Learning about Milk Fat

I learned something new today, thanks to a debate with a friend.

The other day, a friend and I were discussing milk.

I told her I preferred 2% milk but was trying to get to like 1% milk. To me, it was about reducing unnecessary fat and calories in my diet. I’ve been drinking 2% milk for years and actually now prefer its flavor and consistency over whole milk. Whole milk, to me, had become too rich, almost like a light cream. I wanted to start liking 1% milk in an effort to further reduce fat and calories for a healthy diet. I already enjoy fat-free yogurt; indeed, I don’t think I’ve had whole milk yogurt in years, if ever. (Do they even make it? I guess I could make my own.)

My friend was adamantly opposed to reduced fat milk. I gathered from our conversation that she thought they added things to the milk that made it less healthy when they removed the fat. Or that something about the actual process of making reduced fat milk caused it to be less healthy. In any case, she thought reduced fat milk was bad and didn’t want to hear anything else about it.

If there’s one thing I’ve learned, especially in the past three or four years, is that when someone is stuck with an idea in their head it’s no use debating the point. At least not without facts. And although I suspected there was nothing unhealthy about reduced fat milk, I had no evidence to prove my point. So I let the subject drop and we chatted about other things.

But this morning, when I sat down with my coffee and some time to kill before dawn, I set about finding some evidence to support my point of view.

How Reduced Fat Milk is Made

I Googled “How do they make reduced fat milk?” I got a number of search results. The first, from The Kitchn website, had the answer I was looking for: “How is Skim Milk Made?“. Here’s the pertinent info:

So how is skim milk made? Traditionally, the fat was removed naturally from milk due to gravity. If fresh milk is left to sit and settle, the cream — which is where most of the fat is — rises to the top, leaving behind milk with much less fat.

The quicker, modernized way of making low-fat and skim milks is to place the whole milk into a machine called a centrifugal separator, which spins some or all of the fat globules out of the milk. This occurs before the milk is homogenized, a process which reduces all the milk particles to the same size so that natural separation doesn’t occur anymore.

The article goes on to provide some other interesting information about milk and fat free milk. Among that information was a note about additives:

Federal law mandates that most skim milk has to be fortified with vitamin A and sometimes vitamin D. This is due to the fact that even though whole milk naturally has a fair amount of both, the vitamins are fat soluble and thus lost when the milk fat is removed during the skimming process.

Milk solids in the form of dried milk are also added since they contain proteins that help thicken the watery consistency of skim milk.

Not only was this likely the additives that worried my friend, but it also explained how some brands of skim milk were far more palatable than others: they likely added back more dried milk to thicken it up.

2% Milk
The only thing that creeps me out about Shamrock Foods milk is its extraordinarily long shelf life: the quart I bought last week is supposedly good until March. Could it be the plastic packaging?

Now I don’t know if the 2% milk I normally consume has a lot of vitamins or any milk fat added back in. The milk in my camper’s refrigerator now — remember, I’m on the road this winter — is from Shamrock Farms and says it contains “reduced fat milk, Vitamins A & D.” Nothing about milk solids.

So nothing I learned about the production of reduced fat milk has scared me away from drinking it.

Benefits of Whole vs. Reduced Fat Milk

Scrolling down in the same search results, however, brought up links to two different articles in TIME Magazine. I read them both. After all, I wanted to learn the truth — a truth that would either support or even change my own opinions.

  • The Case Against Low-fat Milk Is Stronger Than Ever from April 4, 2016 cites a study of people whose health had been tracked for 15 years. The conclusion was that, if anything, people who consumed whole fat dairy products were less likely to be obese or suffer from type 2 diabetes.
  • Why Full-Fat Dairy May Be Healthier Than Low-Fat from March 5, 2015 cites the results of over 25 studies that concluded that “people who eat full-fat dairy are no more likely to develop cardiovascular disease and type 2 diabetes than people who stick to low-fat dairy. When it comes to weight gain, full-fat dairy may actually be better for you.”

