Fatal USCG SAR Training Flight: Inadvertent IMC (Airbus MH-65D CH-6535, 28 Feb 2012)
On 28 February 2012 a US Coast Guard (USCG) Airbus MH-65D Dolphin (AS365) CG-6535 impacted the sea in Mobile Bay, Alabama with the loss of all four crew members. This followed an unintended flight into a Degraded Visual Environment (DVE) during a night Search and Rescue (SAR) training flight.
USCG Airbus MH-65 Dolphin (Credit: mark6mauno CC BY 2.0)
The Accident Flight
The helicopter was assigned to USCG Aviation Training Center (ATC) at Mobile, Alabama. It was conducting a night training flight that include approaches to the hover, basket hoists with the 41-foot Motor Vessel (MV) Solomon and rescue swimmer hoists.
The crew consisted of an ATC instructor as Pilot-in-Command (PIC), a pilot under instruction as Copilot (CP), a flight mechanic hoist operator (FM) and a rescue swimmer (RS).
According to the USCG accident report the PIC had 3,972 hours of total, 3,629 on type. The CP had just 263 hours, 39 on type. The CP was nearing the completion of his course, having reported to the ATC on 16 January 2012 for the 7-week MH-65D Transition Course.
The weather at the time of departure and forecast for the evening was VMC. The crew completed planned training but the weather had deteriorated during the RS exercises with a ceiling lowered to 400 feet and reduced visibility (4.4 nm at the nearest met station).
According to the USCG accident report the crew had some difficulty maintaining position during some of the RS hoists according to witnesses on the MV Solomon. Its not clear if that was related to the weather or not.
After the completion of RS hoisting, the PIC transferred the controls to the CP for over-water hover training. The CP spent two minutes practicing over-water hover position keeping using the Hover Augmentation (HOV-AUG) flight director mode.
Following the over-water practice hovering, the PIC directed the aircraft to be reconfigured for forward flight and disengaged the HOV-AUG mode.
Forty-four seconds prior to the mishap, the CP began a manual instrument takeoff/departure (ITO) from the over-water hover. A manual ITO is conducted without the assistance of the aircraft’s flight director modes.
Based on cockpit recorded dialog, it appears that [ANVIS-9] Night Vision Goggles (NVGs) were in use by the PIC.
Investigators say both PIC and CP were using NVGs when the aircraft departed.
During the ITO, the PIC acknowledged that a positive rate of climb was established and discussed hoisting performance with the RS. Shortly after CG-6535 ascended above 200 feet, but below the maximum achieved altitude of 362 feet, the PIC recognized the aircraft had encountered IMC and verbalized a transfer of control of the aircraft.
The PIC assumed control of the aircraft approximately 23 seconds prior to impact. Sixteen seconds prior to impact…
….the PIC stated his intention to slowly come down to try and regain visual conditions and requested that the CP provide the Radar Map page on the PIC’s multi-function display flight instrument.
The PIC did not verbalize the minimum altitude he intended to descend to or alter the pilots radar altimeter warning setting. While maneuvering the aircraft without the assistance of the aircraft’s flight director, CG-6535 entered an attitude indicating a right hand turn greater than 43 degrees angle of bank, 5.5 degrees per second yaw rate to the right, and 22 degrees nose down attitude.
Approximately 2.4 seconds prior to the impact, the PIC increased collective pitch and aircraft torque. The aircraft impacted the water with a descent rate of 2,197 feet per minute at 84.5 knots airspeed
MV Solomon found the helicopter floating inverted.
The RS was found in the water and recovered within minutes of the response approximately 40 feet from CG-6535. Attempts to revive the RS were unsuccessful. No other crewmembers were recovered that evening.
On 1 March 2012, the PIC was recovered from the seabed 400 yards from CG-6535’s fuselage. Later that day, the CP was recovered from the seabed 300 yards from the PIC. On 8 March 2012, the FM was recovered from the water’s surface, several miles from the site of impact.
Safety Investigation
A commercial salvage vessel recovered the wreckage on 1 March 2012. No pre-impact defects were identified with the aircraft. The investigation surprisingly contains analysis of survivability matters.
The investigators note that:
Prior to the evening of 28 February 2012, the PIC’s most recent night/NVG flight was on 11 January 2012. His most recent night/NVG boat or night/NVG RS hoisting was on 19 August 2011. His most recent day boat or RS hoisting was on 16 February 2012.
They concluded that the the PIC lacked recency and proficiency in night/NVG boat hoist and RS operations.
The CP’s most recent night/NVG flight occurred on 9 February 2012 (NVG Check flight). The CP’s total NVG flight time during the transition course was 5.9 hours. The CP’s most recent day rescue swimmer hoist occurred on 17 February 2012. He completed a night operational simulator flight in the MH-65D Operational Flight Trainer on 21 February. This simulator flight included night and NVG approaches to the water as both the pilot at the controls and the safety pilot. This simulator flight also included practicing the use of NVGs while in a hover.
They noted that:
The CP’s training recency is consistent with the MH-65D curriculum and did not contribute to the mishap. The CP’s performance throughout the MH-65D syllabus was to standard.
The investigators opined that:
There are no indications the crew of CG-6535 recognized the changes in weather conditions until 23 seconds prior to the mishap when IMC was inadvertently encountered.
Prior to departure from hover operations, the PIC and CP were using NVGs, which may have affected their ability to recognize weather deterioration.
Investigators identified that the USCG MH-65 Operational Flight Manual did not include inadvertent IMC
procedures. They noted that such procedures exist for several US Navy aircraft and, as per FAA guidance, they call for establishing an instrument scan and climbing to a safe altitude. In this case they noted that the PIC appeared to a have been attempting to descend to regain VMC.
ATC Mobile received an annual USCG standardization visit from 17 to 27 January 2012. While no “deficiencies that had bearing” on the accident were reported, the investigators do not comment on the effectiveness of this standardisation process.
The Investigation Conclusions
Inadvertent IMC entry and lack of established inadvertent IMC entry procedures contributed as did the lack of recent night/NVG over-water operations by the PIC.
Safety Actions
These included:
- Development of inadvertent IMC procedures
- Instituting a 90-day recency for night/NVG hoisting
Safety Resources
The European Safety Promotion Network Rotorcraft (ESPN-R) has a helicopter safety discussion group on LinkedIn. You may also find these Aerossurance articles of interest:
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