Narrative:

Regarding my report. My original txt was as follows. 'FMS boxes do not display the sjd 'VOR DME-1 runway 34' correctly. Boxes show the final approach fix at 6 DME 2200 ft instead of 4 DME 1500 ft as shown on the paper approach chart.' the flight department response was as follows; 'thank you for submitting your report concerning FMS database error on sjd. Flight operations advised the following in response to your event -- the issue here is not a database error but a limitation. The FMS is only capable of displaying one type of approach to each runway. In this case VOR DME-2 runway 34 page and VOR runway 34 page are in the database. The referenced procedure with a FAF at 4 DME at 1500 ft VOR DME-1 runway 34; page is not in the database. If the approach is not in the database; it can still be flown using raw data.' in the interests of safety I must advise that I am reasonably certain the flight department may be wrong in their response. The VOR DME-1 runway 34 is in the FMS database and can be found by selecting the arrivals page; then selecting 'vord 34' being careful to get the one with the D in it; then selecting the 'sjd' transition. This FMS entry shows a tear drop entry to runway 34 tracking outbound on the sjd 143 radial and the only paper page that shows a teardrop entry for runway 34 that tracks outbound on the sjd 143 radial is the VOR DME-1 runway 34 paper page. The VOR DME-2 runway 34 paper page does not depict an sjd transition and does not depict a teardrop entry tracking outbound on the sjd 143 radial. The VOR runway 34 page does not depict a teardrop entry tracking outbound on the sjd 143 radial. This leads me to conclude the VOR DME-1 runway 34 is in the FMS database. This brings me back to my original point in my original report. For the VOR DME-1 runway 34 the FMS shows the final approach fix at 6 DME 2200 ft instead of 4 DME 1500 ft as shown on the paper approach chart. The FMS boxes do not display the sjd 'VOR DME-1 runway 34' correctly. Both boxes show the final approach fix at 6 DME 2200 ft instead of 4 DME 1500 ft as shown on the paper approach chart.callback conversation with reporter revealed the following information: after additional investigations the reporter discovered that some older FMS system coding cannot accept step down fix information. In order to accommodate those machines the apches are coded so that what would be the step down fix becomes a point on the approach and the fix prior to the step down becomes the FAF. The descent path is adjusted so as to arrive over what was the original FAF at the required altitude. This anomaly applies to some early generation FMS and is not confined to just this particular mmsd approach.

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Original NASA ASRS Text

Title: AN ACR PILOT REPORTS THE SJD VOR DME-1 RWY 34 FINAL APCH FIX IS ACTUALLY 1500 FT AT 4 DME BUT THE FMS DATABASE DISPLAYS IT AT 2200 FT AND 6 DME.

Narrative: REGARDING MY REPORT. MY ORIGINAL TXT WAS AS FOLLOWS. 'FMS BOXES DO NOT DISPLAY THE SJD 'VOR DME-1 RWY 34' CORRECTLY. BOXES SHOW THE FINAL APCH FIX AT 6 DME 2200 FT INSTEAD OF 4 DME 1500 FT AS SHOWN ON THE PAPER APCH CHART.' THE FLT DEPARTMENT RESPONSE WAS AS FOLLOWS; 'THANK YOU FOR SUBMITTING YOUR REPORT CONCERNING FMS DATABASE ERROR ON SJD. FLT OPERATIONS ADVISED THE FOLLOWING IN RESPONSE TO YOUR EVENT -- THE ISSUE HERE IS NOT A DATABASE ERROR BUT A LIMITATION. THE FMS IS ONLY CAPABLE OF DISPLAYING ONE TYPE OF APCH TO EACH RWY. IN THIS CASE VOR DME-2 RWY 34 PAGE AND VOR RWY 34 PAGE ARE IN THE DATABASE. THE REFERENCED PROC WITH A FAF AT 4 DME AT 1500 FT VOR DME-1 RWY 34; PAGE IS NOT IN THE DATABASE. IF THE APCH IS NOT IN THE DATABASE; IT CAN STILL BE FLOWN USING RAW DATA.' IN THE INTERESTS OF SAFETY I MUST ADVISE THAT I AM REASONABLY CERTAIN THE FLT DEPARTMENT MAY BE WRONG IN THEIR RESPONSE. THE VOR DME-1 RWY 34 IS IN THE FMS DATABASE AND CAN BE FOUND BY SELECTING THE ARRIVALS PAGE; THEN SELECTING 'VORD 34' BEING CAREFUL TO GET THE ONE WITH THE D IN IT; THEN SELECTING THE 'SJD' TRANSITION. THIS FMS ENTRY SHOWS A TEAR DROP ENTRY TO RWY 34 TRACKING OUTBOUND ON THE SJD 143 RADIAL AND THE ONLY PAPER PAGE THAT SHOWS A TEARDROP ENTRY FOR RWY 34 THAT TRACKS OUTBOUND ON THE SJD 143 RADIAL IS THE VOR DME-1 RWY 34 PAPER PAGE. THE VOR DME-2 RWY 34 PAPER PAGE DOES NOT DEPICT AN SJD TRANSITION AND DOES NOT DEPICT A TEARDROP ENTRY TRACKING OUTBOUND ON THE SJD 143 RADIAL. THE VOR RWY 34 PAGE DOES NOT DEPICT A TEARDROP ENTRY TRACKING OUTBOUND ON THE SJD 143 RADIAL. THIS LEADS ME TO CONCLUDE THE VOR DME-1 RWY 34 IS IN THE FMS DATABASE. THIS BRINGS ME BACK TO MY ORIGINAL POINT IN MY ORIGINAL REPORT. FOR THE VOR DME-1 RWY 34 THE FMS SHOWS THE FINAL APCH FIX AT 6 DME 2200 FT INSTEAD OF 4 DME 1500 FT AS SHOWN ON THE PAPER APCH CHART. THE FMS BOXES DO NOT DISPLAY THE SJD 'VOR DME-1 RWY 34' CORRECTLY. BOTH BOXES SHOW THE FINAL APCH FIX AT 6 DME 2200 FT INSTEAD OF 4 DME 1500 FT AS SHOWN ON THE PAPER APCH CHART.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: AFTER ADDITIONAL INVESTIGATIONS THE REPORTER DISCOVERED THAT SOME OLDER FMS SYSTEM CODING CANNOT ACCEPT STEP DOWN FIX INFORMATION. IN ORDER TO ACCOMMODATE THOSE MACHINES THE APCHES ARE CODED SO THAT WHAT WOULD BE THE STEP DOWN FIX BECOMES A POINT ON THE APCH AND THE FIX PRIOR TO THE STEP DOWN BECOMES THE FAF. THE DESCENT PATH IS ADJUSTED SO AS TO ARRIVE OVER WHAT WAS THE ORIGINAL FAF AT THE REQUIRED ALTITUDE. THIS ANOMALY APPLIES TO SOME EARLY GENERATION FMS AND IS NOT CONFINED TO JUST THIS PARTICULAR MMSD 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.