FAA Delays on Boeing 737 MAX 10 Hit Airline Capacity

Sunday, July 20, 2025

Row of grounded Boeing 737 MAX jets parked on the airport apron at sunset, illustrating certification delays.

Boeing's 737 MAX 10 remains stuck on the runway as the FAA's cautious certification process stretches into a fifth year. What began as a routine approval has mushroomed into a regulatory gauntlet of safety retrofits, quality-control audits, and production setbacks, leaving airlines that banked on the high-capacity jet scrambling for alternatives. With United, Delta, and other carriers now trimming schedules, leasing stop-gap aircraft, and warning of seat shortages during peak travel seasons, the MAX 10 delay is reshaping fleet strategies around the globe and driving home a stark lesson: in aviation, regulatory trust is every bit as critical as technological progress.

FAA Certification Delays: Timeline and Hurdles

The Boeing 737 MAX 10 - the largest variant of the MAX family - has faced a protracted certification process. Originally slated for first delivery in late 2020, its entry into service remains on hold well into 2025. A key stumbling block was a new U.S. safety law requiring modern cockpit alerting systems on any airliner certified after Dec 2022. Boeing secured a legislative extension in late 2022, avoiding a costly redesign of the MAX 10's crew alerting system but agreeing to retrofit earlier MAX jets with safety enhancements (e.g. enhanced angle-of-attack alerts and cut-out switches for stall warnings). Despite this reprieve, Boeing's internal estimates of MAX 10 certification by late 2023 proved overly optimistic. As of mid-2025, both the MAX 10 and its smaller sibling, the MAX 7, remain uncertified by the FAA, with Boeing now targeting late 2025 for approval - a timeline many experts view as uncertain, potentially slipping into 2026.

Several technical and regulatory hurdles have slowed the approval process. Boeing had to address compliance shortfalls in the stall management/yaw damper (SMYD) system and implement an Electronic Alerting Indicator (EAI) to appease regulators in lieu of a full cockpit overhaul. In 2024, concerns also arose about the MAX's resistance to bird strikes after incidents on other MAX models, prompting additional scrutiny of engine and airframe robustness. Above all, the FAA's post-crisis caution has markedly lengthened testing and review. The agency, under pressure after the MAX 8 crashes, vowed a rigorous certification regimen for the MAX 7/10. This meant no shortcuts or fast-tracking, and every new issue - such as a January 2024 incident where an Alaska Airlines 737-9 MAX suffered an in-flight emergency exit plug "blowout" - only amplified the oversight intensity. That Alaska flight's mishap (traced to missing bolts in a door plug) was the "straw that broke the camel's back" for Boeing's schedule hopes. It not only led to FAA-mandated inspections and a temporary grounding of 737-9 MAX fleets, but also solidified regulators' resolve to keep Boeing's production and certification efforts on a short leash.

Compounding these challenges were external disruptions. A seven-week work stoppage in late 2024 at Boeing's Renton factory halted 737 MAX production and diverted engineering resources away from certification efforts. Similarly, a supplier factory fire in early 2025 created new supply chain bottlenecks. These setbacks, on top of pandemic-era delays and quality control lapses, have pushed the MAX 10's certification timeline about five years beyond initial plans. In short, a combination of heightened FAA scrutiny, technical modifications, and production snags has kept the MAX 10 bottled up in testing far longer than airlines banked on.

Disruption of Fleet Planning for Major Carriers

Airlines that staked growth or replacement plans on the MAX 10 are now scrambling to adjust. United Airlines - the launch customer and largest MAX 10 customer with 250+ on order - has been among the hardest hit. In early 2024, United's executives announced they had removed the MAX 10 from internal fleet plans until further notice, essentially conceding that Boeing "is not going to be able to meet their contractual deliveries" in any reasonable timeframe. "We are not cancelling the order. We are taking it out of our internal plans," CEO Scott Kirby explained, underscoring frustration but not a total loss of faith. United had initially hoped for MAX 10s by 2022-23; now it doesn't expect to receive its first until 2027 or 2028. The carrier even directed Boeing to prioritize delivering smaller 737-9 MAX jets in the interim, rather than waiting idly for the -10. United's CFO Mike Leskinen noted the airline is "more bullish" on the MAX 9 as a stopgap, calling it a great aircraft that can shoulder capacity until the 10s arrive. Indeed, United has nearly 100 MAX 9s in service and plans to keep growing that sub-fleet while the MAX 10 is stuck in limbo.

