Private pilot departing an airport under class B airspace commenced climb and clipped the edge of cl...

Attributes
ACN	398660
Time
Date	199804
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sgr
State Reference	TX
Altitude	msl bound lower : 4000 msl bound upper : 4900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iah
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 15 flight time total : 198 flight time type : 90
ASRS Report	398660
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Departed sgr on a VFR flight plan to san antonio. Sgr is under class B airspace with a 4000 ft floor. The class B boundary is approximately 7 mi west of sgr. My normal rule of thumb is that this is 5 mins from sgr at climb speed, and I generally like to stay 500 ft below the floor. After clearing sgr airspace I contacted FSS to open my flight plan. I then contacted houston departure to request VFR flight following. I reported position as 27 mi east of ela, based on my LORAN which was tracking to ela. ATC reported radar contact at 31.8 mi from iah, my altitude at that point was approaching 4900 ft. On my course that was 2.5 mi from the class B boundary -- computing backwards based on my rate of climb, I estimate my altitude to have been 3700-4100 ft at the class B boundary. ATC did not say anything to me about this, but there was a potential I briefly entered class B airspace. I believe the cause was not allowing enough margin in my 5 min rule of thumb, which eroded my planned 500 ft buffer below the class B airspace.

Original NASA ASRS Text

Title: PVT PLT DEPARTING AN ARPT UNDER CLASS B AIRSPACE COMMENCED CLB AND CLIPPED THE EDGE OF CLASS B IN CLB. CTLR MADE NO COMMENT.

Narrative: DEPARTED SGR ON A VFR FLT PLAN TO SAN ANTONIO. SGR IS UNDER CLASS B AIRSPACE WITH A 4000 FT FLOOR. THE CLASS B BOUNDARY IS APPROX 7 MI W OF SGR. MY NORMAL RULE OF THUMB IS THAT THIS IS 5 MINS FROM SGR AT CLB SPD, AND I GENERALLY LIKE TO STAY 500 FT BELOW THE FLOOR. AFTER CLRING SGR AIRSPACE I CONTACTED FSS TO OPEN MY FLT PLAN. I THEN CONTACTED HOUSTON DEP TO REQUEST VFR FLT FOLLOWING. I RPTED POS AS 27 MI E OF ELA, BASED ON MY LORAN WHICH WAS TRACKING TO ELA. ATC RPTED RADAR CONTACT AT 31.8 MI FROM IAH, MY ALT AT THAT POINT WAS APCHING 4900 FT. ON MY COURSE THAT WAS 2.5 MI FROM THE CLASS B BOUNDARY -- COMPUTING BACKWARDS BASED ON MY RATE OF CLB, I ESTIMATE MY ALT TO HAVE BEEN 3700-4100 FT AT THE CLASS B BOUNDARY. ATC DID NOT SAY ANYTHING TO ME ABOUT THIS, BUT THERE WAS A POTENTIAL I BRIEFLY ENTERED CLASS B AIRSPACE. I BELIEVE THE CAUSE WAS NOT ALLOWING ENOUGH MARGIN IN MY 5 MIN RULE OF THUMB, WHICH ERODED MY PLANNED 500 FT BUFFER BELOW THE CLASS B 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.

Private pilot departing an airport under class B airspace commenced climb and clipped the edge of class B in climb. Controller made no comment.