A number of American politicians have called for the US to join the global grounding of Boeing 737 Max 8 aircraft in the wake of the Ethiopian Airlines disaster.

The European Union has joined Australia, China and others in keeping the planes out of the sky after 157 people were killed on board the plane that crashed six minutes out of Addis Adaba on Sunday (local time).

American and Southwest airlines are still flying 737 Max planes, along with Fiji Airways, Icelandair, Flydubai, Spicejet and Canada's WestJet.

A Silkair Boeing 737 Max 8 at Changi Airport in Singapore. (AP/AAP)

But Senators Mitt Romney, Elizabeth Warren, Dianne Feinstein and Richard Blummenthal, all Democrats, have called on the Federal Aviation Administration to follow suit.

Warren, who is one of the Democrat presidential nomination contenders, said: "In the coming weeks and months, Congress should hearings on whether an Administration that famously refused to stand up to Saudi Arabia to protect Boeing arms sales has once again put lives at risk for the same reason.

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"But that is a question to be answered another day. Today, immediately, the FAA needs to get these planes out of the sky".

President Donald Trump's view on the subject was difficult to interpret from the language of his tweet.

The Ethiopian Airlines crash has triggered global groundings of the Boeing 737 Max 8 and 9 aircraft. (AAP)

"Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT. I see it all the time in many products. Always seeking to go one unnecessary step further, when often old and simpler is far better," Trump wrote on Twitter.

"I don’t know about you, but I don’t want Albert Einstein to be my pilot. I want great flying professionals that are allowed to easily and quickly take control of a plan."

The European Aviation Safety Agency (EASA) has issued a directive grounding all Boeing 737 Max 8 and 9 model aircraft following two recent deadly crashes.

The grounding applies to all European Union airspace, spanning 27 nations.

It adds that “based on all available information, EASA considers that further actions may be necessary to ensure the continued airworthiness of the two affected models.”

It says companies may make one noncommercial flight to return their planes to a location where they can be inspected.

A Silkair Boeing 737 Max 8 at Changi Airport in Singapore. (AP/AAP)

Turkish Airlines, Oman, Norwegian Air Shuttle and South Korean airline Eastar Jet were among the latest to halt use of the Boeing model.

India says it is immediately grounding all Boeing 737 Max 8 planes. A statement says the planes will be grounded till appropriate modifications and safety measures are undertaken to ensure their safe operations.

The statement does not say how many planes are affected.

CNN reports the cost of grounding all 737 MAX planes could be between $USD1 billion ($AUD1.4 billion) and $USD5 billion, according to estimates from Wall Street firms Melius Research and Jefferies.

Boeing could afford that cost: It posted record revenue of $USD101 billion last year, and a $USD10.6 billion profit. It had forecast even stronger results this year. But Boeing's stock has fallen 11 per cent this week.

The FAA and Boeing both say a software upgrade will give pilots greater control over plane in case problems emerge with the planes' safety systems. That fix is due in April.

Boeing stock has taken a drubbing with the Ethiopian disaster knocking off about $US25 billion ($35.3 billion) from the market value of the world's largest plane maker.

Among the 157 killed on the Ethiopian Airlines flight were these World Food Program workers. (AAP)

Yesterday the shares fell nearly 6.9 per cent to $US368.88 in afternoon trade.

Earlier, the UK Civil Aviation Authority issued instructions to "stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace".

There are currently five 737 Max aircraft registered and operational in the UK and sixth due to commence operations later this week.

The UK announcement comes hours after Australian aircraft safety authorities issued an identical suspension. Groundings have also been ordered by Ethiopia, Indonesia, China, Singapore, South Korea, South Africa, Mexico, Argentina, Cayman Islands and India.

While no Australian airlines operate the plane - though Virgin Australia has some on order - foreign airlines will be impacted by the Civil Aviation Safety Authority’s (CASA) decision not to allow the aircraft to enter Australian airspace.

Singapore-based SilkAir and Fiji Airways had earlier suspended operation of their 737 MAX aircraft.

Fiji Airways has two Boeing 737 MAX aircraft, as well as other aircraft types in its fleet that will be substituted for the 737 MAX.

A 737 MAX plane, operated by Lion Air, also crashed in October in Indonesia, killing all on board.

CASA’s CEO and Director of Aviation Safety, Shane Carmody, said the temporary suspension was in the best interests of safety.

Aircraft safety bosses have temporarily suspended the operation of Boeing 737 MAX aircraft to and from Australia after the deadly crash in Ethiopia which killed 157 people. (AAP)

“This is a temporary suspension while we wait for more information to review the safety risks of continued operations of the Boeing 737 MAX to and from Australia,” Mr Carmody said.

