Cirrus N146CK crashed on August 4 at Deer Valley, Airzona.  The pilot was killed.  Just before the accident, the aircraft’s door popped open.  We know that because the pilot reported to air traffic control that his door was open and that he needed to return to the airport to close it.  Plus, surveillance cameras confirmed that the pilot’s door was indeed ajar. 

The plane’s door popped open? What’s with that? 

The Cirrus doors are poorly designed.  It’s that simple. They just don’t stay shut in flight.  

The plane flies okay after a door pops open.  But the distraction can be dangerous, and can lead to a loss of control, as demonstrated by this 2009 Cirrus crash.  Following the 2009 accident, John

Ewing, a Cirrus flight instructor, blogged about his experience with the Cirrus doors:

Quite frankly, I found the performances of [the Cirrus] door latches stinks. Cirrus, in an apparent quest to make the aircraft seem as much like an automobile as possible, tried to implement a slam-and-shut-style automobile door. This just in: A high-performance single-engine aircraft is not a car.

Others feel the same way.  Cirrus owner Hamid Shojaeen, after taking delivery of a Cirrus Door Warning System advertisementbrand-new Cirrus SR22 in 2007:

Are you kidding me with this? . . .Even when the door is shut and appears to be latched properly, the door can still unlatch during flight.  That too happened to us twice during training!  . . . all of a sudden there was a loud bang and you could hear the gushing air coming in. . .

The slipstream keeps the door from opening more than a few inches. See the photo, below. (Note: this is not the accident Cirrus.)  But the event can nonetheless be down-right terrifying.  You hear a loud bang.  Then a whooshing noise. The pressure in the cockpit feels like it changes in an instant and, if you’re wearing contact lenses, you can almost feel them jump off your eyeballs.  The adrenaline rush is quite impressive. Especially the first time it happens.

Don’t ask me how I know.

Once a door pops open, i*Not* Accident Aircraftt cannot be closed in flight.  The pilot must land to get the door closed.

So bad is the problem that an after-market supplier offers a "Door Warning System," similar to a "door ajar’ light on a car, to let you know before take-off that your Cirrus door isn’t really closed right.  At $875, it almost seems worth it. (See ad, above.)

When you pay $600,000 for an aircraft, as did the pilot of the aircraft that crashed at Deer Valley, you might expect that it would come with doors that shut right and stay shut. You shouldn’t need to add extra stuff to your new aircraft to make sure the doors don’t open in flight.

We don’t know what caused the Deer Valley crash.  Some witnesses reportedly heard the engine sputter. Whatever challenges the pilot faced, a door popping open couldn’t have helped.