Boeing jet that crashed in Iran was predecessor to 737 Max

The Boeing Co. jet that crashed in Iran on Wednesday was part of the same aircraft family as the 737 Max plane that’s been grounded worldwide since March following two deadly crashes.Ukraine International Airlines Flight 752 was operated by a Boeing 737-800, which crashed shortly after takeoff Wednesday morning, killing all passengers and crew. That family of aircraft is called the 737 NG, for Next Generation, and was a significant source of Boeing’s profits before the 737 Max made its commercial debut in 2017.

First flown in 1967, Boeing Co.’s 737 has become the world’s best-selling commercial aircraft. The 737 Max is the fourth generation in the 737 range and was first flown by an affiliate of Lion Air. The Indonesian discount carrier suffered the first 737 Max disaster in October 2018, when Flight 610 plunged into the Java Sea. A 737 Max operated by Ethiopian Airlines crashed five months later, triggering a global wave of groundings.

While the 737 Max has nearly 4,700 orders from over 100 airlines, only a handful were delivered before it was grounded, meaning several carriers have yet to retire the 737 NG series and the planes are in use around the world. Website planefinder.net said the crashed Ukraine International Airlines 737-800 was only delivered to the airline in July 2016.A popular workhorse for airline fleets, the 737 NG family has one of the best safety records of any jetliner. Out of more than 7,000 of the planes that have been put in service over more than 20 years, only seven have been involved in fatal crashes, Boeing data show. The 737-800 is capable of seating as many as 189 people, according to Boeing’s website, compared with as many as 230 seats for the biggest 737 Max model.

Boeing designed the 737 Max to compete with Airbus SE’s newest A320neo model of narrow-body jets, before the disasters idled the entire new fleet. CFM International, a joint venture between General Electric Co. and France’s Safran SA, is the sole provider of engines for both the 737 series of planes.

When it unveiled plans for the 737 Max in 2011, Boeing estimated that the upgraded single-aisle jet would help it capture half of a $2 trillion market in two decades. It has bigger engines, incorporates more automation, has a higher range and uses less fuel. Boeing had pitched that pilots of an older 737 model would only need a short computer course to fly the Max, but on Tuesday it recommended that airlines put Max pilots through simulator training.

The planemaker has halted production of the 737 Max as it tries to gain approval to resume flying the jet from the Federal Aviation Administration, amid pushback from U.S. lawmakers.