General aviation pilot reported concern with the class B floor limit east of phx.

Attributes
ACN	1552490
Time
Date	201806
Local Time Of Day	1201-1800
Place
Locale Reference	PHX.Airport
State Reference	AZ
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 65 Flight Crew Total 3040 Flight Crew Type 1109
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

Narrative:

Departed falcon field VFR. Climbed to 4;700 feet and leveled off to remain outside class bravo. Just west of boundary to bravo; began climb to enroute altitude. We never entered class B; however; we were within 200 feet of the lower limit when we transitioned the boundary. At that time; we noticed an airliner fly directly overhead. I don't believe there was any conflict; and I was not inside the bravo; however it was closer proximity than usual; so I thought I would report. My flightaware data shows me flying level at 4;700 feet below the bravo. This airspace is too low considering the proximity to the terrain to the east. There has been at least one fatal accident as a result. I don't believe the FAA would have kept the base of the class bravo at 5;000 feet that far east had they flown the area. It creates an unnecessary hazard.

Original NASA ASRS Text

Title: General aviation pilot reported concern with the Class B floor limit east of PHX.

Narrative: Departed Falcon Field VFR. Climbed to 4;700 feet and leveled off to remain outside class Bravo. Just west of boundary to Bravo; began climb to enroute altitude. We never entered class B; however; we were within 200 feet of the lower limit when we transitioned the boundary. At that time; we noticed an airliner fly directly overhead. I don't believe there was any conflict; and I was not inside the Bravo; however it was closer proximity than usual; so I thought I would report. My flightaware data shows me flying level at 4;700 feet below the Bravo. This airspace is too low considering the proximity to the terrain to the east. There has been at least one fatal accident as a result. I don't believe the FAA would have kept the base of the Class Bravo at 5;000 feet that far east had they flown the area. It creates an unnecessary hazard.

Data retrieved from NASA's ASRS site 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.