Small aircraft flew less than 1000', possibly less than 500' above the ground.

Attributes
ACN	105058
Time
Date	198902
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : phx
State Reference	AZ
Altitude	agl bound lower : 450 agl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : phx
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 30 flight time total : 232 flight time type : 190
ASRS Report	105058
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Descended below 1000' AGL (may have descended below 500' AGL). Miscalculated altitude required MSL vrs, AGL. Requested and was granted clearance to said altitude by phx approach and phx tower. Corrective measure: pilot should plan more carefully before takeoff. ATC should inform and caution pilot that his altitude request will put him less than 1000' (500') above surface.

Original NASA ASRS Text

Title: SMA FLEW LESS THAN 1000', POSSIBLY LESS THAN 500' ABOVE THE GND.

Narrative: DSNDED BELOW 1000' AGL (MAY HAVE DSNDED BELOW 500' AGL). MISCALCULATED ALT REQUIRED MSL VRS, AGL. REQUESTED AND WAS GRANTED CLRNC TO SAID ALT BY PHX APCH AND PHX TWR. CORRECTIVE MEASURE: PLT SHOULD PLAN MORE CAREFULLY BEFORE TKOF. ATC SHOULD INFORM AND CAUTION PLT THAT HIS ALT REQUEST WILL PUT HIM LESS THAN 1000' (500') ABOVE SURFACE.

Data retrieved from NASA's ASRS site as of August 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.