TCASII RA creates an altitude deviation altitude excursion by first officer, PF.

Attributes
ACN	187512
Time
Date	199108
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : phl
State Reference	PA
Altitude	msl bound lower : 4000 msl bound upper : 4600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : straight in enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 20 flight time total : 5500 flight time type : 2000
ASRS Report	187512
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

We were level at 4000 ft on a 270 degree heading to intercept final for 27R at phl. Approach control mentioned traffic at 10 O'clock at 3500 ft heading north. We did not have this traffic visually but had someone on our TCASII, in the approximately position mentioned. However, this traffic was shown as only 300 ft below us. As we converged the TCASII issued an RA. I was hand flying and put the aircraft in a 1200-1400 FPM climb. After gaining approximately 500-600 ft, TCASII issued an all clear. We returned to our assigned altitude of 4000 ft and the captain informed phl approach of our reason for busting our altitude. He thanked us for the report but said it was a positively idented aircraft. He was busy, cleared us for a visual and gave us a frequency change. This was my first RA issued by TCASII, so I have little to base performance on. It does seem to work as advertised and should be an additional safety tool.

Original NASA ASRS Text

Title: TCASII RA CREATES AN ALT DEV ALT EXCURSION BY FO, PF.

Narrative: WE WERE LEVEL AT 4000 FT ON A 270 DEG HDG TO INTERCEPT FINAL FOR 27R AT PHL. APCH CTL MENTIONED TFC AT 10 O'CLOCK AT 3500 FT HDG N. WE DID NOT HAVE THIS TFC VISUALLY BUT HAD SOMEONE ON OUR TCASII, IN THE APPROX POS MENTIONED. HOWEVER, THIS TFC WAS SHOWN AS ONLY 300 FT BELOW US. AS WE CONVERGED THE TCASII ISSUED AN RA. I WAS HAND FLYING AND PUT THE ACFT IN A 1200-1400 FPM CLB. AFTER GAINING APPROX 500-600 FT, TCASII ISSUED AN ALL CLR. WE RETURNED TO OUR ASSIGNED ALT OF 4000 FT AND THE CAPT INFORMED PHL APCH OF OUR REASON FOR BUSTING OUR ALT. HE THANKED US FOR THE RPT BUT SAID IT WAS A POSITIVELY IDENTED ACFT. HE WAS BUSY, CLRED US FOR A VISUAL AND GAVE US A FREQ CHANGE. THIS WAS MY FIRST RA ISSUED BY TCASII, SO I HAVE LITTLE TO BASE PERFORMANCE ON. IT DOES SEEM TO WORK AS ADVERTISED AND SHOULD BE AN ADDITIONAL SAFETY TOOL.

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.