A B757 captain reported he regularly receives false egpws terrain warnings flying into ege when the ...

Attributes
ACN	771728
Time
Date	200801
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ege.airport
State Reference	CO
Altitude	msl single value : 7300
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : ege.tower artcc : zzzz.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	771728
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : company policies
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Aircraft Company
Primary Problem	Aircraft

Narrative:

Continue to receive 'terrain terrain' and 'terrain terrain pull up' on final to runway 25 due to map shift on B757 basic FMC aircraft. Pilots and check airmen state that the company is aware of the problem but unable to fix it. I am not sure but have been told this problem does not occur on other FMC equipped B757's. Check airmen brief that this may/can occur on final due to map shift. Also brief about turning off the GPWS switch to silence the very loud alert that can be heard by flight attendants and first class passenger. Problem is this occurs at night and less than clear (ie; snowstorm). B767 QRH maneuvers manual says that compliance with escape maneuver is required (must be daylight clear VMC conditions) even though the runway is clearly visible and the offending terrain is off to the left of centerline. I donT' want capts getting violated for a procedure that check airmen are saying is ok because the company knows about it. Also don't want to get called into the chief pilot's office because a DFDR GPWS event. Solution is to only fly other FMC aircraft into ege.

Original NASA ASRS Text

Title: A B757 CAPT REPORTED HE REGULARLY RECEIVES FALSE EGPWS TERRAIN WARNINGS FLYING INTO EGE WHEN THE AIRCRAFT IS EQUIPPED WITH THE BASIC FMC THAT IS PRONE TO MAP SHIFTS. HE RECOMMENDED HIS ACR ONLY FLY THE MORE ADVANCED FMC AIRCRAFT INTO EGE.

Narrative: CONTINUE TO RECEIVE 'TERRAIN TERRAIN' AND 'TERRAIN TERRAIN PULL UP' ON FINAL TO RWY 25 DUE TO MAP SHIFT ON B757 BASIC FMC ACFT. PLTS AND CHK AIRMEN STATE THAT THE COMPANY IS AWARE OF THE PROB BUT UNABLE TO FIX IT. I AM NOT SURE BUT HAVE BEEN TOLD THIS PROB DOES NOT OCCUR ON OTHER FMC EQUIPPED B757'S. CHK AIRMEN BRIEF THAT THIS MAY/CAN OCCUR ON FINAL DUE TO MAP SHIFT. ALSO BRIEF ABOUT TURNING OFF THE GPWS SWITCH TO SILENCE THE VERY LOUD ALERT THAT CAN BE HEARD BY FLT ATTENDANTS AND FIRST CLASS PAX. PROB IS THIS OCCURS AT NIGHT AND LESS THAN CLR (IE; SNOWSTORM). B767 QRH MANEUVERS MANUAL SAYS THAT COMPLIANCE WITH ESCAPE MANEUVER IS REQUIRED (MUST BE DAYLIGHT CLR VMC CONDITIONS) EVEN THOUGH THE RWY IS CLRLY VISIBLE AND THE OFFENDING TERRAIN IS OFF TO THE L OF CTRLINE. I DONT' WANT CAPTS GETTING VIOLATED FOR A PROC THAT CHK AIRMEN ARE SAYING IS OK BECAUSE THE COMPANY KNOWS ABOUT IT. ALSO DON'T WANT TO GET CALLED INTO THE CHIEF PLT'S OFFICE BECAUSE A DFDR GPWS EVENT. SOLUTION IS TO ONLY FLY OTHER FMC ACFT INTO EGE.

Data retrieved from NASA's ASRS site as of May 2009 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.

A B757 captain reported he regularly receives false egpws terrain warnings flying into ege when the aircraft is equipped with the basic FMC that is prone to map shifts. He recommended his air carrier only fly the more advanced FMC aircraft into ege.