Boeing flight line

Planes are lined up along the flight line at Boeing's 787 Dreamliner assembly campus in North Charleston on Monday. Analysts say the crowded flight line could be the result of supplier issues, but Boeing says there are no problems causing a production backup. Staff/David Wren

A growing number of 787 Dreamliners are crowding the flight line at Boeing Co.'s North Charleston campus, with analysts pointing to supplier delays as one of the causes.

"The flight line has been increasingly crowded as Dreamliners are rolled out of the main assembly building ... and parked in every spot that is available, including the (North) Charleston Delivery Center," Uresh Sheth said on his All Things 787 website.

Sheth, who tracks Dreamliner production activity, said at least six planes have been delayed because of slow deliveries of seats or engines, with two more planes held up at the request of customers.

Another jet for Air China has been sitting in storage for unknown reasons.

"The aircraft was assembled over five months ago, but it hasn't had its engines installed," Sheth said.

Boeing is downplaying the existence of any problems at the South Carolina plant.

"Deliveries can vary from month to month for a variety of reasons, including customer-preferred timing," said Boeing spokesman Victor Scott. "We remain on track to meet our full-year delivery commitments."

Boeing delivered 136 Dreamliners to customers in 2017. The company did not announce a target for 787 deliveries this year, but it said it expects all commercial plane deliveries to increase by about 6.8 percent over last year's record numbers. Cowen Group analysts predict 144 Dreamliner deliveries in 2018.

Boeing plans to increase its monthly 787 production rate to 14 from 12 in 2019, split between North Charleston and its other Dreamliner assembly plant in Everett, Wash.

Sheth's production numbers show the North Charleston campus delivered three planes in July and he expects the same total this month. That compares with seven deliveries in June and six in May.

"Unless Charleston deliveries pick up very soon, Boeing may have to look for new and innovative ways to store undelivered 787s," Sheth said.

Scott Hamilton, editor of aviation website Leeham News and Comment, said Boeing's overall supply chain "is in meltdown," pointing to dozens of 737s parked at the aerospace giant's Renton, Wash., site because they are awaiting parts.

"I would not be surprised if this issue applies to 787s as well," Hamilton said, adding that the planned production increase could further stress an already tight supply chain.

Cowen analyst Cai von Rumohr said in an Aug. 16 report that Boeing's supply issues were made worse by the company's conversion in June to a new planning system that helps to manage its supply chain.

"In several cases, the new system could not provide the property 'ship to' address on a timely basis," von Rumohr said in the report.

Hamilton said he understands the new software continues to cause delivery problems.

"It is no secret that the supply chain is under significant stress," aviation analyst Dhierin Bechai said in a recent post on Seeking Alpha, adding that planned production rate increases by Boeing and rival Airbus are stretching supplier resources.

"Demand forecasts do support further rate increases, but it is now time for all parties involved to shape the entire supply chain, production system and quality system to support this growing demand," Bechai said.

Boeing is one of the Charleston region’s largest employers, with about 6,800 workers at the Dreamliner campus and other sites in North Charleston.

Reach David Wren at 843-937-5550 or on Twitter at @David_Wren_