Pilot on remote sensing mission in hnl class B has critical conflict with DASH8.

Attributes
ACN	788271
Time
Date	200805
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : hnl.airport
State Reference	HI
Altitude	msl single value : 2300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : hcf.tracon
Operator	general aviation : personal
Make Model Name	Piper Twin Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	cruise : level ground : maintenance
Flight Plan	None
Aircraft 2
Controlling Facilities	tracon : hcf.tracon
Operator	common carrier : air carrier
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 820 flight time type : 50
ASRS Report	788271
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac
Independent Detector	aircraft equipment : tcas other flight crewa
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I was on a single pilot aerial sensing mission over diamond head and to the east approximately 4 mi at 2500 ft MSL and within the hnl surface B area. Prior to the flight; I had called the hcf supervisor to coordination the mission within the class B since the area I intended to work was in the departure corridor of runway 8L/right. I took off from hnl less than 30 mins earlier and stayed on with the local departure controller. I heard a dash-8 check in after takeoff and he was assigned a heading and altitude. I looked briefly but was not able to make contact with the dash-8. At this point I was approximately 3 mi ese of the airport eastbound at 2500 ft so the airport was behind and slightly to my left. As I was approaching the beach at diamond head I heard the dash-8 say they were descending due to an RA. I looked over my shoulder in time to see the dash-8 pass directly under me and a few hundred ft below. By the time I started a climb; the other airplane had already passed. After taking a few seconds to collect myself; I checked my altimeter which read about 2350 ft. The pilot of the dash-8 said that they were indicating 200 ft of separation. In my opinion; the conflict arose primarily from my fixation on other instruments in the course of my aerial sensing mission and not maintaining a visual lookout in VMC. My attention was focused on keeping my ground track on the prescribed flight line and I drifted off my altitude. The plane was fairly well trimmed but it was not perfect. I make significant throttle adjustments on each line to keep my ground speed within the limits for the sensing equipment. With short lines and quick turnarounds; I often don't have time to fine tune the elevator trim. Additional factors may have been the dash-8 pilot's not maintaining a visual lookout in VMC and the controller's assigning the dash-8 a converging heading. However; had I maintained 2500 ft; we would have had 500 ft of vertical separation during the crossing. I place the blame on myself. My bad; lesson learned.

Original NASA ASRS Text

Title: PILOT ON REMOTE SENSING MISSION IN HNL CLASS B HAS CRITICAL CONFLICT WITH DASH8.

Narrative: I WAS ON A SINGLE PLT AERIAL SENSING MISSION OVER DIAMOND HEAD AND TO THE E APPROX 4 MI AT 2500 FT MSL AND WITHIN THE HNL SURFACE B AREA. PRIOR TO THE FLT; I HAD CALLED THE HCF SUPVR TO COORD THE MISSION WITHIN THE CLASS B SINCE THE AREA I INTENDED TO WORK WAS IN THE DEP CORRIDOR OF RWY 8L/R. I TOOK OFF FROM HNL LESS THAN 30 MINS EARLIER AND STAYED ON WITH THE LCL DEP CTLR. I HEARD A DASH-8 CHK IN AFTER TKOF AND HE WAS ASSIGNED A HDG AND ALT. I LOOKED BRIEFLY BUT WAS NOT ABLE TO MAKE CONTACT WITH THE DASH-8. AT THIS POINT I WAS APPROX 3 MI ESE OF THE ARPT EBOUND AT 2500 FT SO THE ARPT WAS BEHIND AND SLIGHTLY TO MY L. AS I WAS APCHING THE BEACH AT DIAMOND HEAD I HEARD THE DASH-8 SAY THEY WERE DSNDING DUE TO AN RA. I LOOKED OVER MY SHOULDER IN TIME TO SEE THE DASH-8 PASS DIRECTLY UNDER ME AND A FEW HUNDRED FT BELOW. BY THE TIME I STARTED A CLB; THE OTHER AIRPLANE HAD ALREADY PASSED. AFTER TAKING A FEW SECONDS TO COLLECT MYSELF; I CHKED MY ALTIMETER WHICH READ ABOUT 2350 FT. THE PLT OF THE DASH-8 SAID THAT THEY WERE INDICATING 200 FT OF SEPARATION. IN MY OPINION; THE CONFLICT AROSE PRIMARILY FROM MY FIXATION ON OTHER INSTS IN THE COURSE OF MY AERIAL SENSING MISSION AND NOT MAINTAINING A VISUAL LOOKOUT IN VMC. MY ATTN WAS FOCUSED ON KEEPING MY GND TRACK ON THE PRESCRIBED FLT LINE AND I DRIFTED OFF MY ALT. THE PLANE WAS FAIRLY WELL TRIMMED BUT IT WAS NOT PERFECT. I MAKE SIGNIFICANT THROTTLE ADJUSTMENTS ON EACH LINE TO KEEP MY GND SPD WITHIN THE LIMITS FOR THE SENSING EQUIP. WITH SHORT LINES AND QUICK TURNAROUNDS; I OFTEN DON'T HAVE TIME TO FINE TUNE THE ELEVATOR TRIM. ADDITIONAL FACTORS MAY HAVE BEEN THE DASH-8 PLT'S NOT MAINTAINING A VISUAL LOOKOUT IN VMC AND THE CTLR'S ASSIGNING THE DASH-8 A CONVERGING HDG. HOWEVER; HAD I MAINTAINED 2500 FT; WE WOULD HAVE HAD 500 FT OF VERT SEPARATION DURING THE XING. I PLACE THE BLAME ON MYSELF. MY BAD; LESSON LEARNED.

Data retrieved from NASA's ASRS site as of May 2009 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.