Small aircraft pilot lands off airport as engine sputters on approach.

Attributes
ACN	153806
Time
Date	199008
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : btr
State Reference	LA
Altitude	agl bound lower : 70 agl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : btr
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach landing other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 7 flight time total : 70
ASRS Report	153806
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

About to turn final for 4L btf, engine seemed to be choking--went on and off. Mississippi river and urban area ahead before the runway. Runway was 405 mi ahead. I checked flight controls and engine INS (mixture, carburetor heat, etc). I decided to make an emergency landing as I was not sure I had enough time to make to the runway with unidented engine trouble. Landed on an empty highway (rural highway la 98?) 2 or 3 mins short of the airport. Checking fuel level, there was some reserve although the fuel level was low. I believe I had 30-40 mins of reserve as flying time from austin to btr was 3 hours, 15 mins. Factors leading to emergency landing: in my opinion, aircraft altitude and turbulence on descent and turn to final prevented engine from getting appropriate proportion of fuel from both wing tanks with the low fuel level. Slight deviation from optimum cruise RPM setting caused a higher fuel burn rate than originally calculated in flight plan.

Original NASA ASRS Text

Title: SMA PLT LANDS OFF ARPT AS ENGINE SPUTTERS ON APCH.

Narrative: ABOUT TO TURN FINAL FOR 4L BTF, ENG SEEMED TO BE CHOKING--WENT ON AND OFF. MISSISSIPPI RIVER AND URBAN AREA AHEAD BEFORE THE RWY. RWY WAS 405 MI AHEAD. I CHKED FLT CTLS AND ENG INS (MIXTURE, CARB HEAT, ETC). I DECIDED TO MAKE AN EMER LNDG AS I WAS NOT SURE I HAD ENOUGH TIME TO MAKE TO THE RWY WITH UNIDENTED ENG TROUBLE. LANDED ON AN EMPTY HWY (RURAL HWY LA 98?) 2 OR 3 MINS SHORT OF THE ARPT. CHKING FUEL LEVEL, THERE WAS SOME RESERVE ALTHOUGH THE FUEL LEVEL WAS LOW. I BELIEVE I HAD 30-40 MINS OF RESERVE AS FLYING TIME FROM AUSTIN TO BTR WAS 3 HRS, 15 MINS. FACTORS LEADING TO EMER LNDG: IN MY OPINION, ACFT ALT AND TURB ON DSNT AND TURN TO FINAL PREVENTED ENG FROM GETTING APPROPRIATE PROPORTION OF FUEL FROM BOTH WING TANKS WITH THE LOW FUEL LEVEL. SLIGHT DEVIATION FROM OPTIMUM CRUISE RPM SETTING CAUSED A HIGHER FUEL BURN RATE THAN ORIGINALLY CALCULATED IN FLT PLAN.

Data retrieved from NASA's ASRS site as of July 2007 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.