Chesley “Sully” Sullenberger, the retired US Airways captain known for “The Miracle on the Hudson,” told a congressional panel Wednesday that pilots of the grounded Boeing 737 MAX should get new simulator training before the plane returns to service.

Sullenberger, who has slammed Boeing and the Federal Aviation Administration for their roles in two recent 737 MAX crashes that killed 346 people, also said the US system of certifying new planes is not working.

The global fleet of about 400 MAX planes was grounded after two fatal nose-dives triggered by the misfiring of the anti-stall system in Ethiopian Airlines Flight 302 in March and Lion Air Flight 610 in October.

“These crashes are demonstrable evidence that our current system of aircraft design and certification has failed us. These accidents should never have happened,” the hero pilot told the House Transportation and Infrastructure Committee.

“I know that we must consider all the human factors of these accidents, and how system design determines how many, and what kinds of, errors will be made and how consequential they will be,” he said, noting that he has 52 years of flying under his belt.

“These two recent crashes happened in foreign countries, but if we do not address all of the important issues and factors they can and will happen here,” he added.

Sullenberger famously ditched Flight 1549, an Airbus A320, safely on the Hudson River on Jan. 15, 2009, after bird strikes caused dual engine failure shortly after takeoff from LaGuardia Airport. All 155 people aboard the stricken plane survived because of Sullenberger’s quick thinking and skilled airmanship.

“I’m one of the relatively small group of people who have experienced such a sudden crisis — and lived to share what we learned about it,” he said Wednesday.

“I can tell you firsthand that the startle factor is real and it is huge — it interferes with one’s ability to quickly analyze the crisis and take effective action. Within seconds, these crews would have been fighting for their lives in the fight of their lives,” he said.

In May, Boeing said it had completed an update to software for the anti-stall Maneuvering Characteristics Augmentation System, or MCAS, that would stop erroneous data from triggering it and automatically turning down the plane’s nose.

On Wednesday, Sullenberger described how the failure of “angle-of-attack” sensors caused “multiple instrument indication anomalies” and “false warnings” as MCAS overrode the pilots’ commands.

He said his own experience in recent 737 MAX simulator training demonstrated to him the unprecedented difficulties the pilots of the doomed planes encountered when trying to handle the malfunctions.

“It is clear that the original version of MCAS was fatally flawed and should never have been approved,” he said. “Reading about it on an iPad is not even close to sufficient.”

Others who testified disputed the FAA’s insistence that pilots had been properly trained how to use MCAS — as well as Boeing’s suggestion that international crews did not “completely follow” instructions of how to prevent malfunctions.

“Again, the failure was Boeing did not disclose the existence of MCAS to the pilot community around the word,” said Capt. Daniel Carey, president of the Allied Pilots Association. “Therefore robust training was not conducted.”

Carey said that getting all pilots in simulators before the plane returns to the skies poses logistical issues, with 4,200 737 MAX pilots at American Airlines and 9,000 at Southwest Airlines.

Boeing has said simulator training is not required for the 737 MAX, and recommends a mandatory computer-based course about MCAS that could be completed at a pilot’s home in about an hour.

Acting FAA Administrator Dan Elwell last month said he had not decided whether to require simulator training.

Committee Chairman Peter DeFazio assailed Boeing for failing to disclose details about the anti-stall system to pilots.

“The pilots didn’t know it existed,” said DeFazio, adding that he plans a future hearing with Boeing.

Two people briefed on the matter told Reuters that Boeing plans to conduct a certification flight as early as next week before it formally submits its software upgrade and training proposal.

Carey also said earlier that Boeing made mistakes in its design of the 737 MAX and not telling pilots about new flight-control software.

In a statement, Boeing spokesman Peter Pedraza said the company was providing information to regulators, airlines and pilots “to re-earn their trust and know we must be more transparent going forward.”

Meanwhile, the Wall Street Journal reported that efforts to unground the jets have been delayed in part amid concerns about whether the average pilot possesses enough strength to turn a manual trim crank during emergencies.

Sources told the newspaper that regulators also are concerned about whether female pilots — who typically have less upper-body strength than men — may find it difficult to turn the crank.