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A good reminder to not hand prop an unsecured aircraft without a certificated pilot on board. Dude had to have some uumph to hand prop an engine that big.

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Sex vs. Intelligence: Bigger balls mean smaller brain

Rhett A. Butler, mongabay.com

December 13, 2005

In a recent study of bats, Scott Pitnick, professor of biology at Syracuse University, found that testis size is inversely related to brain size. In other words, the bigger the balls of a bat species, the smaller its brain.

Comparing brain size and testis size for 334 species of bats, Pitnick’s team looked to explore the contribution of sexual selection to brain evolution. Specifically, the research tested and confirmed two theories:

  1. larger testis are found in males with smaller brain size, and
  2. relative testis depends on female promiscuity.

Pitnick and his team showed that among bat species, those with promiscuous females have relatively smaller brains than species with females that are faithful to their mates. The study also found that male infidelity, by contrast, had no evolutionary impact on relative brain size.

Pitnick says a likely explanation for this relationship relates to the energetic demands of producing and maintaining both brain and sperm cells; males cannot afford a lot of both. Under this explanation, males with relatively large testes and small brains leave more offspring than larger-brained, less fertile, competitors.

“When females mate with more than one male, sperm compete to fertilize the female’s eggs. Such sperm competition’ is rife in many bat species, perhaps due in part to the unusual ability (among mammals at least) of sperm to survive inside the female’s reproductive tract for a very long time,” says Pitnick. “The male who ejaculates the greatest number of sperm may win at this game, and hence many bats have evolved outrageously big testes—as much as 8.5% of their body mass. Because they live on an energetic knife-edge, bats may not be able to evolutionarily afford both big testes and big brains. We’re excited about these results, as they may stimulate more research into the correlated evolution of brains, behavior and the extravagant and costly ornaments and armaments favored by sexual selection.”

The finding is consistent with research conducted on primates. Promiscuous primates like chimpanzees, where any individual male’s sperm will have to compete with the sperm of a number of other males, have large testis to produce bigger amounts of sperm whereas less promiscuous species, like gorillas and orangutans, produce less sperm and have smaller testis-, and penis-, size since females are unlikely to mate with more than one male during a breeding season. For humans — considered moderately promiscuous for a higher primate — the testis to body weight ratio falls between that of chimps and gorillas.

Also involved in the research were Dr. Kate Jones of the Institute of Zoology at the Zoological Society of London and Dr. Jerry Wilkinson of the Department of Biology at the University of Maryland. The study was funded by the National Science Foundation. The full results of Pitnick’s study have recently been published in Proceedings B (London), a biology journal of the Royal Society.

This article used excerpts and quotes from a news release (“SU biology professor: big brain not key to evolutionary success in bats”) written by Carol Kim at Syracuse University.

HRM Note: airplanes are normally considered as 'female' (my own E is called 'The Mistress'). 

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That's a CB right there... hand propping a $750k to $1M AMU aircraft. Why, why, why would one do that! Unless that one is a Super Cheap B@$t@rD (SCB)!!! Did I just coin a new MS phrase?

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8 hours ago, jonhop said:

That's a CB right there... hand propping a $750k to $1M AMU aircraft. Why, why, why would one do that! Unless that one is a Super Cheap B@$t@rD (SCB)!!! Did I just coin a new MS phrase?

Maybe that's the minimum requirement for being president of the CBC.

On a more serious note, it's an example of poor situational awareness and speaks to a weak sense of personal minimums. An aircraft that includes a starter motor  and has to be hand-propped to get it started means that something is wrong, eh? How one proceeds when something is wrong is a path that branches to either success or failure -- the latter can be extreme.

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34 minutes ago, HRM said:

Maybe that's the minimum requirement for being president of the CBC.

On a more serious note, it's an example of poor situational awareness and speaks to a weak sense of personal minimums. An aircraft that includes a starter motor  and has to be hand-propped to get it started means that something is wrong, eh? How one proceeds when something is wrong is a path that branches to either success or failure -- the latter can be extreme.

I agree, but that "something wrong" could have been forgetting to turn off the interior light.

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So the Cherokee I used to fly had the battery under the back seat.  Weird, but that's Cherokees.  Its a pretty big voltage drop to get to the engine, and if the battery wasn't utterly tip top you could have problems.  I hand propped that sucker a bunch of times until I finally lit on the idea of a battery tender.  I always had the parking brake engaged, and I always had a qualified pilot at the controls.  I always checked that the airplane wouldn't move before I touched the prop.  Had there not been a trained pilot to sit at the controls while I did this, I'd stay put.

Mostly this got done when I'd flown somewhere and the airplane refused to start for the return trip home.  Like I said, putting the battery on a tender fixed the problem permanently.

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Why you ask?

People either buy airplanes because they are cool, or they buy airplanes because they need to get somewhere.

People who don't need an airplane have the luxury of spend as much time as it takes to do things as perfectly as possible. For someone who actually needs to get somewhere in a timely manor, it is an easy decision, a couple of hours to find a mechanic to put a charger on the battery, charge it up and get you on your way, or a couple of minutes to hand prop the engine. No matter how much you spend on an airplane it is worthless as a traveling machine if it doesn't work.

 

That being said. If you don't know how to hand prop an airplane, you should find someone who does. There is no question that it is dangerous, if done wrong. Not only for the one doing it but for those around them.