Crucially, the MAX 10 delay forced United to revise its capacity forecasts for the mid-2020s. It had 64 MAX deliveries (across all variants) slated in 2024 alone. By April 2024 United cut its expected Boeing deliveries for the year - trimming its MAX 8 arrivals to 37 (from 43) and anticipating 15 fewer MAX 9s than planned. This shortfall directly translates to less growth. United has been hiring pilots and crew for new planes that now won't materialize on schedule, even leading it to offer voluntary unpaid leave to pilots and pause new hiring classes in summer 2024 to mitigate overstaffing while planes are delayed. In CEO Kirby's words, the industry-wide pullback in aircraft has created a "transformed" environment of constrained seat supply - one that United is grudgingly adapting to as the new reality.

Other U.S. carriers are in similar positions. Delta Air Lines, which broke with tradition to order 100 Boeing 737-10s in 2022, does not expect to see its first MAX 10 delivered until at least 2026. Delta's CEO Ed Bastian has been clear that the airline will not induct the MAX 10 until they have "1000% confidence" in its safety and certification, given Boeing's recent track record. In the meantime, Delta is likely relying on its Airbus A321neo deliveries and existing 737-900ER/757 fleet to cover the capacity that MAX 10s were meant to provide.

On the West Coast, Alaska Airlines had ordered 45 MAX 10s as part of its narrowbody fleet renewal. Those plans are deferred by default, with Alaska now expecting its first MAX 10 no earlier than late 2025 or 2026. More urgently, Alaska felt the ripple effects of Boeing's quality issues when that January 2024 door plug incident led to a temporary grounding of all 79 of Alaska's 737-9 MAX jets (which share the door plug design). For Alaska, roughly 8% of its total capacity was suddenly out of service pending inspections. The airline's CEO, Ben Minicucci, voiced anger at Boeing after finding "loose bolts on many" of its MAX 9s, calling the situation "frustrating" and demanding Boeing improve its production quality control. This grounding in the middle of the busy Winter Travel season drove Alaska's unit costs up ~3% in Q1 2024 and forced it to reassign aircraft to cover routes. Such incidents erode airlines' trust in Boeing's timelines - Alaska is still committed to its MAX 10 order, but like others, has had to keep older aircraft in service longer as a bridge.

Beyond the U.S., international carriers are also adjusting fleet strategies. In December 2024, Turkey's Pegasus Airlines placed a massive order for up to 200 Boeing 737-10s (100 firm, 100 options) - a strong vote of confidence in the aircraft's long-term value. Yet Pegasus, and other airlines with MAX 10s on order (from Europe's TUI and Ryanair to Asia's Lion Air and India's Akasa Air), all remain at the mercy of the FAA's certification timeline. Many have to plan interim lift solutions until the jets arrive. For example, flydubai in the Middle East, while mainly operating smaller MAX models, cited "ongoing challenges with the manufacturer's delivery schedule" and took the extraordinary step of wet-leasing additional 737s to meet demand. Globally, Boeing's order book shows over 1,200 orders for the MAX 10 as of early 2025, representing dozens of airlines banking on this model. Each additional month of delay forces those carriers to juggle resources - whether by deferring aircraft retirements, leasing substitutes, or reducing capacity growth - to fill the gap.

Projected Seat Shortages in Peak Travel Periods

The most immediate consequence of these delays is a shortfall in seat capacity during high-demand travel periods. Airlines plan fleets years in advance to align with expected passenger demand, especially for peak seasons like summer and holidays. The persistent absence of MAX 10 deliveries (and delays in other Boeing jets) has created a cascading capacity crunch just as Air Travel demand rebounds strongly post-pandemic. United Airlines, for instance, warned of a potential "flight capacity crunch for summer 2024" due to having dozens fewer new aircraft than anticipated. SouthWest Airlines, which isn't a MAX 10 customer but is affected by delays of the smaller MAX 7, provides a parallel example - it expected 79 new 737 MAXs in 2024 but revised that down to 46, leaving 33 fewer planes to operate its summer schedule than planned. This industry-wide aircraft shortfall was projected to contribute to an 8% reduction in global air travel capacity for summer 2024 compared to original plans, according to some analyses.

