The 737 MAX 10 delay: Why it matters

Analysis date: 29 September 2026

The 737 MAX 10 now represents roughly 31% of Boeing’s undelivered 737 firm orders. The aircraft is also embedded in the growth and fleet-renewal plans of Ryanair, United, Alaska Airlines, Delta, WestJet and others.

That makes the latest certification delay a useful test of the full Boeing value chain: production → certification → delivery → cash. Boeing can build aircraft, but until they are certified and accepted by customers, production does not convert cleanly into revenue, working-capital release or free cash flow.

What changed

The US Federal Aviation Administration has delayed certification of the 737 MAX 10 while Boeing fixes a software problem affecting automated flight guidance in a specific missed-approach scenario. Boeing completed the model’s final planned certification flight in July after 976 flights and more than 2,060 flight hours, and the programme had appeared close to approval. The FAA now plans a Corrective Action Review Board before certification can move forward. Reuters; Boeing certification update.

The issue does not mean the existing 737 MAX fleet is grounded. Pilots retain control of the aircraft, and Boeing is developing a software fix. The financial question is therefore not whether the MAX family remains operational, but how long MAX 10 certification moves to the right.

How a certification delay reaches Boeing’s profit and cash flow

A MAX 10 delay reaches Boeing through four channels:

1. Delivery timing: aircraft cannot be handed over until certification is complete.
2. Inventory: production costs can accumulate before customer cash is collected.
3. Compensation: materially late deliveries can lead to credits, concessions or schedule renegotiations.
4. Programme economics: substitutions or future order shifts can reduce the value Boeing ultimately extracts from the backlog.

The duration matters more than the headline. A delay of weeks is mainly an engineering and schedule issue. A delay lasting several quarters begins to affect working capital, customer fleet plans and the economics of the programme itself.

Why the MAX 10 matters so much to Boeing

As of 30 June 2026, Boeing reported 4,397 undelivered firm orders across the 737 programme. The company said approximately 31% were 737-10s, equivalent to roughly 1,360 aircraft on an approximate basis. The MAX 10 is therefore close to one-third of Boeing’s remaining 737 order book. Boeing Q2 2026 Form 10-Q.

That exposure matters because Boeing Commercial Airplanes has not yet returned to profit. The division generated $11.75bn of revenue in Q2 2026 but recorded a $322m operating loss, equivalent to a negative 2.7% operating margin. Boeing generated $631m of free cash flow in the quarter, but first-half free cash flow remained negative $823m. Boeing Q2 2026 results.

The recovery therefore depends on converting higher factory output into completed aircraft, deliveries and cash. We examined that mechanism in Boeing’s cash recovery is moving slower than its production plan. The MAX 10 delay adds another barrier between production and cash conversion.

Inventory is where the delay becomes visible first

Boeing can incur labour, supplier and production costs before an aircraft is delivered, but a large part of the cash conversion occurs only when the customer accepts the jet. If certification moves later while MAX 10 production continues, more working capital stays tied up in aircraft that cannot yet be handed over.

Boeing reported $74.4bn of commercial-aircraft programme inventory at the end of June, up from $70.8bn at the end of 2025. Within the 737 programme, deferred production costs rose from $11.8bn to $13.1bn. Boeing also said it had around 40 737-7 and 737-10 aircraft already in inventory awaiting certification and explicitly warned that delays to certifying or delivering the two variants could adversely affect its financial position, results and cash flows. Boeing Q2 2026 Form 10-Q.

The full $74.4bn is not related to the MAX 10. The point is different: Boeing is already carrying a large amount of commercial-aircraft inventory, which makes delivery timing particularly important for cash generation.

Customer compensation is the second pressure point

When aircraft arrive substantially later than their contractual schedules, customers can seek delivery changes, pricing concessions or credits. Boeing’s filings note that customers may have contractual rights to reject individual aircraft if actual delivery dates become significantly later than agreed schedules. Boeing Q2 2026 Form 10-Q.

