Found a thorough document on aerial runway at Pioneering Made Easy (although document is hosted at ScoutBase UK). Take a look at it before your next aerial runway pioneering project.
Aerial runways are potentially dangerous and remain so, even when all reasonable precautions, both in their construction and use, have been taken. Indeed, without some apparent element of hazard, much of their appeal and training value would be lost. The aim should be, therefore, to eliminate all avoidable risk and thereafter to exercise the highest degree of responsibility in the use of the aerial runway without destroying the challenge and excitement generated by the activity.