Boeing shares fall 7% as more carriers ground the 737 Max 8 jets

Boeing shares fell 7% on Tuesday, adding to the 5% it dropped on Monday, after more countries joined China and Indonesia in the grounding of the 737 Max 8 jet after the Sunday crash in Ethiopia that took the life of all its 157 passengers.

Countries that have most recently said the flights of the jet model are facing bans are: Britain, Australia, Malaysia, Ireland, Italy, Germany and Norway, Turkey and Singapore.

The head of the global air travel watchdog said on Tuesday that no one should draw any conclusions before the results of its investigation into the deadly crash of the Ethiopian Airlines Boeing 737 Max 8 crash were known

"The most serious and vigorous attitude is to check and verify and establish facts," International Air Transport Association (IATA) Director General, Alexandre de Juniac, said to Reuters from Singapore.

"On this issue our permanent position is to wait for the results of the investigation to draw any conclusion."

Separately, the New York Times reported that what information was already available had revealed "some" similarities between the Ethiopian Airlines crash on Sunday that killed 157 and some of the circumstances and the crash of a Lion Air flight in October that claimed the lives of 189 passengers and crew.

Five months before, another Boeing 737 Max 8 jet belonging to the Indonesian airline had also crashed shortly after takeoff about 13 minutes after leaving Jakarta.

Overnight, the Argentine and Mexican flag carriers, Aerolíneas Argentinas and Aeromexico, respectively, joined their Chinese and Ethiopian peers in grounding their Boeing 737 Max 8 aircraft.

They were followed by another 12 airlines globally, although 18 carriers, including American Airlines and Southwest Airlines had opted to continue operating their 737 Max 8s.

Indonesia's air transport regulator went further ordering for a second time that all 737 Max 8 jets owned by the country's airlines be temporarily grounded.

Amid the heightened concern generated by the two crashes, America's Association of Flight Attendants urged the Federal Aviation Administration in the US to review the Max 8 jet.

“We need help from the regulators when the entire world is looking at two catastrophic incidents that happened on the same aircraft type within five months of each other,” said Sara Nelson, the president of the flight attendants’ union. “Our system is so safe that these things don’t happen today. That is why people are questioning what is going on here.”

Former pilots at America Airlines also expressed "concern" with Senator Dianne Feinstein calling for all Boeing 737 Max 8 planes to be grounded until the FAA's investigation was complete.

According to experts cited by the New York Times, the investigation could take over a year to conclude.

However, overnight the FAA issued a Continued Air Worthiness notification for the Boeing jet.

As well, some experts were reportedly surprised by the disparity in experience between the two pilots in the Ethiopian jet, with one having 8,000 hours of flight experience (versus a minimum of 3,500 hours needed for some models of Boeing jets) but the other having just 200.