Such seat shortages manifest in very tangible ways for travelers. Airlines have been capping growth and even canceling or postponing routes that they lack aircraft to serve. For example, American Airlines (dealing with Boeing 787 delays) preemptively cut several planned long-haul routes and frequencies for summer 2023. On the narrowbody front, carriers like Ryanair in Europe trimmed their passenger traffic targets for 2024/25 because Boeing couldn't deliver all the 737s needed to fly their full schedules. United's leadership likewise indicated that some domestic capacity growth would be dialed back. In fact, domestic seat growth in 2024-25 is now expected to be the slowest in at least a decade, in large part because airlines simply don't have enough new jets to expand with. High-demand flights that would have been added to schedules aren't there, and older aircraft can only be stretched so far to pick up the slack.

The cascading effect is higher load factors (i.e. fuller flights) and upward pressure on fares. With travel demand surging and seat supply constrained, the classic supply-demand imbalance is driving airfares up. United's Kirby noted that industry-wide discipline in adding capacity has created a "constructive backdrop" for airline revenues. Data from late 2024 showed U.S. ticket prices rising at their fastest clip in nearly two years, directly attributable to "tight supply and strong travel demand" in the domestic market. In practical terms, this means popular flights during holidays or summer may sell out faster and see significantly higher prices than in past years. As Business Insider succinctly noted, "lower seat capacity" inevitably results in higher ticket prices for customers. Passengers attempting to book close to their travel date or in peak season might find fewer available seats and limited flight options, especially on routes where airlines would have deployed the high-capacity MAX 10 to meet the demand. In essence, the delayed aircraft are creating a gap between demand and supply that is felt in the form of seat shortages on busy travel days.

Looking ahead, airlines are already signaling that if the MAX 10 (and other backlogged jets) don't arrive before the mid-to-late 2020s high-demand periods, they may face tough choices: restrict capacity growth or risk operational strain by overutilizing older planes. Industry forecasts by IATA and others predict passenger numbers will continue rising in 2025 and beyond, so a prolonged aircraft shortage could make sold-out flights and fare hikes a recurring theme during summers to come. United has even called the constrained capacity environment a durable trend - a stark change from the pre-2019 era when seat growth often kept up with demand. In summary, unless relief comes in the form of certified MAX 10s (and more Airbus deliveries), airlines may be hard-pressed to provide enough seats during the busiest travel waves, potentially crimping the industry's ability to fully capitalize on demand surges.

Mitigation Strategies: Wet-Leasing, Fleet Shuffles, and Schedule Cuts

To bridge the capacity gap, carriers are employing a mix of stopgap measures. One common strategy has been wet-leasing aircraft from charter or leasing operators. Wet-leasing provides an immediate injection of capacity by renting both an aircraft and crew from another airline on a temporary basis. For example, flydubai revealed it entered a wet-lease deal for six 737-800s from Smartwings (a Czech carrier) specifically due to Boeing's delivery delays - it received four fewer MAX jets than expected in 2023. By leasing those additional 737s with crews, flydubai could maintain its planned schedule and add capacity to meet passenger demand. This wasn't an isolated case: the agreement was the third of its kind between flydubai and Smartwings, indicating a sustained need to outsource lift because new aircraft were late. Other airlines have taken similar steps; Europe's TUI Airways and Canada's Air Transat, for instance, have at times leased extra planes during summer peaks when their fleet deliveries were delayed (Smartwings had 11 of its 33 jets wet-leased out to various airlines in early 2024, underscoring the demand for such capacity). In India, low-cost giant IndiGo resorted to wet-leasing Boeing 737 MAX 8s from Turkey's Corendon Airlines to cover for late Airbus A320neo deliveries - a parallel situation in which delivery delays forced creative sourcing of aircraft. While wet-leasing is expensive and not ideal (airlines lose some control over product and incur higher operating costs), it has proven to be a vital relief valve to prevent severe capacity shortfalls.

