Cafe Einstein : LPTP #9...onward and upward

Mike Hewson
Mike Hewson
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@David : sounds like you have

@David : sounds like you have a good mix of aerobic and anaerobic gym happening there. Plus a few of those logic exercises like in Impossible Mission, a classic Commodore 64 game from the 80's. Maybe [url=http://en.wikipedia.org/wiki/Ratchet_%26_Clank_(video_game)]Ratchet & Clank[/url] could do an Illinois Railway Museum version ! The General Manager would be the obvious choice for the wild-card in the game. :-0

Another little mental game I play with myself : suppose that shot of the streetcar was the only image of Earth that aliens could see. What would they deduce about us ? There's not much to see of what we look like in that photo. But even if you could construct our anatomy from that, you could reasonably deduce that for some reason we spend all of our time in vehicles and/or ground structures. Not true, sometimes we walk the dog ! The aliens might think that we are parasites within the vehicle lifeforms who in turn go back to their dwellings to rest at night. I can imagine the alien xenologists arguing the point, with some strenuously asserting that it is symbiotic! :-)

The reason I think of that is our probes visiting other planets' surfaces and snapping off photos around the landing zone, which we eagerly analyse in great detail. I remember one of the Mars rovers where there was much made of a particular rock. How representative is that ? In Australia you could drop in anywhere along a line from Coober Pedy to Wilcannia, say, and have a very low chance of seeing anything that you could relate to the human race. Much less intelligent life. Mind you, the kangaroos are pretty smart.:-0

Cheers, Mike.

( edit ) Now I remember : there's this recent game called AntiChamber and it's a real brain-melter. The idea is to traverse a multi-dimensional maze with the clock running, but the semantics are definitely non-Euclidean topology. Some portions recreate what it would be like to be within a ( forked! ) Klein bottle for instance, or reminiscent of Escher constructs. NB I said multi-dimensional, I didn't say three, as it's up to the player to deduce how many ! :-)

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

mikey
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RE: Another little mental

Quote:


Another little mental game I play with myself : suppose that shot of the streetcar was the only image of Earth that aliens could see. What would they deduce about us ? There's not much to see of what we look like in that photo. But even if you could construct our anatomy from that, you could reasonably deduce that for some reason we spend all of our time in vehicles and/or ground structures. Not true, sometimes we walk the dog ! The aliens might think that we are parasites within the vehicle lifeforms who in turn go back to their dwellings to rest at night. I can imagine the alien xenologists arguing the point, with some strenuously asserting that it is symbiotic! :-)

The reason I think of that is our probes visiting other planets' surfaces and snapping off photos around the landing zone, which we eagerly analyse in great detail. I remember one of the Mars rovers where there was much made of a particular rock. How representative is that ? In Australia you could drop in anywhere along a line from Coober Pedy to Wilcannia, say, and have a very low chance of seeing anything that you could relate to the human race. Much less intelligent life. Mind you, the kangaroos are pretty smart.:-0

Cheers, Mike.

I too like to think about how we humans tend to impose our own ways of doing things on other life forms, lots of people think Giant Pandas and Koalas are cute and cuddly, and some are, but...some aren't!!

One of the problems with landing on a planet in a 'habitable' area is the cities on Earth. If an alien race were to send a probe to Earth it would probably try to land in a big open space, not in the middle of some major metro area, reducing the chances of seeing life forms, other than bugs and perhaps some passing birds. Trying to land on Mars, or any far away place, is it is normally a Scientific Mission FIRST, with the actual life finding mission an add on. So they find a nice wide open spot that looks good and has few chances of failure during landing, ie flat and barren, and then when they find no 'life' declare it dead. DUH...we humans don't live in 'flat, barren' regions, why would an alien race? Unless they are trying to kill each other all the time they would tend to group, as we humans do, for both reproduction and the sharing of skills and resources. 'Flat and barren', ie 'the outback', doesn't fit either of those scenarios.

Even the Russian Lander 'Lunakov', either one of them, didn't roll around very far when on the Moon. Each was there for about a year and yet neither was able to go very far in it's research. Going less than 2 miles in any direction in the middle of 'the outback' could result in similar findings, fairly uninhabitable by average humans.

David S
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continuing... Forgot to

continuing...

Forgot to answer the question: see the green boards below the doors? They fold down when the doors open. They're still rather high steps, especially if the ground is below the level of the rail. Not good for my knees.

Anyway... I move up to Depot St. and get some passengers. I explain to them that I will be ping-ponging and it will take about 30 minutes altogether. Proceed to Electric Park and give the car talk. Proceed to Springfield and give the spiel about the shelter. Proceed to Barn 9 North, tell them what's in the barns out here and it's where I change ends. Change ends and head back. Lose the %@#^ pole going through those switches. Get off to fix it and kill my knee getting on again. Take it very slow through there the rest of the day.

