Helideck Lightning Strike: Damage Missed

Helideck Lightning Strike: Damage Missed

 On 8 August 2019 the pilot of an Airbus Helicopters AS350B2 had shut down and tied down on a Gulf of Mexico (GOM) offshore installation, EI-333B, as a storm approached.  The helicopter was on charter to the Bureau of Safety and Environmental Enforcement (BSEE) to ferry inspectors to offshore installations.  A second helicopter from another company was landing to also take shelter when a lightning strike occurred that set off one of the installation’s alarms.  The pilot of the AS350B2 commented:

I had intended to go up and help him tie down. However, as I was getting ready to walk out the door, the bolt that set off the platform alarm hit and I decided to stay indoors.  The other pilot came in shortly after and said he was pretty sure the platform had just been hit by lighting.

After the storm passed, I went up stairs and looked over my aircraft. I didn’t see any obvious damage to the outside of the aircraft. I proceeded to turn on the Battery, avionics, and all exterior lights. All systems were functioning properly. After the inspectors returned to the platform, we departed and returned to Lafayette with no incident. Startup was normal with no indications of anything out of the ordinary.

Upon return to Abbeville, I did inform the Lead Mechanic that lighting had stroke the platform. I told him that I had looked over the aircraft, but that on the post flight, he may want to take a close look at the aircraft.

On inspection at Abbeville maintenance personnel found damage to the top of the vertical fin (Figure 1), the aft strut (Figure 2), and the bottom of one skid (Figure 3).

bsee as350 lightning strike 1

bsee as350 lightning strike 2

bsee as350 lightning strike 3

Illustrations Credit: BSEE.

This occurrence report highlights the need to carefully inspect for damage when a lightning strike was possible, even when the aircraft was parked.  The main danger of lightning strikes is the arcing damage they can do to rotors, transmissions and engines.

Other Helideck Safety Resources

Aerossurance regularly assists oil and gas companies and vessel operators review and update their helideck procedures and adverse weather policies, examine helideck structural integrity issues and provide independent assurance of helideck readiness.

Aerossurance has extensive air safety, operations, helidecks, airworthiness, human factors, aviation regulation and safety analysis experience.  For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com