Lba-lgw
mighty
Yes, this route has been tried several times, and I think the prime attraction would be the much quicker access to South London or the South coast area, both of which have direct train links, as you say. Connecting onto charter routes will account for only a small number of passengers.
The last airline to have a shot at it was BRAL with a 4x per weekday Jetstream 41 service. The passenger numbers were looking reasonable, over 3,000 per month, but then BRAL closed their LBA base and Eastern chose not to continue that route. Given that Flybe are now muscling in on two of Eastern's remaining LBA routes that might have been an error.
The major difficulty is accessing decent slot times at LGW. The peak times of morning and evening are exactly when every other airline wants to arrive at LGW, so slots are very hard to get. Also, a moderately successful route (as LBA-LGW probably would be) is not really good enough when there are potentially much more profitable routes to run. Easyjet, for example, has plenty of slots at LGW and could run almost as many daily flights to LBA as it wanted, starting yesterday, but there are better loads and yields to be had on the routes it does operate.
LGW would be a useful addition to LBAs routes, but the sticking point is more the LGW end of the operation. Similarly LBA-LCY should raise some demand, but when it has been tried too much capacity has been supplied and other background factors have seen the route rapidly withdrawn.
PTH