B737-300 flight crew was cleared for an ILS approach. DME was OTS and the flight crew initially desc...

Narrative:

As we were on arrival into mco; the ATIS given indicated they were landing south. We briefed the runway 35R approach and then noted the differences if we were to land on runway 36L. After being switched to approach control about costr intersection; was advised now landing runway 18R. We reprogrammed the FMC for runway 18R. We were still on the LNAV for costr arrival. We were given an easterly heading and a descent. We switched to VOR mode. Noticed DME not working for runway 18R. Checked identify on localizer frequency and had good identify with no indication of DME outage. Given another heading and descent. Inquired to ATC about DME inoperative on runway 18R. He said that that was the first report he had; so I figured we had an equipment failure. I selected the mco VOR quickly to verify DME functionality on aircraft and it worked ok. I switched back to ILS frequency and did not have DME for the frequency. During this time approach gave us a final heading to intercept and another descent. The first officer armed the VOR/localizer approach mode. The first officer noted that there were no points in the FMC for runway 18R except for the FAF and runway 18R and the missed approach points. I then tried to reprogram the FMC to obtain the other fixes. I put in runway 18R and again only the FAF and runway 18R and missed approach points went in. None of the other points along the extended localizer were in the FMC. When I looked up; the aircraft had flown through the localizer. I directed the first officer to fly to the right to re-intercept and called ATC and notified them that we went through the localizer. He gave us a new heading to intercept and another descent. When the first officer re-armed the VOR/localizer mode; the aircraft started to turn left to intercept. He disconnected the autoplt and went back to the right towards the localizer. Told to maintain 3000 ft to hammy. We had no waypoint for hammy in the FMC and no DME to identify the fix. ATC then came back and said that the DME was OTS. Finally intercepted the localizer and was given a descent to 2300 ft to tuffe. About this time the GS came in and we started down the GS. At some point about this time ATC asked us if it was too late to switch to runway 17R. Going down the GS at about 1700 ft; the GS quickly went full scale up. We did not have an abnormal sink rate at any time. I told the first officer to level off and we were at about 1700 ft. By this time we were about tuffe and about 500 ft low but now in VMC and had the field in sight. The GS came back into 'on' GS indication. The landing and taxi in were uneventful. If we had not been in VMC when we realized our altitude and when the GS went quickly full up; we would have gone missed approach. Approach was working multiple aircraft with multiple equipment failures at the field. Runway 17L GS OTS and then the DME failure for runway 18R. The approach chart indicates that DME or radar is required. When the DME was OTS; I'm not sure if ATC tried to reset the ILS for runway 18R which caused the GS deviation we experienced. I never saw a GS flag during the approach.

Original NASA ASRS Text

Title: B737-300 FLT CREW WAS CLEARED FOR AN ILS APCH. DME WAS OTS AND THE FLT CREW INITIALLY DESCENDED ON A 'FALSE' GS; PLACING THEM 500 FT LOW AT THE OM.

