Roger Bohn

USA in >4 simultaneous major crises: 1 Pandemic (Worst in 100 years) 2 Major recession (100 years? Not clear yet) 3 Equality crisis (Crisis 150 years old; public pain worst in 50 years) 4 Constitutional crisis (85 years?) + 5 Slow environmental crisis (worst in 20,000 years)

Whoah. This hits hard: unreplug.com/blog/dear-mich…

@ogre_86 @RSE_VB Thanks for mentioning this accident. A good summary. I live along the flight path (which also included several public schools!). The crash totally destroyed a house with 3 generations in it (wife, baby, grandmother). The father was at work and survived.

Ugh, reading that was a punch in the gut. We had a RAG student going through CQ with a similar problem in a Hornet—engine fail, degraded hyds. Anyway, the punch in the gut was “overflew North Island” for Miramar, where he ejected and survived, but the Hornet crashed in a neighborhood. Very bad day. The young pilot was never the same, and unfortunately (and rightly so)… if he hadn’t had input from way too many duty officers, he would have landed at North Island and called for a ride home.

#TomcatTails Number 59 #TomcatTuesday “Single Engine Landing? No Sweat! ” Every multi-engine airplane is designed to have the capability to continue to fly with an engine out. Certainly, you’re in a bit of extremis and your climb rate is significantly reduced, but all things being equal it’s generally a survivable emergency. For the Tomcat, a single engine landing is quite a handful given that the motors are 9 feet apart so asymmetric thrust is an issue, but again all things being equal it’s something we’re prepared to execute and generally did so successfully. There’s some aviation lore about a F-16 pilot’s radio call as he was landing at an AFB and was pretty tight on fuel. It goes something like this: Viper: “Request priority landing due to minimum fuel.” Tower: “You’re number 2 behind the B-52 with an engine shut down.” Viper: "Ah, the dreaded seven-engine approach." Thinking back on it, I seem to recall I had maybe five single engine landings during my time flying the Tomcat. That might sound like a lot but in reality with 800 carrier landings and uncounted field landings, it’s a very small percentage. Since the vast majority of my flight time was in the F-14A (TF-30 motors, not the most reliable engine), it’s not too far a stretch that it would happen on rare occasion. A single engine landing in the Tomcat is relatively stable depending on other system degrades and the environment. For us, we transitioned to the same landing configuration as a normal, two engine approach. Gear down, flaps down full, speed brakes out, Direct Lift Control (DLC) engaged. Certainly, the reduced thrust was a big challenge but the jet was perfectly flyable in that configuration. You just had to be VERY judicious on the throttle (the ONE throttle!) and your glide slope since it was much slower to correct for an under speed or below glides lope condition. Naturally, if you have to wave off (add power and go around to try landing again) you’d need to go to afterburner pretty quickly, and with the motors nine feet apart it took “a boot full” of rudder to counter the asymmetric thrust. Doing a single engine approach on “the beach” (shore based) was relatively straight forward. You had some time to consider your best options and you had as long as a straight-in path as you wanted to fly to get the jet on deck. Oh, and you had 10,000+ feet of runway, it wasn’t moving away from you at 20 knots, and the environmentals were predictable. Not so much at the boat! The real constraints (aside from any other system problems) were fuel and time. Of course, having enough fuel to actually stay airborne was critical. No gas = no Bernoullis = falling like a turd off a tall moose. The other matter about fuel was at what point in the flight you lost a motor. The fuel in the Tomcat is contained in the main box beam (titanium center box of the jet), fuselage tanks, the wing tanks, and the drop tanks. All in all about 20,000 pounds of gas, almost 3,000 gallons. The fuel is moved around via a bleed air system that takes air from the engine (bleeds it from the compressor, hence “bleed air”) and uses that to pressurize and move fuel to the main feed tanks and then into the motors. It’s a VERY complicated system and is worked on by the same Sailors that work on the engines (AD’s or “mechs”). This is why they all still smell like JP5 20 years after they retire. It’s in their DNA and we LOVE our Mechs! Shoutout to @DukeDogDad!! When you have an engine out, the supply of bleed air is reduced to half and so the fuel will move much slower. The order of flow is usually drop tanks, wings, fuselage, then feed tank. With the reduced bleed air pressure you can get a fuel imbalance over time. If you had the engine failure early in the flight, you had lots of gas to move with a diminished system. Again, on the beach not that big a deal. On the boat? That can be a challenge if you have fuel stuck in your drop tanks (can’t trap in that configuration). The other constraint, time, has some to do with fuel, some to do with other system degrades, and (most importantly) the potential for a hydraulic failure. How do those relate? Well, simply put the Tomcat had two hydraulic systems; Combined side and Flight side. Both powered the flight controls but the Combined side added things like landing gear, speed brakes, flaps, etc. The left engine powered the Combined, the right engine powered the Flight. With an engine out, one side wasn’t receiving any power to its main hydraulic pump. So positioned in the boat tail between the vertical fins was a unit called the Bi-Directional Pump or “Bi-Di”. This was where the two systems met at two impellers, one for each side but separated (no fluid exchange). If the right motor was off and the Flight side hydraulics weren’t powered by its main pump, the Bi-Di would kick in (automatically or manually if needed) so the Combined side would spin the impeller thereby powering the Flight side. And vice