Large transport in holding pattern as light transport descends through assigned altitude. TCASII RA.

Attributes
ACN	243589
Time
Date	199306
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gqe
State Reference	AZ
Altitude	msl bound lower : 9000 msl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Light Transport
Flight Phase	descent other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 18000 flight time type : 8000
ASRS Report	243589
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 18000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

We were in a holding pattern at gilmore VOR just starting a turn outbound. We were in a clear area with cells all around. We received a TCASII alert followed in rapid succession by descend, increase descent, (4000 FPM) followed by clear of traffic. We descended to 9000 ft as we tried to comply with the TCASII. This all happened in a period of about 30 seconds. At this point, we advised ATC of our altitude and climbed back up to 10000 ft. The traffic was a business jet that decided to dive down through open area where we were holding. We were never closer than a mi or 2 and had him in sight. The problem was caused by his violating our TCASII area, and the resulting TCASII resolution command which caused us to leave an assigned altitude. I am glad I had the TCASII, it worked as advertised. However, we do have to respect its limits to prevent problems like we had.

Original NASA ASRS Text

Title: LGT IN HOLDING PATTERN AS LTT DSNDS THROUGH ASSIGNED ALT. TCASII RA.

Narrative: WE WERE IN A HOLDING PATTERN AT GILMORE VOR JUST STARTING A TURN OUTBOUND. WE WERE IN A CLR AREA WITH CELLS ALL AROUND. WE RECEIVED A TCASII ALERT FOLLOWED IN RAPID SUCCESSION BY DSND, INCREASE DSCNT, (4000 FPM) FOLLOWED BY CLR OF TFC. WE DSNDED TO 9000 FT AS WE TRIED TO COMPLY WITH THE TCASII. THIS ALL HAPPENED IN A PERIOD OF ABOUT 30 SECONDS. AT THIS POINT, WE ADVISED ATC OF OUR ALT AND CLBED BACK UP TO 10000 FT. THE TFC WAS A BUSINESS JET THAT DECIDED TO DIVE DOWN THROUGH OPEN AREA WHERE WE WERE HOLDING. WE WERE NEVER CLOSER THAN A MI OR 2 AND HAD HIM IN SIGHT. THE PROB WAS CAUSED BY HIS VIOLATING OUR TCASII AREA, AND THE RESULTING TCASII RESOLUTION COMMAND WHICH CAUSED US TO LEAVE AN ASSIGNED ALT. I AM GLAD I HAD THE TCASII, IT WORKED AS ADVERTISED. HOWEVER, WE DO HAVE TO RESPECT ITS LIMITS TO PREVENT PROBS LIKE WE HAD.

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.