<span>A growing number of countries have grounded or banned </span><span>Boeing's 737 Max 8 following two fatal crashes in five months involving the jet. </span><span>This has put pressure on the US plane maker </span><span>facing the worst crisis since battery-related issues with its 787 Dreamliner. </span> <span>Regulators and airlines </span><span>are raising doubts over the Boeing's best-selling jet by grounding or banning it, despite the US aviation regulator </span><span>backing the plane's airworthiness, following the Ethiopian Airlines </span><span>crash this week. </span><span> </span> <span>The UAE's General Civil Aviation Authority is "closely assessing" the situation</span><span>, it said on Tuesday. </span> <span>Flydubai, the sole UAE operator of the 737 Max 8 and the second-biggest customer of the jet globally, said it continued to follow the investigations.</span> <span>“We have reviewed the continued airworthiness notification received from the Federal Aviation Administration in relation to the Boeing 737 Max 8 and Max 9 aircraft, and no further action is required at this time,” a flydubai spokeswoman said. “We are continuing to follow closely the ongoing investigations.”</span> <span>The UK Civil Aviation Authority also issued instructions on Tuesday to stop 737 Max 8 commercial passenger flights from arriving, departing or overflying UK airspace, Reuters reported.</span> <span>Civil Aviation Authority of Singapore </span><span>temporarily suspended the 737 Max from its airspace, too, which means the industry workhorse </span><span>is blocked from Asia's second-busiest international airport. </span> <span>“During the temporary suspension, CAAS will gather more information and review the safety risk associated with the continued operation of the Boeing 737 Max aircraft into and out of Singapore,” the regulator said. </span> <span>Australia also took a similar stand. </span> <span>Many airlines have grounded the jet including Brazil's </span><span>GOL, Grupo Aeromexico, Aerolineas Argentinas, Cayman Airways, South Africa's Comair Airways and South Korea's Eastar Jet. </span> <span>China, Indonesia and Ethiopia were among the first to halt its 737 Max operations.</span> <span>In the Middle East, Oman halted all flights operating 737 Max 8 jets in </span><span>its airspace until further notice, the </span><span>civil aviation said yesterday. Oman Air has five 737 Max 8 aircraft in its fleet.</span><span> </span> Ryanair is not planning to make any changes to its first 737 Max delivery in April following the Ethiopian Airlines crash, chief executive Michael O'Leary told the <em>Irish Independent </em>newspaper. <span>The fact that the 737 Max 8 model was the aircraft flown during both the deadly accidents – the </span><span>Ethiopian Airlines on Sunday and Indonesia's Lion Air in October </span><span>– have prompted travellers to raise questions over the jet's safety. Many of them inquired </span><span>if their </span><span>journeys were booked on the fateful jet.</span> <span>Boeing, the world's largest plane maker, said it will introduce software updates to its 737 Max within weeks, shortly after the </span><span>FAA said it will mandate the manufacturer to implement design changes in the aircraft by April.</span> <span>Boeing has been working on a flight-control software improvement on the 737 Max to "make an already safe aircraft even safer" for several months since </span><span>the Lion Air crash</span><span>, the company said </span><span>on Monday. </span> <span>An investigation into the Lion Air crash found that the pilot struggled with the plane's anti-stall system, and </span><span>as a result of erroneous data, the nose of the aircraft was forced downward despite attempts by the pilot to pull it up. All </span>all 189 passengers on-board died.<span> </span> <span>Boeing subsequently advised airlines how to address the issue. The company expressed condolences this week to families of the victims dead in the Ethiopian Airlines crash, but did not refer to the accident in relation to the software upgrade.</span> <span>“Boeing has been working closely with the Federal Aviation Administration on development, planning and certification of the software enhancement, and it will be deployed across the 737 Max fleet in the coming weeks,” the company said.</span> Boeing said there is no need to issue new guidance to operators of the aircraft based on the information it has so far.<br/> <span>The FAA indicated its confidence in the aircraft's safety </span><span>by issuing a confirmation of its "continued airworthiness"</span><span>. The US </span><span>regulator said there is no conclusive evidence linking the Ethiopian Airlines crash </span><span>to the Lion Air disaster</span><span>.</span> <span>Mounting concerns have wiped billions of dollars off the market value of Boeing's shares</span><span>. </span><span>The stock extended its one week losing streak yesterday declining 4 per cent at 6pm UAE time.</span> Former inspector general of the US Transportation Department, Mary Schiavo, told CNN that all 737 Max 8 planes should be grounded given it was involved in two deadly incidents. The new Max 8 variant of the 737, which entered service in 2017, has bigger engines designed to use less fuel and there are 4,661 on order. The crash of Nairobi-bound Ethiopian Airlines' 737 Max 8 killed all 157 travellers on-board, raising questions about the safety of the new variant of the popular industry cash cow. Investigators in Ethiopia found two black box recorders that will provide information about what happened before the plane plunged into farmland minutes after take-off from Addis Ababa. As long as the recordings are undamaged, the cause of the accident can be identified. It typically takes a year to fully complete an investigation.