Atx cargo pilot misidentifies kwang intersection on VOR runway 25 at sba, descends early.

Attributes
ACN	144933
Time
Date	199005
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : gvo airport : sba
State Reference	CA
Altitude	msl bound lower : 2100 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sba
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	descent : approach
Route In Use	approach : straight in enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 2600 flight time type : 30
ASRS Report	144933
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : published procedure non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : insufficient time
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

When cleared for the sba VOR runway 25 approach, I was issued the restriction 'cross kwang at 4000.' I apparently misidented kwang intersection nd commenced my descent to 2100' more than 3 mi early, leading to an admonition from ATC. I used the san marcus 119 degree right and the final approach course to identify the intersection, leaving the DME in the hold function displaying the ILS DME distance to the airport. Therefore I had no backup means to verify my position over the intersection (which has a DME definition off the gaviota VOR). I later verified proper operation of the equipment, so the most likely explanation is that the obs on the #2 VOR was misset. The #2 VOR display head is difficult to see in this aircraft west/O bending the head and upper torso well down for a better look. Knowing this to be the case, I should have used DME to confirm my identify of the fix.

Original NASA ASRS Text

Title: ATX CARGO PLT MISIDENTIFIES KWANG INTERSECTION ON VOR RWY 25 AT SBA, DESCENDS EARLY.

Narrative: WHEN CLRED FOR THE SBA VOR RWY 25 APCH, I WAS ISSUED THE RESTRICTION 'CROSS KWANG AT 4000.' I APPARENTLY MISIDENTED KWANG INTXN ND COMMENCED MY DSNT TO 2100' MORE THAN 3 MI EARLY, LEADING TO AN ADMONITION FROM ATC. I USED THE SAN MARCUS 119 DEG R AND THE FINAL APCH COURSE TO IDENT THE INTXN, LEAVING THE DME IN THE HOLD FUNCTION DISPLAYING THE ILS DME DISTANCE TO THE ARPT. THEREFORE I HAD NO BACKUP MEANS TO VERIFY MY POS OVER THE INTXN (WHICH HAS A DME DEFINITION OFF THE GAVIOTA VOR). I LATER VERIFIED PROPER OPERATION OF THE EQUIP, SO THE MOST LIKELY EXPLANATION IS THAT THE OBS ON THE #2 VOR WAS MISSET. THE #2 VOR DISPLAY HEAD IS DIFFICULT TO SEE IN THIS ACFT W/O BENDING THE HEAD AND UPPER TORSO WELL DOWN FOR A BETTER LOOK. KNOWING THIS TO BE THE CASE, I SHOULD HAVE USED DME TO CONFIRM MY IDENT OF THE FIX.

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.