Huh.

Both articles suggested that there might be something special about the fat in dairy that works with our bodies to help them process the foods we eat and help us feel full. Dairy fat could actually be preventing us from eating less healthy sugars and carbs to feel sated. And these articles maintained that it was foolhardy for diets to recommend cutting (or eating) just one kind of nutrient — for example, low fat or fat-free diets — when the body naturally works with all consumed nutrients together.

I understand how these studies could have gotten these results. Back in the late 1970s and early 1980s when the fat-free diet craze was in full swing, stores were full of fat-free processed foods. I know because I still lived at home (or at least visited regularly) and saw that my mother bought them. She, like so many other people, thought that the answer to keeping weight under control was to keep as much fat out of their diets as possible. But rather than do this by eating naturally low fat foods like fruits and vegetables and whole grains, they did it by buying processed foods labeled “fat free.” They then consumed as much as they wanted, not paying attention to the ingredients that made this food taste good despite the lack of fat: mostly sugar. Calorie counts were sky high. It was around this time that I started reading labels and making food choices based on what I read. While I don’t have a perfect diet, I’ve learned to minimize my time in a supermarket’s middle aisles where all the processed foods reside.

The Calorie Argument

Okay, so what about calories? The articles both confirmed that one of the benefits of reduced fat dairy products was the accompanying reduction in calories. So I decided to see just how many calories I was saving by switching between whole, 2%, and 1% milk. (I really detest fat-free milk and generally only have it in lattes because I think it froths better. Fat free yogurt tastes fine to me.)

So I Googled “What is the calorie count for whole, 2%, 1%, and fat free milk?” The PopSugar website had the answer I sought: “Whole vs. Reduced vs. Low-Fat vs. Nonfat Milk.” Here’s the nutritional information that interests me for one 8-ounce cup of milk:

 Whole2%1%Fat-free
Calories15013011090
Total Fat (g / %)8 / 35 / 22.5 / 1~0 / 0

What’s interesting when you read data in the article’s table is that they all the same fiber, carbs, and protein but 1% and fat-free milks actually have more sugar — although admittedly it isn’t much more: 11g vs. 12g.

Now I don’t drink a lot of milk, although I probably do drink more than the average adult. I’ll go through a half gallon in about a week. Every cup of 2% is saving me only 20 calories over whole milk and a switch down to 1% milk would only save another 20 calories. Is it worth it? I don’t think so.

At this point, I sort of regret getting so used to 2% milk.

An Exercise in Critical Thinking

So what did I learn?

In a way, my friend was right: reduced fat milk isn’t any better for you than whole milk. And if she believed that there were additives, she’s right — although I’m not sure those additives make reduced fat milk any less healthy.

But in a way, she was also wrong: reduced fat milk isn’t really bad for you. It just doesn’t give the health benefits we’ve been led to believe.

As for me, I was wrong. There’s no real reason to switch to reduced fat milk. I have no evidence to show her. I have nothing to stand on for pressing my original point of view.

Will I change the way I buy milk? Probably not — at least for now. I really do like 2% milk. I’m used to it. To me, drinking whole milk is almost like drinking cream. I’m not so picky, however, that I’ll turn down whole milk if that’s the only thing available. I’m not worried about 2% milk hurting my health.

But 1% and fat-free milk have definitely become a little bit less attractive. No real calorie benefit and what’s with the added sugar? And what if milk fat really is good for you? Should I really be minimizing it?

And that’s what critical thinking is all about, folks. Gathering information and forming your own opinions after thinking about what you’ve learned. Even if you begin researching with a preconceived notion, you need to be ready to change your mind when the evidence clearly tells you your notion is wrong. You shouldn’t just look for evidence that supports your view. You should look for evidence that tells the whole story, the true story, or at least the story that properly conducted research and established facts support.

I sure wish more people would learn to think critically in today’s world.

