Mode C readout problem.

Attributes
ACN	292857
Time
Date	199501
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : cge
State Reference	MD
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	general aviation : corporate
Make Model Name	Citation II S2/Bravo
Operating Under FAR Part	Part 91
Flight Phase	other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 7000
ASRS Report	292857
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
ASRS Report	292860
Events
Anomaly	aircraft equipment problem : less severe other anomaly other other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Unable to receive flight service or ATC or ground at cge. Decided to depart VFR and pick up IFR flight plan airborne over cge, in holding pattern. Upon climb out to 3000 ft MSL, ATC was very busy with military training aircraft and told to stand by for clearance. While circling at 3000 ft MSL we asked center if we were below 3500 ft MSL, would we remain clear of restr areas in vicinity. Response was affirmative. We remained at 3000 ft MSL. After 9 mins of circling, we were assigned a squawk code. After radar identify, controller advised us radar contact at 4000 ft MSL in restr area (R4006) descend and maintain 3000 ft MSL heading 270 degrees. We advised him we were presently at 3000 ft MSL and taking up a course of 270 degrees. We then offered (and then performed) a transponder recycling. We were then handed off to a second center frequency controller 10 mins later. Second controller advised us he did not have a mode C readout and asked us for our climb out (present) altitude. After recycling transponder again, controller had a correct mode C readout. Subsequent controllers reported no problems with our mode C readout. Factors involved: 1) in descent into cge, ZDC advised us we would be unable to receive ATC clearance via radio or ground, depart VFR and pick up IFR airborne. 2) ambiguity of low altitude map (L-30) commercial publication shows R4006 south of area at cge. Copy of L-30 enclosed (it shows restr airspace 3500 ft and above). 3) mode C transponder problems. Note: with all information available to us, we feel we never penetrated any restr airspace.

Original NASA ASRS Text

Title: MODE C READOUT PROB.

Narrative: UNABLE TO RECEIVE FLT SVC OR ATC OR GND AT CGE. DECIDED TO DEPART VFR AND PICK UP IFR FLT PLAN AIRBORNE OVER CGE, IN HOLDING PATTERN. UPON CLBOUT TO 3000 FT MSL, ATC WAS VERY BUSY WITH MIL TRAINING ACFT AND TOLD TO STAND BY FOR CLRNC. WHILE CIRCLING AT 3000 FT MSL WE ASKED CTR IF WE WERE BELOW 3500 FT MSL, WOULD WE REMAIN CLR OF RESTR AREAS IN VICINITY. RESPONSE WAS AFFIRMATIVE. WE REMAINED AT 3000 FT MSL. AFTER 9 MINS OF CIRCLING, WE WERE ASSIGNED A SQUAWK CODE. AFTER RADAR IDENT, CTLR ADVISED US RADAR CONTACT AT 4000 FT MSL IN RESTR AREA (R4006) DSND AND MAINTAIN 3000 FT MSL HDG 270 DEGS. WE ADVISED HIM WE WERE PRESENTLY AT 3000 FT MSL AND TAKING UP A COURSE OF 270 DEGS. WE THEN OFFERED (AND THEN PERFORMED) A XPONDER RECYCLING. WE WERE THEN HANDED OFF TO A SECOND CTR FREQ CTLR 10 MINS LATER. SECOND CTLR ADVISED US HE DID NOT HAVE A MODE C READOUT AND ASKED US FOR OUR CLBOUT (PRESENT) ALT. AFTER RECYCLING XPONDER AGAIN, CTLR HAD A CORRECT MODE C READOUT. SUBSEQUENT CTLRS RPTED NO PROBS WITH OUR MODE C READOUT. FACTORS INVOLVED: 1) IN DSCNT INTO CGE, ZDC ADVISED US WE WOULD BE UNABLE TO RECEIVE ATC CLRNC VIA RADIO OR GND, DEPART VFR AND PICK UP IFR AIRBORNE. 2) AMBIGUITY OF LOW ALT MAP (L-30) COMMERCIAL PUB SHOWS R4006 S OF AREA AT CGE. COPY OF L-30 ENCLOSED (IT SHOWS RESTR AIRSPACE 3500 FT AND ABOVE). 3) MODE C XPONDER PROBS. NOTE: WITH ALL INFO AVAILABLE TO US, WE FEEL WE NEVER PENETRATED ANY RESTR AIRSPACE.

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.