Private text for techies

AeroEng

Filing Flight Plan
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AeroEng
With any luck I will have my ground instructor rating in the near future, and my first prospective class is entirely composed of engineers and techies. What textbooks would be a good fit for a room full of obsessive compulsives?
 
It seems like most texts steer clear of showing the underlying math and geometry but I think this crowd would eat it up. I was thinking just use one of the standards then spice it up .a bit. But then I got lazy,..
 
Stay with the basic books, but be prepared for a lot of more challenging questions. Based on your user name, I'd guess that you probably have a decent background in the technical side of things and should be able to give better answers to your students than they can get from the typical books. Also be prepared to say "I don't know, but I'll look it up and get back to you" when (not if) you get a question you truly don't know the answer to.

Don't try to BS a bunch of technical people. You'll just **** them off.
 
Right.. I am an aero engineer teaching gnc and software gurus so there will be little room for sloppy presentation and sadly the FAA exams are pretty sloppy. The questions about aspect ratio make my skin crawl. I am getting the impression from sample sections that the standard texts are not all that different in presentation. The bottom line is getting them to pass the test and also be safe smart pilots. The local university book store has both jeppeson and asa so we will go from there.
 
Stay with the basic books, but be prepared for a lot of more challenging questions. Based on your user name, I'd guess that you probably have a decent background in the technical side of things and should be able to give better answers to your students than they can get from the typical books. Also be prepared to say "I don't know, but I'll look it up and get back to you" when (not if) you get a question you truly don't know the answer to.

Don't try to BS a bunch of technical people. You'll just **** them off.


As I near retirement, for the past seven years I've been teaching technical classes related to my career field, and everything in the quote above, is a piece of best advice for any instructor. Never BS.

If you don't know, or are not sure, say so. Your students will better respect you for your honesty. And, I don't care how smart you are, or you think you are, there's something new to learn each and every day, and always somebody out there smarter than you.

Years ago, when I eventually got my head screwed on straight, it fell on me to pay for my education. I became very dedicated. I would lay in wait for the half prepared, and the bullshooter instructors. I'm no different today, except I try to be a bit less aggressive, and a little more diplomatic.
 
I think something my first CFI used to say to me when I went off into the engineering head weeds might be in order...

“You can look that up on your own time. I’ve been flying for twenty years and haven’t ever needed to know that. Right now you need to focus on the material here so you’ll pass the damned test. I can still outfly your ass.”

Engineers know how to shut up and focus on a goal if you tell them to. :)
 
“You can look that up on your own time. I’ve been flying for twenty years and haven’t ever needed to know that. Right now you need to focus on the material here so you’ll pass the damned test. I can still outfly your ass.”

Engineers know how to shut up and focus on a goal if you tell them to. :)

I’m paying for The instructors time. Don’t tell me what I’m curious about isn’t relevant. I don’t care if it’s important for the test or my daily flying. I just find learning things interesting. If you don’t know the answer tell me that and offer to look it up or give me suggestions on where I can find the info. If you don’t want to do either of those, then I’ll find a different instructor that will help me.
 
As an engineer, you likely can appreciate the understanding the why.
I am a "techie", and I learned much faster when the instructor or material gives a why rather then just a dumb rule to memories. Even if the why is incomplete, and says in general. This is good enough.

Also, "if ain't broke don't fix it" does not work....

Last point, consider splitting class time. And be upfront about it. Tell them the more the prepare, and the less time you have to run the standard material, the more time they have for questions and tangents.

Tim
 
I’m paying for The instructors time. Don’t tell me what I’m curious about isn’t relevant. I don’t care if it’s important for the test or my daily flying. I just find learning things interesting. If you don’t know the answer tell me that and offer to look it up or give me suggestions on where I can find the info. If you don’t want to do either of those, then I’ll find a different instructor that will help me.

I don’t think you realize the level of minutae I could go to back then. LOL.

Your reaction to the scenario is overblown though. Most people want to accomplish a goal, not talk about why a door latch was manufactured a particular way.

The instructor does have to control the room in this case and not let a group drag him off into stuff that there’s no time for in a ground school class and won’t help the majority of the people in the classroom learn the material they paid to learn.

One on one, if someone wants minutiae, I’ll oblige to a point. Like you said, it’s their money. In a classroom they’re wasting other people’s money and time.
 
Most people want to accomplish a goal, not talk about why a door latch was manufactured a particular way.

It depends... I have actually discussed that with the contractor when they were replacing my door a couple of days ago (switching from leaky double doors to a sliding glass door). :D

Tim
 
Why not go with the FAA books? (PHAK and AFH)

--They're free in electronic form (PDF) and relatively inexpensive in printed form.

--They are the official FAA source documents from which the written questions are drawn. It'll also teach the students where the FAA answers are for when they want to look up answers to questions that come up after they've finished you class.

https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/
 
It depends... I have actually discussed that with the contractor when they were replacing my door a couple of days ago (switching from leaky double doors to a sliding glass door). :D

Tim

In talking with my wife (an architect), one of the most technically complicated things they deal with are doors. Between security/badge access, operators for handicap people, and fail-safe for fire safety the stuff gets very complicated. Most people don’t think about it, but doors aren’t easy.

Now if you want to talk bearings or driveshafts, let me know. I spent a number of years designing custom versions of both of those for the aerospace industry.
 
Now if you want to talk bearings or driveshafts, let me know. I spent a number of years designing custom versions of both of those for the aerospace industry.

Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim
 
Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim

Turboprops have to be geared because turbines spin around 10,000rpm more or less. That's one fast, noisy prop! So, gear it and slow it down. Many kit planes that have Jabiru and Rotax engines utilize gear reduction drive units. Why add the weight, complexity and additional maintenance if it's not necessary, though?
 
