M20P pilot entered pbi class C airspace without clearance, while following GPS navigation.

Attributes
ACN	503480
Time
Date	200103
Day	Thu
Local Time Of Day	1201 To 1800
Place
State Reference	FL
Altitude	msl single value : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mlb.tower
Operator	general aviation : personal
Make Model Name	M-20 B/C Ranger
Operating Under FAR Part	Part 91
Navigation In Use	other other
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 30 flight time total : 3500 flight time type : 100
ASRS Report	503480
Events
Anomaly	airspace violation : entry non adherence : far non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended or assigned course flight crew : exited penetrated airspace none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Almost made incursion into pbi TCA airport area. Had a GPS glitch. Had tuned in 'nearest' and GPS showed ilna, my original destination. Somehow the GPS dropped klna and switched to kpbi! Since it was almost same track, I did not notice that the GPS was now on kpbi and continued on. When I saw the airport in the distance, I knew it was not klna, as I am very familiar with the area, but was relying on the GPS. I don't know for sure if I breached the TCA area, but am reporting this very near miss.

Original NASA ASRS Text

Title: M20P PLT ENTERED PBI CLASS C AIRSPACE WITHOUT CLRNC, WHILE FOLLOWING GPS NAV.

Narrative: ALMOST MADE INCURSION INTO PBI TCA ARPT AREA. HAD A GPS GLITCH. HAD TUNED IN 'NEAREST' AND GPS SHOWED ILNA, MY ORIGINAL DEST. SOMEHOW THE GPS DROPPED KLNA AND SWITCHED TO KPBI! SINCE IT WAS ALMOST SAME TRACK, I DID NOT NOTICE THAT THE GPS WAS NOW ON KPBI AND CONTINUED ON. WHEN I SAW THE ARPT IN THE DISTANCE, I KNEW IT WAS NOT KLNA, AS I AM VERY FAMILIAR WITH THE AREA, BUT WAS RELYING ON THE GPS. I DON'T KNOW FOR SURE IF I BREACHED THE TCA AREA, BUT AM RPTING THIS VERY NEAR MISS.

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.