I was not able to locate a plane crash ratio but your chances of being involved in an aircraft accident are about 1 in 11 million.
Aviation accidents and incidents
An aviation accident is defined by the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft, which takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked, where a person is fatally or seriously injured, the aircraft sustains damage or structural failure or the aircraft is missing or is completely inaccessible.
The first fatal aviation accident occurred in a Wright Model A aircraft at Fort Myer, Virginia, USA, on 17 September 1908, resulting in injury to the pilot, Orville Wright and death of the passenger, Signal Corps Lieutenant Thomas Selfridge.
United Airlines Flight 409
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift caused by the vehicle's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft in which the wings form a rotor mounted on a spinning shaft and ornithopters in which the wings flap in similar manner to a bird.
The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang-gliders, variable-sweep wing aircraft and aeroplanes using wing-warping are all fixed-wing aircraft.
United Airlines Flight 409 was a scheduled flight departing from Denver, Colorado to Salt Lake City, Utah on October 6, 1955. The aircraft registration number was N30062, a Douglas DC-4 propliner. The aircraft crashed into Medicine Bow Peak, near Centennial, Wyoming, killing all 66 people on board (63 passengers, 3 crew members). The victims included five female members of the Mormon Tabernacle Choir and military personnel. At the time, this was the deadliest airline crash in the history of American commercial aviation. Another 66 lives had been lost earlier that year in the March 22 crash in Hawaii of a United States Navy Douglas R6D-1 Liftmaster military transport aircraft, making both crashes the deadliest aviation incidents in 1955.
Aviation safety is a term encompassing the theory, investigation, and categorization of flight failures, and the prevention of such failures through regulation, education, and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.
A disaster is a natural or man-made (or technological) hazard resulting in an event of substantial extent causing significant physical damage or destruction, loss of life, or drastic change to the environment. A disaster can be ostensively defined as any tragic event stemming from events such as earthquakes, floods, catastrophic accidents, fires, or explosions. It is a phenomenon that can cause damage to life and property and destroy the economic, social and cultural life of people.
In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazard/s and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in uninhabited regions.