Quite agree RG, nevertheless, the regulations require the following for aircraft like the Yak:
For an aircraft that has been certificated under CASR 21.189 in the LIMITED category, each passenger must be told that:
• the design, manufacture, and airworthiness of the aircraft are not required to meet any standards recognised by CASA, and
• CASA does not require the aircraft to be operated to the same degree of safety as an aircraft on a commercial passenger flight; and
• persons fly in the aircraft at their own risk
The operator or the pilot in command must ensure that each person carried is told about the matters mentioned above before boarding the aircraft, and if the passenger is being carried on an 'adventure' flight, then before the passenger pays for the flight.
That sort of warning might (or might not) cause a passenger to think twice. Most people who fly in warbirds (myself included) are just happy to get the opportunity to go up - bugger the risks - but they would be enthusiasts, not Joe Public. Hence the CASA requirement for the information to be provided to a potential passenger.