Citation first officer reports descending below MSA while visually searching for tvl airport.

Attributes
ACN	788592
Time
Date	200805
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tvl.airport
State Reference	CA
Altitude	msl single value : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : rno.tracon
Operator	Other
Make Model Name	Cessna Citation Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer only : 18 other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : atp pilot : multi engine pilot : cfi
Experience	flight time last 90 days : 50 flight time total : 8000 flight time type : 30
ASRS Report	788592
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

While descending for tvl we requested vectors hoping to get the visual approach. We then decided since we were both unfamiliar with the area we should ask for the lda/DME-1 runway 18. We then received a vector and lower altitude for the lda/DME-1 runway 18 approach at tvl. We were asked by center if we were going to be able to make the approach from there. We decided they must think we are too high to make the descent. We responded indicating we would be able to make it. We were handed off to reno approach. We were VMC and the captain stated; this is the lake (by the airport). I believed I could see the runway and stated where I thought it was. The captain stated the airport would not be in the position indicated. We looked at the approach plate and agreed it was not the airport I was seeing. The captain then initiated a descent over the lake. I pointed out we had not intercepted the lda and were not receiving any DME. I stated we should not descend until we are on the lda and had reached a step down point. The captain indicated we were visual so it did not matter. Reno approach called us and told us to check altitude and gave us an altimeter setting. Reno approach then called us and stated an altitude alert; stated the minimum altitude; and what altitude they were showing us at. The captain immediately climbed to the minimum altitude. We then realized the lake we were descending over was not the lake by the airport we were landing at. We had been descending over a smaller lake to the northeast. Contributing factors: not adhering to SOP. Loss of situational awareness. Lack of CRM. Fatigue.

Original NASA ASRS Text

Title: CITATION FO REPORTS DESCENDING BELOW MSA WHILE VISUALLY SEARCHING FOR TVL ARPT.

Narrative: WHILE DSNDING FOR TVL WE REQUESTED VECTORS HOPING TO GET THE VISUAL APCH. WE THEN DECIDED SINCE WE WERE BOTH UNFAMILIAR WITH THE AREA WE SHOULD ASK FOR THE LDA/DME-1 RWY 18. WE THEN RECEIVED A VECTOR AND LOWER ALT FOR THE LDA/DME-1 RWY 18 APCH AT TVL. WE WERE ASKED BY CTR IF WE WERE GOING TO BE ABLE TO MAKE THE APCH FROM THERE. WE DECIDED THEY MUST THINK WE ARE TOO HIGH TO MAKE THE DSCNT. WE RESPONDED INDICATING WE WOULD BE ABLE TO MAKE IT. WE WERE HANDED OFF TO RENO APCH. WE WERE VMC AND THE CAPT STATED; THIS IS THE LAKE (BY THE ARPT). I BELIEVED I COULD SEE THE RWY AND STATED WHERE I THOUGHT IT WAS. THE CAPT STATED THE ARPT WOULD NOT BE IN THE POS INDICATED. WE LOOKED AT THE APCH PLATE AND AGREED IT WAS NOT THE ARPT I WAS SEEING. THE CAPT THEN INITIATED A DSCNT OVER THE LAKE. I POINTED OUT WE HAD NOT INTERCEPTED THE LDA AND WERE NOT RECEIVING ANY DME. I STATED WE SHOULD NOT DSND UNTIL WE ARE ON THE LDA AND HAD REACHED A STEP DOWN POINT. THE CAPT INDICATED WE WERE VISUAL SO IT DID NOT MATTER. RENO APCH CALLED US AND TOLD US TO CHK ALT AND GAVE US AN ALTIMETER SETTING. RENO APCH THEN CALLED US AND STATED AN ALT ALERT; STATED THE MINIMUM ALT; AND WHAT ALT THEY WERE SHOWING US AT. THE CAPT IMMEDIATELY CLBED TO THE MINIMUM ALT. WE THEN REALIZED THE LAKE WE WERE DSNDING OVER WAS NOT THE LAKE BY THE ARPT WE WERE LNDG AT. WE HAD BEEN DSNDING OVER A SMALLER LAKE TO THE NE. CONTRIBUTING FACTORS: NOT ADHERING TO SOP. LOSS OF SITUATIONAL AWARENESS. LACK OF CRM. FATIGUE.

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.