Come barreling toward Car Line Junction, thinking the switch is set for me. Notice at the last moment it isn't. Technically, it's a spring switch, but they don't want us to spring through it anymore. Emergency stop. Radio code to throw it. Dispatcher says I'm probably in the circuit and that won't work, and I'll have to back up. I'm about to do so when it throws after all, despite me being almost on top of it. Tell myself to calm down and relax. Proceed to Central Ave. Change ends. Close the doors from the outside, chock the wheel, go to the euphemism.

And so I go back and forth all day. Again. Really don't want to do that this Sunday when I'm also handing out prizes and treats to little kids in costume.

Frustration and/or fatigue returns at the end of the day when I forget to lower the front pole changing ends to put the car to bed. Fortunately, someone yells at me to stop before I do any damage.

I had a flash of inspiration about the air tank drain cocks. It worked fairly well in the morning and almost as good as I hoped in the evening. Further killing of my knee is minimized. Even better, doctor's advice about my big toe callouses is helping; they don't hurt as much.

Winning!

David

Miserable old git
Patiently waiting for the asteroid with my name on it.

Mike Hewson
Mike Hewson
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RE: ... I'm also handing

Quote:
... I'm also handing out prizes and treats to little kids in costume ...


So you're the one in the costume, not the kids ? :-)

Well as long as you don't look like Ronald MacDonald you'll be alright.

I've looked up the double tank idea, apparently they are typically in series after the compressor even though both are drawn upon. So the first acts as a moisture trap by passive cooling of the air that has been heated by compression. You can get water from both tank drains, but allegedly more from the first. I'd guess that first-tank cooling would be more prominent in cooler weather.

I didn't mention that for ( Piper ) light plane fuel systems there are two more fuel drain bowls with spigots on the way to the engine. Those are checked in the pre-flight round of course. But here the engine is sited a good foot higher than the wing tanks, so the likelihood is to catch & drain any water from the tank taps primarily.

But with a high wing type ( say Cessna ) there is a decent fall from tank to the engine bay. That gives a different problem : you are more likely to have clearer wing drains than those sampled more proximal to the engine. A Cessna 182 say has about 15 drain points and to be exact should be sampled in a certain sequence. It's do-able for sure and most Cessna pilots say it's a pain, but what choice do you have ?

The other interesting fuel issue is that the Cessna 180 series have the maximum take-off weight exceeding the maximum-landing weight by a good margin. That leaves one open to the scenario of taking off fully loaded and having to burn fuel before one ought land. For longer flights going to plan that is no biggie but otherwise maybe not. I say 'ought' as you land if you really need to regardless. The maximum landing weight is for the sake of the continued integrity of the landing gear, and if you are light fingered on the yoke you may ease it down real nice but conditions have to permit that gentility.

Otherwise in crosswinds the high wing types can be a real beehatch for gusts lifting the upwind wing during landing. It's much easier to keep the upwind wing held down with crossed controls ( roll to the windy side, rudder kick opposite ) on low wing types, to prevent flipping over. Though that is best done on grass strips as one can easily ground & thus damage the wingtip, especially in reflex response to the gust. I've seen flipping nearly happen at bayside Moorabbin where some afternoons the seabreeze gets quite brisk and squirrelly ! One additional technique is to set full flap and at least that slows the roll response, but then you have to fly a wallowing bucket of meat ! All pilots hate 'low & slow' but you have to do that to land safely .... :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

archae86
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RE: The other interesting

Quote:
The other interesting fuel issue is that the Cessna 180 series have the maximum take-off weight exceeding the maximum-landing weight by a good margin. That leaves one open to the scenario of taking off fully loaded and having to burn fuel before one ought land. For longer flights going to plan that is no biggie but otherwise maybe not. I say 'ought' as you land if you really need to regardless. The maximum landing weight is for the sake of the continued integrity of the landing gear, and if you are light fingered on the yoke you may ease it down real nice but conditions have to permit that gentility.
Cheers, Mike.


For long-distance commercial airline flight it is bog standard to take off at far above maximum landing weight. Those types generally have fuel dumping systems, which can speed the time to get down to "legal" landing weight in case of need, but they don't dump so fast as you would think, and folks sometimes abstain dumping because of location.

As you say in case of real need to rule is to land anyway, and mechanics (in the USA, engineers in the UK--don't know the terminology in Oz) get to check for structural damage (not just to landing gear) before the bird flies again. Often it is cleared with no adjustments.

Part of what killed Swissair 111 was a delay of landing for dumping plus a delay of dumping for suitable location. Had they made haste for nearest suitable they just might have got down before the fire got them.

mikey
mikey
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RE: RE: The other

Quote:
Quote:
The other interesting fuel issue is that the Cessna 180 series have the maximum take-off weight exceeding the maximum-landing weight by a good margin. That leaves one open to the scenario of taking off fully loaded and having to burn fuel before one ought land. For longer flights going to plan that is no biggie but otherwise maybe not. I say 'ought' as you land if you really need to regardless. The maximum landing weight is for the sake of the continued integrity of the landing gear, and if you are light fingered on the yoke you may ease it down real nice but conditions have to permit that gentility.
Cheers, Mike.

