What do you do when you do not believe your most important customer? Answer: Fake it until they make it.

At the latest annual SpeedNews Commercial Aviation Industry Suppliers Conference in Los Angeles in June, there was a clear schism between aircraft OEMs and their suppliers over future airliner production rates. While presentations and discussions occurred on background without attribution, suffice it to say that OEM representatives essentially begged the suppliers for belief, while the latter openly professed skepticism.

“They should be skeptical,” Bank of America analyst Ron Epstein told Aviation Week on the sidelines of the conference. “I mean, it’s their job. If they just take the OEMs at face value, then they’re taking risks that maybe they don’t want to. However, I would say if we’re talking about the Airbus rates that got thrown out there—particularly the target in 2025—and you think about the success that Airbus has had with [the] A321 plus the A320, those numbers might not be all that optimistic, right?”

When asked by Aviation Week to assess how much suppliers were discounting recent Airbus and Boeing commentary on where monthly production of new large commercial aircraft rates could be in a few years, one industry expert with deep ties in the supplier base estimated 10-20% off OEM guidance. Another way to look at it: Many suppliers would not be surprised if the OEMs came in up to a year behind meeting their own recent so-called rate guidance.

“While the Airbus and Boeing goals perhaps should be viewed as aspirational, we believe the industry still remains generally cautious on how quickly rates can ramp [up],” Canaccord Genuity analyst Ken Herbert wrote in a conference wrap-up for his investor clients. “For example, we believe the industry expects rates by 2023 to be under 100 [aircraft] per month combined for Boeing and Airbus.”

For OEMs, according to conference participants, several challenges remain. First and foremost is China: If the U.S. rival does not recertify the Boeing 737 MAX relatively soon and continues to use it as barter in the trade war with Washington, then about a quarter of the Chicago-based OEM’s order backlog is at risk.

“It appears that China is not yet satisfied it has fully seen the benefit of the MAX grounding, and recent political pressure from Washington on the relationship with China could be adding to the risk,” Herbert wrote.

Next comes the challenge of trying to resynchronize the OEMs’ respective supply chains—and in the case of Boeing, which has privately and publicly issued up to four different rate schemes, just getting it together on paper may not happen until the end of 2022. Part and parcel to the latter also will be the health of the supply chain, which also remains to be seen.

“While there’s more optimism about [passenger volume], at the same time the supply chain is completely unprepared,” AeroDynamic Advisory Managing Director Kevin Michaels tells Aviation Week. “When you talk to suppliers, and especially smaller suppliers, the long-lead items required even for what Airbus is talking about next year—they don’t have the working capital, a lot of them, to order it. And they don’t have firm purchase orders from Airbus. So is Airbus going to walk the talk and come through with purchase orders? Because the supply chain is weakened, as we all know.”

After liquidity concerns come human capital concerns and, namely, not having enough workers to meet the rate ramp-ups. “It’s kind of like a huge ramp,” Epstein says. “The capital base: The bricks and mortar are there, but the people aren’t. So you’re sort of re-ramping up in an industry that just got decimated. How are you going to get the people back?”

Last but not least, when it comes to the trust factor between suppliers and OEMs, there are questions. In the decade leading up to the COVID-19 and 737 MAX crises, suppliers were bruised and felt battered by supply chain squeezes from the OEMs. To add insult to injury, Boeing also seemed to be attacking the business models of several providers by vertically integrating capabilities.

Many suppliers believe the pendulum will swing back. In the post-crisis world, 30% of suppliers expect less vertical integration overall, according to survey results from Herbert. Likewise, 26% also see greater supplier pricing power.

Of course, suppliers hope the OEMs ultimately are correct in their rate predictions. If they are, suppliers likely will be scrambling to catch up—just as they were before the crises occurred. “As you come back online, a lot of those Achilles’ heels [are] going to reemerge,” Michaels says. “They’re still there.”