Public Transport
If people are travelling from London they can either get the District Line to West Ham then change to overground to Rainham station. District Line runs every 4-7 mins and on Sundays about every 10 mins.  Unfortunately there are no buses from Rainham station but there are a couple of local cab firms:-

A.L Mini Car Service Tel 01708 522222 / 521600 / 521000 which is 5 minute walk from station followed by a 10minute ride to the airfield.
 
Broadway Cars Tel 01708 522600  in village.

Another option is to get the C2C train from Fenchurch Street station to Rainham, you have to check time table as some trains branch off just after Barking, or they will carry on to Upminster where you can get a bus No.370 to Lakeside and get off at Corbetts Tey RM14 (South Ockendon Rd) and then walk for approx 15 minutes to the show. Journey from Upminster station takes about 40 minutes.  On Saturday buses run about every 30 mins starting  from Romford station at 6.40 am and on Sundays run every 60 mins starting from Romford station at 7.00 am