Clive Cussler Doesn’t Know Much about Helicopters

Apparently, even best-selling authors can’t be bothered to do their homework.

Atlantis Found CoverIn my never-ending quest for light reading while I sit around in Wickenburg waiting for my marriage to be terminated, I picked up a copy of Atlantis Found by Clive Cussler from the library. This book features Cussler’s protagonist, Dirk Pitt, a man so outrageously skilled and lucky that he makes James Bond look as inept as Inspector Clouseau.

Hey, I did say I wanted light reading, didn’t I? (And yes, I do realize I was bitching about a supposed Cussler book just the other day.)

But no matter how light reading is, it really bugs me when an author gets something insanely wrong. Take, for example, this passage from the book:

Purchased by Destiny Enterprises from the Messerschmitt-Bolkow Corporation, the Bo 105LS-7 helicopter was designed and built for the Federal German Army primarily for ground support and paramilitary use. The aircraft chasing the Skycar carried a crew of two, and mounted twin engines that gave it a maximum speed of two hundred and eighty miles an hour. For firepower, it relied on a ventral-mounted, swiveling twenty millimeter cannon.

My helicopter pilot brain shouted “How fast?

You see, there’s a little thing called retreating blade stall which normally limits the airspeed of a helicopter. I don’t know of any helicopter capable of going 280 miles per hour. Certainly not one with a single main rotor system.

But hell, I’m not an expert. I’m just a pilot. What do I know?

Bo 105P
German Army BO 105P photo by Joey Quan.

So I looked it up the MBB Bo 105 on Wikipedia. And I scrolled down to the Specifications Section. And I learned the following specs:

  • Never exceed speed: 270 km/h (145 knots, 167 mph)
  • Maximum speed: 242 km/h (131 knots, 150 mph)
  • Cruise speed: 204 km/h (110 knots, 127 mph)

280 miles per hour? How about 150 miles per hour? That’s more reasonable.

And, coincidentally, it’s the never exceed speed for my Robinson R44 Raven II — although, admittedly, I don’t have any ventral-mounted, swiveling twenty millimeter cannons.

Come on, guys! Do your homework! I know it’s fiction, but when you discuss the capabilities of an aircraft that actually exists, how about getting it right?

Transponders for Dummies

Get the facts straight.

One of the podcasts I listen to on my morning walk is called Stuff You Should Know. Produced by the folks responsible for the How Stuff Works website, Stuff You Should Know is a pretty thorough discussion of a specific topic by two hosts, Josh and Chuck, who base their discussion on a website article and some of their own research. It’s a great way to learn new things when you’re stuck doing something mindless — like walking, driving, flying, etc. So far, I’ve learned about revenge, diamonds, Atlantis, social security numbers, air traffic control (ATC), and bullfighting. You can find its RSS feed here.

The April 24, 2012 episode of the podcast was titled “How Air Traffic Control Works.” It was based on a How Stuff Works article of the same name by Dr. Craig Freudenrich. The article was very detailed; the podcast was based on that article and several other articles on How Stuff Works.

As a pilot, I know quite a bit about air traffic control — but not everything. The article (and podcast) was mostly concerned with ATC as it relates to airliners. After all, that’s how most people interact with aviation. But I’m involved with general aviation (as opposed to airline aviation or military aviation). And, as a helicopter pilot, I don’t interact with ATC nearly as much as, say, an instrument rated pilot flying a King Air from Phoenix to Seattle.

So I was hoping that I could learn something new. And I did.

But I also heard the podcasters misinforming listeners about transponders (among a few other things). And if there’s one thing I hate, it’s when an informational article or podcast or video — or anything else — includes errors. So I thought I’d set things straight.

What Is a Transponder?

Garmin Transponder
This is the Garmin 330 Transponder I have in my helicopter.

A transponder is a part of an aircraft’s avionics. It assists air traffic control by making it easier for ATC radar to “see” an aircraft. It basically sends out a signal that says “Here I am!” ATC radar can pick up this signal, along with any additional information encoded within it, to plot the aircraft as a “blip” on the radar display and differentiate it from other aircraft.

