Date: 201305
Local time of day: 0601-1200
Location: TRI.Airport, TN
Flight conditions: IMC
Weather elements / visibility: Rain
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Initial Approach
Airspace: Class E TRI
ATC / advisory: TRACON TRI
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Confusion; Distraction; Situational Awareness; Workload
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning; Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; Flight Crew Executed Go Around / Missed Approach; Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Weather
Primary problem: Human Factors

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!




Synopsis: 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.