WOW switches doesnt prevent wheel brakes (main and emergences) from engaging. Only they prevent AUTObraking and AUTOreverse function and interceptors opening. Brakes are unblocked by wheels spinning signal (more than 150 kmh).
Greasing of WOW switches will not prewent malfunction, because it is caused by moisture penetrated into their inside through weared or defective rubber membrane and freesed
opening of the
normally closed contacts. In case of
normally opened contacts force from WOW links can break ice on contacts and
close even faulty switch, but
removing force from contacts in case they are frosen can't
open them.
There is two WOW swithes on every strut - on cylinder and on trolley.
All information from forumavia and aviaforum ru
2
BOAC - latest directive isn't about WOW switches (which was sent day BEFORE accident), it's about swithing off thrust in case of reverse malfunction to prevent landing with engines on full throttle (look at 2009 report and
Novosibirsk overrun case).
Avherald:
On Dec 29th 2012 it became known after another TU-204 overran the runway at Moscow Vnukovo, see Accident: Red Wings T204 at Moscow on Dec 29th 2012, overran runway on landing, that on Dec 28th Rosaviatsia had alerted the aircraft manufacturer Tupolev of a brakes malfunction as cause of the overrun at Novosibirsk. In a letter dated Dec 24th 2012 Rosaviatsia demanded with reference to this overrun that all operators of Tupolev TU-204 should perform an extra lubrication to grease the drive mechanism limit switches that are crimped onto the main landing shock absorber before next departure.
On Dec 31st 2012 Rosaviatsia released a modification to aircraft operations manual requiring flight crew to apply reverse thrust only if the engine is operating (stating application of reverse thrust is prohibited on a malfunctioning engine). To apply reverse thrust the engine should be pulled to idle for 1-2 seconds, then command reverse thrust at minimum thrust, verify yellow "thrust reverser unlocked" followed by green "REV" indications appear, only then apply high reverse thrust. Rosaviatsia reported there have been a number of cases where the green "REV" indication did not appear (editorial note: there have been rumours since this overrun, that the crew had applied reverse thrust, the reverser however had not opened and at least one of the engine was delivering full forward thrust instead).