C172 pilot discovers after being cleared for the ILS that his glide slope has failed. This informati...

Attributes
ACN	910930
Time
Date	201009
Local Time Of Day	0001-0600
Place
Locale Reference	A90.TRACON
State Reference	NH
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	ILS/VOR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 160 Flight Crew Total 385 Flight Crew Type 345
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

In flight I discovered that my glide slope was not working. I failed to communicate this to ATC. I was not aware of this failure before the flight. Boston approach asked me if I had intercepted the localizer which I had. I followed the localizer and got distracted because my glide slope never came in. The localizer went almost to full scale deflection before I noticed that it was deflected. Boston approach never questioned my vertical or lateral navigation except to ask me if I had intercepted the localizer. When I passed over the LOM; I descended as I would on a localizer approach (without vertical guidance). After being handed over to lwm tower; I was informed of a low altitude warning. I reported that I had broken out of the clouds and had the runway in sight. From my perspective; I broke out of the clouds at an altitude to make a normal glide path to the runway. To prevent this from reoccurring; ATC should question the pilot in flight of the error in navigation. Boston must have noticed some error and did not notify me until I was on the ground with lwm ground. I was in error for not reporting an equipment malfunction.

Original NASA ASRS Text

Title: C172 pilot discovers after being cleared for the ILS that his glide slope has failed. This information is not conveyed to ATC. The approach is continued using LOC minimums and a low altitude alert is generated before the reporter descends below the overcast and lands.

Narrative: In flight I discovered that my glide slope was not working. I failed to communicate this to ATC. I was not aware of this failure before the flight. Boston Approach asked me if I had intercepted the localizer which I had. I followed the localizer and got distracted because my glide slope never came in. The localizer went almost to full scale deflection before I noticed that it was deflected. Boston Approach never questioned my vertical or lateral navigation except to ask me if I had intercepted the localizer. When I passed over the LOM; I descended as I would on a localizer approach (without vertical guidance). After being handed over to LWM Tower; I was informed of a low altitude warning. I reported that I had broken out of the clouds and had the runway in sight. From my perspective; I broke out of the clouds at an altitude to make a normal glide path to the runway. To prevent this from reoccurring; ATC should question the pilot in flight of the error in navigation. Boston must have noticed some error and did not notify me until I was on the ground with LWM Ground. I was in error for not reporting an equipment malfunction.

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.

C172 pilot discovers after being cleared for the ILS that his glide slope has failed. This information is not conveyed to ATC. The approach is continued using localizer minimums and a low altitude alert is generated before the reporter descends below the overcast and lands.