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 SkyLife Helicopter Crashwill killed, including the patient being transported.

The flying conditions at Porterville were acceptable.  Though it was dark, the weather was 3300 overcast

Experimental amateur-built aircraft crash more often than those assembled in a factory. The Australian Transport Safety Bureau found that, when compared to factory-built aircraft used in similar flight operations, amateur-built aircraft crash three times as often.  Our own National Transportation Safety Board studied the amateur-built accident rates and made similar findings.Victoria Vabre photo

One might expect that, because

Robinson Helicopters began installing crash-resistant fuel tanks in 2010.  Robinson Helicopters with fuel tanks installed before then tend to catch fire during accidents that, but for the fire, would have been survivable.

The Australian authorities thought that the safer tanks were a good idea.  Enough Robinsons had caught fire after minor accidents that in 2013

NTSB preliminary reports do not draw conclusions as the cause of a crash.  But the NTSB’s preliminary report of the Turbine Otter crash that killed 9 near Ketchikan on June 25 suggests a weather-related “CFIT” crash, exactly as described here.

First, the report indicates that the flight was conducted under Visual Flight Rules.  That means