In March, a Boeing 737-800 cruising straight and level on a routine domestic flight suddenly nose-dived into a hillside, killing all 132 aboard.

A full report on the cause of that China Eastern Airlines crash is probably months away, but with no other explanations, suspicion has landed on the pilots. The Wall Street Journal reported this week that flight data indicate someone in the cockpit put the plane into an intentional dive, as occurred in a Germanwings airline crash in 2015, and at least two other foreign carrier crashes in the late 1990s.

Nothing puts aviation safety on the front burner like a mysterious and chilling plane crash, and the issue of safety is especially relevant as the U.S. grapples with its worst pilot shortage in recent memory.

Congress, the Federal Aviation Administration and the major carriers are mulling revised pilot qualifications to make more pilots available, while pilot unions are pushing back against measures that would weaken bargaining positions made stronger by the shortage.

The ideas include some reasonable steps, such as raising the mandatory retirement age for commercial pilots from 65 to 67 or older, and some potentially alarming ones, such as reducing training hours, and allowing a single pilot instead of the current minimum two-person crew for certain commercial flights. Some rules under review were approved just a decade ago after pilot error caused the deadly crash of a regional carrier’s flight in Buffalo, N.Y.

The approach we recommend, then and now, is putting safety first.

Given the high stakes of traveling at 30,000 feet, the U.S. should not introduce new safety risks. Some refinements to the rules still could be appropriate — if the safety-first principle is respected.

Most of the current shortage is a function of the COVID-19 pandemic, when airlines responded to plunging demand with hiring freezes and early retirement packages, generous federal aid notwithstanding. As demand has risen again, airlines have had to curtail potentially busy and profitable summer schedules for lack of crew.

While the pipeline of up-and-coming pilots is returning to normal, there’s no quick fix.

The pilot retirement age, raised from 60 to 65 in 2007, could be safely increased again, if that step is accompanied by sophisticated programs to ensure fitness. The U.S. should take a page from European regulators and modernize current physical assessments to more thoroughly account for mental health as well.

But simply raising the age won’t fix the shortage, as the most senior pilots usually fly the biggest planes on the longest routes and get the most days off. The retirement age under international rules remains 65, so a change to the U.S. standard would affect only domestic flights that are less attractive to pilots with seniority: The shortage is most acute on the younger end of the pilot pecking order, among regional carriers with lesser pay and tougher working conditions.

Another change that could have a bigger effect on the shortage might be alarming on the surface: Require fewer flying hours for incoming pilots. Under current U.S. law, pilots of commercial passenger planes must log at least 1,500 hours of flight time before they’re good to go. The problem is that not all flying hours are created equal, and the 1,500-hour law already has a well-founded exception for those with high-quality military training.

The per-hour experience is much more valuable if gained as a pilot of an Air Force cargo jet, for instance, than as a pilot of a single-engine plane towing a banner around a beachfront.

Many experts believe that graduates of certified training programs backed by major airlines don’t need 1,500 hours to be qualified. Republic Airways, for one, says its training program proves the point. The law could be safely updated to create more carefully considered exceptions.

As for one-pilot cockpits, that’s a big N-O. For now, anyway.

Today’s commercial passenger flights require at least two pilots, with one actively operating the aircraft and the other monitoring the instruments, communications, weather — and the flying pilot. It’s possible to identify emergencies where the side-by-side presence of two or more pilots averted disaster, perhaps most famously when a US Airways flight had to ditch in New York’s Hudson River after bird strikes disabled its engines in 2009.

The 155 passengers and crew all survived, and it’s a safe bet none would have wanted to try that maneuver with a single, overworked pilot at the controls — even one as celebrated as Chesley “Sully” Sullenberger, who credits co-pilot Jeffrey Skiles for the teamwork needed when the engines cut out.

Modern aircraft can indeed “fly themselves.” Between automation and the presence of pilots on the ground who can help manage a flight remotely, it is theoretically possible to eliminate pilots in the air. But who would want to take that flight?

Any set of rules can only go so far in protecting the flying public. In the China Eastern Airlines case, the pilots were qualified and the plane relatively new. Its maintenance records and safety checks were in good order, according to a preliminary investigative report. There was no evidence cited of system failures, the weather was fine and nothing dangerous lurked in the cargo. Still, the plane hit the ground almost vertically.

Commercial aviation is not perfect. But it is the safest mode of transportation and getting safer decade-by-decade. Let’s keep that record going.