versa. Perfect system, right? Well, sort of. While we did a post start check on the Bi-Di every time we started up, it was notorious for not lasting very long. Lots of RPM and pressure on a seldom used system. The philosophy went that a single engine emergency is actually an impending hydraulic emergency, because if the Bi-Di came apart (as has happened) you now have NO hydraulics and all the Bernoullis in the world will not keep 64,000 pounds of uncontrollable titanium and aluminum airborne. The proof in the pudding is a mishap in the late 80s where guys had a single engine emergency over water and headed back to Miramar. They bypassed NAS North Island in favor of getting to home station and as they started their long straight in out near Gillespie Field (10 miles southeast of Miramar), the Bi-Di sh*t the bed and they shelled out. I’m sure @TexSandlin knows all about this one! Key lesson; never pass up a perfectly good airfield to get home in an emergency. Of the five or so single engine landings I did, I know I only had two at the boat. Those can be rather……memorable. My “favorite” was when I was in the VF-24 Renegades flying of the USS Nimitz in the mid-90s. Fortunately it was a day landing so I didn’t have the added pressure trying to get it aboard at night. Unfortunately, the sea state was a bit varsity. Not REALLY bad (like 10-15 foot pitching deck), but bad enough…maybe 8 foot pitch…to add a notable “complication”. If a perfect landing has you miss the back of the boat by 11 feet and the deck is up 8 feet, and I’m a little low, and I don’t have the thrust to fix that quickly, then……well, that gets complicated. My right engine had failed due to an oil pressure problem. We caught it early and shut it down so it didn’t come apart. We then talked to the boat and started heading back from our working area off the coast of San Diego. Things were pretty stable. No other system degrades, it was later in the flight so our fuel was distributed correctly and we had plenty for a couple of “looks” at the deck. Weather wasn’t awful, ceilings at 4,000 feet or so, but you could see the whitecaps on the water as we got lower. Hmm. Windy and the deck was going to be moving a bit. As the rest of the airplanes in that particular launch were recovering, we set up behind the boat at 10 miles and 3,000 feet waiting for everyone to land. Get the working birds down first, THEN bring in the broken one in case something bad happens, right? As the last plane trapped, CATC (Carrier Air Traffic Control) calls us and says “the deck is yours, push when ready.” We turned inbound and got the jet dirty (landing configuration) and stable by about 8 miles. Gear, flaps, hook, speed brakes, DLC, check. As we trundled toward the ship, I set the jet to on-speed for landing and then began to trim out the stick and rudder control surfaces. This is key to reduce the pilot workload. The trimming process is a little switch on the stick for up/down/left/right, and the rudder trim was a switch to the lower left of the left knee. Once in a trimmed condition, the jet would be pretty stable if you took your hands/feet of the controls. Not ALL the way stable, but you didn’t have to fight it so much. We descended to 1,200 feet and re-trimmed for on speed as best able. And since getting slow isn’t a really good option, I gave a few extra RPM and some more trim and got us just over on-speed, maybe 14 units of AOA vice 15. The thinking here is to have a few extra knots “for mom and the kids” (family back home) that I could easily bleed off in close and crossing the ramp just prior to landing. We’re coming down the final bearing line (course that puts you right down the angle) and hit the push point at 3 miles. A few more corrections, good ILS “Bullseye” needles and we settled in for a fairly smooth run in toward the ball call at three-quarter mile. Normally you’re mostly heads in the cockpit with this portion of the approach, watching your instruments. But the unusual attitude of the jet, slightly off kilter with yaw/roll, and the non-standard feet/hand positions (half a boot of rudder on the left, left hand clutching only one throttle) you needed to come out and look at the boat and horizon to make it make sense. It’s hard to describe but that’s the best way I can say it. Things just felt weird so you needed some physical reference to settle your mind. Veeeeeery smooth throttle corrections all the way in….do NOT get low or slow (or both!)…keep the power on the jet. “Rage 202, Tomcat ball, 5.5, single engine” says my RIO. Stay just on the slightly high side, slightly fast side. And I mean slightly. If you go too high/too fast, you’ll have to suck off some power to get back to a good position and then NOT have the power available you’re used to for correcting your new down vector. Danger, Will Robinson. We were looking great….nice and smooth…then just slightly low. Sh*t. Get to the in-the-middle position and the deck starts coming up (I was told later) and Paddles decides to pickle me (wave me off) based on the safety margin. Great. Full Zone 5 on the left engine, BIG extra boot full of rudder to keep tracking straight, sloooowly pull the stick back to set 10° to fly away attitude, and away we go over the boat. Easy Peasy (with a modicum of seat cushion pucker). So what now? Well, we’re the only game in town so we just get level, turn to downwind, head aft of the ship and turn back in at about 4 miles. Attempt number two. MUCH better this time. For as smooth as you have to be on the controls while landing at night, you have to go EXTRA smooth with an engine out. Stay ahead of the jet, keep your energy up, do NOT get low/slow. This time worked out much better. Crossed the ramp a slightly high with an extra knot or two and settled slightly to a two-wire, my bread-and-butter pass with a broken jet (The Corky 1 Arrival). Paddles liked it too since it didn’t look scary. Flaps up, wings back, taxi to park, chock and chain, hop out and go get some sliders in the dirty shirt. Just another day flying the Big Fighter!

