Small aircraft pilot has navigation equipment problem. ATC assist through TCA.

Attributes
ACN	150676
Time
Date	199007
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ttn
State Reference	NJ
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl tower : ttn
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 40 flight time total : 200 flight time type : 100
ASRS Report	150676
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	controller : provided flight assist other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Proceeding N40 to flying west at 2500'. In contact with trenton tower, cleared through the air traffic area. Approaching yardley VOR #1 navigation failed. Dg disagreed with wet compass. This fact not noticed for several mins while I programmed LORAN, N40 to flying west and attempted to resolve course disagreement between #2 navigation and LORAN. When I realized the 2 functioning navigation units totally disagreed and the compass disagreed with the dg I asked trenton for present position and direction to flying west. I felt this action would result in a more accurate course allowing me to remain clear of phl TCA while trying to determine which navigation unit was in error. Trenton had me south of trenton, west of robbinsville and told me to contact phl approach. Phl approach gave me vectors into and through TCA over phl to flying west. They asked if I had a functioning UHF navigation on board, to which I replied no as I did not know at that point what was reliable. Phl approach control gave me my first taste of working with a true professional. While I resolved the navigational error after landing as programming error to the LORAN and discovered the #2 navigation was functioning properly, the phl controller saved me having to attempt navigation with instruments whose reliability were strongly suspect. In the future I check instruments better before takeoff.

Original NASA ASRS Text

Title: SMA PLT HAS NAVIGATION EQUIPMENT PROBLEM. ATC ASSIST THROUGH TCA.

Narrative: PROCEEDING N40 TO FLYING W AT 2500'. IN CONTACT WITH TRENTON TWR, CLRED THROUGH THE ATA. APCHING YARDLEY VOR #1 NAV FAILED. DG DISAGREED WITH WET COMPASS. THIS FACT NOT NOTICED FOR SEVERAL MINS WHILE I PROGRAMMED LORAN, N40 TO FLYING W AND ATTEMPTED TO RESOLVE COURSE DISAGREEMENT BTWN #2 NAV AND LORAN. WHEN I REALIZED THE 2 FUNCTIONING NAV UNITS TOTALLY DISAGREED AND THE COMPASS DISAGREED WITH THE DG I ASKED TRENTON FOR PRESENT POS AND DIRECTION TO FLYING W. I FELT THIS ACTION WOULD RESULT IN A MORE ACCURATE COURSE ALLOWING ME TO REMAIN CLR OF PHL TCA WHILE TRYING TO DETERMINE WHICH NAV UNIT WAS IN ERROR. TRENTON HAD ME S OF TRENTON, W OF ROBBINSVILLE AND TOLD ME TO CONTACT PHL APCH. PHL APCH GAVE ME VECTORS INTO AND THROUGH TCA OVER PHL TO FLYING W. THEY ASKED IF I HAD A FUNCTIONING UHF NAV ON BOARD, TO WHICH I REPLIED NO AS I DID NOT KNOW AT THAT POINT WHAT WAS RELIABLE. PHL APCH CTL GAVE ME MY FIRST TASTE OF WORKING WITH A TRUE PROFESSIONAL. WHILE I RESOLVED THE NAVIGATIONAL ERROR AFTER LNDG AS PROGRAMMING ERROR TO THE LORAN AND DISCOVERED THE #2 NAV WAS FUNCTIONING PROPERLY, THE PHL CTLR SAVED ME HAVING TO ATTEMPT NAV WITH INSTRUMENTS WHOSE RELIABILITY WERE STRONGLY SUSPECT. IN THE FUTURE I CHK INSTRUMENTS BETTER BEFORE TKOF.

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.