Narrative: AS WE WERE ON ARR INTO MCO; THE ATIS GIVEN INDICATED THEY WERE LNDG S. WE BRIEFED THE RWY 35R APCH AND THEN NOTED THE DIFFERENCES IF WE WERE TO LAND ON RWY 36L. AFTER BEING SWITCHED TO APCH CTL ABOUT COSTR INTXN; WAS ADVISED NOW LNDG RWY 18R. WE REPROGRAMMED THE FMC FOR RWY 18R. WE WERE STILL ON THE LNAV FOR COSTR ARR. WE WERE GIVEN AN EASTERLY HDG AND A DSCNT. WE SWITCHED TO VOR MODE. NOTICED DME NOT WORKING FOR RWY 18R. CHKED IDENT ON LOC FREQ AND HAD GOOD IDENT WITH NO INDICATION OF DME OUTAGE. GIVEN ANOTHER HDG AND DSCNT. INQUIRED TO ATC ABOUT DME INOP ON RWY 18R. HE SAID THAT THAT WAS THE FIRST RPT HE HAD; SO I FIGURED WE HAD AN EQUIP FAILURE. I SELECTED THE MCO VOR QUICKLY TO VERIFY DME FUNCTIONALITY ON ACFT AND IT WORKED OK. I SWITCHED BACK TO ILS FREQ AND DID NOT HAVE DME FOR THE FREQ. DURING THIS TIME APCH GAVE US A FINAL HDG TO INTERCEPT AND ANOTHER DSCNT. THE FO ARMED THE VOR/LOC APCH MODE. THE FO NOTED THAT THERE WERE NO POINTS IN THE FMC FOR RWY 18R EXCEPT FOR THE FAF AND RWY 18R AND THE MISSED APCH POINTS. I THEN TRIED TO REPROGRAM THE FMC TO OBTAIN THE OTHER FIXES. I PUT IN RWY 18R AND AGAIN ONLY THE FAF AND RWY 18R AND MISSED APCH POINTS WENT IN. NONE OF THE OTHER POINTS ALONG THE EXTENDED LOC WERE IN THE FMC. WHEN I LOOKED UP; THE ACFT HAD FLOWN THROUGH THE LOC. I DIRECTED THE FO TO FLY TO THE R TO RE-INTERCEPT AND CALLED ATC AND NOTIFIED THEM THAT WE WENT THROUGH THE LOC. HE GAVE US A NEW HDG TO INTERCEPT AND ANOTHER DSCNT. WHEN THE FO RE-ARMED THE VOR/LOC MODE; THE ACFT STARTED TO TURN L TO INTERCEPT. HE DISCONNECTED THE AUTOPLT AND WENT BACK TO THE R TOWARDS THE LOC. TOLD TO MAINTAIN 3000 FT TO HAMMY. WE HAD NO WAYPOINT FOR HAMMY IN THE FMC AND NO DME TO IDENT THE FIX. ATC THEN CAME BACK AND SAID THAT THE DME WAS OTS. FINALLY INTERCEPTED THE LOC AND WAS GIVEN A DSCNT TO 2300 FT TO TUFFE. ABOUT THIS TIME THE GS CAME IN AND WE STARTED DOWN THE GS. AT SOME POINT ABOUT THIS TIME ATC ASKED US IF IT WAS TOO LATE TO SWITCH TO RWY 17R. GOING DOWN THE GS AT ABOUT 1700 FT; THE GS QUICKLY WENT FULL SCALE UP. WE DID NOT HAVE AN ABNORMAL SINK RATE AT ANY TIME. I TOLD THE FO TO LEVEL OFF AND WE WERE AT ABOUT 1700 FT. BY THIS TIME WE WERE ABOUT TUFFE AND ABOUT 500 FT LOW BUT NOW IN VMC AND HAD THE FIELD IN SIGHT. THE GS CAME BACK INTO 'ON' GS INDICATION. THE LNDG AND TAXI IN WERE UNEVENTFUL. IF WE HAD NOT BEEN IN VMC WHEN WE REALIZED OUR ALT AND WHEN THE GS WENT QUICKLY FULL UP; WE WOULD HAVE GONE MISSED APCH. APCH WAS WORKING MULTIPLE ACFT WITH MULTIPLE EQUIP FAILURES AT THE FIELD. RWY 17L GS OTS AND THEN THE DME FAILURE FOR RWY 18R. THE APCH CHART INDICATES THAT DME OR RADAR IS REQUIRED. WHEN THE DME WAS OTS; I'M NOT SURE IF ATC TRIED TO RESET THE ILS FOR RWY 18R WHICH CAUSED THE GS DEV WE EXPERIENCED. I NEVER SAW A GS FLAG DURING THE APCH.

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.

Attributes
ACN	770431
Time
Date	200801
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mco.airport
State Reference	FL
Altitude	msl single value : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mco.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 18r
Flight Phase	descent : approach
Route In Use	arrival star : costr
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 290 flight time type : 290
ASRS Report	770431
Events
Anomaly	altitude deviation : crossing restriction not met other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended or assigned course flight crew : overcame equipment problem
Supplementary
Problem Areas	Navigational Facility Flight Crew Human Performance Aircraft
Primary Problem	Navigational Facility

B737-300 flight crew was cleared for an ILS approach. DME was OTS and the flight crew initially descended on a 'false' GS; placing them 500 ft low at the OM.