I saw the following 57 aircraft at London Heathrow on Friday, June 21, 2019:
9M-MAD A350-941 Malaysia Airlines
A6-APG A380-861 Etihad Airways
C-FVLU 787-9 Dreamliner Air Canada
EI-DVH A320-214 Aer Lingus
F-HEPE A320-214 Air France
G-BYGC 747-436 British Airways
G-BYGF 747-436 British Airways
G-BYGG 747-436 British Airways
G-CIVA 747-436 British Airways
G-CIVB 747-436 British Airways
G-CIVC 747-436 British Airways
G-CIVL 747-436 British Airways
G-CIVW 747-436 British Airways
G-EUOB A319-131 British Airways
G-EUOH A319-131 British Airways
G-EUOI A319-131 British Airways
G-EUPK A319-131 British Airways
G-EUPO A319-131 British Airways
G-EUPP A319-131 British Airways
G-EUPW A319-131 British Airways
G-EUUE A320-232 British Airways
G-EUUI A320-232 British Airways
G-EUUN A320-232 British Airways
G-EUUR A320-232 British Airways
G-EUXL A321-231 British Airways
G-EUYK A320-232 British Airways
G-EUYV A320-232(WL) British Airways
G-EUYW A320-232(WL) British Airways
G-MEDF A321-231 British Airways
G-NEOP A321-251NX(WL) British Airways
G-NEOS A321-251NX(WL) British Airways
G-STBJ 777-336(ER) British Airways
G-TTNA A320-251N(WL) British Airways
G-TTNB A320-251N(WL) British Airways
G-VCRU 787-9 Dreamliner Virgin Atlantic Airways
G-VIIE 777-236(ER) British Airways
G-VSKY A340-311 Virgin Atlantic Airways
G-VWHO 787-9 Dreamliner Virgin Atlantic Airways
G-YMMN 777-236(ER) British Airways
G-YMMP 777-236(ER) British Airways
G-ZBJC 787-8 Dreamliner British Airways
G-ZBJE 787-8 Dreamliner British Airways
G-ZBJI 787-8 Dreamliner British Airways
G-ZBKC 787-9 Dreamliner British Airways
G-ZBKF 787-9 Dreamliner British Airways
G-ZBKK 787-9 Dreamliner British Airways
G-ZBKL 787-9 Dreamliner British Airways
G-ZBKP 787-9 Dreamliner British Airways
G-ZBKR 787-9 Dreamliner British Airways
G-ZZZA 777-236 British Airways
I-BIXP A321-112 Alitalia
JA731J 777-346(ER) Japan Airlines
N182DN 767-332(ER)(WL) Delta Air Lines
N781AN 777-223(ER) American Airlines
N860NW A330-223 Delta Air Lines
OE-LBC A321-111 Austrian Airlines
VH-ZNH 787-9 Dreamliner Qantas