Near midair collision between a DC9 and an acrobatic aircraft doing a loop 4 mi west of btl, mi.

Attributes
ACN	510060
Time
Date	200105
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : azo.airport
State Reference	MI
Altitude	msl single value : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : private pilot : multi engine pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 14000 flight time type : 8000
ASRS Report	510060
Events
Anomaly	conflict : nmac non adherence : far
Resolutory Action	none taken : insufficient time
Miss Distance	horizontal : 500 vertical : 0
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Airspace Structure
Primary Problem	Flight Crew Human Performance

Narrative:

On vectors for approach to runway 17 at azo, descending from 8000 ft to 4000 ft, we received a TCASII alert and visually sighted the aircraft in front of us at a lower altitude. The aircraft then did a couple of acrobatic maneuvers finishing with a loop that resulted in a TCASII RA to evade the aircraft. Aircraft passed off our right wing 500 ft horizontally from below our altitude to above our altitude. We had no time to react to the TCASII RA due to the other aircraft maneuvering faster than the TCASII could react.

Original NASA ASRS Text

Title: NMAC BTWN A DC9 AND AN ACROBATIC ACFT DOING A LOOP 4 MI W OF BTL, MI.

Narrative: ON VECTORS FOR APCH TO RWY 17 AT AZO, DSNDING FROM 8000 FT TO 4000 FT, WE RECEIVED A TCASII ALERT AND VISUALLY SIGHTED THE ACFT IN FRONT OF US AT A LOWER ALT. THE ACFT THEN DID A COUPLE OF ACROBATIC MANEUVERS FINISHING WITH A LOOP THAT RESULTED IN A TCASII RA TO EVADE THE ACFT. ACFT PASSED OFF OUR R WING 500 FT HORIZLY FROM BELOW OUR ALT TO ABOVE OUR ALT. WE HAD NO TIME TO REACT TO THE TCASII RA DUE TO THE OTHER ACFT MANEUVERING FASTER THAN THE TCASII COULD REACT.

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.