MA
There's really not that many incidents at Heathrow or Gatwick. The last crash I think was the BA one in 2006(?) and that happened outside the airport. Weather problems are more common, but it's normally fog and that's going to obscure the camera too.
January 2008, a BA jet suffered fuel stavation on approach and crash landed within the airfield, just short of the runway
https://en.wikipedia.org/wiki/British_Airways_Flight_38
However, that's all an aside, as you say, permanent cameras at LHR or LGW (or any other UK airport) would be largely pointless
There's really not that many incidents at Heathrow or Gatwick. The last crash I think was the BA one in 2006(?) and that happened outside the airport. Weather problems are more common, but it's normally fog and that's going to obscure the camera too.
January 2008, a BA jet suffered fuel stavation on approach and crash landed within the airfield, just short of the runway
https://en.wikipedia.org/wiki/British_Airways_Flight_38
However, that's all an aside, as you say, permanent cameras at LHR or LGW (or any other UK airport) would be largely pointless