Boeing’s estimate to bring its troubled 737 Max aircraft back to the skies by October is too optimistic but there is hope the grounded narrowbody jet could resume commercial operations by the end of the year, the head of the International Air Transport Association said. The process of clearing Boeing's best-selling aircraft to fly was delayed because of a "fragmented" regulatory system and a lack of trust that has resulted in more disagreements between safety regulators on the back of two 737 Max crashes, Alexandre de Juniac, director general and chief executive of the global aviation body told <em>The National</em> in an interview. Some “political issues” have also added to the lengthy grounding of the aircraft, said Mr de Juniac, who is advocating for a single safety clearance certificate for the grounded jet. “If there is one [separate safety] certification process per country or per region, it’ll be a nightmare and I will tell you, the consistency and the effectiveness of the safety system will be significantly reduced,” he said on the sidelines of London’s Aviation Festival last week. “We strongly advocate the single [safety] authorisation and so when you see fragmentation among the regulators on the 737 Max, we are very worried.” Over the summer, the aviation trade body organised meetings between airlines, Boeing and aviation regulators to discuss 737 Max issues, which was grounded in July following two fatal crashes that claimed the lives of 346 people. The continued grounding of the jet has cost airlines billions of dollars as they scramble for replacement airplanes to continue operations. Some airlines have cancelled orders on the Max variant of Boeing 737s and others have said they are monitoring the situation as the jet remains grounded. Boeing is working to fix the flight control system software that caused the fatal crashes. The plane maker earlier this year said it looked to resolve the issues and get the aircraft flying again by October. Mr De Juniac said that Iata is not planning to arrange further Max-related meetings for the time being. The grounding of the 737 is adding to the woes of global airlines, most of which have struggled to maintain revenue and passenger growth in the wake of a trade war between the US and China, which along with geopolitical uncertainty and volatile oil prices has contributed to a global economic slowdown. Despite his optimism about the long-term growth of the aviation sector, Mr De Juniac said Iata’s profit guidance in December will likely be revised down. Despite the global economic slowdown, the Iata chief ruled out a significant recession, which could pose challenges to aviation. While passenger revenue grew in the first seven months of this year, the pace of growth has slowed, he noted. “When we released the last figures in June, they were below the expectations in January. The negative trends have continued all over 2019. If there's a revision, I do not see a positive one,” he noted. “The mid- to long-term trend is still significant growth – 4 to 5 per cent a year for passengers,” he said. Mr De Juniac is bullish about growth prospects in Asian markets, most notably China and India. “In 20 years, among the top 10 city pairs in terms of traffic, five of them will be in China,” he said. “India is also growing very, very fast but the key issue there is whether it has the infrastructure to cope with the demand.”