An first officer report on a speed deviation during an encounter with moderate chop over the rockies...

Attributes
ACN	503940
Time
Date	200103
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : den.ils
State Reference	CO
Altitude	msl bound lower : 33000 msl bound upper : 33800
Environment
Flight Conditions	IMC
Weather Elements	Turbulence Windshear
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : multi engine pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 180 flight time total : 3800 flight time type : 70
ASRS Report	503940
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : turbulence non adherence : clearance other anomaly
Independent Detector	other controllera
Resolutory Action	controller : separated traffic controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Airspace Structure Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We encountered light to moderate chop over the rockies en route to ord from lax. The captain asked me to ask ZAB for higher (FL370). ZAB asked us if we could accelerate to .81 mach (we were at .80 mach). Captain instructed me to reply in the affirmative. We accelerated to .81 mach. Shortly after, the aircraft hit a pocket of moderate chop, sending our airspeed into the overspd warning momentarily. Captain began dialing back the airspeed. I asked if he wanted me to say anything. He answered that we would accelerate back to .81 mach in a few seconds. About 5 mins later, while the captain was adjusting our airspeed, ATC inquired as to our airspeed. The captain responded, 'tell them we're doing .80 mach.' (we were flying at .78 mach.) next, ZAB gave us a climb to FL370. We began our climb. While in the climb, we were at .74 mach. ZAB instructed us to descend back to FL330 and lectured us on the importance of maintaining assigned airspeed. Prior to initiating the climb, the captain attempted to accelerate to .81 mach after ATC inquired about our airspeed, and once again we got a momentary overspd warning due to moderate chop. I felt, in this case, we should have informed ATC that we could not maintain .81 mach due to existing conditions. The captain was continually adjusting the airspeed with the intention first officer accelerating back to .81 mach but conditions prevented this from being possible. Other factor: high time captain and low time probationary first officer.

Original NASA ASRS Text

Title: AN FO RPT ON A SPD DEV DURING AN ENCOUNTER WITH MODERATE CHOP OVER THE ROCKIES 100 MI NW OF DEN, CO.

Narrative: WE ENCOUNTERED LIGHT TO MODERATE CHOP OVER THE ROCKIES ENRTE TO ORD FROM LAX. THE CAPT ASKED ME TO ASK ZAB FOR HIGHER (FL370). ZAB ASKED US IF WE COULD ACCELERATE TO .81 MACH (WE WERE AT .80 MACH). CAPT INSTRUCTED ME TO REPLY IN THE AFFIRMATIVE. WE ACCELERATED TO .81 MACH. SHORTLY AFTER, THE ACFT HIT A POCKET OF MODERATE CHOP, SENDING OUR AIRSPD INTO THE OVERSPD WARNING MOMENTARILY. CAPT BEGAN DIALING BACK THE AIRSPD. I ASKED IF HE WANTED ME TO SAY ANYTHING. HE ANSWERED THAT WE WOULD ACCELERATE BACK TO .81 MACH IN A FEW SECONDS. ABOUT 5 MINS LATER, WHILE THE CAPT WAS ADJUSTING OUR AIRSPD, ATC INQUIRED AS TO OUR AIRSPD. THE CAPT RESPONDED, 'TELL THEM WE'RE DOING .80 MACH.' (WE WERE FLYING AT .78 MACH.) NEXT, ZAB GAVE US A CLB TO FL370. WE BEGAN OUR CLB. WHILE IN THE CLB, WE WERE AT .74 MACH. ZAB INSTRUCTED US TO DSND BACK TO FL330 AND LECTURED US ON THE IMPORTANCE OF MAINTAINING ASSIGNED AIRSPD. PRIOR TO INITIATING THE CLB, THE CAPT ATTEMPTED TO ACCELERATE TO .81 MACH AFTER ATC INQUIRED ABOUT OUR AIRSPD, AND ONCE AGAIN WE GOT A MOMENTARY OVERSPD WARNING DUE TO MODERATE CHOP. I FELT, IN THIS CASE, WE SHOULD HAVE INFORMED ATC THAT WE COULD NOT MAINTAIN .81 MACH DUE TO EXISTING CONDITIONS. THE CAPT WAS CONTINUALLY ADJUSTING THE AIRSPD WITH THE INTENTION FO ACCELERATING BACK TO .81 MACH BUT CONDITIONS PREVENTED THIS FROM BEING POSSIBLE. OTHER FACTOR: HIGH TIME CAPT AND LOW TIME PROBATIONARY FO.

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.

An first officer report on a speed deviation during an encounter with moderate chop over the rockies 100 mi northwest of den, co.