Если гражданство РФ, то не нужна. Т.к. летят в Канаду, то могут даже выйти из транзитной зоны:
National Russian Fed. (RU) /Embarkation Russian Fed. (RU)
Transit United Kingdom (GB) /Destination Canada (CA)
ALSO CHECK DESTINATION INFORMATION BELOW
United Kingdom (GB)
TWOV (Transit Without Visa):
Visa required, except for Nationals of Russian Fed. holding
confirmed onward tickets making an airside transit at London
Gatwick (LGW), London Heathrow (LHR) or Manchester (MAN) on
the same calendar day to a third country (excluding Ireland
(Rep.)).The following conditions must be complied with:
- passenger must arrive and depart by air; and
- passenger only intends to transit through the United
Kingdom; and
- passenger must hold all documents required for the next
destination; and
- passenger must not leave the transit area.
- OR:
Visa required, except for Passengers holding confirmed onward
tickets passing through United Kingdom immigration to make a
landside transit to a third country on a flight that departs
before 23:59 the next day. The following conditions must be
complied with:
- passenger must arrive and depart by air; and
- passenger must have no purpose in entering the United
Kingdom other than to pass through in transit; and
- passenger must hold all documents required for the next
destination; and
- passenger must pass through United Kingdom Immigration; and
- passenger travels with a document listed in the following
warning(s):
- ***Warning*** Passengers may make a landside transit if
holding a valid visa which allows entry into Australia,
Canada, New Zealand or USA and traveling as part of a
journey to, from or transit through the country that has
issued the visa.
03.02.2018 в 06:30