Divalent

The idea is that with the engine inside the hull, the exhaust can be treated before exiting. (Something that can't be done now with the engine out of the wing, as that exhaust it the thing that is giving the airliner the thrust.) See a link I posted a page or two back on the concept. (https://www.dropzone.com/forums/topic/266444-electric-aircraft-the-thread/?do=findComment&comment=4936934)

I think you are strawmanning what is being proposed. The proposal is that an engine that provides less than the needed power to take off (say, 80%) is combined with an electric with batteries that can provide the needed 20% additional for takeoff climb. Then when cruising, where you need (say) 75% power, the remaining 5% of combustion power charges the batteries. So you don't need a 100% combustion engine to take off and charge. ~20 minutes of charging while cruising would then recover the initial battery power, which then gives you your reserve. Further, when the flight is descending and using only a fraction of the combustion engine output, you could charge the batteries even faster (meaning you might not need less than 5% excess capacity to charge your reserve). Yes, the economics will depend on whether the actual combination of weights and power make sense. But the scheme can't be dismissed on a logical basis by assuming you absolutely need a 100% combustion engine at some point in the flight, as that is not what is being proposed.

Couldn't they recharge the batteries in flight? Maybe design for cruising at a tad less than 100% WOT, with the remaining % available to run a generator. Then you'd be able to call on that reserve later in the flight.

Well, I think there is a bit of "chicken or egg" here: a dead looking forum doesn't encourage users, and no users reinforces the image that the forum is dead. There actually is some activity in the canopy forum, but you don't see it immediately as the ancient top pinned posts are cluttering up the initial view.

An interesting variant is hybrid electric planes, even the size of big airliners. The idea is to have fuel burning engines inside the plane, which generate electricity to drive the electric motors. The benefit is that the exhaust can be passed through a pollution control system before exiting the plane, greatly reducing (90%+) nitrogen oxide emissions, which are apparently are a major source of harmful pollutants from airliners. But it's not a CO2 saver (would somewhat increase CO2 due to additional weight). https://scitechdaily.com/hybrid-electric-plane-concept-may-reduce-aviations-air-pollution-problem/ Another hybrid variant I ran across for smaller planes would include some batteries to provide additional power for takeoff. It's utility would depend on whether the weight saving of a smaller generator motor would offset the additional static weight of the batteries.

Also important IMO is that many of the topical forums look like fossils from the past, no longer being actively curated. Just look at the "Pinned" threads in almost all of them. This place just screams "no one here but us rats". For example, in the Canopy forum, one of the pinned threads is the 2014(!) Canopy Pilot event list. I mean, someone new browsing that forum would instantly conclude it was a dead forum, abandoned by anyone serious.

Another article that gives more specific details on the Ampaire hybrid version of the Cessna Skymaster (named the Electric EEL), which has two engines in a front-and-back orientation (push-pull). The front engine has been replaced with an electric, so it is configured with a 300 hp piston in the back, and a ~200 hp electric in front. Mokulele Airlines is current doing a month long series of trial flights on a 20 min route between two airports on Maui. Apparently it does the whole round trip (40 min) set on just one electric charge. Should provide good data on reliability and performance under simulated real route use. https://www.flyingmag.com/story/aircraft/ampaire-hybrid-electric-trials-begin/ Here's the Wikipedia page for the Electric EEL: https://en.wikipedia.org/wiki/Ampaire_Electric_EEL

So I ran across this interesting article about the electric aviation industry. More of a survey of the companies and products that are underdevelopment, but not a lot about the technical details. Still ... https://qz.com/1943592/electric-airplanes-are-getting-close-to-a-commercial-breakthrough

Bill worked in a pickle factory. He had been employed there for a number of years when he came home one day to confess to his wife that he had a terrible compulsion. He had an urge to stick his penis into the pickle slicer. His wife suggested that he should see a sex therapist to talk about it, but Bill indicated that he'd be too embarrassed. He vowed to overcome the compulsion on his own. One day a few weeks later, Bill came home absolutely ashen. His wife could see at once that something was seriously wrong. "What's wrong, Bill?" she asked. "Do you remember that I told you how I had this tremendous urge to put my… umm… member into the pickle slicer?" "Oh, Bill, you didn't." "Yes, I did." "My God, Bill, what happened?" "I got fired." "No, Bill. I mean, what happened with the pickle slicer?" "Oh - she got fired too."

I dunno, "Washington" doesn't seem very politically-incorrect to me, even tho he was a white guy. But if they want to change, how about the "District Redskins"?

Did you hear about the cannibal that passed his brother in the forest?

