The P-8 Poseidon is intended to be the Navy’s chief maritime patrol plane over the coming decades. But according to the Pentagon’s annual report on major weapons obtained by Bloomberg Businessweek, the new patroller is unable to effectively conduct two of its main missions: anti-submarine warfare and wide-area reconnaissance.

That’s bad news for the Boeing-made P-8, an advanced naval surveillance jet that will cost $35 billion to develop and build more than 100 copies. With the reorienting of U.S. forces to the vast Pacific, the Navy really needs a modern and capable patrol plane to monitor the seas—and track China’s submarines.

Worse, there are problems throughout the P-8’s design, which is based on the 737 twin-engine airliner. The radar, sensor integration and data transfer are all flawed, according to the Pentagon report.

Michael Gilmore, the Pentagon’s top weapons tester and the report’s author, said the new aircraft shows “all of the major deficiencies identified in earlier exercises when subjected to more stressful realistic combat testing from September 2012 to March 2013.”

For this reason, the Poseidon “is not effective for the intelligence, surveillance and reconnaissance mission and is not effective for wide-area anti-submarine search.” But Gilmore’s test office found that the Poseidon is effective at small-area search, much like the P-3 Orion it’s replacing.

Flaws and all, the Navy has already deployed six of the Poseidon aircraft—out of 13 delivered so far—to Japan to perform the wide-area patrol mission. The Navy plans to eventually operate a fleet of 113 P-8s.

The main problems are with the costly sensors that should be the real added value of the new aircraft. These include the surface-search radar and the ESM—Electronic Support Measures—that make both anti-submarine warfare and surveillance missions possible. Or, at least, should.

To be fair, the Poseidon is still a young system and will no doubt get better in time. And even if its internal systems have teething problems, the airframe itself is already more reliable and boasts increased range, payload and speed compared to the 40-year-old, prop-driven P-3.

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War Is Boring

From drones to AKs, high technology to low politics, exploring how and why we fight above, on and below an angry world

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    We go to war so you don’t have to

    War Is Boring

    From drones to AKs, high technology to low politics, exploring how and why we fight above, on and below an angry world

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