CG1705
2009-OCT-29 · Pacific Ocean, 24 km east of San Clemente Island, California

Multi-aircraft Event — United States Coast Guard CG1705 / United States Marine Corps Marine Cobra

On October 29, 2009 (local time), a U.S. Coast Guard HC-130H Hercules and a U.S. Marine Corps AH-1W Super Cobra collided in mid-air over the Pacific Ocean. The HC-130 was conducting a search and rescue mission for a missing boat, while the Super Cobra was participating in a multi-aircraft training exercise. All nine personnel across both aircraft were killed. Investigations by the Coast Guard and Marine Corps identified significant failings in Navy air traffic control, which was responsible for the airspace, as well as limitations in the 'see and avoid' principle under the mission conditions.

Aircraft 1
United States Coast Guard — Flight CG1705
Lockheed HC-130H Hercules · 1705
Sacramento-McClellan Airfield, CA?
Souls 7 · Fatal 7
Aircraft 2
United States Marine Corps — Flight Marine Cobra
Bell AH-1W Super Cobra · 164596
Camp Pendleton, CA?
Souls 2 · Fatal 2
Phase
Cause
Total Souls
9
Total Fatalities
9
Report

Investigation Summary

The collision occurred at 19:09:37 local time in Warning Area W-291, controlled by the U.S. Navy. The HC-130H was conducting a search for a 12-foot skiff with one person aboard, which had been missing since October 27, 2009. Simultaneously, a Marine Corps 'flight of four'—consisting of two CH-53E Super Stallions and two AH-1W Super Cobras—was conducting an escort/assault training mission. The formation initiated a right-hand turn and climb to 1,000 feet to avoid another Navy helicopter (Lonewolf 55), placing them directly in the path of the HC-130. The Navy air traffic control center (FACSFAC San Diego) failed to provide adequate separation or warnings, despite the HC-130 squawking the FAA-approved SAR transponder code 1277.

Final Conclusions

The joint investigation concluded that no single factor caused the mishap, but rather a confluence of procedural and policy failures. A primary contributing factor was that FACSFAC San Diego did not grant the HC-130 operational priority for its SAR mission, despite FAA and Navy policies stating that SAR missions should preempt training activities. The controllers failed to effectively manage the airspace or provide safety alerts to the aircraft involved, and the 'see and avoid' principle was compromised by the high-task environment and formation flight protocols.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

United States Coast Guard CG1705 — Lockheed HC-130H Hercules · 1705

Engines
Allison T56-A-15

Systems & Failure Modes

i

Transponder (IFF)

The HC-130 was squawking the SAR-specific code 1277. However, the mishap AH-1W had its IFF transponder and anti-collision lights switched off, as per 'flight of four' protocol where only the lead and trail aircraft maintain electronic and visual signaling.

i

See and Avoid

The primary method of collision avoidance in the visual flight conditions present, which proved insufficient given the relative speeds, mission profiles, and the use of night vision goggles (NVGs) by the USMC crews.

Interesting Facts

  • 01The HC-130H (serial 1705) was previously an Air Force aircraft (83-0007).
  • 02The AH-1W Super Cobra was operated by Marine Aircraft Group 39 based at Camp Pendleton.
  • 03The HC-130 was searching for an overdue john boat at the time of the collision.
  • 04All seven crew members on the HC-130 and both crew members on the AH-1W were killed.
  • 05The collision occurred within airspace managed by a U.S. Navy air traffic control center.

Safety Actions & Advisories

Airspace Coordination Improvements

Recommendations were made to improve communication and coordination between different military branches when search and rescue missions overlap with active training ranges.

Location

Pacific Ocean, 24 km east of San Clemente Island, California · 32.9610, -118.0920

Case File History

  1. Final reportUpdated event timeline, investigation summary, systems analysis and final conclusions.

Related Cases

Case ID · california-mid-air-2009Last updated · Filed

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