I've probably hand propped a Mooney 20 times or so. I always had it tied down with tight chains so it could not move forward and a qualified person at the controls. (not necessary a pilot)

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1 hour ago, steingar said:

So the Cherokee I used to fly had the battery under the back seat.  Weird, but that's Cherokees.  Its a pretty big voltage drop to get to the engine, and if the battery wasn't utterly tip top you could have problems.  I hand propped that sucker a bunch of times until I finally lit on the idea of a battery tender.  I always had the parking brake engaged, and I always had a qualified pilot at the controls.  I always checked that the airplane wouldn't move before I touched the prop.  Had there not been a trained pilot to sit at the controls while I did this, I'd stay put.

Mostly this got done when I'd flown somewhere and the airplane refused to start for the return trip home.  Like I said, putting the battery on a tender fixed the problem permanently.

The Modern Mooneys have batteries in the tail, so they also have a long lead to the starter.  I think that your Cherokee had a current leak, major resistance somewhere or a bad starter, if it was that sensitive.     

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40 minutes ago, Dan at FUL said:

The Modern Mooneys have batteries in the tail, so they also have a long lead to the starter.  I think that your Cherokee had a current leak, major resistance somewhere or a bad starter, if it was that sensitive.     

If the battery is that remote I bet they have their fare share of problems.  But hand propping a Lycoming 0320 is a lot easier than hand propping one of those big Continentals.  Like I said, once the battery got its tender the problem vanished permanently.

What you fail to realize is if you're a VFR plot, you fly clear wx, which can be hard to find in a Northern winter.  Even IFR pilots can have long layoffs due to icing.  Airplane sits for weeks, even months at a time and the battery gets weak. No way around it.  For a short flight maybe you have power to get going, but you don't fly enough to charge the battery to start again.  Happens all the time to my other vehicles.  

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1 hour ago, N201MKTurbo said:

I've probably hand propped a Mooney 20 times or so.

Two questions:

  1. 1) Engine.
  2. 2) Did the FM/POH forbid hand-propping?

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2 minutes ago, HRM said:

Two questions:

  1. 1) Engine.
  2. 2) Did the FM/POH forbid hand-propping?

1. I was always successful with my old M20F with shower of sparks. Have never been able to do my M20J with impulse coupler. 

2. IDK, never looked for it and don't recall seeing anything about it.

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20 minutes ago, N201MKTurbo said:

1. I was always successful with my old M20F with shower of sparks. Have never been able to do my M20J with impulse coupler. 

2. IDK, never looked for it and don't recall seeing anything about it.

Thanks, those were the two issues I wondered about. 

Then again, AeroElectric sez:

          Further an airplane fitted with SOS magneto cannot be started by hand since the SOS system is battery powered and effective only while the cockpit controls are in the start position. In cases were a battery is too low to actually crank the engine, it might very well have enough energy to power the SOS vibrator. A starter disable switch would allow the SOS vibrator and retard points to be made active without energizing the starter. When the man on the prop yells “contact” and hears the vibrator buzzing away on the firewall, a gentle nudge of the propeller through top-dead-center will light ‘er off. Another suggestion is to make provisions for a small, aux battery to power the SOS system through special "hand propping" circuitry in lieu of taking power from the main ship's battery.

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10 minutes ago, HRM said:

Thanks, those were the two issues I wondered about. 

Then again, AeroElectric sez:

          Further an airplane fitted with SOS magneto cannot be started by hand since the SOS system is battery powered and effective only while the cockpit controls are in the start position. In cases were a battery is too low to actually crank the engine, it might very well have enough energy to power the SOS vibrator. A starter disable switch would allow the SOS vibrator and retard points to be made active without energizing the starter. When the man on the prop yells “contact” and hears the vibrator buzzing away on the firewall, a gentle nudge of the propeller through top-dead-center will light ‘er off. Another suggestion is to make provisions for a small, aux battery to power the SOS system through special "hand propping" circuitry in lieu of taking power from the main ship's battery.

The switch on my F would get the SOS going when turned all the way to the right. You had to push it in to engage the starter. The SOS would run with a battery which was too dead to crank, but not completely dead.

Don't just run out and try this unless you can find someone with experience to do it with you the first time. It is important how you stand. It is important how your body moves as you swing the prop. Your follow-through is important so you move away from the prop. Remember if you get this wrong you could die! 

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18 minutes ago, N201MKTurbo said:

Don't just run out and try this unless you can find someone with experience to do it with you the first time. It is important how you stand. It is important how your body moves as you swing the prop. Your follow-through is important so you move away from the prop. Remember if you get this wrong you could die! 

Not planning to do it anytime soon. Then there are the words of the sage:

            NOTE: Whenever hand propping a Mooney or any aircraft with Shower of Sparks system, be sure and disconnect the starter relay. The SOS must be activated during the hand propping and you don’t want the starter to engage while someone is near the prop.

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2 hours ago, Dan at FUL said:

The Modern Mooneys have batteries in the tail, so they also have a long lead to the starter.  I think that your Cherokee had a current leak, major resistance somewhere or a bad starter, if it was that sensitive.     

The pipers used aluminum battery cables. They are notoriously bad. A lot of them have been replaced with copper cables. Mooney has always used copper cables.

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3 hours ago, N201MKTurbo said:

The pipers used aluminum battery cables. They are notoriously bad. A lot of them have been replaced with copper cables. Mooney has always used copper cables.

VW vs Porsche.

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My transition instructor said I was too tall to try hand propping a mooney.   I have a rule of never go forward of the wing when plane engines are running.  It's a good rule since the plane lives in a $100 hamburger airport and there are lots of yahoos with spinning props.

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7 hours ago, Yetti said:

My transition instructor said I was too tall to try hand propping a mooney.

Someday a Cessna 180 may have a dead battery...

 

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On 9/20/2018 at 7:19 PM, DXB said:

Feel free to laugh - no one was hurt

 

This is why they don't trust Cirrus owners with a retractable landing gear.

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