Transponders include a feature that enables the pilot to send a specific “squawk” code. Normally, in VFR (visual flight rules) flight, an aircraft’s transponder is set to send the code 1200 — in fact, this code is used so often that many transponder models — including mine — have a VFR button the pilot can press to quickly enter that code.

IFR (instrument flight rules) flights are assigned a discreet discrete squawk code. This code is used by ATC to identify that particular aircraft. Sometimes, when operating within tower-controlled airspace, ATC will assign a discreet discrete code to a VFR flight. Or perhaps a specific code is used by signatories to a letter of agreement between ATC and pilots — for example, 0400 is used by Sharp Alpha signatories in the Phoenix class bravo airspace.

Most transponders are equipped with automatic altitude reporting features, which is known as Mode C. Indeed, Mode C transponders are required within 30 miles of a class Bravo airport — think major airports like the kinds most airlines serve — and in a bunch of other places detailed in Part 4-1-20 of the Aeronautical Information Manual (AIM), “Transponder Operation.” (This, by the way, is an excellent resource for learning more about transponders in general.) Mode C transponders interface with an aircraft’s altimeter to get the altitude of the aircraft and send that information to ATC.

Garmin 420 GPS
My Mode S transponder interfaces with my Garmin 420 GPS to show traffic when information is available. I blogged about this here.

A Mode S transponder, which is what I have on my helicopter, is also capable of two-way communication with ATC radar. In certain radar coverage areas — primarily near Class Bravo and Class Charlie airspaces — a Mode S transponder receives traffic information from ATC. This information can then be plotted on compatible GPS equipment to create a simple traffic information system (TIS).

There are some other things about transponders that are interesting, including the fact that there are special squawk codes a pilot can use in certain emergency situations. And although the transponders were turned off on the 9/11 airliners, that didn’t make them invisible; it just made it impossible for ATC to definitively identify what they were.

What the Stuff You Should Know Guys Said

There’s no transcript available for the podcast, so I had to create one for the part that irked me. It was related to when the transponder is turned on and what the transponder is/does.

At 22:55, Josh has just described how the tower controller hands off the airplane to a departure controller.

Chuck: All right, so now we’re in the air, we are enroute. And you have to, if you’re a pilot, activate your transponder, which will basically make you the little blip on the radar. Very important thing to do.

Josh: Yeah.

Chuck: That’s how they can follow you as you move across the country. Or around the world.

Josh: [laughter]

Chuck: Right?

Josh: You are covering all bases on this episode.

Chuck: Well, the little blip is going to obviously represent your plane and it’s going to have your flight number, your altitude, your airspeed, and your destination.

Josh: Uh-huh.

Chuck: And, uh, so where are we now?

Josh: It’s also how they find you if you go plummeting into the ocean or the earth.

Chuck: Sure. Is that the black box?

Josh: Uh, I think that’s probably a part of the transponder.

Chuck: Okay. Yeah.

Then they continue talking about what TRACON does.

What’s Wrong

There are a few things wrong with this.

First, a pilot usually turns on the aircraft’s transponder when he (or she, of course) powers up the rest of the avionics, including the radio. On my helicopter, in fact, the transponder turns itself on automatically when I turn on the “Master Battery” switch, which provides electrical power to the helicopter before I even start it.

Part 4-1-20 of the Aeronautical Information Manual (AIM), “Transponder Operation,” states:

3. Civil and military transponders should be turned to the “on” or normal altitude reporting position prior to moving on the airport surface to ensure the aircraft is visible to ATC surveillance systems. IN ALL CASES, WHILE IN CONTROLLED AIRSPACE EACH PILOT OPERATING AN AIRCRAFT EQUIPPED WITH AN OPERABLE ATC TRANSPONDER MAINTAINED IN ACCORDANCE WITH 14 CFR SECTION 91.413 MUST OPERATE THE TRANSPONDER, INCLUDING MODE C IF INSTALLED, ON THE APPROPRIATE CODE OR AS ASSIGNED BY ATC. IN CLASS G AIRSPACE, THE TRANSPONDER SHOULD BE OPERATING WHILE AIRBORNE UNLESS OTHERWISE REQUESTED BY ATC.

