Lancair Evolution
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 20; Flight Crew Total 1323; Flight Crew Type 314
Time Pressure; Troubleshooting
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; Flight Crew Landed in Emergency Condition; General Maintenance Action
Aircraft; Weather
There were snow drifts on the taxiway and runway.  Due to the snow; upon climb out; pilots side landing gear door would not close completely.  I cycled the gear several times to try and clear the snow to allow the gear to close fully.  We were unsuccessful getting the gear to close; so I decided to land and see if we could resolve the issue.  Feeling the departure airport was unsafe due to the runway conditions; I decided to divert to ZZZ1 to assess the situation.  I am familiar with the airport and they have a Tower and other facilities.  Roughly 20-30 minutes after ATC gave us our clearance to ZZZ1 (while we were at FL270); there was an explosion like sound and all cabin pressure immediately departed.  This blow out knocked off all of our headsets.  Understanding that we had a cabin de-presserization; I immediately pulled the power back to idle; dropped the landing gear and nosed the plane over for rapid descent.  Once we were going down; I changed our squawk to 7700 (knowing that this was our only form of communication with the outside world); set the autopilot to level off at 12;500 feet and re-engaged the autopilot in case I were to black out.  I didn't grab for my oxygen mask because at the time we were already coming down at a rate of over 8;000 ft/min and the wind/cold and just chaotic nature of the cabin; I didn't feel comfortable taking my hands off of the controls.  I also didn't go for my headset for similar reasons; as well as there being so much noise; I knew there would be no way for me to hear ATC let alone they be able to hear me. After we were able to level off at 12;500 feet; I looked for the closest airport (ZZZ2); brought up their weather and loaded the approach we wanted and turned to the appropriate heading.  I opened the inertial separator; turned on our landing and wigwag lights and decided to leave the gear down for the remainder of the flight.  I didn't want to accidentally add any other complications to our situation.  After what seemed like the longest approach in history; we finally touched down safely at ZZZ2; where I taxied the plane to the already waiting emergency vehicles.
Lancair Evolution pilot reported landing gear door failed to close followed by pressurization failure resulting in emergency descent and landing.