Air carrier at FL240 experienced a TCAS RA; reportedly from a flight of military fighter jets restri...

Narrative:

Approximately 40 miles south of booze intersection at FL240 and 15 miles east of shaw AFB; jax center issued a clearance direct to booze; to cross at 1;100 ft at 250 KTS. A few minutes later; while [we were] still in the descent; jax center issued an amended clearance to level off at FL180. At approximately 18;300 ft we received a TCAS RA command to climb; which we complied with and at the end of conflict this resulted in a climb to approximately 19;300 ft. We advised ATC of the TCAS RA; our altitude and that we were descending back to FL180. Jax center advised us that a flight of two F-18's; in a high rate of climb; caused our TCAS RA and their altitude clearance was 16;000 ft. The fighter jets were at our 8 to 9 o'clock position and approximately 4;500 ft below us when the TCAS sounded. They went behind and below us at 2;000 ft horizontal separation. During the whole TCAS event; we did not have the fighter jets in sight. The TCAS RA climb maneuver was not abrupt or evasive and passengers and crew were not affected; but some did notice the change from a descent to a climb. TCAS RA was caused by high rate of climb by fighter jets that were below our aircraft altitude.

Original NASA ASRS Text

Title: Air Carrier at FL240 experienced a TCAS RA; reportedly from a flight of military fighter jets restricted at a lower altitude; but climbing at a very high rate of climb.

Narrative: Approximately 40 miles south of BOOZE Intersection at FL240 and 15 miles east of Shaw AFB; JAX Center issued a clearance direct to BOOZE; to cross at 1;100 FT at 250 KTS. A few minutes later; while [we were] still in the descent; JAX Center issued an amended clearance to level off at FL180. At approximately 18;300 FT we received a TCAS RA command to climb; which we complied with and at the end of conflict this resulted in a climb to approximately 19;300 FT. We advised ATC of the TCAS RA; our altitude and that we were descending back to FL180. JAX Center advised us that a flight of two F-18's; in a high rate of climb; caused our TCAS RA and their altitude clearance was 16;000 FT. The fighter jets were at our 8 to 9 o'clock position and approximately 4;500 FT below us when the TCAS sounded. They went behind and below us at 2;000 FT horizontal separation. During the whole TCAS event; we did not have the fighter jets in sight. The TCAS RA climb maneuver was not abrupt or evasive and passengers and crew were not affected; but some did notice the change from a descent to a climb. TCAS RA was caused by high rate of climb by fighter jets that were below our aircraft altitude.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1006952
Time
Date	201204
Local Time Of Day	1201-1800
Place
Locale Reference	ZJX.ARTCC
State Reference	FL
Environment
Light	Daylight
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Aircraft 2
Make Model Name	Hornet (F-18)
Operating Under FAR Part	Part 91
Flight Phase	Climb
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Conflict Airborne Conflict

Air carrier at FL240 experienced a TCAS RA; reportedly from a flight of military fighter jets restricted at a lower altitude; but climbing at a very high rate of climb.