MD88 flight crew maintaining visual separation causes TCASII alert in separation traffic aircraft.

Attributes
ACN	423424
Time
Date	199812
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bos
State Reference	MA
Altitude	msl bound lower : 17000 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mem
Operator	common carrier : air carrier
Make Model Name	MD-88
Navigation In Use	Other
Route In Use	approach : visual departure other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	SF 340A
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 220 flight time total : 9600 flight time type : 3500
ASRS Report	423424
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa other other : unspecified
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 15000 vertical : 1500
Supplementary
Air Traffic Incident	other

Narrative:

We were level at 16000 ft after climbing out of boston on ZBW frequency. An air carrier saab 340 traffic was called out to us at 11 O'clock position and 15 mi, crossing left to right. We picked up the traffic and had a visual at 10 mi. He was level at 17000 ft. When we called visual, center asked us to maintain visual separation and cleared to climb to FL230. We started an immediate climb maintaining visual separation. Passing through 17000 ft, we were climbing at 5000 FPM and still had adequate visual separation. As we crossed over him, he was slightly right of the nose and approximately 1300-1500 ft below us. The TCASII called out the traffic and we were visually well clear. Apparently he was a little concerned because he never had a visual on us and his TCASII was giving him a TA or RA warning. He asked center for our call sign. The TCASII lagged behind us a bit because of our high rate of climb. In the future I will hesitate to take visual climbs taking TCASII and its warnings into consideration. We both should have had a visual or, better yet, I should have had maintained 16000 ft until well clear and declined the visual climb.

Original NASA ASRS Text

Title: MD88 FLC MAINTAINING VISUAL SEPARATION CAUSES TCASII ALERT IN SEPARATION TFC ACFT.

Narrative: WE WERE LEVEL AT 16000 FT AFTER CLBING OUT OF BOSTON ON ZBW FREQ. AN ACR SAAB 340 TFC WAS CALLED OUT TO US AT 11 O'CLOCK POS AND 15 MI, XING L TO R. WE PICKED UP THE TFC AND HAD A VISUAL AT 10 MI. HE WAS LEVEL AT 17000 FT. WHEN WE CALLED VISUAL, CTR ASKED US TO MAINTAIN VISUAL SEPARATION AND CLRED TO CLB TO FL230. WE STARTED AN IMMEDIATE CLB MAINTAINING VISUAL SEPARATION. PASSING THROUGH 17000 FT, WE WERE CLBING AT 5000 FPM AND STILL HAD ADEQUATE VISUAL SEPARATION. AS WE CROSSED OVER HIM, HE WAS SLIGHTLY R OF THE NOSE AND APPROX 1300-1500 FT BELOW US. THE TCASII CALLED OUT THE TFC AND WE WERE VISUALLY WELL CLR. APPARENTLY HE WAS A LITTLE CONCERNED BECAUSE HE NEVER HAD A VISUAL ON US AND HIS TCASII WAS GIVING HIM A TA OR RA WARNING. HE ASKED CTR FOR OUR CALL SIGN. THE TCASII LAGGED BEHIND US A BIT BECAUSE OF OUR HIGH RATE OF CLB. IN THE FUTURE I WILL HESITATE TO TAKE VISUAL CLBS TAKING TCASII AND ITS WARNINGS INTO CONSIDERATION. WE BOTH SHOULD HAVE HAD A VISUAL OR, BETTER YET, I SHOULD HAVE HAD MAINTAINED 16000 FT UNTIL WELL CLR AND DECLINED THE VISUAL CLB.

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.