TRACON indications showed the reporter flew through the phx class B airspace at 6500 ft when actuall...

Attributes
ACN	317120
Time
Date	199510
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iwa
State Reference	AZ
Altitude	msl bound lower : 2000 msl bound upper : 11500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phx
Operator	general aviation : corporate
Make Model Name	Citation I
Operating Under FAR Part	Part 91
Flight Phase	descent other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 8 flight time total : 9000 flight time type : 400
ASRS Report	317120
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	non adherence : far non adherence : clearance other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We were descending VFR from 17500 ft, en route from lake havasu to gateway airport. We leveled at 11500 ft until crossing the outer boundary of the phoenix class B airspace. We descended rapidly to enter the gateway airport traffic area and landed. I was then asked to call phoenix TRACON. I spoke to the supervisor and together we reviewed the flight, and discussed the boundaries of the phoenix airspace. We then discussed several arrival and departure procedures that will in the future keep me well clear of those boundaries when VFR. I intend to use the procedures outlined by the supervisor from now on and I sincerely appreciate his cooperation and education. In the future, I intend to file IFR or receive a transponder code from gateway tower prior to departure. Callback conversation with reporter revealed the following information: the reporter stated he was giving instruction to a pilot in a cessna citation 500. The problem was the transponder altitude encoder was telling the phx TRACON he was at 6500 ft when actually the airplane was at 11500 ft.

Original NASA ASRS Text

Title: TRACON INDICATIONS SHOWED THE RPTR FLEW THROUGH THE PHX CLASS B AIRSPACE AT 6500 FT WHEN ACTUALLY THE AIRPLANE WAS AT 11500 FT.

Narrative: WE WERE DSNDING VFR FROM 17500 FT, ENRTE FROM LAKE HAVASU TO GATEWAY ARPT. WE LEVELED AT 11500 FT UNTIL XING THE OUTER BOUNDARY OF THE PHOENIX CLASS B AIRSPACE. WE DSNDED RAPIDLY TO ENTER THE GATEWAY ARPT TFC AREA AND LANDED. I WAS THEN ASKED TO CALL PHOENIX TRACON. I SPOKE TO THE SUPVR AND TOGETHER WE REVIEWED THE FLT, AND DISCUSSED THE BOUNDARIES OF THE PHOENIX AIRSPACE. WE THEN DISCUSSED SEVERAL ARR AND DEP PROCS THAT WILL IN THE FUTURE KEEP ME WELL CLR OF THOSE BOUNDARIES WHEN VFR. I INTEND TO USE THE PROCS OUTLINED BY THE SUPVR FROM NOW ON AND I SINCERELY APPRECIATE HIS COOPERATION AND EDUCATION. IN THE FUTURE, I INTEND TO FILE IFR OR RECEIVE A XPONDER CODE FROM GATEWAY TWR PRIOR TO DEP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED HE WAS GIVING INSTRUCTION TO A PLT IN A CESSNA CITATION 500. THE PROB WAS THE XPONDER ALT ENCODER WAS TELLING THE PHX TRACON HE WAS AT 6500 FT WHEN ACTUALLY THE AIRPLANE WAS AT 11500 FT.

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.

TRACON indications showed the reporter flew through the phx class B airspace at 6500 ft when actually the airplane was at 11500 ft.