Another lever carriers are pulling is reassigning and optimizing their existing fleets. In the absence of the MAX 10, airlines are upgauging flights to slightly smaller models or shifting aircraft to where they are needed most. United's contingency plan, as noted, leans heavily on the 737 MAX 9: routes that were projected to use MAX 10s (which seat roughly 188-204 passengers in two classes) will instead use the 178-seat MAX 9 or other available aircraft. This sometimes means running more flights with smaller planes to carry the same passenger volume, or accepting a modest capacity reduction on each flight. United also indicated it might extend the life of some 737-900ERs and 757s that the MAX 10s were intended to replace, to avoid losing capacity on key routes. Likewise, other airlines are deferring retirements of older jets. American Airlines, for example, delayed retiring some 737-800s and Airbus A320s to ensure enough narrowbodies for its schedule, given new MAXs were arriving slower than anticipated (American's MAX fleet consists primarily of the -8 variant; while it didn't order the MAX 10, delays in any MAX variant reverberate across Boeing's production line). The cost of keeping older planes flying - in maintenance and fuel - is a trade-off airlines are accepting to maintain network coverage.

Carriers are also trimming schedules and growth plans as a last resort. Rather than overextend with too few planes, airlines have opted to cut frequencies or even entire routes that were marginal. SouthWest Airlines, facing a shortfall of dozens of MAX 7s in 2024-25, announced it would slash its growth plans - focusing on core routes and suspending some expansion initiatives. Southwest's CEO Bob Jordan noted they would "hedge our bets" given Boeing's delivery slippages, implying conservative scheduling until the fleet is reinforced. United similarly signaled it would reduce planned flying: in a memo, United told staff that delivery delays were reducing aircraft utilization in 2024, and it planned to tighten schedules accordingly to match the smaller fleet. In practical terms, this could mean fewer off-peak frequencies or postponing service to secondary destinations. Airlines are prioritizing the most profitable and high-demand routes for the planes they do have, leaving some smaller markets or new route launches to wait another year or two. This "capacity discipline" is a direct outcome of aircraft shortages and has even been praised by Wall Street for keeping yields high. However, it runs counter to travelers' interests in more flight options.

Lastly, airlines are engaging manufacturers other than Boeing as leverage and backup. United's CEO openly started talks with Airbus about a potential large narrowbody order in 2024, hinting that if Boeing can't deliver, United might top-up its Airbus A321neo orders. This kind of fleet diversification can alleviate future risk - if one manufacturer falters, the airline isn't completely handcuffed. For now, though, switching suppliers doesn't solve the immediate crunch since Airbus itself has a backlog; it is more of a long-term strategic adjustment. In summary, airlines are using every tool in the box - leasing stopgaps, reassigning existing jets, delaying retirements, scaling back schedules, and considering alternate suppliers - to navigate the MAX 10 delay. Each of these measures has costs, but they help contain the disruption and ensure that the seat shortage doesn't become an outright capacity crisis. As one aviation analysis observed, airlines have been forced to "cut routes and spend more to keep older planes flying, even as travel demand soars" - a concise description of the compromises being made across the industry.

Downstream Effects on Passengers and Operational Reliability

For passengers, the ripple effects of the MAX 10's delay are becoming evident in the travel experience. The most noticeable impact is on fares and availability. During peak travel periods, flights are consistently fuller and tickets pricier due to the capacity constraints discussed. Travelers in summer 2023 and 2024 saw fewer promotional fares, and those waiting to book last-minute often found flights either sold out or very expensive, particularly on routes where airlines would have added extra capacity had the aircraft been available. Industry observers have noted that with airlines keeping supply tight, airfares have risen to levels that help offset their higher costs. United's Kirby even suggested this pullback in seats is durable - in other words, passengers shouldn't expect a glut of empty seats or ultra-low fares to return soon. In some cases, travelers may also face reduced flight choices. An airline that might have offered, say, five daily flights on a popular route with additional MAX 10s might only offer three or four with smaller planes. This could mean less convenient timing options or more difficulty redeeming Frequent Flyer miles during busy periods (as those limited seats fill quickly).

