...just where is this "cranbrock university" that you refer to and what exactly was the sound scienitific research?
I suspect that it is actually
Cranfield University that is being referred to. Over the years, they have conducted numerous studies related to passenger safety. Here are a few additional links with their current information:
Cranfield: Aircraft Cabin Simulators
Cranfield: Passenger Safety Research
Much of the research related to aircraft evacuations has been conducted by Cranfield as well as the
Civil Aerospace Medical Institute in the US and their
Cabin Safety Research Team.
It is possible that one of the research documents being referred to might be the following: “Influence of cabin crew during emergency evacuations at floor level exits”, Civil Aviation Authority, CAA Paper 95006, 1995.
For additional information related to evacuations, there is quite a bit available at the following site:
Cabin Safety Research Technical Group
Simple question, but does 1:50 include infants? If not how many additional could be carried?
As the ratio is to be based on the number of seats, rather than passengers, then infants that are transported on the laps of passengers are not counted towared the ratio for determining the number of cabin crew. Typcially, the limitation on the number of infants that can be lap-carried relate to the availability of supplemental oxygen and infant flotation equipment.