Deliveries of the MAX, which had climbed to 52 narrowbody jets in March, dropped to 17 planes last month.
That left passenger jet deliveries for the U.S. planemaker at their lowest level since July 2022, as well as below the 35 planes delivered last April.
Boeing booked 13 net orders after factoring in 21 cancelled orders, including a sale-leaseback deal for three MAXs for lessor BOC Aviation Ltd (2588.HK) for planes originally ordered by Dominican Republic operator Arajet.
In addition to the MAXs, Boeing also delivered six 787 Dreamliners, one 767 freighter, one 777 freighter and one 737-800 jet to its defense business to be converted into a P-8 Poseidon maritime patrol aircraft for South Korea.
Aircraft deliveries are closely watched by Wall Street because planemakers are able to collect the majority of its money when they hand over jets to customers.
The latest impediment to Boeing's deliveries involves two brackets that connect the MAX's aft fuselage with its vertical tail that were incorrectly installed by fuselage maker Spirit AeroSystems Holdings Inc (SPR.N).
Boeing estimates that about 75% of the 225 MAXs in its inventory have brackets that will need to be reinstalled before customers can take possession of the jets.
Boeing Chief Financial Officer Brian West told investors in an earnings call last month that MAX deliveries would slow through the second quarter, but then grow to about 40 jets per month, with sequential quarterly improvement in the second half.
Boeing has delivered 156 jets over the first four months of 2023, including 128 MAXs. Rival Airbus SE (AIR.PA) has not yet released its April order and delivery statistics.
