Altitude excursion from assigned.

Attributes
ACN	313870
Time
Date	199508
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pbi
State Reference	FL
Altitude	msl bound lower : 22400 msl bound upper : 23000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zma
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 125 flight time total : 5700 flight time type : 2800
ASRS Report	313870
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

Cruising through--around storms at FL230 on flight from mco to mia. IMC with light turbulence occasional moderate. ZMA gave clearance to turn left to 140 degrees and descend from FL230 to 14000 ft. Captain started turn to 140 degrees and started to program dfgc to descend. ZMA then said to turn but remain at FL230. At that same moment moderate variable severe turbulence caused the autoplt to disengage and the captain, PF, did not hear ATC rescind the descent clearance. First officer noted the descent, but with the severe turbulence distracting both of us, we had descended to 22400 ft before calling ATC and climbing back up. The turbulence, general bad WX caused enough workload in itself, but ATC giving a clearance to turn and descend then changing their minds so quickly could not be dealt with quick enough.

Original NASA ASRS Text

Title: ALT EXCURSION FROM ASSIGNED.

Narrative: CRUISING THROUGH--AROUND STORMS AT FL230 ON FLT FROM MCO TO MIA. IMC WITH LIGHT TURB OCCASIONAL MODERATE. ZMA GAVE CLRNC TO TURN L TO 140 DEGS AND DSND FROM FL230 TO 14000 FT. CAPT STARTED TURN TO 140 DEGS AND STARTED TO PROGRAM DFGC TO DSND. ZMA THEN SAID TO TURN BUT REMAIN AT FL230. AT THAT SAME MOMENT MODERATE VARIABLE SEVERE TURB CAUSED THE AUTOPLT TO DISENGAGE AND THE CAPT, PF, DID NOT HEAR ATC RESCIND THE DSCNT CLRNC. FO NOTED THE DSCNT, BUT WITH THE SEVERE TURB DISTRACTING BOTH OF US, WE HAD DSNDED TO 22400 FT BEFORE CALLING ATC AND CLBING BACK UP. THE TURB, GENERAL BAD WX CAUSED ENOUGH WORKLOAD IN ITSELF, BUT ATC GIVING A CLRNC TO TURN AND DSND THEN CHANGING THEIR MINDS SO QUICKLY COULD NOT BE DEALT WITH QUICK ENOUGH.

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.