After two fatal crashes the Boeing 737-MAX is finally back in airline service, American Airlines leading the way with US domestic flights.

Passengers boarding the plane are unlikely to tell the difference except for the distinctive huge 'double' winglets at the end of the wing.

Without a shadow of doubt, it is the most tested aircraft of all time.

The Boeing 737 first flew in 1967, just over 10,000 have been built, the MAX variant claimed to use less than 20% fuel than the previous model and far more environmentally friendly.  After the 2018 accidents the US FAA (Federal Aviation Authority) and other national safety administrators undertook the most detailed investigation into the cause of the disasters whilst Boeing stopped the production and delivery of the aircraft.

At the present time the Seattle-based manufacturer has outstanding orders for 4,129 of the planes with 387 delivered, all of which will require updating.  IAG (group includes British Airways, Iberia and Aer Lingus) has confirmed its commitment for 200.  Michael O’Leary of Ryanair in recent times signed an order for a further 75 aircraft bringing the Irish airline's total to 210.  His version, called the Boeing 737 MAX 8200, is for use on the airline's extensive European network in a high density 197-seat configuration.  The Ryanair fleet, which is all Boeing 737 variants, currently stands at 427, with some of the more elderly aircraft bound to be disposed of as the MAX arrives.  Ryanair UK Ltd is a member of Airlines UK, the British operators' trade organisation, but only has a single aircraft registered in the UK.