King air flight crew reported inadvertently entering class B airspace.

Attributes
ACN	1538590
Time
Date	201804
Local Time Of Day	1801-2400
Place
Locale Reference	CPS.Airport
State Reference	MO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	King Air C90 E90
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	None
Flight Plan	None
Person 1
Function	Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 17300 Flight Crew Type 1000
Person 2
Function	Pilot Flying
Qualification	Flight Crew Private Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 20 Flight Crew Total 2050 Flight Crew Type 60
Events
Anomaly	Airspace Violation All Types Deviation - Procedural FAR Deviation - Procedural Published Material / Policy

Narrative:

Acting as safety pilot for pilot relatively new to aircraft. Conditions were good VFR. Repositioning aircraft to drop off pilot flying. Departed cps to north-northeast to remain below class B airspace. We had left cps tower airspace but were not receiving radar advisories. Looking at outer rings of class B and saw floor of ring we thought we were inside as 5000 ft.misidentified confines (segment of the ring) and failed to realize there was a dividing line. Floor was actually 4000 ft. We had climbed to 4500 ft and realizing the mistake immediately returned to 3500 feet. We crossed that dividing line moments later to the higher floor. We continued to circumnavigate the class B until our direct route kept us clear.[I] was viewing the class B chart on a jeppesen VFR electronic chart and did not readily spot the proper class B limits for that area of the chart which lead to the possible inadvertent penetration of the airspace. In the future; plan to closely examine the airspace prior to VFR flight in the vicinity of unfamiliar class B airspace.

Original NASA ASRS Text

Title: King Air flight crew reported inadvertently entering Class B Airspace.

Narrative: Acting as safety pilot for pilot relatively new to aircraft. Conditions were good VFR. Repositioning aircraft to drop off pilot flying. Departed CPS to north-northeast to remain below Class B airspace. We had left CPS Tower airspace but were not receiving radar advisories. Looking at outer rings of Class B and saw floor of ring we thought we were inside as 5000 ft.Misidentified confines (segment of the ring) and failed to realize there was a dividing line. Floor was actually 4000 ft. We had climbed to 4500 ft and realizing the mistake immediately returned to 3500 feet. We crossed that dividing line moments later to the higher floor. We continued to circumnavigate the Class B until our direct route kept us clear.[I] was viewing the Class B chart on a Jeppesen VFR Electronic Chart and did not readily spot the proper Class B limits for that area of the chart which lead to the possible inadvertent penetration of the airspace. In the future; plan to closely examine the airspace prior to VFR flight in the vicinity of unfamiliar Class B airspace.

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.