E120 crew exceeded 200 KTS below atl class B airspace.

Attributes
ACN	420878
Time
Date	199811
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : atl
State Reference	GA
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : atl tower : atl
Operator	common carrier : air carrier
Make Model Name	Medium Transport, Low Wing, 2 Turboprop Eng
Navigation In Use	Other
Flight Phase	descent : approach descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 2900 flight time type : 2000
ASRS Report	420870
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	non adherence : far other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Flew below class B airspace at 250 KIAS. Contributing factors: return leg from continuous duty overnight (less than 5 hours sleep). Airspace system. Atl approach regularly brings propeller driven aircraft in at such altitudes that a 10 mi 'speed trap' is formed under floor of class B airspace. Why not drop the floor down 2000 ft in those corridors?

Original NASA ASRS Text

Title: E120 CREW EXCEEDED 200 KTS BELOW ATL CLASS B AIRSPACE.

Narrative: FLEW BELOW CLASS B AIRSPACE AT 250 KIAS. CONTRIBUTING FACTORS: RETURN LEG FROM CONTINUOUS DUTY OVERNIGHT (LESS THAN 5 HRS SLEEP). AIRSPACE SYS. ATL APCH REGULARLY BRINGS PROP DRIVEN ACFT IN AT SUCH ALTS THAT A 10 MI 'SPD TRAP' IS FORMED UNDER FLOOR OF CLASS B AIRSPACE. WHY NOT DROP THE FLOOR DOWN 2000 FT IN THOSE CORRIDORS?

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.