Date: 201211
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Lancair IV/IVP
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Exterior Pax/Crew Door
Component problem: Failed
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Private
Human factors: Training / Qualification; Situational Awareness; Physiological - Other; Communication Breakdown; Workload
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Other / Unknown; Inflight Event / Encounter Loss Of Aircraft Control
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport; Flight Crew Regained Aircraft Control; General Maintenance Action
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: After departing; we were being vectored around traffic during the climb sequence of the flight. Upon receiving clearance to FL230; I noticed the cabin pressure light begin to intermittently flash. I increased the cabin inflow and adjusted the cabin altitude; with only a slight improvement of the annunciator panel. The door lock and door seal lights were in their normal lit configuration at this time. I recycled the door seal to test its integrity. Shortly thereafter; the door flew open; with resultant depressurization. Cabin contents were flying about the cabin; my headset and glasses departed the plane; along with my passenger's purse; papers; and pillows. A blanket from the back seat covered my head and face; and was pulling my head out of the cabin into the slipstream. My passenger pulled the blanket off my head; and I saw we were in a steep nose down attitude. I pulled back power and eased the descent. The plane was very difficult to control at this point; and cabin contents were flying around; hitting us both. I elected to try to get the plane under control before considering an attempt at landing. I asked my passenger to replace my headset onto my head; and I was able to communicate with ATC; informing them that we had lost our door. At some point; the door completely departed the plane; improving the flight characteristics considerably. After slowing down and aggressively trimming; I was able to get back control of the plane and said we would return to the departure airport since the plane was now flyable and the runway environs were familiar. After a couple of minutes of trying to communicate with Center; I checked my headset cord; and realized it had been shredded by the prop wash and was unusable. I had my passenger place her headset on my head and used her push-to-talk button to communicate. I asked for permission to change to Tower frequency and requested a downwind approach to Runway 01; since it would give me a chance to test the flight characteristics in the landing configuration at pattern altitude. Tower immediately cleared us to land. With flaps and gear down; the plane was more stable; and the landing was uneventful.

Callback: The Reporter stated that the gull wing door had been checked and appeared closed. He is not certain at this point what could have been done differently. He would tell anyone flying that aircraft to get factory training because this type event is taught in training and without that training he is not certain that he could have recovered.



Synopsis: A Lancair IV/G door departed in flight at 12;500 FT after the pilot checked the door seal. The cabin pressure light was flashing intermittently even though the door lock and door seal lights were normally configured.