“CASA regrets any inconvenience to passengers but believes it is important to always put safety first.”

CASA said it is closely monitoring updates from Boeing, the United States Federal Aviation Administration and accident investigators.

Flight 302 took off from the Ethiopian capital on Sunday morning bound for Nairobi but crashed six minutes later. (AAP)

A former A-380 captain believes the global crisis engulfing Boeing's 737 MAX 8s is due to secrecy regarding the implementation of the new anti-stall system.

James Nixon said the computer system, which forces the plane’s nose down if it detects it’s flying at too steep an angle, was introduced without telling pilots.

“When it went haywire, they didn’t know what they were doing,” he told 9News.

Virgin Australia is also "closely watching the situation" after ordering 30 of the planes for its fleet.

Mr Nixon believes Virgin will have its order delivered by the time the problem gets fixed.

“By the time Virgin gets the first one in November, the problem will be fixed. But, in the meantime we cannot have people killed in plane crashes like this.”

A Virgin spokesman said this morning: "Virgin Australia will not introduce any new aircraft to the fleet unless we are completely satisfied with its safety.

"There are currently no Boeing 737 Max 8 aircraft in our fleet.

"We are closely monitoring the situation and will continue to work with Boeing, CASA, and other relevant authorities as more information becomes available."

There are approximately 350 Boeing 737 Max 8 aircraft in operation worldwide, being flown by 54 operators, according to the US Federal Aviation Administration (FAA).

Travellers can check the full list of airlines that fly the plane on the Boeing website .

While the cause of an aeroplane crash that killed 157 people in Ethiopia remains unclear, fears abound that the Boeing 737 MAX 8 aircraft involved could have been at fault.

GLOBAL GROUNDINGS

Here is a breakdown of the groundings so far:

AUSTRALIA

Australia's Civil Aviation Safety Authority (CASA) announced the temporary suspension of Boeing 737 MAX aircraft from flying to or from Australia.

No Australian airlines operate the aircraft. Fiji Airways, which has two in its fleet, is the only operator that will be affected by the suspension.

"This is a temporary suspension while we wait for more information to review the safety risks of continued operations of the Boeing 737 MAX to and from Australia," the authority's chief executive Shane Carmody said .

ETHIOPIA

Ethiopian Airlines, which operated the doomed flight from Addis Ababa, said a day after Sunday's crash that is was grounding its 737 MAX 8 fleet until further notice as an "extra safety precaution."

The airline now has four of the planes left.

INDONESIA

Indonesia decided to take the same action, following a decision from the Transportation Ministry, after the second crash involving the aircraft in just over four months.

In October last year, a Boeing 737 MAX 8 plane operated by Indonesian budget carrier Lion Air plummeted into the Java Sea shortly after take off, killing 189 people.

There are 11 such aircraft in Indonesia - 10 belonging to Lion Air and one operated by national carrier Garuda Indonesia, the ministry said.

CHINA

China ordered all Boeing 737 MAX 8s grounded soon after Sunday's crash, pending further investigation.

This was a major blow for the company, since Chinese airlines have 96 Boeing 787 MAX 8 planes in use, according to the Civil Aviation Administration of China.

SINGAPORE

Singapore's SilkAir, which flies the aircraft to Australia, has already temporarily suspended the operation of its entire 737 MAX fleet.

SOUTH KOREA

South Korean budget airline Eastar Jet has voluntarily suspended operation of its two 737 Max 8, the Yonhap news agency reported.

This led to two flights scheduled for Wednesday being cancelled as the airline announced on its website, giving a "safety check" of the planes in question as its reason.

SOUTH AFRICA

South African airline Comair, a British Airways franchisee which also operates as low-cost carrier Kulula, has temporarily grounded its one Boeing 737 MAX 8 aeroplane.

MEXICO

Mexican airline Aeromexico said it has decided to temporarily suspend the operation of its six jets pending the outcome of investigations into the accident.

ARGENTINA

Argentina's pilots association advised its members not to pilot any of the five airliners in Aerolineas Argentinas' fleet until the jets' safe operation could be guaranteed.

The country's flag carrier announced on its website that it had suspended commercial operations of its Boeing 737 MAX 8 aircraft.

CAYMAN ISLANDS

Cayman Airways, the flagship carrier of the autonomous British territory in the Caribbean, also grounded its 737 MAX 8 planes after Sunday's crash.

INDIA

India's aviation regulator has ruled that airlines can continue to use their Boeing 737 MAX 8 aircraft but under strict safety regulations.

The Directorate General of Civil Aviation's new guidelines for operating the planes include additional maintenance checks as well as directions to Indian carriers to ensure that pilots have 1000 hours and co-pilots have 500 hours of flying experience on the 737 MAX 8, a government official said.