During descent on a maintenance flight, a test pilot took evasive action to avoid another aircraft.

Attributes
ACN	295103
Time
Date	199501
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dpa
State Reference	IL
Altitude	msl bound lower : 3200 msl bound upper : 3200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dpa
Operator	other
Make Model Name	PA-34-200T Turbo Seneca II
Operating Under FAR Part	Part 91
Flight Phase	descent other
Flight Plan	None
Aircraft 2
Make Model Name	Cessna Single Piston Undifferentiated or Other Model
Operating Under FAR Part	other : unknown
Flight Phase	cruise other
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 90 flight time total : 13500 flight time type : 5
ASRS Report	295103
Person 2
Affiliation	Other
Function	observation : observer
Qualification	other other : other
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

The flight was for a maintenance check of a seneca ii turbo-charging system. The tests had been carried out south and west of rockford airport (rfd) using flight following of ZAU and rockford approach. A mechanic was occupying the copilot seat to record engine data and help watch for traffic. Having completed the tests, we were returning to dpa airport. We descended to 3500 ft MSL and intercepted the dpa runway 10 localizer course. Rfd approach advised us that radar service was terminated and to squawk VFR. We changed frequencys and I listened to dpa ATIS. Beginning the descent from 3500 ft MSL I tuned dpa tower. At approximately 12-15 NM west of dpa airport and passing through 3200 ft MSL, my attention, and immediately, the attention of the mechanic, was caught by a single engine cessna (I believe a 182RG or 210) approaching 12:00 O'clock toward us, and slightly below. I pulled back on the yoke to clear the traffic, but because of late sighting and rate of closure, it is difficult to know how much the evasive action helped to clear the traffic. Contributing factors to this incident include: 1) flying in unfamiliar aircraft, which requires more time locating controls, instruments, and switches, and detracting from focusing attention outside. 2) the light color of the conflicting traffic, blending in with the snow covered terrain. 3) the approach angle giving little relative movement for the eye to see. Corrective action includes maintaining active watch for other traffic and increasing the scan during climb and dscnts in busy terminal areas. On a VFR descent, like this one, gentle turns left and right of course may help to give relative movement and make it easier to see and avoid other traffic. Although the mechanic and I saw the traffic at about the same time, having another person on board also looking for traffic is a help. I normally ask a passenger (or in this case a mechanic) in the right seat to help me watch for other aircraft.

Original NASA ASRS Text

Title: DURING DSCNT ON A MAINT FLT, A TEST PLT TOOK EVASIVE ACTION TO AVOID ANOTHER ACFT.

Narrative: THE FLT WAS FOR A MAINT CHK OF A SENECA II TURBO-CHARGING SYS. THE TESTS HAD BEEN CARRIED OUT S AND W OF ROCKFORD ARPT (RFD) USING FLT FOLLOWING OF ZAU AND ROCKFORD APCH. A MECH WAS OCCUPYING THE COPLT SEAT TO RECORD ENG DATA AND HELP WATCH FOR TFC. HAVING COMPLETED THE TESTS, WE WERE RETURNING TO DPA ARPT. WE DSNDED TO 3500 FT MSL AND INTERCEPTED THE DPA RWY 10 LOC COURSE. RFD APCH ADVISED US THAT RADAR SVC WAS TERMINATED AND TO SQUAWK VFR. WE CHANGED FREQS AND I LISTENED TO DPA ATIS. BEGINNING THE DSCNT FROM 3500 FT MSL I TUNED DPA TWR. AT APPROX 12-15 NM WEST OF DPA ARPT AND PASSING THROUGH 3200 FT MSL, MY ATTN, AND IMMEDIATELY, THE ATTN OF THE MECH, WAS CAUGHT BY A SINGLE ENG CESSNA (I BELIEVE A 182RG OR 210) APCHING 12:00 O'CLOCK TOWARD US, AND SLIGHTLY BELOW. I PULLED BACK ON THE YOKE TO CLR THE TFC, BUT BECAUSE OF LATE SIGHTING AND RATE OF CLOSURE, IT IS DIFFICULT TO KNOW HOW MUCH THE EVASIVE ACTION HELPED TO CLEAR THE TFC. CONTRIBUTING FACTORS TO THIS INCIDENT INCLUDE: 1) FLYING IN UNFAMILIAR ACFT, WHICH REQUIRES MORE TIME LOCATING CTLS, INSTS, AND SWITCHES, AND DETRACTING FROM FOCUSING ATTN OUTSIDE. 2) THE LIGHT COLOR OF THE CONFLICTING TFC, BLENDING IN WITH THE SNOW COVERED TERRAIN. 3) THE APPROACH ANGLE GIVING LITTLE RELATIVE MOVEMENT FOR THE EYE TO SEE. CORRECTIVE ACTION INCLUDES MAINTAINING ACTIVE WATCH FOR OTHER TFC AND INCREASING THE SCAN DURING CLB AND DSCNTS IN BUSY TERMINAL AREAS. ON A VFR DSCNT, LIKE THIS ONE, GENTLE TURNS L AND R OF COURSE MAY HELP TO GIVE RELATIVE MOVEMENT AND MAKE IT EASIER TO SEE AND AVOID OTHER TFC. ALTHOUGH THE MECH AND I SAW THE TFC AT ABOUT THE SAME TIME, HAVING ANOTHER PERSON ON BOARD ALSO LOOKING FOR TFC IS A HELP. I NORMALLY ASK A PAX (OR IN THIS CASE A MECH) IN THE R SEAT TO HELP ME WATCH FOR OTHER ACFT.

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.