"On this theory the transponder wasn't disabled, the circuit to the cockpit was hacked to show it as disabled."

"I withdraw the limit order but only because I have other things to track besides my outstanding limit orders."

"Get started on the hand-built emergency radio, flight crew has the ball on that."

"Ack."

"Any else?"

"Nay."

"Cockpit out."  She flips off the cabin-radio switch.

"Hey, uh, 'Mad Investor Chaos', was it?  Nice handle, no trouble telling that apart from other passengers.  This is a quick first pass, I'll be back later, but I want to know your quick background, rough wealth level, any unusual skills."

"Programmer, self-training in mad investing on side, savings on the order of 20K, to my knowledge I have no socially interesting secrets or wealthy relatives."

He doesn't add that he'd have volunteered anything relevant much earlier, because Steward Orange is probably tired of hearing that from people.  This is self-evidently a check in case somebody was shy about being a Top-10 CEO whose death would have exploitable financial implications.

"Thellim?"

"Fiction matchmaker, savings approx 100K, almost certainly irrelevant to whatever's happening."

"Ack."  The Orange Steward finishes writing this down.

"If our Exception-Handling flight escort doesn't show up, I do want in on the isekai planning committee while everyone else is pretending they're too dignified to believe in the possibility long enough to plan for it."

"Ack.  Rules are that resources including people only get to go to isekai planning after all other reasonable planning gets done."  She does take a note, though.

"Wouldn't be volunteering for it if I had other uses."

"Don't worry, we're not taking anything apart to make the radio which we'd need to rebuild Civilization."  The Orange Steward passes on to the next row over, which proves to audibly contain a pair of experimental physicists returning from a conference on superconductivity located next to a giant-ass particle accelerator that doubles as an aspiring monopole detector.  They're only not helping on building a new shortwave radio because engineering-in-adversity isn't properly their hobby.

"Well, that would be refreshingly depressing if I was refreshed by depression."

"Don't mind me.  I was just recently struck by how, if we do land safely in dath ilan--which I still acknowledge to have over fifty percent probability--everyone here who's not a physicist, and most of the people who are, will never have anything more interesting happen to them for the rest of their lives.  And also won't have done anything interesting while it happened to them."

"Speak entirely for yourself, lady, and when you hear about a 'Keltham' in the news it's me."

The scheduled turn is coming up.  There's some halfhearted betting on the Prank Hypothesis which says that the comms will come back on just before the turn is made.

It doesn't.  The aircraft tilts.  They are officially off the planned course and onto the emergency diversion route.

A minute later, there's been no 'Just Kidding!' recording playing in the cabin and the Network is still down.

A thin market settles.  Nobody really believed it would play out that way.

The Captain has finished one round of solar-angle calculations, and then after some hesitation decided to delegate further checking to the most obsessive and scrupulous arithmetician they can find onboard, plus a random volunteer to redo their work more slowly in case the scrupulous arithmetician is a plant.  That kind of position-verification is meant mainly for contingencies where the computer is out, not where you think the computer is probably okay but might've been cleverly sabotaged by a criminal mastermind.  It doesn't make sense for the Captain to spend all her energy on grueling solar-angle checking, versus delegating the calculations and seeing if they say something different from the computer.

She's currently perusing the handbook to double-check her memory of standard checklists for landing on a flat area that isn't a runway, and the checklists for a water landing if you can't find a flat area.  If they do have to navigate by solar angles, following the rough general emergency course might keep them away from cities and nuclear plants, but it isn't likely to get them to the target runway.  And yes, somewhere in the back of her mind is the possibility that the target runway is now a glowing crater, or that they're on a different planet that lacks shortwave.  That probably also looks a lot like "flat field or water landing".

He's flying the plane, or to be more exact watching the autopilot fly the plane and checking the horizon to make sure the horizon angle and cloud height and angle of the sun all match what the instruments are claiming.  Some of those instruments are very simple and not connected to computers, because Civilization distrusts computers more than he does, but even that won't save you from a hypothetical criminal mastermind who got access to the cockpit.  By the same token it should be very hard for the autopilot to kill everyone, there's a checker on the outputs which is another of the more tamperproof pieces of the airplane, but again, hypothetical criminal mastermind.

The leader of the shortwave radio committee--it's actually more of a 'generally investigate the shortwave situation' committee rather than a 'build a shortwave radio' committee per se, because that is how science backs up and begins again after you become confused--regrets to inform the Market that if they were expecting a frantic effort to build a shortwave radio followed by a triumphant announcement that the plane is definitely no longer in dath ilan, that is not how this works.  That is not how any of this works.

They are improvising tools to replace the untrusted multimeter, more than one of each kind of tool so they can check them against each other, and then ruling out a succession of possibilities for how a criminal mastermind could've sabotaged their radio reception.

It starts with seeing if they can verify that the primary and backup shortwaves were transmitting on a frequency anywhere near 3-30MHz, for example.  And despite someone's bright idea about the criminal having changed the frequency spectrum on both radios, that is not how he would pull this off if he was a criminal mastermind because then he would get found out as soon as somebody like Mister Sparklord gets ten minutes to play with other onboard electronics.  He'd have messed with the external antenna that the backup shortwave radio plugs into.  Not as simple as unplugging it, then the backup radio wouldn't have transmitted to the primary radio or vice versa, but if he's allowed to hook up the antenna wire to complicated equipment it's not even slightly hard to--

Anyways, they're going to measure what look like properties of the external antenna, which isn't going to defeat a clever criminal mastermind who's arranged for the external antenna to look normal when anyone tries to use improvised equipment to measure it in the obvious way, and that'll detect or rule out the more casual possible criminal masterminds.

But mainly, the thing you've got to do at this point, is very carefully drill through some appropriate part of the aircraft interior until you reach metal, and then figure out how to use the external body of the aircraft as your shortwave antenna, as tapped at multiple points that the criminal mastermind can't predict in advance.

At that point the hypothetical criminal mastermind can still block you from receiving radio signals, for example by simply jamming your radio, but it'll be obvious and you'll know there is a criminal mastermind.

If the solar-angle checker matches where the computer says they are, so that they still seem on course to land safely on the runway along their emergency route, she is not particularly inclined to allow the risk of trying to drill through the cabin ceiling in order to use the external aircraft body as an antenna.  Pilots do not have sufficiently detailed mental models of the aircraft interior design to be sure that this is possible to do in a safe way.

Prediction markets are at 73% on there existing a criminal mastermind.  The information that a criminal mastermind exists, at all, is not very valuable compared to actually getting back in contact with Civilization.

Well if the criminal really wants to keep them out of contact with Civilization and doesn't mind throwing away the isekai conceit in order to do that, it's just not that complicated to detect the start of a successful shortwave transmission and turn on a high-powered jammer they previously attached to the underbelly of the aircraft.