@findmeabluebird Yes, it would help a lot. Also just putting a PDF of the whole thing somewhere, such as Substack. Thanks for helping all of us.

@findmeabluebird This would be a lot more useful with photos or diagrams. I can’t even be sure of the context. I guess you are talking about face masks to reduce infection?? That interests me, but not if I can’t understand the advice. But thanks for trying.

Please share these mods with your local mask bloc!

‘A bombshell’: doubt cast on discovery of microplastics throughout human body - The Guardian “…good laboratory practices have not necessarily been followed.” Including …blanks, repeating measurements…samples spiked with a known amount of MNPs. apple.news/AtsvOY2uKReiIe….

This is the end. Now no one can cross this level !

It's over, folks. Pack it in.

@JustinWolfers This is a classic “false dichotomy“ fallacy!

There are basically only two positions in the debate about AI. 1. I’ve barely invested any time in learning how to use it effectively. AI sucks. 2. I’ve invested in learning how to use this tool. Holy cow, it’s transformational. Position #1 has lower barriers to entry.

@flowersslop Simplistic. Your argument is that the _Per Episode_ cost of fakes less when they are easy to make. Perhaps. But that ignores TOTAL cost, to individuals +society. If effort to make a fake goes down 90% (10X), the number made will go up. Total loss could go up or down.

People still don’t fucking get it: AI-generated media has more blackmail value when deepfake tools are scarce or hard to use, and less when anyone can make anything. I once again try to explain it in the easiest way possible Why do I think this: When access is tricky, a “leak” looks rare and credible. Falsification is costly. Asymmetry favors the blackmailer. When access is ubiquitous and deepfakes are inflationary, credibility craters. Plausible deniability becomes the norm. We can already generate any deepfake we want. So the rational counter is to flip the social default from “true until proven fake” to “fake until proven true.” That’s the correct cogsec model: it reduces asymmetric harm, demands evidence, and collapses the blackmail payoff.

@BoyanSlat @Liv_Boeree @_HannahRitchie #1 is wrong. Reread the original article. The figure only shows contrail effects, not total effects.

