From: PDX (and now) London, UK
i'm pert' sure that airplanes always use their 'extended range' ordnance load when assigned to ASW or NavSearch. also i've been told here that LowN skill makes no difference, only Exp & ASW skill.
I always use 1k' for ASW patrol. hits are v. unlikely - even w/ Exp in the high 60s and ASW in the low 70s, the majority of reported hits are wishful thinking from FOW.
the primary purpose of ASW air is to raise the DL on enemy subs, to reduce their search capability. detected subs are less likely to attack a convoy, and ASW TFs are more likely to find & attack them.
Well, I'm going to stick with training low nav for ASW as for the IJ it doubles as kami training, but based on 27+ months of my current game, I also do believe it makes a difference to the number of hits 'claimed.' Maybe hits are "unlikely" because you're not training low naval.
When I've looked in a H to H test at an isolated group of 2E flying ASW at 1k I found that a good percentage of hit claims were false, but not as many as I'd thought. They also resulted in really various damage, from just 10-15 flotation and a few system to putting the sub in real jeopardy with 60+ float damage and 20-40 system damage. Over maybe 30-35 runs, a very small sample, I never saw a sub sunk just from air assets, but I think it's entirely possible if it has accumulated system damage or if the player does not send it home after a first hit.
What I've continually been curious about is whether the extended range and low altitude modifiers double up. So does a 2E IJAAF bomber go from 4x250kg to 1x250kg based on both modifiers if flown at below 6k on ASW?
It would really help if we had a combat report on attacks by search and ASW planes.
"Success is the ability to go from one failure to another with no loss of enthusiasm." - Winston Churchill