Pilot of a C310 penetrated class B airspace due to attempting to fly at an appropriate altitude for ...

Attributes
ACN	368820
Time
Date	199705
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : apa
State Reference	CO
Altitude	msl bound lower : 8700 msl bound upper : 9500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den
Operator	general aviation : instructional
Make Model Name	Cessna 310/T310C
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot instruction : trainee
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 90 flight time total : 1180 flight time type : 4
ASRS Report	368820
Person 2
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : commercial pilot : cfi pilot : instrument
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : exited penetrated airspace
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We departed centennial airport's runway 35R and we were cleared for a right downwind departure. The airport elevation is 5883 ft. Another flight instructor was in the right seat and a third instructor rode in the back right seat. I suggested, after the initial turn to the south after takeoff, we head back to colorado springs at 8500 ft. After about 1 min he suggested we fly back at 9500 ft. We took an initial heading of 150 degrees so, 9500 ft sounded better. I had suggested we fly at 8500 ft because the floor of the class B airspace in that area is 9000 ft. I forgot about that when the PNF suggested 9500 ft for proper VFR cruise altitude. The terrain is 6500 ft rising fairly sharply to near 8000 ft. After reaching 9500 ft and flying there for about 3-5 mins, I realized we were probably inside the denver class B. I immediately descended to 8700 ft. I think the incursion started about 5 mi south of centennial airport and ended 5 mi later which is the end of the airspace. Before takeoff the instructor and I agreed that I would fly and he would navigation and work the communications. When I realized we were in the class B, he seemed to be confused about where the line separating the 10000 ft floor and the 9000 ft floor existed. Further, he was using the denver sectional instead of the VFR terminal area chart. I should have remembered where the floor was. Also, the denver class B extends beyond the 30 NM mode C veil. This is confusing because the floor ceiling (120 over 90) symbol is right on the mode C veil line and to the east, the 120 over 100 is between the outer edge of class B and the mode C veil line. I trusted the other pilot/instructor with the navigation (vertical as well as horizontal) but I was PIC and should have paid closer attention to our position. I don't know why the class B floor is 9000 ft in that area as it is between 2 areas whose floor is 10000 ft and it's 25-30 NM from dia. A more thorough pre- brief may have helped. Also, I only have 4 hours in C310's and 60 hours multi, 3 hours in the C310 over 45 days ago.

Original NASA ASRS Text

Title: PLT OF A C310 PENETRATED CLASS B AIRSPACE DUE TO ATTEMPTING TO FLY AT AN APPROPRIATE ALT FOR THE DIRECTION OF FLT DURING A MULTI-ENG INSTRUCTOR PLT TRAINING FLT.

Narrative: WE DEPARTED CENTENNIAL ARPT'S RWY 35R AND WE WERE CLRED FOR A R DOWNWIND DEP. THE ARPT ELEVATION IS 5883 FT. ANOTHER FLT INSTRUCTOR WAS IN THE R SEAT AND A THIRD INSTRUCTOR RODE IN THE BACK R SEAT. I SUGGESTED, AFTER THE INITIAL TURN TO THE S AFTER TKOF, WE HEAD BACK TO COLORADO SPRINGS AT 8500 FT. AFTER ABOUT 1 MIN HE SUGGESTED WE FLY BACK AT 9500 FT. WE TOOK AN INITIAL HDG OF 150 DEGS SO, 9500 FT SOUNDED BETTER. I HAD SUGGESTED WE FLY AT 8500 FT BECAUSE THE FLOOR OF THE CLASS B AIRSPACE IN THAT AREA IS 9000 FT. I FORGOT ABOUT THAT WHEN THE PNF SUGGESTED 9500 FT FOR PROPER VFR CRUISE ALT. THE TERRAIN IS 6500 FT RISING FAIRLY SHARPLY TO NEAR 8000 FT. AFTER REACHING 9500 FT AND FLYING THERE FOR ABOUT 3-5 MINS, I REALIZED WE WERE PROBABLY INSIDE THE DENVER CLASS B. I IMMEDIATELY DSNDED TO 8700 FT. I THINK THE INCURSION STARTED ABOUT 5 MI S OF CENTENNIAL ARPT AND ENDED 5 MI LATER WHICH IS THE END OF THE AIRSPACE. BEFORE TKOF THE INSTRUCTOR AND I AGREED THAT I WOULD FLY AND HE WOULD NAV AND WORK THE COMS. WHEN I REALIZED WE WERE IN THE CLASS B, HE SEEMED TO BE CONFUSED ABOUT WHERE THE LINE SEPARATING THE 10000 FT FLOOR AND THE 9000 FT FLOOR EXISTED. FURTHER, HE WAS USING THE DENVER SECTIONAL INSTEAD OF THE VFR TERMINAL AREA CHART. I SHOULD HAVE REMEMBERED WHERE THE FLOOR WAS. ALSO, THE DENVER CLASS B EXTENDS BEYOND THE 30 NM MODE C VEIL. THIS IS CONFUSING BECAUSE THE FLOOR CEILING (120 OVER 90) SYMBOL IS RIGHT ON THE MODE C VEIL LINE AND TO THE E, THE 120 OVER 100 IS BTWN THE OUTER EDGE OF CLASS B AND THE MODE C VEIL LINE. I TRUSTED THE OTHER PLT/INSTRUCTOR WITH THE NAV (VERT AS WELL AS HORIZ) BUT I WAS PIC AND SHOULD HAVE PAID CLOSER ATTN TO OUR POS. I DON'T KNOW WHY THE CLASS B FLOOR IS 9000 FT IN THAT AREA AS IT IS BTWN 2 AREAS WHOSE FLOOR IS 10000 FT AND IT'S 25-30 NM FROM DIA. A MORE THOROUGH PRE- BRIEF MAY HAVE HELPED. ALSO, I ONLY HAVE 4 HRS IN C310'S AND 60 HRS MULTI, 3 HRS IN THE C310 OVER 45 DAYS AGO.

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.

Pilot of a C310 penetrated class B airspace due to attempting to fly at an appropriate altitude for the direction of flight during a multi-engine instructor pilot training flight.