B737-200 crew reduced indicated airspeed without advising ATC in ZJX class east airspace.

Attributes
ACN	517587
Time
Date	200107
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : fll.airport
State Reference	FL
Altitude	msl single value : 15000
Environment
Flight Conditions	VMC
Weather Elements	Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx.artcc tracon : evv.tracon
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : military pilot : multi engine technician : powerplant technician : airframe
Experience	controller non radar : 2.5 controller radar : 2.5 flight time last 90 days : 200 flight time total : 14000 flight time type : 5000
ASRS Report	547587
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : weather inflight encounter other non adherence : published procedure non adherence : far non adherence : clearance non adherence : company policies other anomaly other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued advisory none taken : detected after the fact other
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

At low cruise altitude (FL240) slowed to 230 KIAS when advised through ATIS and company report that thunderstorms were over field. Flew slow for 200 NM and always in radar contact, then descended to 15000 ft and admonished by ATC for not advising them of reduction 20-30 mins ago. We were just allowing time for the WX to move through. Only on arrival with traffic behind, did it matter, but our speed had not changed for quite a while.

Original NASA ASRS Text

Title: B737-200 CREW REDUCED INDICATED AIRSPD WITHOUT ADVISING ATC IN ZJX CLASS E AIRSPACE.

Narrative: AT LOW CRUISE ALT (FL240) SLOWED TO 230 KIAS WHEN ADVISED THROUGH ATIS AND COMPANY RPT THAT TSTMS WERE OVER FIELD. FLEW SLOW FOR 200 NM AND ALWAYS IN RADAR CONTACT, THEN DSNDED TO 15000 FT AND ADMONISHED BY ATC FOR NOT ADVISING THEM OF REDUCTION 20-30 MINS AGO. WE WERE JUST ALLOWING TIME FOR THE WX TO MOVE THROUGH. ONLY ON ARR WITH TFC BEHIND, DID IT MATTER, BUT OUR SPD HAD NOT CHANGED FOR QUITE A WHILE.

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.