My response (I hope you like it and may submit your own feedback):

Whilst I am a supporter and user of London City Airport, I am concerned that the proposals will route all flights to city airport directly over Forest Hill, this hilly part of London is particualrly suseptable to noise from low flying aircraft. Whilst the planes to city are significantly quieter than those into Heathrow, the density of flights that will end up routed over Forest Hill will be significantly higher due to the drawing of the new 'red route' and boundaries.

I would far prefer that routes into City airport continue to use routes both north and south of the Thames rather than solely flying over south London, following the route of the south circular, which already leads Forest Hill to be a particularly noisy area.