Passenger comfort can be indirectly affected as well. Older aircraft staying in service longer might not have the same amenities (in-seat power, modern cabins, etc.) that the new MAX 10s would have featured. For instance, United's MAX 10s were expected to have its latest interior with seatback screens and roomier cabins, whereas some 20-year-old 757s that continue to fly in their place have an aging product. Additionally, when airlines wet-lease aircraft on short notice, the substitute planes often have different layouts or lack the premium cabins that frequent flyers expect. A traveler booking a flight on Airline X might be surprised to find the plane is operated by a foreign charter carrier with an unfamiliar interior - a side effect of those wet-lease arrangements necessary to cover capacity. Airlines do try to minimize such discrepancies, but during crunch times it has occurred (with full disclosure to passengers).

In terms of operational reliability, the delays create challenges in airline operations planning. With slim spare aircraft margins, any unexpected maintenance issue can cascade into delays or cancellations because there aren't as many backup jets sitting idle. Airlines normally count on new deliveries to not only expand service but also to replace aging planes that are more prone to breakdowns. By flying older jets longer than intended, carriers risk more frequent mechanical problems. There have been instances of higher-than-normal cancellation rates attributed in part to fleet renewal delays - for example, if a carrier planned to retire a subfleet and didn't stock as many spare parts or crews for it, keeping it longer can strain maintenance resources. The January 2024 Alaska Airlines incident serves as a cautionary tale: a brand-new 737 MAX 9 had to divert after part of a door flew off, which was later traced to a manufacturing lapse. Not only did that flight's passengers undergo an emergency landing, but the subsequent grounding of all MAX 9s for inspections caused a wave of flight cancellations and rebookings for Alaska's customers. United, as noted, had a similar hit when its MAX 9 fleet (8% of its capacity) was grounded until fixes were verified. These events illustrate how a single reliability issue in one aircraft type, amid an already tight fleet, can disrupt thousands of travelers' plans. While Boeing and the airlines moved quickly to address the door plug flaw, the episode highlighted the fragility of operations when contingency slack is minimal.

Passengers may also notice airlines being more cautious with scheduling. Some carriers have built extra buffers into schedules or reduced ambitious connection banks to ensure they can recover from delays with fewer planes available. In a sense, the industry is operating in a "lean" mode: tight schedules, high aircraft utilization, and little room for error. When weather or Air Traffic Control issues occur, the lack of spare aircraft makes recovery harder - a delayed inbound plane can't be easily swapped out, potentially causing longer delays or cancellations downstream. On the flip side, one could argue that the capacity crunch has pushed airlines to be more operationally disciplined (e.g. not over-scheduling flights they can't reliably staff or maintain). Indeed, by cutting some marginal flights, airlines can concentrate resources on the remaining schedule, which might improve on-time performance in some cases. But overall, any benefit to airline reliability from "doing less" is likely offset by the strains of older aircraft and fuller loads, which tend to slow down boarding, maintenance, and turnaround times.

From a customer service perspective, the tight capacity means less flexibility when disruptions happen. Airlines have fewer empty seats on later flights to rebook delayed passengers, leading to longer re-accommodation times when irregular operations Strike. Customer complaints about crowded planes and difficulty finding alternate flights have surfaced anecdotally during peak travel meltdowns. All of this can be traced back, in part, to the fact that many airlines did not receive the fleet growth they banked on. As one aviation journalist put it, the high cost of waiting for new jets is that airlines must "scramble to fill seats" on the aircraft they have, making the travel experience more prone to crowding and unpredictability in pricing. In summary, passengers are indirectly paying the price for the MAX 10's delays: through higher fares, fewer flight options, and occasionally a less comfortable or less reliable journey. Airlines are acutely aware of these impacts, which is why most are pressing Boeing hard for clarity and considering alternative ways to boost capacity, all in an effort to restore a better balance between demand and supply for their customers.

Future Outlook: When Will Relief Arrive?

