B757 crew discovered an FMC database error on the mia 4 SID at mia.

Attributes
ACN	476613
Time
Date	200006
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mia.airport
State Reference	FL
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : parked
Route In Use	departure sid : mia 4
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	476613
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Company
Primary Problem	Ambiguous
Situations
Chart	sid : mia 4

Narrative:

FMS navigation database in error. On this flight I was cleared the MIA4 departure with a winco transition. The navigation database erroneously shows the course to departure beginning at the end of runway 9L direct to the winco intersection. Winco intersection is defined by the dhp 322 degree radial. Therefore, the navigation database should show that the magenta course begins at dhp VOR and then continues out the 322 degree radial to winco. My first officer mentioned he has observed similar incorrect courses in the valley transition leaving mia. It seems that only the mia navigation database is in error in these departure courses. I have never observed a similar problem at other airports. I discovered the error at the gate before departure and had no trouble correcting the FMC to properly display the route of flight. The errors in this airport's database are potential traps for flcs on departure.

Original NASA ASRS Text

Title: B757 CREW DISCOVERED AN FMC DATABASE ERROR ON THE MIA 4 SID AT MIA.

Narrative: FMS NAV DATABASE IN ERROR. ON THIS FLT I WAS CLRED THE MIA4 DEP WITH A WINCO TRANSITION. THE NAV DATABASE ERRONEOUSLY SHOWS THE COURSE TO DEP BEGINNING AT THE END OF RWY 9L DIRECT TO THE WINCO INTXN. WINCO INTXN IS DEFINED BY THE DHP 322 DEG RADIAL. THEREFORE, THE NAV DATABASE SHOULD SHOW THAT THE MAGENTA COURSE BEGINS AT DHP VOR AND THEN CONTINUES OUT THE 322 DEG RADIAL TO WINCO. MY FO MENTIONED HE HAS OBSERVED SIMILAR INCORRECT COURSES IN THE VALLEY TRANSITION LEAVING MIA. IT SEEMS THAT ONLY THE MIA NAV DATABASE IS IN ERROR IN THESE DEP COURSES. I HAVE NEVER OBSERVED A SIMILAR PROB AT OTHER ARPTS. I DISCOVERED THE ERROR AT THE GATE BEFORE DEP AND HAD NO TROUBLE CORRECTING THE FMC TO PROPERLY DISPLAY THE RTE OF FLT. THE ERRORS IN THIS ARPT'S DATABASE ARE POTENTIAL TRAPS FOR FLCS ON DEP.

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.