Heathrow achieved an all-time record passenger satisfaction score in a survey produced by the Airports Council International for the third quarter, but the percentage of people passing through central security within the prescribed time was below last year's level at 92.8% in 2012.

BBC: An aeroplane at Heathrow Airport

Thus, if a petition is received by the Court after the expiration of the 90-day period, it is nevertheless deemed to be timely filed if the date of the U.S. Postal Service postmark stamped on the envelope in which the petition was mailed is within the time prescribed for filing.

FORBES: Tax Court Denies Late Petition Sent FedEx Express Saver