i was at BMA LHR 1977-1985 and as I recall in those years we only flew in and out of LTN at weekends to JER and GCI -
same as with those flights to/from SEN and CVT to the CI's
out of LTN the Viscounts were used on the GCI and both DC-9's and Viscounts on the JER
all the LTN (and SEN & CVT) - Channel islands flights were flown on a W pattern originating from either EMA BHX MME or GLA (maybe LPL too)
cannot think of any weekday flights in/out of LTN during my years but going back to late 60's and early 70's there were plenty
(including the use of VC8, Heralds and the new 1-11 523's) i think to JER GCI EMA LBA DUB and GLA plus the IT charters
popular routes were OST PMI BCN BSL
shame about the sign in the skip
