Helicopter pilot reports entering IMC inadvertently at night while using nvg's. Lightening flashes f...

Attributes
ACN	1054626
Time
Date	201212
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Bell Helicopter Textron Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 5826 Flight Crew Type 200
Events
Anomaly	Inflight Event / Encounter Weather / Turbulence Inflight Event / Encounter VFR In IMC

Narrative:

Operating as an air ambulance; I was en route at 2;000 ft MSL in cruise flight heading south to the hospital for a patient pickup. I was following an advancing cold front with thunderstorms well to my east. I had just made contact with approach informing the controller of my intentions of landing at the hospital. I was flying under nvg's and noticed that I lost outside visual reference. I called approach and told them I had entered IFR conditions. The controller immediately gave me vectors for a GPS approach to the local airport. I never declared an emergency. I started a right descending turn and broke-out of the cloud/fog layer at approximately 1;600 ft MSL. I notified the controller that I was VFR again and would like to continue my flight to my destination. I was in IFR conditions for no more than 2 minutes. I had no further incidents after that encounter. I would say that the lightening flashes from the thunderstorm to my east were distorting my view in the nvg's; causing me to not see the cloud/fog layer.

Original NASA ASRS Text

Title: Helicopter pilot reports entering IMC inadvertently at night while using NVG's. Lightening flashes from a thunderstorm ahead had prevented visual detection of a fog bank.

Narrative: Operating as an air ambulance; I was en route at 2;000 FT MSL in cruise flight heading south to the hospital for a patient pickup. I was following an advancing cold front with thunderstorms well to my east. I had just made contact with Approach informing the Controller of my intentions of landing at the hospital. I was flying under NVG's and noticed that I lost outside visual reference. I called Approach and told them I had entered IFR conditions. The Controller immediately gave me vectors for a GPS Approach to the local airport. I never declared an emergency. I started a right descending turn and broke-out of the cloud/fog layer at approximately 1;600 FT MSL. I notified the Controller that I was VFR again and would like to continue my flight to my destination. I was in IFR conditions for no more than 2 minutes. I had no further incidents after that encounter. I would say that the lightening flashes from the thunderstorm to my east were distorting my view in the NVG's; causing me to not see the cloud/fog layer.

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.

Helicopter pilot reports entering IMC inadvertently at night while using nvg's. Lightening flashes from a thunderstorm ahead had prevented visual detection of a fog bank.