Across the northern half of the main Japanese island of Honshu, aerospace managers are bringing factories back online, working around problems left by the March 11 earthquake and tsunami and sending parts out the door.

The hardest hit of the big manufacturers, IHI Corp., has resumed some production at its two aero-engine factories in Soma and hopes to get its whole operation in the city back online by May. Fuji Heavy Industries and Kawasaki Heavy Industries say most of their suppliers are also working again.

Progressive repair work is under way at the Soma No. 1 and No. 2 Aero-Engine works, says an official from IHI’s aero-engine and space operations, which work on international civil and Japanese defense programs. Earthquake damage in some parts of the factories was relatively light, and production has partly resumed in those areas.

Soma is 100 km (60 mi.) south of Sendai and about 200 km from the epicenter of the earthquake. The ensuing tsunami also struck the city. IHI’s plants there make parts for space equipment, aero-engines and other gas turbines.

Apart from physical damage, the region of Japan that includes Soma is suffering electricity outages.

Fuji says its component supplies and product deliveries are assured until the end of April. Fuji is improvising to mitigate the effects of power blackouts, which it said last month were a bigger problem than physical damage to suppliers’ factories. “There is a power failure for three hours almost every day,” says a senior company executive.

Fuji has an aerospace plant at Utsunomiya in Tochigi prefecture, part of the region that is short of electricity. The company is operating a night shift as well as on weekends to make up for time lost due to the power outages, says the executive, adding that it is running its own electricity-generating equipment continuously and bringing a stand-alone generator into service to boost its in-house capacity.

“Most of our suppliers have restarted operations, even if they have not recovered completely,” he says. Suppliers who cannot restart have enough product in stock to keep Fuji supplied until the end of April, he notes.

Apart from its civil programs, which include the Boeing 777 and Boeing 787, Fuji, like the other “heavies,” is a contractor to the Japanese military.

The company is warily looking to summer, when it says the electricity shortage may become serious again, but it thinks that the whole power supply difficulty could be resolved by the end of this month. Japanese electricity companies are progressively repairing coal-fired generating units and bringing them back online.

Mitsubishi Heavy Industries, another 787 partner, says no suppliers have reported production difficulties from either physical damage or the shortage of electricity. Mitsubishi, itself located far from the epicenter of the earthquake, has also had no such trouble internally.

Kawasaki says, “Our suppliers affected by the earthquake are making their best possible efforts to bring their operations back on track, and many of them are recovering from the situation and resuming their production.”

“Suppliers located in areas subject to periodical power cuts seem to be coping with the situation by shifting their operation hours,” says a company official.

Precision machine tool builder Mitsui Seiki Kogyo is now operating almost normally. The company, a crucial supplier to the global aerospace industry, says its machine tools in service with Japanese customers rode out the earthquake and can work to specification.

Mitsui Seiki fears a decline in business from Japanese customers, however, because of the effect of the double disaster on the domestic economy.

The company’s factory, about 60 km northwest of Tokyo, suffered only minor damage, thanks to its extraordinarily strong construction, says President Kouichi Iwakura. Machine tools being built at the plant are bolted to squares of factory floor that are actually the tops of concrete columns sitting on bedrock 37 meters (120 ft.) below.

Mitsui Seiki is operating on weekends to make up for hours lost due to electricity outages. Gasoline is also in short supply in Japan, but Mitsui Seiki’s factory has its own stock and is using it to fill employees’ automobile tanks so they can travel between work and home.

“We have only one supplier that has suffered severe damage,” Iwakura says. That supplier’s plant was in Sendai and has been knocked out for an unknown period of time. “All its machines must be checked,” he says. But the supplier also had two other plants, one of which says it can make the same Mitsui Seiki part to the same standard.

Mitsui Seiki says its production is now almost normal, although the equivalent of two days’ work has been lost, partly because the factory needed to be checked after the earthquake.

Experience following another earthquake seven years ago confirmed that completed machine tools operating in customers’ plants would have suffered no distortion from the shaking, provided they did not fall over and nothing fell on them, Iwakura adds. Last month, the company checked the machines of a customer in Yokohama, southwest of Tokyo, and found them to be working within specification.