Dave G
I pretty much grew up in the area you are talking about and the rivers are indeed the Colne and the D of N Canal. Apparently the longest stretch of parallel waterways in UK (?)They once ran from the SW corner of the airport all along the south side before heading off towards Bedfont. Most of the way there was path between them. They were diverted when 28L/10R was extended beyond its original length at block79 if I remember the airport geography correctly and the perimeter road had to be diverted requiring new bridges. Later on when the T4 to 10R southern holding point was built they disappeared into a kind of tunnel.
Back in the day though the river bank west of the emergency access gate opposite the pub in Stanwell Rising Sun?) was great place to spot on a nice day especially if on easterlies. With Deux Ponts , CV990s etc breaking up the flow of BA Viscounts and Vanguards who couldn’t love it. (Mind you at 59 I am feeling the effects of watching or hearing all those VC10s depart from about 300m away) Bit different in winter as the wind swept across the Tundra that was LHR Southside pre cargo centre.
What’s this got to do with C46s ? Well living where I did I had a great view of anything coming off 28L and remember the excitement of seeing the C46 for the very first time – would have spoiled the day had I know it would be a fixture for 4 years. It really seemed to wallow and struggle aloft even for a piston prop but needless to say it made it every day. ( No surprise that they fell out the sky seemingly monthly in Andean S America)
Moving on a decade and all that was left of the big props was the Kar air DC6 which rumbled gorgeously out at 7 every morning until LLHR stopped providing Avgas and the wonderful sound of four straining pistons was never heard again in anger at LHR .
Apologies for thread drift
PB