Flight crew of B737-300 experiences flags on the ILS instruments during an IMC approach. Executing t...

Attributes
ACN	399181
Time
Date	199804
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : jac
State Reference	WY
Altitude	msl bound lower : 10000 msl bound upper : 15000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing : missed approach landing : go around
Route In Use	approach : straight in
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 12000 flight time type : 400
ASRS Report	399181
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	controller : issued new clearance other other
Consequence	Other
Miss Distance	vertical : 1000
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We were on an ILS approach in IMC just inside of saker intersection to the jackson hole, wy, airport. At this point I was flying the approach when I got the ILS GS and localizer flags. I asked the copilot if he had lost his ILS guidance, to which he said yes. I then called missed approach, configured the aircraft and had the first officer call center that we had missed the approach. The missed approach altitude is 15000 ft MSL. We were climbing to that altitude when we contacted ATC. ATC then told us to level off at 14000 ft due to another aircraft on the outbound leg of their approach at 15000 ft. We popped out of the clouds about 13500 ft to see another aircraft go right above us at 15000 ft in the opposite direction. Had we not called ATC in such a timely fashion, this could have been a bad deal. When the initial outbound approach and missed approach are published at the same altitude, there is the possibility of a conflict. Had our company not recently published a heads up on this fact, and given the very busy nature of a missed, I may have not called ATC so soon, which could have been hazardous. I have added another feature to my non controled airport procedures -- execute the missed and immediately call ATC. This worked only because we talked to center and I hope others will too. Callback conversation with reporter revealed the following information: reporter states that he filed a report with his chief pilot and called the operations department to assure he was following the procedure properly. He was told that 'you own that space when on a missed approach.' so it appears that the altitude for beginning the approach ought to be at 16000 ft and the missed approach remain at 15000 ft -- at a non tower airport especially. This would separate traffic during the transition for both the approach and the missed. It is just a bad situation to have both flight paths at the same altitude. Without the navigation guidance they were quick to tune in the VOR for some help and were vectored around for a landing. Reporter states that he has had signal interruptions before, but usually further out on the approach.

Original NASA ASRS Text

Title: FLC OF B737-300 EXPERIENCES FLAGS ON THE ILS INSTS DURING AN IMC APCH. EXECUTING THE MISSED APCH THEY RECEIVE A CLRNC TO REMAIN BELOW THE MISSED APCH ALT DUE TO AN ACR ON THE INBOUND FOR THE SAME APCH AT THE SAME ALT.

Narrative: WE WERE ON AN ILS APCH IN IMC JUST INSIDE OF SAKER INTXN TO THE JACKSON HOLE, WY, ARPT. AT THIS POINT I WAS FLYING THE APCH WHEN I GOT THE ILS GS AND LOC FLAGS. I ASKED THE COPLT IF HE HAD LOST HIS ILS GUIDANCE, TO WHICH HE SAID YES. I THEN CALLED MISSED APCH, CONFIGURED THE ACFT AND HAD THE FO CALL CTR THAT WE HAD MISSED THE APCH. THE MISSED APCH ALT IS 15000 FT MSL. WE WERE CLBING TO THAT ALT WHEN WE CONTACTED ATC. ATC THEN TOLD US TO LEVEL OFF AT 14000 FT DUE TO ANOTHER ACFT ON THE OUTBOUND LEG OF THEIR APCH AT 15000 FT. WE POPPED OUT OF THE CLOUDS ABOUT 13500 FT TO SEE ANOTHER ACFT GO RIGHT ABOVE US AT 15000 FT IN THE OPPOSITE DIRECTION. HAD WE NOT CALLED ATC IN SUCH A TIMELY FASHION, THIS COULD HAVE BEEN A BAD DEAL. WHEN THE INITIAL OUTBOUND APCH AND MISSED APCH ARE PUBLISHED AT THE SAME ALT, THERE IS THE POSSIBILITY OF A CONFLICT. HAD OUR COMPANY NOT RECENTLY PUBLISHED A HEADS UP ON THIS FACT, AND GIVEN THE VERY BUSY NATURE OF A MISSED, I MAY HAVE NOT CALLED ATC SO SOON, WHICH COULD HAVE BEEN HAZARDOUS. I HAVE ADDED ANOTHER FEATURE TO MY NON CTLED ARPT PROCS -- EXECUTE THE MISSED AND IMMEDIATELY CALL ATC. THIS WORKED ONLY BECAUSE WE TALKED TO CTR AND I HOPE OTHERS WILL TOO. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT HE FILED A RPT WITH HIS CHIEF PLT AND CALLED THE OPS DEPT TO ASSURE HE WAS FOLLOWING THE PROC PROPERLY. HE WAS TOLD THAT 'YOU OWN THAT SPACE WHEN ON A MISSED APCH.' SO IT APPEARS THAT THE ALT FOR BEGINNING THE APCH OUGHT TO BE AT 16000 FT AND THE MISSED APCH REMAIN AT 15000 FT -- AT A NON TWR ARPT ESPECIALLY. THIS WOULD SEPARATE TFC DURING THE TRANSITION FOR BOTH THE APCH AND THE MISSED. IT IS JUST A BAD SIT TO HAVE BOTH FLT PATHS AT THE SAME ALT. WITHOUT THE NAV GUIDANCE THEY WERE QUICK TO TUNE IN THE VOR FOR SOME HELP AND WERE VECTORED AROUND FOR A LNDG. RPTR STATES THAT HE HAS HAD SIGNAL INTERRUPTIONS BEFORE, BUT USUALLY FURTHER OUT ON THE APCH.

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.

Flight crew of B737-300 experiences flags on the ILS instruments during an IMC approach. Executing the missed approach they receive a clearance to remain below the missed approach altitude due to an air carrier on the inbound for the same approach at the same altitude.