Heathrow is about to publish its Fly Quiet & Green results for the
first quarter of 2019 - they have been up on the website for the last 3 weeks, but so far protected from public scrutiny (why?) by the usual secret password.
After the embarrassment of last quarter's results, which had to be clandestinely altered (and, even after that, were nonsense), it remains to be seen whether Heathrow can get over the first hurdle - keeping track of the number of flights that land and take off on its runways in order to identify the 50 busiest airlines.
In an attempt (probably in vain) to help LHR with at least that part of the number-crunching, I did take the liberty of sending a list of the relevant airlines, but received no acknowledgement. For the record, in Q1 2019 they were (in descending order of frequency):
BA/SH, BA/LH, VS, EI, LH, AA, SK, UA, EW, LX, KL, AC, DL, IB, AF, BE, EK, QR, AZ, TP, CX, SU, SQ, AI, 9W, AY/SH, EY, TK/LH, OS, LO, SN, A3, CA, BC, TK/SH, VY, GF, JL, MH, QF, TG, WY, KM, SV, LY, CZ, ME/SH, KU, PK, FI/SH
It remains to be seen how many of the 50 appear in the results, once the public is finally permitted to see them.