The risk is not hypothetical. United has previously received Boeing credits connected partly to MAX 10 delays. Another material slip would increase the probability of further renegotiation across the customer base — protecting relationships, but potentially reducing the economics Boeing eventually earns from the backlog.

Which airlines are most exposed?

The order count is only part of the answer. The more important questions are when an airline expected the aircraft, whether the MAX 10 is for growth or replacement, and how easily another type can substitute for it.

Ryanair: a delay can become a unit-cost problem

Ryanair has 150 firm MAX 10s and options for another 150. On 23 September, CEO Michael O’Leary said the group expected its first 15 aircraft in spring 2027. Ryanair plans to configure the MAX 10 with 228 seats, making the aircraft central not only to growth but also to lowering cost per seat. Reuters; Boeing/Ryanair order announcement.

If certification moves only a few weeks, Ryanair has room to absorb it. If deliveries move materially beyond spring, the economics change: fewer new seats for the 2027 peak season, slower retirement of older aircraft and later arrival of the unit-cost benefit from putting more passengers on each flight.

Alaska Airlines: the clearest near-term exposure

Alaska ordered 105 MAX 10s in January 2026, with options for another 35. Only days before the FAA delay, Alaska management said it expected certification by the end of September, its first aircraft in spring 2027 and passenger service between April and mid-May. Boeing/Alaska order announcement; Reuters.

That makes Alaska unusually sensitive to timing. The airline has built 2027–28 capacity plans around receiving the larger variant, so a delay lasting several months would have a more direct network effect than it would for a customer whose deliveries are years away.

United: the largest firm exposure, but more flexibility

United has 167 firm MAX 10 commitments, making it one of the largest customers for the model. Its disclosed year-end 2025 fleet plan expected 21 MAX 10 deliveries in 2027 and the majority of the remaining aircraft after that. United also has large orders for the MAX 9, A321neo and A321XLR, giving it more ability than a single-type operator to rework capacity plans. United aircraft commitments.

That flexibility reduces immediate operational risk, but not necessarily the financial consequence for Boeing. The more United substitutes other aircraft, renegotiates schedules or seeks compensation, the less cleanly Boeing converts its MAX 10 backlog into revenue and cash.

Delta and WestJet: fleet-renewal savings arrive later

Delta has 100 firm MAX 10s and options for 30 more. When it placed the order, Delta said the aircraft would be 20–30% more fuel efficient than the aircraft being replaced. The original delivery plan has already moved substantially from the 2025 start envisaged in 2022. Another delay therefore extends an existing problem: older aircraft remain in service and the planned fuel, maintenance and capacity benefits arrive later. Delta order announcement.

WestJet added 60 MAX 10s and 25 options in 2025 as part of its largest-ever aircraft order. The carrier has described the larger MAX as an important part of its growth and low-cost strategy. The financial effect of a delay is therefore similar: lower-cost replacement capacity remains unavailable for longer. Boeing/WestJet order announcement.

Lufthansa and Air India show why timing matters

Lufthansa Group exercised options for 20 MAX 10s in September, but deliveries are not due to begin until the early 2030s. Lufthansa therefore has meaningful strategic exposure but very little immediate operational exposure to a delay measured in months. The group expects the type to reduce unit costs by around 20% compared with the older aircraft it replaces. Lufthansa Group.

Air India has 10 firm MAX 10s from an order announced in January 2026. Its direct exposure is smaller, but the aircraft forms part of a much broader growth programme in a rapidly expanding domestic and regional market. Boeing/Air India order announcement.

Three delay scenarios

Weeks: mostly manageable

First customer deliveries are planned for 2027, so Boeing still has some schedule buffer. A short delay would mainly add engineering work and certification cost while compressing preparation for initial deliveries.

Into early 2027: cash and fleet plans start to move

Completed aircraft could accumulate, delivery payments move into later periods and airline schedules require adjustment. Alaska and Ryanair would be among the customers where the operational effect becomes easiest to see.

