Altitude bust. - NASA ASRS

Attributes
ACN	269070
Time
Date	199404
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pbi airport : bct
State Reference	FL
Altitude	msl bound lower : 3500 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pbi
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other cruise other descent : approach
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 35 flight time total : 3000 flight time type : 95
ASRS Report	269070
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On IFR flight plan from grand strand to boca raton, fl, approaching fl mainland from northeast over ocean. Controller issues following clearance. 'Cleared to palm beach, direct boca, descend to 4000 ft, expect VOR approach.' frequency (radio) very congested. Approach chart calls for descent to 1700 ft after palm beach. After crossing palm beach VOR, I started to descend to 1700 ft. Controller asked for altitude and I replied that I was descending to 1700 per published approach chart. He said that he had not cleared me for the approach and that there was traffic at 3 O'clock. I said that I had the traffic. We then had conversation about whether I was VFR and just canceled. Landing was made with no further problem. Confusion was whether or not I was actually cleared for the approach. Controller should have made it clear that I should have maintained 4000 ft even after crossing VOR fix. I confused clearance 'to palm beach direct boca' to mean I was cleared for the approach. The frequency was so busy that there wasn't even an opportunity to clear up the confusion. There was never any traffic conflict.

Original NASA ASRS Text

Title: ALT BUST.

Narrative: ON IFR FLT PLAN FROM GRAND STRAND TO BOCA RATON, FL, APCHING FL MAINLAND FROM NE OVER OCEAN. CTLR ISSUES FOLLOWING CLRNC. 'CLRED TO PALM BEACH, DIRECT BOCA, DSND TO 4000 FT, EXPECT VOR APCH.' FREQ (RADIO) VERY CONGESTED. APCH CHART CALLS FOR DSCNT TO 1700 FT AFTER PALM BEACH. AFTER XING PALM BEACH VOR, I STARTED TO DSND TO 1700 FT. CTLR ASKED FOR ALT AND I REPLIED THAT I WAS DSNDING TO 1700 PER PUBLISHED APCH CHART. HE SAID THAT HE HAD NOT CLRED ME FOR THE APCH AND THAT THERE WAS TFC AT 3 O'CLOCK. I SAID THAT I HAD THE TFC. WE THEN HAD CONVERSATION ABOUT WHETHER I WAS VFR AND JUST CANCELED. LNDG WAS MADE WITH NO FURTHER PROB. CONFUSION WAS WHETHER OR NOT I WAS ACTUALLY CLRED FOR THE APCH. CTLR SHOULD HAVE MADE IT CLR THAT I SHOULD HAVE MAINTAINED 4000 FT EVEN AFTER XING VOR FIX. I CONFUSED CLRNC 'TO PALM BEACH DIRECT BOCA' TO MEAN I WAS CLRED FOR THE APCH. THE FREQ WAS SO BUSY THAT THERE WASN'T EVEN AN OPPORTUNITY TO CLR UP THE CONFUSION. THERE WAS NEVER ANY TFC CONFLICT.

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.