Sorry, looks like I Triple(!) posted this

To put this in perspective, assuming your flu numbers are correct, 490,000 hospitalizations over the duration of a flu season is a pretty low load for a country that has 160,000 ventilators. It's also about 1% of all that got the flu. So even if all 2018-19 flu hospitalizations required an ICU bed, when spread over 4-6 months it would not have come close to overwhelming the system. From the Diamond Princess cohort, ~50% of the 700 Covid-19 positives had symptoms, and IIRC, 30% required hospitalization, and half of them (15% of 700) needed an ICU bed with ventilator. But if 15% of just 35 M get Covid, (about 10% of US population), we're talking about 5 million needing an ICU at some point. (And is it reasonable to think we can limit this to just 10% of the population?) It would appear that we could only tolerate about 1 million or so people being infected at any one time to fill our existing ventilator capacity, unless we ramp up ICU beds and ventilators. (And what to do with non-Covid folks that would normally be occupying those beds? Estimates are that only 30% of them are available on average at any one time under normal circumstances.) Italy reached the breaking point with official counts in the tens of thousands. Yes, case counts are way below reality due to testing constraints, but our trajectory is about 10 days behind Italy, and based on per capita ventilator numbers, maybe we have another 6-10 days before the US would have hit the breaking point had we waited as long as Italy did to react. A lot is unknown and/or unclear, but hopefully the time we are buying will allow additional tools to come into play. If nothing else, time produce more masks and hazmat suits so at least we keep our existing medical folks from getting taken out of action (permanently or for recovery) and acquire more ventilators, test kits, and increased hospital space so we can handle a higher load. And more time to discover better treatments.

Looks like I double posted this

Supremacy would only be an issue if a local gov passed a law that conflicts with fed law. Here it would be a *Federal law* that explicitly gives local govs the right to pass laws regulating local noise beyond what Fed law does. So any local restrictions would not conflict with the federal law.

Bob forgot his wedding anniversary. His wife was mad. She told him "Tomorrow morning, I expect to find a gift in the driveway that goes from 0 to 200 in 6 seconds! AND IT BETTER BE THERE!!!" The next morning when his wife woke up, she looked out the window to see a box ... gift wrapped in the middle of the driveway. She opened it and found a brand new bathroom scale... Bob has been missing since Friday.

There wasn't a knot (at least as far as I could tell). I'm pretty sure the bunching of the lines on the right side is due to the line that caused the lineover. A front line that goes over the top and down the back has to course outside around all the remaining lines to reach it's attachment point on the front riser. (and vice versa if it was a back line). You would expect that bunching to not look as extreme if the lineover was nearer the end (shorter distance, fewer good lines to get past).

FYI, here's what my lineover looked like on a Pilot 189. I'm sure it fully pinched in the middle, but hidden by adjacent cell fabric.

Umm, I don't get it.

The dropzone you will be jumping at almost certainly will have experienced licenced skydiving photographers for the jump portion of your experience (but call and ask to be sure). The DZ may or may not let you bring your own outside photographer for photographing the jump portion (if you find someone qualified who would be willing to do this for you) so ask about that too if you decide to bring your own. The DZ should be fine allowing an outside photographer to shoot ground scenes, but call about that too to be sure, and so that they can prepare for it (DZ's don't normally allow spectators to be out in the landing area, or near the plane). Happy wedding!

Bump. (Because it is a very entertaining thread)

Wasn't there a wingsuiter that survived a no pull when he crashed into trees? His vertical velocity may not have been typical free fall speeds, but total velocity speed must have been pretty fast; as was, I would guess, Connery's as well. (I would assume that Connery's speed can be determined from the video; did that ever get revealed?)

An interesting story about a somewhat similar problem in the Airbus A330 from 10 years ago. A brutal experience, although fortunately they were able to land intact. But a case where the computer controls overrode the commands of the pilot. https://www.smh.com.au/national/i-ve-become-very-isolated-the-aftermath-of-near-doomed-qf72-20190514-p51n7q.html

I google searched for "parachute found in Amboy was not from Flight 305 as it was too large at 34-feet in diameter", and first link was this (which contains the exact phrase): https://themountainnewswa.net/2012/05/14/the-hunt-for-db-cooper-looking-for-the-amboy-chute/ Does this help?

I don't know any of the details about what went on (I'm just a skydiver mildly interested in DB Cooper), so excuse me if what I say is so obviously contradicted by the known details. But I'm curious why you assume he didn't use his own rig? I certainly wouldn't trust a rig given to me by the authorities if I were in his shoes, particularly when jumping into unknown terrain at night. Even if I could assume they wouldn't jimmie it so I had a total malfunction, they might make the parachute small, or with other defects, that would ensure a rapid descent and a hard, injurious, landing. And I would have also thought about a tracking device being hidden inside. So why ask for parachutes? Could be because he assumed they'd put in a tracking device, and he would toss that out 50+ miles from where he actually exited so that any search would focus on where he wasn't. And/or use some or all of the rigs or reserves to do the final descent of some of the load he was carrying. (What did he exit with, and how much did it weigh?) And a night jump into unknown and gnarly terrain with tall trees? He could almost be assured he'd be hung up in the trees: maybe extra rigs were for rope/lines, etc to help extricate himself. Anyway, just some thoughts