A pilot flying the tri runway 23 localizer approach had a CFIT when he descended early below the FAF...

Narrative:

On diverting to an alternate; I received the ATIS; and was being vectored and cleared for the ILS runway 23 to tri. After receiving the clearance; the controller came back to me and explained that he had just 'come on' and was not aware that the glideslope was out of service. He apologized; and amended my approach clearance to the localizer runway 23. I don't remember the specific ceiling being reported; but I asked if anyone had got in on the localizer thinking that the weather was too low. He checked with the tower; and replied 'yes.' I remember the surface winds being reported as 'calm' and inquired about the ILS runway 5. I accepted the clearance for localizer runway 23; but with all the radio transmissions going on (cockpit distractions); I never gave myself time to 'brief the approach.' as soon as I was established; I started down to my first step down fix. Problem was I was still outside the FAF. I never received a taws alert; but realized my mistake when I received a terrain alert from my number 2 nav comm (GNS430.) I arrested my descent; and in doing so the alert went away; and I had that 'holy crap' moment realizing what I had done and my potentially fatal CFIT situation. At that point I continued on the approach; and being in 'shock' over the mistake I just made; missed my next and final step down fix to MDA. As I continued to map there was a small break in the overcast; but being high and in no place to make a stabilized approach to landing; I executed and reported 'missed approach' to the tower. They handed me back to TRACON and I was vectored to the ILS runway 5 approach which concluded in a normal approach and landing. While I found no unusual hazards in my preflight risk assessment; it is apparent that my lack of familiarity with my destination airport combined with the lack of time for an approach briefing led to a lack of situational awareness in the approach procedure. In hindsight; better CRM may have included asking for vectors to come around again to intercept the final approach course which would have allowed time for an appropriate approach briefing. What a trap! Never again!

Original NASA ASRS Text

Title: A pilot flying the TRI Runway 23 LOC approach had a CFIT when he descended early below the FAF crossing altitude because he failed to debrief the approach after being told the ILS was out of service.

Narrative: On diverting to an alternate; I received the ATIS; and was being vectored and cleared for the ILS Runway 23 to TRI. After receiving the clearance; the Controller came back to me and explained that he had just 'come on' and was not aware that the glideslope was out of service. He apologized; and amended my approach clearance to the LOC Runway 23. I don't remember the specific ceiling being reported; but I asked if anyone had got in on the localizer thinking that the weather was too low. He checked with the Tower; and replied 'yes.' I remember the surface winds being reported as 'calm' and inquired about the ILS Runway 5. I accepted the clearance for LOC Runway 23; but with all the radio transmissions going on (cockpit distractions); I never gave myself time to 'brief the approach.' As soon as I was established; I started down to my first step down fix. Problem was I was still outside the FAF. I never received a TAWS alert; but realized my mistake when I received a terrain alert from my Number 2 Nav Comm (GNS430.) I arrested my descent; and in doing so the alert went away; and I had that 'holy crap' moment realizing what I had done and my potentially fatal CFIT situation. At that point I continued on the approach; and being in 'shock' over the mistake I just made; missed my next and final step down fix to MDA. As I continued to MAP there was a small break in the overcast; but being high and in no place to make a stabilized approach to landing; I executed and reported 'missed approach' to the Tower. They handed me back to TRACON and I was vectored to the ILS Runway 5 approach which concluded in a normal approach and landing. While I found no unusual hazards in my Preflight Risk Assessment; it is apparent that my lack of familiarity with my destination airport combined with the lack of time for an approach briefing led to a lack of situational awareness in the approach procedure. In hindsight; better CRM may have included asking for vectors to come around again to intercept the final approach course which would have allowed time for an appropriate approach briefing. What a trap! Never again!

Data retrieved from NASA's ASRS site as of July 2013 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	1090356
Time
Date	201305
Local Time Of Day	0601-1200
Place
Locale Reference	TRI.Airport
State Reference	TN
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	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 47 Flight Crew Total 4005 Flight Crew Type 796
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

A pilot flying the tri runway 23 localizer approach had a CFIT when he descended early below the FAF crossing altitude because he failed to debrief the approach after being told the ILS was out of service.