ice system.

Original NASA ASRS Text

Title: SPD DEV FROM CLRNC WHEN THE FLT CREW OF A CE560 ALLOWS THE SPD TO DROP OFF WHILE USING THE VERT SPD MODE OF THEIR AUTOPLT ON FREQ WITH ZDC, DC.

Narrative: ON CLBOUT FROM IAD, I WAS GIVEN AN ALT ASSIGNMENT OF APPROX FL270. SOON AFTER, I WAS GIVEN '280 KTS OR BETTER.' AT ABOUT 16000 FT, THE WING/ENG ANTI-ICE SYS WERE ACTIVATED WHICH REDUCED MY AIRPLANE PERFORMANCE. IN ADDITION, WE WERE REQUIRED TO REDUCE PWR SLIGHTLY TO STAY WITHIN ENG LIMITATIONS WHEN THE ANTI-ICE SYS IS ACTIVE. AT ABOUT FL180, I REALIZED THAT OUR SPD HAD DECAYED TO 265 KTS. I REDUCED THE CLB RATE TO REGAIN 280 KTS. AT FL220, THE CTLR QUERIED US. HE ASKED IF WE WERE STILL KEEPING 280 KTS. WE RESPONDED THAT WE WERE BACK UP TO 270 KTS AND ACCELERATING, BUT WOULD HAVE A VERY LOW CLB RATE. THE CTLR REMINDED US THAT 280 KTS WAS OUR ASSIGNED SPD AND THAT HE NEEDED THAT SPD. HE ALSO REMINDED US THAT THERE WAS TFC BEHIND US. I QUICKLY REGAINED MY AIRSPD. WE EXITED ICING/IMC AT APPROX FL260. TO MY KNOWLEDGE, NO OTHER ACFT HAD TO MANEUVER OR BE VECTORED FOR MY ERROR. THIS WAS A FAIRLY BUSY DAY WHICH CONTRIBUTED TO MY BEING DISTR. THE MAIN ACTION THAT COULD HAVE PREVENTED THIS SIT ALTOGETHER WOULD HAVE BEEN TO CLB USING THE 'SPD MODE' ON THE AUTOPLT INSTEAD OF THE 'VERT SPD' MODE. THIS IS A COMMON PRACTICE AMONG PLTS OF THIS TYPE OF AIRPLANE AS 'VERT SPD MODE' SEEMS TO BE SMOOTHER AND 'SPD' OF 'INDICATED SPD MODE' TENDS TO 'HUNT' FOR THE SPD WHILE OSCILLATING SLIGHTLY IN PITCH. I SHOULD HAVE ALSO ANTICIPATED THE REDUCED AIRPLANE PERFORMANCE FROM ACTIVATING THE ANTI-ICE SYS.

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.

Speed deviation from clearance when the flight crew of a CE560 allows the speed to drop off while using the vertical speed mode of their autoplt on frequency with ZDC, dc.