The SkyLife Bell 407 air ambulance helicopter departed from Porterville Airport at 6:52. It crashed minutes later, halfway into its 50 mile flight to San Joaquin Hospital in Bakersfield. The four aboard will killed, including the patient being transported.
The flying conditions at Porterville were acceptable. Though it was dark, the weather was 3300 overcast, with light rain, light winds, and 9 miles visibility. Under those conditions, the crew could fly “VFR,” meaning they could avoid terrain and other aircraft by simply looking out the windscreen. Were the conditions significantly worse, the pilot would have had to fly “IFR,” and would have had to rely on instruments and help from air traffic control.
The helicopter crashed east of McFarland. The airport nearest the crash site does not have weather reporting equipment. But first responders say that by the time they arrived it was raining hard. Photos of the crash area show dense ground fog.
Heavy rain, by itself, does not necessarily pose a safety risk. But the restricted flight visibility that generally accompanies heavy rain or fog, does. A helicopter pilot who inadvertently wanders into clouds, fog, or heavy rain can quickly become disoriented and lose control of the aircraft .
One challenge of night flying is seeing and avoiding poor weather conditions before you wander into them. Inadvertent flight into clouds is called “continued VFR into IFR conditions.” Sometimes pilots, trying to stay out of the clouds, will fly lower and lower until they strike hillsides or power lines that are hidden in the darkness. The results of that sort of “CFIT” accident are almost always fatal.
It’s too early to say if weather was even a factor in this case. After all, the first responders who reported the poor conditions didn’t get to the site for more than an hour after the crash. But ground scars should provide clues to whether the helicopter might have crashed because the pilot lost control or whether, instead, he struck the ground, wires or a radio tower that he could not see while in controlled flight.
Investigators will also want to know whether the air ambulance crew had night vision goggles available to them. Night vision goggles have been a hot button for the NTSB for some time.