Well into 2027: the problem becomes strategic

The longer Boeing misses customer growth windows, the more likely airlines are to seek compensation, use substitute aircraft, retain older fleets, lease additional capacity or reconsider later fleet decisions. Airbus cannot instantly absorb hundreds of replacement orders, so widespread MAX 10 cancellation is not the base case. The bigger risk is gradual erosion of the programme’s economic value through concessions, substitutions and deferred cash collection.

The bigger lesson

Demand is not Boeing’s main problem. The company ended June with a $596.7bn Commercial Airplanes backlog and more than 4,300 undelivered 737 firm orders. The challenge is converting that demand into aircraft that can be certified, delivered and paid for on schedule. Boeing Q2 2026 Form 10-Q.

For airlines, the same logic applies in reverse. An order book creates future capacity only when the aircraft arrives. Until then, growth assumptions, retirements and cost savings remain theoretical.

That is why the most important number in this story may be 31%. With roughly one-third of Boeing’s undelivered 737 orders tied to the MAX 10, another prolonged delay would no longer be a small certification problem at the edge of the programme. It would sit directly in the path of Boeing’s cash recovery and several airlines’ growth plans.

What to watch next

1. The FAA review: whether the software fix can be approved without reopening a wider part of the certification programme.
2. The first-delivery date: certification can slip without major airline disruption as long as the 2027 delivery schedule remains intact.
3. Inventory: whether Boeing continues building MAX 10 aircraft ahead of certification and how many accumulate.
4. Customer compensation: signs that airlines are receiving credits or renegotiating contractual delivery positions.
5. Ryanair and Alaska: their spring/summer 2027 plans provide the clearest near-term test of whether the certification delay becomes an airline capacity problem.

Boeing delivery and backlog data are also available in the Aviation Intelligence Boeing manufacturer page.

Methodology

Order exposure is based on publicly disclosed firm commitments and options from Boeing, airline investor disclosures and company announcements. The approximate 737-10 backlog figure is derived from Boeing’s disclosure that 31% of 4,397 undelivered 737 firm orders were MAX 10s at 30 June 2026. Airline impact is assessed from disclosed delivery timing, replacement plans, seating/cost objectives and fleet flexibility. The scenarios illustrate mechanisms rather than forecast a certification date or financial loss.

Primary sources

• Reuters — FAA delays 737 MAX 10 certification
• Boeing — Q2 2026 Form 10-Q
• Boeing — Q2 2026 results
• Boeing — 737-10 final planned certification flight
• Boeing / Ryanair — MAX 10 order
• Boeing / Alaska Airlines — MAX 10 order
• Delta — MAX 10 order
• Boeing / WestJet — MAX 10 order
• Lufthansa Group — 20 MAX 10 aircraft

Tables and key figures

Boeing exposure

Measure	Figure	Why it matters
Undelivered 737 firm orders	4,397	Overall narrowbody backlog at 30 June
737-10 share	Approx. 31%	Roughly 1,360 aircraft on an approximate basis
BCA Q2 operating result	−$322m	Commercial Airplanes remains loss-making
BCA Q2 operating margin	−2.7%	Recovery not yet complete
Q2 Boeing free cash flow	+$631m	Delivery conversion improved
H1 Boeing free cash flow	−$823m	Second-half cash generation remains important
Commercial aircraft programme inventory	$74.4bn	Large amount of capital tied up in aircraft production
737-7 / 737-10 inventory	Approx. 40 aircraft	Already built but dependent on certification before delivery

Largest disclosed airline exposures

Airline	Firm MAX 10 commitments	Near-term sensitivity
United Airlines	167	Medium
Ryanair	150	High
Alaska Airlines	105	High
Delta Air Lines	100	Medium
WestJet	60	Medium
Lufthansa Group	20	Low near term
Air India	10	Low / medium

This analysis reflects information available on 29 September 2026. Certification timing remains subject to FAA review. Scenario discussion is illustrative and is not a forecast of Boeing earnings, cash flow or airline financial performance. This article is for information purposes and is not investment advice.