Torsional vibration becomes a bigger problem the with longer driveshafts. I believe a number of pushers have suffered from these issues (bd-5, vk30, mini-imp and Learfan). Gears also have mechanical losses that negatively affect efficiency.

I have to admit to having never dealt with system level issues. At my job we tended to try to stay more to component-level analysis.
 
All powerful radials are geared, using planetary gearset. They need a large diameter prop for efficiency, and the larger the diameter, the slower is the rotational speed limit. The modern Rotec radial is like that too, although purely in order to save weight.

Cessna 175 had a GO-300, a geared engine.

I don't think Jabiru is often used with a gearbox, although Rotax 912 series always is. My Carlson has an HKS-700E that spins at 5800 rpm and drives the prop through a 1:2.58 conventional reduction gear.

BTW, Stemme has a 912 located behind the crew, which drives the prop in front through a long shaft. The overall configuration resembles P-39 Aircobra. I'm not exactly sure just what the merit of it is, considering other motorgliders that use a conventional layout, such as Phoenix and Grob 109. Clearly the technical challenges of a long driveshaft are not insurmountable. You just don't want to look at the price tag of the Stemme.
 
Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim

I am NOT an engineer, but the way I think about it is... In a machine that's flying thousands of feet off the ground, that could theoretically fall out of the sky and kill you (and others) if a part breaks, fewer moving parts = fewer things to break, and therefore safer.

I know that might be a naive way for me to look at it, but I can't help but think prop<->engine is "safer" than prop<->bunch of other stuff<->engine
 
o_O
Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim

Every bit of engineering design is a compromise trying to resolve for competing requirements.

The direct drive air-cooled engine is actually a pretty elegant solution. Simple, reliable and comparatively light weight. All of which would seem pretty important when it comes to airplanes.

One could make the pistons smaller, run the RPM higher, install a gear reduction for the prop and end up at precisely the same place from the perspective of the prop and the air it's pushing. So what exactly is the benefit? o_O

Water cooling, with a remote radiator installation, offers the opportunity for more streamlined cowls, but now one is adding more complexity, more failure modes, the weight of the pumps, lines and coolant. And the drag of rejecting excess heat to the air hasn't been eliminated. :(

On the Continental diesel Mercedes auto engine based conversions I think the time before replacement (replacement, not overhaul) is up to 2100 hours, but the gearbox has to be replaced at 1200 hours.

If the prop needs to be moved forward in any given aircraft design (such as my Aztec), a prop extension can be used; again simple, reliable and a whole lot less weight than a gearbox.

If mass produced automotive or snowmobile engines could be used right out of the box in an airplane that could be pretty economical compared to what we pay to buy and maintain our power plants today. Unfortunately that doesn't appear possible as the aviation conversions seems to require considerable modifications and lots of $$$.
The list price of a new 100 hp Rotax 912 is starting to push $20,000. I can buy a brand new 4-stroke, water-cooled 90 hp BRP Expedition Sport sled for half that. Not just the engine...the whole machine. :)
 
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Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim

Because the RPM of most piston aircraft engines running at peak torque happens to coincide with the optimal prop RPM for a given desirable prop diameter for that plane.
 
I am totally fascinated by the violent topic drift. Thank you all. I like the idea of using the FAA source documents. Our flight instructor uses Gleim at his day job so I can follow their general syllabus. Good enough, thank you.
 
In addition to the other advice, don't be afraid to say "I don't know but I can find out" to a question, but don't overuse it. Used sparingly, students will appreciate the candor. Used generously, and students will believe that you don't know anything they can't get from the book. Engineers tend to be types that can teach themselves from the book, though there are still many who need some sage guidance.

Going completely off topic, why are so many planes direct drive instead of having a gear transmission with a prop shaft? I would think a prop shaft would be better at pushing the prop away from the cowling allowing better aerodynamics, a transmission would allow the engine to turn at more optimal speeds...
These issues are solvable, I mean look at all turbine aircraft they have gearing....
With modern software design, this has to have become easier than the days of the slide rules.

Tim

Let's not underestimate the fact that engine design for light aircraft has hardly changed in the last 70 years or so. In the early part of the 20th century our manufacturing was relatively primitive, so simplicity was regarded as "best," and there was little need for effiency. It made the engines lighter and more reliable. That meant things like gearboxes were a no-no unless absolutely necessary, and liquid cooling was heavy.

Our manufacturing and engineering have come a long way since then, so we can make gearboxes that are light, robust, and reliable. We can make liquid cooling systems that are more efficient, requiring smaller radiators and less coolant. We can make electronic ignition systems that are light years more reliable and sophisticated than mechanical magnetos.
 
With any luck I will have my ground instructor rating in the near future, and my first prospective class is entirely composed of engineers and techies. What textbooks would be a good fit for a room full of obsessive compulsives?

Good luck man, that’s the biggest demographic that I find is a pain in the butt to teach.

Not the ground or theory of flight or anything, they are great at that.

But flying, oh man, it’s all 1s and 0s with them, very binary thinking with little feel, it should be a good challenge for ya, especially the round out on landings.
 
One could make the pistons smaller, run the RPM higher, install a gear reduction for the prop and end up at precisely the same place from the perspective of the prop and the air it's pushing. So what exactly is the benefit?
Lower fuel consumption for the power, lower weight. Smaller cylinders weigh less - in fact the savings exceed the additional weight of the gearbox. Compare the same experimentals or LSA with O-200 and Rotax 912, such as Zenith CH750. The difference is pretty obvious. In fact the difference is fule consumption is so noticeable, that even the lower purchase price could not offset it for the factory Zenit completions in Alabama. The only people who still buy O-200 are those for whom the acquisition price is paramount, and performance is less important.
 
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