For years he was a lone voice in the aviation industry despite being one of its best-known economists, a Cassandra-like figure whose warnings of a slump in oil prices went unheeded.

But at an annual jamboree for aviation bankers this week, Adam Pilarski's prophesy of $40-a-barrel crude haunted many who had confidently predicted oil would stay north of $100.

"People chuckled when I was saying this. Now they are saying O-M-G you were right," said Pilarski, former chief economist of Douglas Aircraft, now part of Boeing (BA.N).

Pilarski's irreverent but well-researched presentations are a popular feature of aviation conferences. But on oil prices, the 66-year-old economist has long been in a minority of one, urging airlines to plan for $40 crude by his 70th birthday.

"I wasn't 100 percent right. My timing was wrong," Pilarski admitted as North Sea Brent traded below $50 a barrel this week.

So one of the questions in Dublin aviation gatherings this week has been what the maverick forecaster will predict next.

"Oil prices will stay low for some time," Pilarski said in an interview, adding this would result in lower demand for new jets and delays in the retirement of older models.

That remains an unusual view in an industry that believes airplane demand will remain high, supporting a global supply chain tied to huge investments in fuel-saving technology.

The battering of oil prices has implications from air fares to the price of a second-hand jumbo and aviation experts debated fiercely whether it would bounce back and how quickly.

"One of the safest bets is to say this (low oil) can't last," Standard Chartered researcher Paul Horsnell told the Airline Economics conference, suggesting a bounce back toward $80-100 would begin as early as the end of the first quarter.

Defending his bearish view, Pilarski said those betting on sharply higher oil prices had under-estimated the depth of Saudi Arabia's attachment to steady output, driven by geopolitical considerations rather than just short-term market discipline.

He said his view had not changed despite the death early on Friday of Saudi King Abdulllah, which lifted Brent crude. Abdullah was succeeded by his brother Salman.

Speaking in a separate interview before Abdullah's death was announced, Robert Martin, chief executive of BOC Aviation, cited the Gulf monarchy as an area to watch in an industry that constantly calibrates political and economic risk.

"(Abdullah's) potential successor (Salman) is also not in the best of health. Saudi Arabia is important to the rest of the world...so we will be watching that situation," he told Reuters.

Later on Friday, King Salman pledged continuity in energy and foreign policies and then quickly moved to appoint younger men as his heirs.

Led by Saudi Arabia, the OPEC producers club announced last November it was keeping output steady at 30 million barrels per day despite an oil glut. The decision was aimed at defending market share against U.S. shale oil production as well as other non-OPEC exporters such as Brazil or Russia.

The Gulf is fast becoming aviation's focal point as a source of aircraft demand, some financing from sovereign funds and as an arbiter of oil prices, the biggest variable airline cost.

While cheap oil is good for most airlines, delegates said it is posing headaches for some financiers who suddenly find carriers flush with cash and less willing to seek outside funds.

Martin estimated oil prices would hit bottom soon and rise gradually in what he called a "tilted L-shaped recovery," leveling around $60-70. "The speed at which shale oil can be turned on and off has changed the dynamics," he told Reuters.