NOAA’s Gulfstream IV-SP (N49RF) “hurricane hunter” jet on the ramp at Reagan National Airport. (Richard de Triquet/NOAA)

A Gulfstream jet, which collects critical data for hurricane forecasts, was flying through Hurricane Maria’s swirling winds Monday when the seal on the cabin door failed, emitting a loud noise. The mission was aborted, and the crew returned to NOAA’s Aircraft Operations Center — wearing oxygen masks.

It marked the third aborted or scrubbed flight of the aircraft, known as Gonzo, in the past eight days in the midst of the most severe month for hurricanes ever recorded. Lawmakers and hurricane researchers have expressed deep concern about its tenuous condition.

The data obtained by the aircraft improves hurricane track forecasts by about 20 percent on average, according to NOAA. But there is no backup aircraft to gather this information if and when it experiences technical issues.

The aircraft’s vulnerability has long troubled Sen. Bill Nelson (D-Fla.). He introduced language into comprehensive weather legislation — signed into law by President Trump in April — that requires NOAA to have a second aircraft available to “prevent a single point of failure.”

In a letter to NOAA’s acting head in early September, obtained by The Washington Post, Nelson wrote that “NOAA has taken no major steps to acquire reliable backup” despite the new law. “It is unacceptable that we again find ourselves in the midst of hurricane season without reliable NOAA aircraft reconnaissance and without backup capability,” Nelson wrote.

Nelson concluded the letter imploring NOAA to be “diligent in complying with the law. Truly lives and property depend on it.”

Rep. Darren Soto (D-Fla.), who co-sponsored the legislation on the House side, also expressed dismay about the plane’s status. “Since Hurricane Hermine [which struck Florida in 2016], we’ve known that our hurricane hunters have had problems,” Soto told The Post. “It’s critical that we have these planes up and running. For too long, we’ve had to rely on other agencies, such as NASA, NSF and our military, in order to monitor these hurricanes. We’re extremely disappointed the Trump administration hasn’t procured the aircraft … and the lack of doing so puts the entire southeast and Caribbean at risk.”

National Weather Service spokesman Chris Vaccaro said NOAA is working to meet the requirements of the law but offered no specifics. “The safety of the American public and our flight crews are top priorities and we take these requirements and our mission very seriously,” he said.

Nelson called the latest three failures of the Gulfstream jet “outrageous” in a statement to The Post Tuesday. “The agency utterly failed to heed several warnings,” he said.

Nelson’s office said NOAA had not been forthcoming with information on the plane’s status until it had placed inquiries. On Wednesday afternoon, it sent a letter to Commerce secretary Wilbur Ross, who oversees NOAA, requesting all of the plane’s recent maintenance records.

The Gulfstream jet is part of a fleet of hurricane hunter aircraft that penetrate storms. NOAA also relies on NOAA P-3s and Air Force C-130s that fly into storms at lower altitudes, dropping probes to collect data about a storm’s winds and pressure. The Gulfstream is the only aircraft in the fleet that flies into storm environments at high altitudes and is able to gather the data so important for computer model predictions of a given storm’s path.

The Gulfstream first ran into trouble on Sept. 17 during a flight into Hurricane Jose. “While flying at flight level 45,000 feet the aircraft crew noted louder-than-normal air sounds and a high-pitch squeal,” NOAA wrote in a report provided to Nelson’s office. There was a pressurization issue with the seal on the main cabin door. “The crew diverted preemptively to manage the onset of an emergency, preserving the highest levels of safety for the flight crew and aircraft, and potentially reducing the down time to effect repairs to meet follow-on hurricane surveillance tasking for Hurricane Maria.”

Then on Sunday, the plane wouldn’t start before a flight into Hurricane Maria due to an issue with one of its ignition systems. The planned mission was scrubbed while the system was fixed.

But on Monday, the plane encountered trouble again — as the pressure problem with the door seal happened for a second time. “The aircraft was flying at 45,000 feet when a loud noise was observed from the main door seal,” NOAA reported to Nelson’s office. “The crew was on oxygen for about 2.5 hours as a normal precautionary measure undertaken when there is a possibility of losing pressure.”

Since Monday’s incident, the plane has been unavailable for missions. A tasked flight into Maria Tuesday was scrubbed, and NOAA’s Aircraft Operations Center is conducting a 150-hour inspection of the aircraft — meaning it may be out of commission until Oct. 3.

“NOAA needs to have a fully operational high-altitude aircraft for monitoring and observing hurricane genesis, development and intensification,” said Antonio Busalacchi, president of the University Corporation for Atmospheric Research. “Having an aircraft that is not 100 percent reliable is not consistent with NOAA’s mission for protecting life and property.”

The University Corporation for Atmospheric Research has, in the past, made the Gulfstream aircraft that it maintains available to NOAA for backup. (The plane is owned by the National Science Foundation.) For example, last fall, it flew missions into hurricanes in the eastern and central Pacific that were threatening Hawaii. At the time, President Barack Obama was on his way to Hawaii for an environmental conservation meeting.

But Busalacchi said his organization’s aircraft isn’t always available because of its own planned research missions. “NOAA does need to find a solution to its problem,” he said.