As of mid-2025, the industry consensus is that Boeing is still many months away from finally achieving FAA certification for the 737 MAX 10. Boeing has indicated optimism about clearing the remaining hurdles by late 2025. If that timeline holds, the first MAX 10 could enter airline service in 2026 - roughly six years late. Airlines like United and Delta are cautiously hopeful but have now built their internal plans assuming no MAX 10s for several more years. United's latest fleet plan revision doesn't count on any MAX 10s until 2027, and even then only modest numbers, ramping up in 2028. This suggests that even after certification, it will take time to accelerate deliveries and make a dent in the order backlog. Boeing will likely prioritize delivering some MAX 10s to key customers (United, Delta, Alaska, etc.) as soon as approval is granted - the manufacturer has about 35 already-built MAX 7/10 aircraft in storage, ready to hand over once certified. That stockpile could help jump-start entry into service and alleviate some immediate capacity needs for those airlines. However, ramping up production to fill hundreds of orders will be a multi-year effort, especially given Boeing's still-cautious 737 MAX production rate (capped at 38 per month until the FAA is satisfied with quality improvements).

In the interim, carriers will continue leveraging the mitigation tactics outlined above. We can expect more wet-lease deals in summer peaks of 2025 and 2026 if delays persist - for example, European holiday airlines and even mainline carriers will bring in temporary lift to cover shortfalls (as was seen with Smartwings, Malta Air, etc., supporting carriers like Flydubai and Ryanair). Fleet life extension projects will also go on: airlines might invest in refurbishing cabins of older planes if they know those planes must fly an extra 3-5 years due to new jets arriving late. An upside of the MAX 10 delay for Airbus has been a spike in A321neo family orders, as airlines seek alternatives. If Boeing cannot get the MAX 10 certified by 2025, some customers could convert their orders to Airbus or other models. Indeed, Delta's significant A321neo orders and United's talks with Airbus are signals that Boeing risks losing market share in the large narrowbody segment if it cannot deliver soon. Congress and the FAA are also keenly watching Boeing's next steps - any further regulatory hiccups could prompt more oversight or even legislative action, given the MAX program's visibility.

From a passenger standpoint, a real inflection point may only come once new aircraft like the MAX 10 (and Airbus's backlog) are delivered in volume, which might be 2026-2027. At that stage, airlines could finally add significant capacity, potentially easing the supply crunch. Ticket prices might stabilize or even decrease on competitive routes as more seats become available. New Routes that have been on hold could launch, and frequencies on popular routes could increase, improving convenience. Operationally, airlines will benefit from the MAX 10's efficiency and higher seat count, which should help lower unit costs (Boeing advertises the MAX 10 as having the lowest seat-mile cost of any single-aisle jet). That could eventually be passed through to consumers in the form of more affordable fares or better service investments. However, such benefits will only be realized if Boeing meets its revised schedule. Any further delays would prolong the status quo of constrained growth. As one aeronautics journal put it, the successful certification of the MAX 7 and MAX 10 will be "a pivotal moment" for Boeing and its customers - if it slips much further, airlines' confidence could erode and their fleet plans would require even more drastic overhauls.

The Boeing 737 MAX 10's persistent certification delays have sent shockwaves through airline fleet planning. A process that airlines hoped would be routine has instead become an extended saga of regulatory compliance and corporate recovery for Boeing. The cascading impacts - from seat shortages in peak seasons and higher fares to creative leasing arrangements and stress on operations - illustrate how deeply an aircraft delay can affect the aviation ecosystem. Carriers like United, Delta, and Alaska have demonstrated resilience by adjusting strategies on the fly, but not without cost to growth ambitions and passenger experience. All eyes are now on the FAA and Boeing to finish the MAX 10 certification so that airlines can put these much-needed jets into service. Until then, the industry will continue to walk a tightrope, balancing burgeoning travel demand with a fleet that is just a bit more stretched, older, and thinner than planned. The hope is that by the late 2020s, this chapter will close - the MAX 10 will be flying passengers, airlines will regain a margin of capacity, and travelers will see the benefits in renewed network expansion and possibly a moderation of fares. But as the past few years have shown, until the regulators sign off, those seats remain grounded - and the challenges on the ground remain very real.