New Year’s Day will mark 70 years since Heathrow became a commercial airport.

While the then newly named London Airport was officially opened on May 31 1946, it was on January 1 1946 the site originally built for military purposes during the Second World War was handed over to the Minister of Civil Aviation.

The first commercial flight to depart on the day was a British South American Airlines Lancastrian ‘Star Light’ which flew to Buenos Aires, with the first wave of passengers to fly from the airport in May.

Long standing employee Keith Haywood of Ruislip, nearly 87, has worked at the airport for over 70 years.

He was among a group young traffic trainees who watched the first flight depart and currently works two days a week at the British Airways Heritage centre at the airline's headquarters at Waterside.

He said: “I feel very privileged to have seen Heathrow develop and grow from its first day in 1946.”

READ MORE:How many famous faces can you spot at Heathrow through the decades?

Heathrow will officially celebrate its 70th birthday on May 31 2016 but will mark a number of milestone moments with colleagues, passengers and the local community throughout the year.

Heathrow CEO John Holland Kaye said: “This is a significant milestone which marks the incredible transformation of Heathrow.”

“Heathrow has come a long way from being a military airfield to a national asset which is now a globally recognised brand.

“I am very proud to be a part of ‘Team Heathrow’ and the 75,000 colleagues helping to make every passenger’s journey better.

“I’m looking forward to celebrating the history of this amazing airport this year but I’m also looking forward to the next 70 years as Heathrow aims to be the best connected and most environmentally responsible airport in the world.”

In 1946 passenger terminals were made from ex-military marquees which formed a tented village along the Bath Road where passengers walked over wooden duckboards to reach the aircraft parked on the muddy airfield.

By the end of Heathrow’s first year in operation, 63,000 passengers had travelled through London’s new airport, growing to 796,000 by 1951, and to date has rocketed to 73 million passengers annually.

Since 2003, Heathrow has invested £12bn in transforming Heathrow with the opening of Terminal 5 in 2008; followed by a major refurb of Terminal 4 in 2009; the demolition of Terminal 2 in 2010 to pave the way for The Queen’s Terminal which opened in June 2014 by Her Majesty Queen Elizabeth II; and the closure of Terminal 1 in June 2015 to make way for the an extension of Terminal 2.

If the Government supports a third runway at Heathrow in the summer then Terminal 2 will be extended and a new terminal will be built adjacent to Terminal 5.

Heathrow timeline

1944: Construction of London Airport’s runways begins

1946: London Airport officially opens as a commercial airport

1955: Her Majesty the Queen opens the Central Terminal Area and Control Tower

1957: The first non-stop flight to California sets a new record for distance and time

1964: The Beatles are mobbed at London Airport

1966: The British Airports Authority is created. London Airport is renamed ‘Heathrow’

1969: Terminal 1 is opened and existing buildings renamed Terminals 2 and 3

1976: Concorde makes its first passenger flight

1977: The London Underground link is opened

1986: His Royal Highness Prince Charles and Princess Diana inaugurate Terminal 4

1987: The British Airports Authority is privatised as BAA plc

1997: The Terminal 5 public planning inquiry ends – the longest in UK history

1998: The Heathrow Express rail service is launched

2003: Three Concordes make their final touchdown at Heathrow

2006: The Airbus A380 makes its first UK landing into a newly built Pier 6 at Terminal 3

2007: A new air traffic control tower is operational – the tallest in the UK

2008: Terminal 5 is officially opened by Her Majesty The Queen in March; The first commercial A380 flight arrives at Heathrow

2009: Terminal 4 underwent a major refurbishment to improve facilities

2010: Demolition work started on Terminal 2 to make way for its £1 billion replacement which opens on 4 June 2014

2014: The brand new Terminal 2: The Queen’s Terminal opened for business on 4 June. The first airline to move in was United Airlines

2015: Icelandair moved in to Terminal 2 on 25 March

2015: Terminal 1 closed