Learned something new today: 1. About half of the warming from flying comes from contrails, not CO₂ 2. Just 3% of flights cause 80% of contrail-related warming 3. Rerouting those flights to avoid contrails would increase flight time by only ~1% Via @_HannahRitchie

@Yash25571056 Explain? What is data on cognitive decline? I don’t read X regularly so I probably missed it.

The prevalence of cognitive decline is reflected in the prevalence of violent behavior.

@kareem_carr That’s great! A PhD from Harvard will be a major accomplishment forever. I’m sure you have lots of opportunities for your next phase. Perhaps even abroad, since US will continue anti-science for a while. Curious about applications of the research. Please post ur abstracts.

submitted the final draft of my dissertation last night. feeling extremely proud but also extremely exhausted.

@BeingWellpub @Gil_Bashe @sallyafrank @Microsoft That’s sure an empty slogan. As if startups need MS to tell them their purpose!

“Scale with #Purpose” isn't just a tagline—it’s the core of what @sallyafrank at @Microsoft Health & Life Sciences brings to health startups. ✨ Tune into this feature of Health UnaBASHEd on BeingWell with @Gil_Bashe: 🔗medium.com/beingwell/heal… #Microsoft #Health #LifeSciences

Unfortunately there is no theorem that says glamorous new technologies will ultimately be beneficial for humanity. Even though in past that’s been true. Marcus predicts LLM benefits will be positive but small, while side effects will be serious. (Kind of like social networking?)

My overall view at this point (slightly more positive than @LuizaJarovsky below) is that generative AI chatbots (distinct from domain-specific tools like AlphaFold) will on net increase productivity to a moderate degree in many domains, with large benefits in a few areas. (I also agree with all of Luiza’s cautions round the costs in making this work.) But those productivity benefits will also come with strong costs to society (misinformation undermining democracy, deep fakes for scams and politics, disruption of high school and college education, delusions that bring some to mental illness, nonconsual deepfake porn, increased cybercrime, greater surveillance, negative environmental impact, etc, to say nothing of an increasingly oligarchical society) Overall, I am not convinced that GenAI will be of significant net benefit to society. I would welcome @emollick’s latest take on this.

@CALonghurst @BeckersHR @GilesBruce @UCSDHealth @InnovationUCSDH @UCSDJacobs Narrowly targeted wearables can be useful eg CGM. But universal ones will produce lots of noise and false alarms. Wasted $. Anecdote: my Apple Watch fall detection gives only false + redundant alarms. I did have 1 major fall w head injury; but watch was smashed by the fall!

“Wearables have the potential to transform healthcare by enhancing personalized, preventive and scalable care, but realizing this potential nationally will require payment innovation to match the technological advances” ⤵️ beckershospitalreview.com/healthcare-inf…

@jasonfurman @ramez @ArthurLHerman Sorry, but a minor change in accounting rules cannot have a major effect! The reviewer you cite calls that argument “amusing.”

One of the ways the United States won World War II was, evidently, beating Nazi Germany to shorter depreciable lives for military investments. This and much more in a fascinating book, Freedom's Forge by @ArthurLHerman, link to my review in the next post.

@RadioFreeTom @TheAtlantic I’m glad that at least a few people are still concerned about nuclear weapons. The recent book by Annie Jacobsen was a good reminder about accidental but disastrous war.

Join The Atlantic editor in chief Jeffrey Goldberg and staff writers Ross Andersen, Tom Nichols, and Missy Ryan for a conversation at the intersection of national defense, technology, and global conflict. theatlantic.com/national-secur… @TheAtlantic

X (and other social media sites) make our 1990s optimism about the Information Age seem silly. Even with all of the world's information a click away (& a free AI that can help explain that information in a personalized way), half-mangled anecdotes with no source win every time.

@alexhnoyes @WarOnTheRocks @jessehumpal But despite this and other verbal bugs, article is interesting and worth considering.

Great piece by ⁦@jessehumpal in ⁦@WarOnTheRocks⁩, dude knows what he’s talking about! | A Signal Point of Failure: Integrating BeiDou into U.S. Positioning, Navigation, and Timing Systems warontherocks.com/2025/05/a-sign…