A PA-28 pilot descended on the false glide slope on the mfr runway 14 ILS; before the final approach...

Attributes
ACN	883407
Time
Date	201004
Local Time Of Day	0601-1200
Place
Locale Reference	MFR.Airport
State Reference	OR
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Flight Plan	IFR
Component
Aircraft Component	ILS/VOR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 10000 Flight Crew Type 2000
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

I was vectored for an ILS to runway 14 at medford; oregon. After being cleared for the approach and intercepting the localizer; I observed the glide slope indicator showing glide slope interception. I began decent and tracked the glide slope and localizer about 2 miles prior to reaching the actual glide slope intercept as depicted on the approach plate. I decended 500 ft to an altitude of 4;500 ft at about amase (12.7 DME). Cascade approach called to inform me that I was too low and to cross amase at 5;000 ft. I realized that the glide slope indication was false and began a climb. I then was instructed to climb to 6;300 ft and given vectors for another approach. On the second approach I used the localizer minimums. The false glide slope indication did not show an 'off' flag. I believe that the ILS/VOR receiver installed in the plane was very old and was not receiving signals adequately for navigation. The next day; in VFR weather I could not duplicate the problem. The aircraft owner; also a pilot; was in the right seat and also observed the false reading.

Original NASA ASRS Text

Title: A PA-28 pilot descended on the false glide slope on the MFR Runway 14 ILS; before the Final Approach Fix. TRACON issued a low altitude alert with a climb and vectors for another approach.

Narrative: I was vectored for an ILS to Runway 14 at Medford; Oregon. After being cleared for the approach and intercepting the localizer; I observed the glide slope indicator showing glide slope interception. I began decent and tracked the glide slope and localizer about 2 miles prior to reaching the actual glide slope intercept as depicted on the approach plate. I decended 500 FT to an altitude of 4;500 FT at about AMASE (12.7 DME). Cascade Approach called to inform me that I was too low and to cross AMASE at 5;000 FT. I realized that the glide slope indication was false and began a climb. I then was instructed to climb to 6;300 FT and given vectors for another approach. On the second approach I used the localizer minimums. The false glide slope indication did not show an 'OFF' flag. I believe that the ILS/VOR receiver installed in the plane was very old and was not receiving signals adequately for navigation. The next day; in VFR weather I could not duplicate the problem. The aircraft owner; also a pilot; was in the right seat and also observed the false reading.

Data retrieved from NASA's ASRS site as of April 2012 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 PA-28 pilot descended on the false glide slope on the mfr runway 14 ILS; before the final approach fix. TRACON issued a low altitude alert with a climb and vectors for another approach.