NAVAID problem. - NASA ASRS

Attributes
ACN	300536
Time
Date	199503
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mex
State Reference	FO
Altitude	msl bound lower : 9600 msl bound upper : 9600
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mex
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other other vortac
Flight Phase	descent : approach landing : missed approach
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : cfi
Experience	flight time last 90 days : 140 flight time total : 9000 flight time type : 700
ASRS Report	300536
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other
Situations
ATC Facility	procedure or policy : unspecified
Airport	other physical facility
Navigational Aid	Unspecified

Narrative:

On intercept heading for ILS runway 23L at mex city airport, approach coupler captured localizer, aircraft started to turn to inbound heading when localizer signal was lost. Then LNAV had a large map shift. Approach, when asked if localizer was still working, simply cleared us for a VOR runway 23L approach. We were unable to get any signal for mex VOR, and with airport finally in sight but too high, we executed a go around and told tower who said to fly the published missed approach. Catch 22, the miss is a climb to plaza NDB (mw) then turn left to mex VOR which is off the air. On vectors for the 2ND ILS runway 23L approach, the controller gives us a 110 degree intercept, 4 mi outside the final approach fix. Communication is still a problem but the biggest one is that monitoring equipment for navaids isn't located in the tower or control room where it is needed. Even in the states, the monitor equipment is at the FSS across the field. It should be next to the final controller so when asked by a pilot, he can instantly check it and reply. Then if it is out, the controller can switch to another type of approach or runway.

Original NASA ASRS Text

Title: NAVAID PROB.

Narrative: ON INTERCEPT HDG FOR ILS RWY 23L AT MEX CITY ARPT, APCH COUPLER CAPTURED LOC, ACFT STARTED TO TURN TO INBOUND HDG WHEN LOC SIGNAL WAS LOST. THEN LNAV HAD A LARGE MAP SHIFT. APCH, WHEN ASKED IF LOC WAS STILL WORKING, SIMPLY CLRED US FOR A VOR RWY 23L APCH. WE WERE UNABLE TO GET ANY SIGNAL FOR MEX VOR, AND WITH ARPT FINALLY IN SIGHT BUT TOO HIGH, WE EXECUTED A GAR AND TOLD TWR WHO SAID TO FLY THE PUBLISHED MISSED APCH. CATCH 22, THE MISS IS A CLB TO PLAZA NDB (MW) THEN TURN L TO MEX VOR WHICH IS OFF THE AIR. ON VECTORS FOR THE 2ND ILS RWY 23L APCH, THE CTLR GIVES US A 110 DEG INTERCEPT, 4 MI OUTSIDE THE FINAL APCH FIX. COM IS STILL A PROB BUT THE BIGGEST ONE IS THAT MONITORING EQUIP FOR NAVAIDS ISN'T LOCATED IN THE TWR OR CTL ROOM WHERE IT IS NEEDED. EVEN IN THE STATES, THE MONITOR EQUIP IS AT THE FSS ACROSS THE FIELD. IT SHOULD BE NEXT TO THE FINAL CTLR SO WHEN ASKED BY A PLT, HE CAN INSTANTLY CHK IT AND REPLY. THEN IF IT IS OUT, THE CTLR CAN SWITCH TO ANOTHER TYPE OF APCH OR RWY.

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.