Now that Practical Test Standards allow acceleration in ground effect (low ground effect is much more effective,) it will be interesting if manufacturers will begin to publish data on when their airplane will be able to fly in ground effect. Yes, they will have to define the AGL altitude of that ground effect.

For those who have carried heavy loads from uncharted fields for years, Ag and bush for instance, this has been experiential data collection. Knowing about where we should be able to get into low ground effect, well below POH stall speeds and well above POH gross weight, is essential in safely leaving these areas.

Present POH is for safety, not for figuring how to overcome great load and or high density altitude. Evidence of this is the fact that for years gross weight was legally 115% POH gross weight in Alaska. Present backcountry flyers either need the much bigger than normal engines and various mods or they need to do the experiential data collection. We need to know about where, given the tactical situation, we should be able to haul the airplane off into low ground effect and level it there so as to take advantage of the tremendous extra kinetic energy available in low ground effect.