The continued grounding of the 737 Max will affect Boeing, suppliers, and operators alike, and the longer the crisis goes on the more disruption to the industry it will cause. For the airline sector, the exposure also depends directly on the number of Max jets a particular operator has already taken in proportion to its total fleet. Even though the likes of Southwest Airlines await the return to the air of 34 grounded Max jets, the fact that it flies more than 700 airplanes—all 737NGs—no doubt mitigates the damage.

Several Max operators, such as Norwegian and Air Canada, have managed to maintain schedules through not only direct replacement with other types of 737s but with Boeing 787s flying fewer frequencies, for example. Other measures include wet leasing, lease extensions of unaffected aircraft types, or simply cancellation of some service. All such actions, however, threaten to increase unit costs, the burden for which might ultimately fall on Boeing in the form of compensation to the airlines.

Another effect few analysts have considered involves maintenance planning. Again, the more Max airplanes a particular operator has taken in relation to the size of its fleet as a whole, the more complicated the job of juggling maintenance burdens will prove—and the longer the grounding continues, the more scheduled maintenance events will come due, particularly those unrelated to the number of hours a particular airplane has flown. Airlines bear a cost as a result, both due to the need to perform upkeep on grounded aircraft and the need to revisit overall maintenance plans.

Calendar-driven maintenance tasks cover items such as seals or parts subject to corrosion. Other tasks maintenance crews need to perform on grounded airplanes include running the APU, draining engine oil, and replacing it with special conservation oil, placement of desiccant bags in the cabin, and removal of certain avionics among several other preventive steps to protect the airplane from climatic effects.

“Because the airplanes are not flying...calendar activities versus the activities based on flight hours and flight cycles, they become out of sync,” explained Yann Cambier, the London-based aviation analyst for global consultant ICF International. “So, one objective when you do your maintenance is to do as many activities as possible at once to reduce the amount of time your aircraft is grounded for maintenance purposes. And most airlines have an automated way of bundling tasks. So if you have a calendar task at 24 months, based on your expected utilization you know which flight-related task you have to do at the same time. But because you are not flying anymore, that kind of automation is kind of falling on its head.”

MRO providers face the same predicament, in addition to the direct loss of business resulting from the grounding. “Recently...SIA Engineering was mentioning that they have a large contract with Silkair, and because the maintenance activity is not happening, it has an impact on their bottom line,” said Cambier.

The grounding’s financial effect also stands to hit the leasing market hard, as several airlines have opted not to pay their rents on grounded airplanes, noted Cambier, leaving the lessor holding the burden of pursuing compensation from Boeing. “You have a number of airlines that are refusing to pay the lessors because they don’t want to pay rent on an aircraft that is not flying,” he reported. “So the burden is now on the lessors to go back to Boeing to try to sort the issue out.

So, in effect, airlines that have leased their Max jets might face less exposure than those that own their airplanes outright. Out of 354 grounded 737 Max 8s, operators lease 151, or 41 percent of the fleet.

“I would expect that technically [the airlines] are still bound to [pay],” added Cambier. “But contracts are not always worth the paper they are written on. When it’s such a massive and widely known industry issue, it is a challenge to get someone to pay for something they can’t use.”