UK Transit Visa - DATV

[desibhai75]

I am traveling from USA to India via London. I am a green card (issued 2003) holder and would like to know for sure if I need UK transit visa.

Based on *** 20 it sounds like I don't need a visa. However the IATA Timaticweb that all airlines use says:

http://www.delta.com/planning_reservations/plan_flight/international_travel_information/visa_passport_information/

TWOV (Transit Without Visa):
Visa required, except for Passengers who may be granted permission by the Immigration authorities to enter the United Kingdom, for a stay not exceeding 24 hours.

which is quite misleading. Given the uncertainty, I am stuck with difficult choices:
- Do not apply for transit visa and risk not being allowed to board airplane
- Apply for transit visa and spend time and money which could have been saved

Can anyone who has recently travelled through UK with similar visa situation as mine describe their experience traveling without getting a UK transit visa.

Thanks.