(The FAA used those caps; I didn’t. I guess they wanted to shout about it.)

So the FAA says to turn on the transponder before you move the aircraft and keep it turned on during flight. The pilot does not wait until the flight is turned over to departure control to turn it on. It’s already on. In fact, it’s one of the ways ground control can track the airliner as it taxis between the runway and the gate.

Note: I was fortunate enough to be able to visit the Phoenix TRACON and tower back March 2012. I got to see the radar screens and their blips firsthand. It’s interesting to note that there are no windows in the TRACON facility. It’s a dark room filled with computer screens. If you’ve seen the movie Pushing Tin, which was mentioned in the podcast, you’ll get the idea.

So although the podcast guys made a big deal over the fact that ground controllers are only one of two kinds of controllers that can use binoculars, the reality is that only ground controllers and tower controllers have windows to look out of. They’re the only ones close enough to the airplanes they guide to actually see them.

To say that activating the transponder “makes you the little blip on the radar” is misleading. Radar does not need a transponder to see aircraft traffic. After all, do you think fighter planes use transponders when they’re out on patrol or attack? If a transponder was required to put an aircraft on radar, there would be no need for stealth technology. Instead, radar works by bouncing radio waves off objects. It doesn’t need a transponder signal. The transponder simply makes it easier for ATC radar equipment to find targets and provides additional information to ATC.

While it’s true that a radar blip might include an airliner’s flight number, this information is not sent by the transponder. The transponder sends the discrete squawk code assigned to the airplane from its flight plan. The ATC computer equipment looks up the code in the flight plan database and provides the information from the flight plan on the blip.

Josh is partially right when he says that the blip is how they find you if you crash. The transponder helps keep the aircraft on radar. Radar tracks where you are. But there comes a point — especially in remote or mountainous terrain — when radar coverage is limited. If you are flying too low, you can literally fly “below the radar” and not be tracked. Helicopter pilots commonly fly this low — that’s why its so difficult to get flight following in certain areas. An airliner should never be that low, but if it’s having trouble, it may disappear off radar before an actual crash. So although a transponder and the resulting radar blip can help locate a downed aircraft, it doesn’t guarantee that it’ll be found. Think about Steve Fossett. His plane likely had a transponder, yet he wasn’t found for well over a year after his crash.

Chuck and Josh are completely wrong when they suggest that the black box is part of the transponder. It’s not. They’re two completely separate devices. The transponder sends live information to ATC as an aircraft moves around on the ground and in the sky. Most aircraft have them. The black box is a virtually indestructible device that records data during an aircraft’s operation and stores it in the event of a mishap. Only aircraft providing certain air transportation services have them. For example, although I have a transponder on my helicopter, I don’t have a black box.

It’s interesting to me that the guys got this so wrong when the How Stuff Works website actually has an article called “How Black Boxes Work.” Maybe they should have read it?

Other Things

In listening again to parts of the podcast — mostly to find the passage quoted above — I heard other things that weren’t quite right. That bugs me. It calls into question the rest of the podcast — the stuff I don’t already know for sure. It also calls into question other podcasts that these guys do. How factual are they?

When I’m listening to a podcast titled “Stuff You Should Know,” I expect it to be factual, not conjectural. If these guys are guessing about something, they should make it clearer that it’s a guess. To state that a pilot activates a transponder after the aircraft is enroute and handed off to departure control is an incorrect statement of fact. To say “I think” a transponder is part of the black box helps identify it as conjecture or a guess, but is there really any place for guesses in a podcast like this?

Or am I expecting too much?