For long-distance commercial airline flight it is bog standard to take off at far above maximum landing weight. Those types generally have fuel dumping systems, which can speed the time to get down to "legal" landing weight in case of need, but they don't dump so fast as you would think, and folks sometimes abstain dumping because of location.

Yeah I'm not sure I would want some plane dumping jet fuel while flying over my own home. While most of it may disperse the part that hits my roof, driveway and deck could be a mess!

archae86
archae86
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RE: check for structural

Quote:
check for structural damage (not just to landing gear) before the bird flies again. Often it is cleared with no adjustments.

Famously, during flight tests of the MD-80, a landing which was meant to be right at the impact limit was appreciably above.

As this youtube video shows, in this particular case the some important damage was not to the landing gear.

On the other hand, this was not an overweight landing, so I am guilty of thread drift.

David S
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Kids in costume get the

Kids in costume get the treats. I am, however, considering wearing my white dress shirt and all the appropriate accoutrements I have for the occasion instead of my standard white museum polo shirt. I just bought more accoutrements on Sunday, although I don't have a proper hat to wear the CTA badge on. I may have to go new on that to get one my size.

David

Miserable old git
Patiently waiting for the asteroid with my name on it.

Mike Hewson
Mike Hewson
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So it's Halloween then ? We

So it's Halloween then ? We don't really do the pumpkin thing DownUnda, not even a close vegetable ( fruit ? ).

As for thread drift : we've been slipping and sliding for ages. :-)

To be exact we call them Licensed Aircraft Mechanical Engineers with the unhappy acronym of LAME. Mind you the Designated Aviation Medical Examiner is a DAME.

The Piper's I flew had maximum weights the other way around ie. if you could take off the weight was fine to land on. Or alternatively if you couldn't get off the ground then landing wasn't an issue. :-)

From memory the core structural support was a cruciate shaped section from engine mount to rear seat longitudinally and laterally across the wing roots from inboard of the wheels. The weakest part of that was the only door on the starboard side. Typically that would buckle, indeed we were instructed to unlatch that prior to forced landing so that when it distorted from impact it would fail by popping out and thus not be unbreachable if closed. That's your only exit.

I liked to glide the plane at slightly different speeds ( engine idling with carby heat on to prevent venturi icing ) to test the rates ( altitude drop per time ). I'd set a given speed then stopwatch the time for, say, a 2000ft descent. It really was true that the optimal unpowered glide was at 73 knots, that being at the crossover of the lift & drag curves for that airframe. Thus the first task with power loss is to set that speed ( and trim to suit ). The hardest part is to glide in a gentle bank in order to arrive above a particular ground feature, but greater than some minimum height. That way one could actually sensibly plan an ingress into a final landing attempt, which you only get one chance at.

An especially curly bit is wind speed and direction - because you gliding within a mass of air that is in it's turn moving in bulk over the landscape. The 73 knots is with respect to that not the ground. I was taught a neat trick, which is to set the ( otherwise typically unused ) heading indicator marker on the compass to the prevailing wind direction prior to takeoff. That way you would waste no time establishing that when it mattered. Well, there could still be a change when you're up with weather/windshear etc, but it was a good start. You want to preferably land into the wind, and up slope if there is one.

The New Guinea highlands are legendary for brown-trouser flying, one can really fly by the seat of soiled pants. The bush strips are all too short. One can take off, or at least gain the air, not because you have exceeded stall speed but because the ground has fallen away at the end of the strip. It is not unusual to then get actual lift exceeding weight on the way down from the ledge you have just departed from. Then you climb out of the valley. Nearly all flight paths are deadman curves ie. lose power and you're dead. That's a fact of history. It is really rugged terrain up there. Every now and then someone comes across WWII military and other aircraft that have been dissolving into the jungle.

Cheers, Mike.

( edit ) I've just done a >*bright pink mohawk*< @ #1 clippers head shave for our breast cancer day. I'll post a photo later ..... :-)

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Phil
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During Desert Storm, when I

During Desert Storm, when I was flying on KC130s, we regularly took off overweight. A KC130 max weight was 155,000 lbs, with max overload being 175,000 lbs. We took off all the time at 192,000. Being a tanker aircraft we wanted all the gas we could get to give to the fighters during aerial refueling.

One time we had just cleared the runway and were ordered to land immediately with no recourse. We stayed at 200 feet and turned on all the dump pumps and started a large circle to land. We landed at 167,000 lbs, 12,000 above max landing weight.

During our circling around to land, we had the bad luck to fly over a small fishing fleet that was on it's way in after a night of fishing. Considering minimum normal dump altitude for jet fuel is 6000 feet (this height ensures it will not get to the ground) we soaked down all those boats and their cargo of fresh fish. Uncle Sam had to pay for the lost fish, decontaminating all those boats, and most importantly, the medical bills for sick fisherman.

No explanation was ever given for the rushed order to land. We did a "hot" refuel (engines running) and took off on our mission.

War is one of humankinds dumber activities.

Phil

I thought I was wrong once, but I was mistaken.

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