The single-aisle duopoly has sold a decade of production it has not built

Methodology

This index answers one question: the single-aisle duopoly has sold roughly a decade of production it has not built — can it build it? Every chart isolates one input to that answer: how deep the queue is, which way it is moving, what rates have been announced against it, what is actually coming off the lines, and whether the engine makers are keeping up. SCOPE. Single-aisle programmes only: A320neo family, A220, 737 MAX and the residual 737 NG book. Twin-aisle figures appear only where they are needed as a denominator (the June output-mix chart). BASIS — BACKLOG COMPARISON. The June source reports the Boeing 737 backlog as one combined line (4,888); the July source splits it into MAX (4,817) and NG (34). The July value in the month-on-month chart is the sum, 4,851, so both months sit on the same basis. That addition is stated in the value_basis of the point. It is arithmetic on two published figures, not an estimate. CAVEAT — TARGETS ARE NOT RATES. Every value in the rate-target chart is a stated management target with a future date, not an approved or achieved rate. Airbus has announced 70-75 A320-family aircraft a month by end-2027 and 13 A220s a month in 2028. Boeing has named 52 a month as the step beyond the 47 it began transitioning to in Q2 2026, with NO published FAA approval and no timetable. For scale, the 2025 realised monthly averages were 50.6 (A320 family), 37.3 (737) and 7.8 (A220). No single-aisle programme at either company has ever run at its own stated target rate. CAVEAT — ENGINES, ONE FAMILY ONLY. GE Aerospace publishes LEAP delivery GROWTH percentages and does not publish absolute LEAP unit counts, so the engine chart is in percent and the base is unknown. Pratt & Whitney GTF delivery counts, which cover the other half of the A320neo book, were sought and not found in a citable primary release; they are OMITTED rather than estimated. Read that chart as evidence about one engine family, not about total narrowbody engine supply. CAVEAT — ONE MONTH IS NOT A TREND. The June-to-July backlog movement and the June output-mix split are single-month observations. July is an order-announcement-heavy month in this industry. They are shown because they are cleanly sourced and directional, not because one month establishes a rate. SOURCE TIERS. Company primary disclosure (Airbus, Boeing, GE Aerospace) is used wherever the figure exists there. Monthly backlog splits are not published in that form by either OEM and come from a trade compilation; the Boeing year-to-date figure from that compilation reconciles exactly against Boeing’s own quarterly releases (143 + 171 + 53 = 367), which is the corroboration standard applied. SUPERSEDES. This index absorbs and extends the three H1-2026 sections of /data/airbus-vs-boeing, which remains live so no URL is lost. Compiled and verified 2026-08-14. Working sheet with every source passage: Topics_Content/data/batch-6_aerospace_2026-08-14.md