Some observations about President-elect Donald Trump's defense-policy-by-Twitter announcement last week that he had asked the Boeing Co. to "price-out" an F-18 Super Hornet to compete with Lockheed-Martin's F-35 Joint Strike Fighter:

This would be very good news for Boeing-St. Louis, where the aircraft now called F/A (fighter/attack) Super Hornets and its variants are built.

However, the Super Hornet and the F-35 Lightning are entirely different aircraft, designed 20 years apart for different missions. It's as if Trump decided the Porsche 919 was too expensive and asked Ford to upgrade a 1995 pickup to race at Le Mans.

The F-35 was designed as a stealth aircraft; everything on it is designed for low radar signatures. The F/A-18 is about as stealthy as an Airbus.

The F/A-18 was designed to land on aircraft carriers, meaning it has to be heavily reinforced. The Navy variant of the F-35 is carrier-capable, and the short-takeoff Marine variant can land vertically. But most of the F-35s are destined for the Air Force, which needs fast, lightweight aircraft capable of the high speeds and tight turns of aerial combat.

Trump has created something called "Twitter risk." His tweet caused Lockheed's share price to drop 2 percent, costing the company $1.2 billion in market value. Roman Schweizer, a defense analyst at the Cowan Research Group, told clients, "We have no idea how this plays out but believe 'Twitter risk' for defense companies could be a significant issue over the next four years."

None of this means that Trump isn't onto something: The Joint Strike Fighter program, at $1.5 trillion the biggest contract in defense history, has been plagued with missed deadlines and cost overruns. Boeing's competing X-32 proposal lost out in 2001 - the Air Force thought the X-32 looked dumpy - a big blow to both St. Louis and the defense budget.

With production of the Navy's F-35s running late, the Navy could order additional F/A-18s to bridge the gap. Sen. Claire McCaskill, D-Mo., a member of the Armed Services Committee, says she's ready to help. But a "priced-up" Super Hornet is not capable of meeting the demands of the Air Force, Marines or foreign clients, not unless it's totally redesigned, which would price-up into the billions and take years.

Besides, like any savvy defense contractor, Lockheed has made sure that components of the F-35 are made in congressional districts all over the country. The parts are assembled in Fort Worth, in deep-red Texas, but they supply jobs in 45 different states and Puerto Rico. Getting rid of it would be politically difficult. As Sen. John McCain, R-Ariz., once observed, weapons systems are "very much like vampires. You can kill one occasionally, but not very often."

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