A C150 and a PA28-200R had less than standard separation in lan's class C airspace. The reporting C1...

Attributes
ACN	337202
Time
Date	199605
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lan
State Reference	MI
Altitude	msl bound lower : 2500 msl bound upper : 2800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lan
Operator	general aviation : personal
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	None
Aircraft 2
Make Model Name	PA-28 Cherokee Arrow IV
Operating Under FAR Part	Part 91
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : cfi pilot : commercial
Experience	flight time last 90 days : 15 flight time total : 1400 flight time type : 130
ASRS Report	337202
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	aircraft equipment problem : less severe conflict : airborne less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 600
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Inter Facility Coordination Failure other

Narrative:

Flew from michigan city, in, direct to flint, mi. Got advisories from sbw with no mention of no mode C. Kalamazoo approach said I had no mode C. Asked if this would be a problem landing in flint class C airspace. I was told to keep them advised of no mode C. On return, I notified flint ground mode C was inoperative. When I was handed off from flint to lansing approach, I was questioned by the controller if I had mode C. I was with lansing approach, but outside of the class C airspace. I either reported my altitude as 3500 ft when it was 2500 ft, or the controller misunderstood. I was given a TA that I had traffic at 11 O'clock and 2700 ft. I looked and called no joy. I did see traffic at 8 O'clock and 2500 ft and less than 1/2 mi. I climbed above the traffic and advised the controller traffic went behind me, and I was back at 2500 ft. He was surprised I was at 2500 ft. I am sure I reported 2500 ft previously, but I am also sure there was confusion between me and ATC. The traffic that was called by ATC was never seen by me, but the aircraft that was on a converging course with me was never called out by the controller. I should have periodically reported my altitude to the controller since my mode C was inoperative. Controller should have questioned my altitude as he thought I was at 3500 ft going wbound.

Original NASA ASRS Text

Title: A C150 AND A PA28-200R HAD LTSS IN LAN'S CLASS C AIRSPACE. THE RPTING C150'S MODE C XPONDER BECAME INOP WHILE AIRBORNE.

Narrative: FLEW FROM MICHIGAN CITY, IN, DIRECT TO FLINT, MI. GOT ADVISORIES FROM SBW WITH NO MENTION OF NO MODE C. KALAMAZOO APCH SAID I HAD NO MODE C. ASKED IF THIS WOULD BE A PROB LNDG IN FLINT CLASS C AIRSPACE. I WAS TOLD TO KEEP THEM ADVISED OF NO MODE C. ON RETURN, I NOTIFIED FLINT GND MODE C WAS INOP. WHEN I WAS HANDED OFF FROM FLINT TO LANSING APCH, I WAS QUESTIONED BY THE CTLR IF I HAD MODE C. I WAS WITH LANSING APCH, BUT OUTSIDE OF THE CLASS C AIRSPACE. I EITHER RPTED MY ALT AS 3500 FT WHEN IT WAS 2500 FT, OR THE CTLR MISUNDERSTOOD. I WAS GIVEN A TA THAT I HAD TFC AT 11 O'CLOCK AND 2700 FT. I LOOKED AND CALLED NO JOY. I DID SEE TFC AT 8 O'CLOCK AND 2500 FT AND LESS THAN 1/2 MI. I CLBED ABOVE THE TFC AND ADVISED THE CTLR TFC WENT BEHIND ME, AND I WAS BACK AT 2500 FT. HE WAS SURPRISED I WAS AT 2500 FT. I AM SURE I RPTED 2500 FT PREVIOUSLY, BUT I AM ALSO SURE THERE WAS CONFUSION BTWN ME AND ATC. THE TFC THAT WAS CALLED BY ATC WAS NEVER SEEN BY ME, BUT THE ACFT THAT WAS ON A CONVERGING COURSE WITH ME WAS NEVER CALLED OUT BY THE CTLR. I SHOULD HAVE PERIODICALLY RPTED MY ALT TO THE CTLR SINCE MY MODE C WAS INOP. CTLR SHOULD HAVE QUESTIONED MY ALT AS HE THOUGHT I WAS AT 3500 FT GOING WBOUND.

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.

A C150 and a PA28-200R had less than standard separation in lan's class C airspace. The reporting C150's mode C transponder became inoperative while airborne.