Accident Shorts 360-300 N372AC,

ASN Wikibase Occurrence # 322238

Date:	Sunday 5 February 2006
Time:	16:53
Type:	Shorts 360-300
Owner/operator:	Air Cargo Carriers
Registration:	N372AC
MSN:	SH.3720
Year of manufacture:	1987
Total airframe hrs:	21996 hours
Engine model:	Pratt & Whitney Canada PT6A-67R
Fatalities:	Fatalities: 0 / Occupants: 3
Other fatalities:	3
Aircraft damage:	Substantial
Category:	Accident
Location:	Juneau-Dodge County Airport, WI (UNU) - United States of America
Phase:	En route
Nature:	Test
Departure airport:	Milwaukee-General Mitchell Airport, WI (MKE/KMKE)
Destination airport:	Milwaukee-General Mitchell Airport, WI (MKE/KMKE)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Two Air Cargo Carriers Shorts 360 cargo planes, N372AC and N3735W, had been in maintenance for the installation of some auxiliary fuel tanks. Flights were planned to verify the fuel flow rates for those tanks. Prior to departure, both flight crews decided that they would join-up after departure in order to take video and still photography of each airplane. N3735W and N372AC departed Milwaukee (MKE) at 15:55 and 16:15, respectively. After departure and clearing MKE airspace, the flight crew of N372AC established radio and visual contact with N3735W. N3735W then proceeded to perform several fly-bys past N372AC who remained on constant headings and altitude. N3735W then came up along the other Shorts' left side and flew in formation with approximately 100-150 feet lateral separation. A pilot of N3735W then announced over the radio that they would turn right and descend below N372AC. During that manoeuver N3735W's left wing impacted the left wing and engine of the other plane. The captain of N372AC attempted to climb in an attempt to avoid impacting N3735W. The outboard 3/4 of the left wing of N3735W separated and the airplane crashed out of control, into a field southeast of the intersection of Highway Q and Highway 19 and caught fire. After the collision, N372AC rolled to the left and pitched down significantly before the flight crew regained control of the airplane. The flight crew declared an emergency and diverted to Juneau-Dodge County Airport, WI (UNU) for an emergency landing. N372AC experienced a complete hydraulic failure and was losing hydraulic fluid. The flight crew performed an emergency landing on runway 08 (5,069 feet by 100 feet, asphalt) with flaps retracted and a partially extended landing gear. The airplane overran the end of the runway, coming to rest about 100 feet from the departure threshold.

PROBABLE CAUSE: "The flight crew failed to maintain clearance from another aircraft as they turned to break formation flight while maneuvering. Contributing to the accident was the decision of both flight crews to fly in formation."

Accident investigation: