New Cactus

I love raising cacti, so I guess you could call me cactaceous. I've had this cactus pot for over a decade now, and two of the cacti in it are as old as the pot they are potted in. My mom and I had put this pot together 10 years ago and it was time to repot the soil. The gravel on top had all disappeared and the whole thing was way too heavy to move. My mother and I mistakenly put four inches of gravel in the bottom of the pot needlessly making it a real bear to move in off the porch in the autumn for the cold winter ahead.

While I planted our trees out back, Laura repotted the soil and took out all the gravel in the bottom and put new rocks on the surface of the pot and I think it looks really great now. We got two new cacti, the round bulb shaped one on the left and the multi-towered one on the right. A cactus is great because it takes so little care, and reminds me of my home, in Texas. With the new potting, I hope these little guys last a long time. Thanks, Laura!

TobyLaura.com

747 Walk around

My last trip took me through Chicago O'hare. It wasn't my turn, but because I brought my camera along, I volunteered to do the walk around inspection. It was a beautiful morning and it gave me the chance to take a few photos of the majestic bird I get to fly. I had just landed her in Chicago, in from our flight from New York's JFK, while the captain was going to be taking her up to Anchorage. It was a great trip for sure. Click on the photo for a link to a slideshow on our website, of photos I took on that walk around and flight to Anchorage.

TobyLaura.com

Trees; old and new

A few weeks ago, Laura and I bought some Flowering Cleveland Pear trees and yesterday, we were finally able to plant them. Click on the picture to see more photos.

I dug the hole for the first tree and it about killed me. There were roots growing in the ground that had to be cut through with my hatchet and the hard clay ground was like picking through granite with a toothpick. After that first hole I had to take a break before I tried to move the first tree in it's burlap bulb over to the new hole. About 150 feet separated the tree bulb and the hole I dug and try as I might, I couldn't get the bulb into the wheelbarrow. I ended up having to roll it along the ground and that took over an hour to do. The bulb was wet and probably weighed 100 lbs or more and it was all I could to do to move it, let alone get it across the yard.

Well, that was then and today was a new day. I had Laura there to help and she suggested using a dolly. I asked her what a cloned sheep had to do with this project and she said no, a metal one! Our wonderful neighbors had one and we moved both in about five minutes -- yea!

We now have three nice pear trees (we have three, not a pair) and we hope they live a long time. The city was good enough to come in and cut down the two dead trees that were in the same area. They will be by in a few days to grind the stumps down so we will have a nice yard again. This project was somewhat expensive and cost me a lot of sweat and blood, but in the end, I think it was worth it.

TobyLaura.com

New photos

I've uploaded a few new pictures in our Photos page, under 2009. Click the photo above to see what's new. Thanks for stopping by!

TobyLaura.com

The new Star Trek

My family hit the new Star Trek movie this past week and I have to give it two thumbs up. I really enjoyed it.

The great thing about the movie is that you don't need to know anything about previous Star Trek movies to understand it, but there is a lot of fun things to see if you are a Trekkie, too. J.J. Abrams directs it, and I enjoy his style, as we are huge Lost fans, another one of his projects.

I also enjoy Leonard Nimoy and he does makes a cameo appearance in this episode. I was curious to see if Bill Shatner was going to also be in it, but I remembered after the movie that his character dies in Star Trek Generations. The writers stay true to most of the proper story line, but there are a few differences, especially with Spock's mother.

No spoilers here and if you need a break from the summer heat or like Sci-fi at all, this movie is worth it and I hope you enjoy it.

TobyLaura.com

Redo: Texas Trip

The last time I tried to visit my family in Texas, all but a day and a half of it were ruined by a volcano in Alaska, where I was stuck for a week. This past week, the trip worked flawlessly and made it much more enjoyable. My trip for Cathay ended me up in Miami, so I caught a flight from there to DFW, and Laura was at home, so she caught a flight from Columbus, and we met in the middle there in Texas.

My last trip to Texas was cut short a great deal, outlined in all too many details here. I was able to see my family that lives in the Metroplex, including my grandparents, but not much of my parents. This time around, it was my parent's turn, so Laura and I spent our time two hours away in Tyler.

My dad got a new Mac Mini, so it was nice to spend some time with him helping him figure it all out. Mac's are very intuitive, but sometimes, especially having worked in the miserable windows environment for so long, the learning curve for a Mac can be quite steep. Why? Because things are so easy and so well laid out and thought out, that the easy thing to do or the easy way around an issue doesn't present itself. But, once he's hooked on Mac, he'll never go back.

I recently heard some people complaining about having to pay the Mac "tax" -- the money spent on more expensive Mac's for the luxury of using an Apple. There are also some windows commercials depicting how cool Mac's are, but that they are unaffordable. Like Southwest Airlines tries to tell us they are the cheapest (they aren't), windows is doing the same thing. When I bought my Mac, I priced an equivalent Dell, with the same hard drive space, same ram, built in video camera, and so forth, and the Mac was actually $300 dollars cheaper! This is because Apple is small, so they don't produce 50 versions of laptops; they have four or five. They don't sell crappy low end versions like Compaq and HP do. Sure, you can spend $500 dollars on a laptop, but you'll not have the same features as the Mac will, which isn't a fair comparison. But, windows is favored by geeks around the world because they can screw with the programming. Those geeks then become managers of IT departments and spread the windows ilk into mainstream business everywhere. Fine with me. With Apple being below the radar of virus writers, that keeps my Mac running great.

Ken Rockwell has a great article about this (Search his site for "windows is bad") where he makes a convincing argument that companies waste billions each year because they still use windows.

Beyond helping my dad, it was good to see my mom, too. That is, when she wasn't busy falling into the pool. The other morning, my dad and I were at the breakfast table and my mom was in the other room with a fever. We heard her go into the back yard and then a few seconds later, a loud, blood curdling scream. This was then followed by the sound of a huge swoosh and ker-plunck. We ran out to the yard (not because we were concerned, but so that she would see us running and not walking) to see what all the commotion was about. My dad tugged her out and we found out that she had pulled on a garden hose and it stuck on something, recoiling and pulling her off balance and into the pool. They've lived there nearly four years, so I guess it was bound to happen sometime. I didn't have my camera . . .

We also had my grandma, aunt and uncle, cousins, and friends over for burgers. It was nice to catch up on old stories and see everyone. I don't get back to Texas often enough to see everyone all the time, so when I do, it really is great. Next time we're down, it will be my mom's side of the family's turn to see us. We'll be back in a few weeks because we're going on a cruise that leaves out of Galveston, Texas. We're really looking forward to that!

Because my mom and dad both work during the week, Laura and I found some things to do to entertain ourselves. We did some shopping for our cruise, bought my parents some late Christmas presents (really late), visited the Tyler Zoo, and Cherokee Trace animal park, where you drive through and feed the exotic animals from your car. Some pictures from the zoo are here and some pictures of the animal park are here. It was unseasonably cool all week which made both the zoo and animal park much more enjoyable. In the animal park, we got to see a kangaroo, antelope, and even a camel. It was funny because Laura was nervous to have the camel stick his head near her window. As he brought his head down to her closed window, I, from the driver's side, rolled it down and she freaked. I thought it was funny, but I don't think she did . . .

I'll end on this: The better pictures of our trip are found on the previous links, but below are three funnies from our time in the animal park. I was feeding an Emu from the window of our car. The thing about Emu's is that they have these terribly beady eyes and they always look like they are about to strike with their beak. I was never sure if they were going to eat the food pellets off the ground, or pinch a hunk of skin out of my arm. The following pictures are a sequence of three in a row, shot by Laura, from the safety of the other side of the car. Notice that she had the camera, and left me to the evil and scary Emu! Am I a sissy? Look at these photos and you be the judge.







TobyLaura.com

Liters vs. Gallons

A reader asked, "I heard Chinese and Russian air space uses the metric system while most other countries use the imperial system of measurement. Is it alot of trouble converting the different system of measurement? I remember a Air Canada 767 having to make an emergency landing due to running out of fuel from wrong metric conversion. That won't happen with Cathay?" -- Tomcat1



Two great questions that I wanted to answer in my blog, one at a time. The first issue deals with metric flight levels and the second issue deals with metric fuel volume. I'll answer the fuel question below, and the flight level question is addressed in the previous blog entry here.

Fuel is always an important topic of conversation on the flight deck of today's commercial airliners. We always want to have enough of that stuff out in the wings while we're airborne. Fuel can be put onboard an aircraft in several different ways: By weight in pounds or in kilograms, or by Volume, in gallons, liters, or imperial gallons. Many regional airlines in the U.S. don't have to worry much about this, as all fuel in the U.S. is sold by weight in pounds with the less important amount of gallons somewhere on the fuel receipt. Problems can arise at international carriers, where they visit countries that use different units of measurement. An example would be like one of my flights that starts out in the U.S. where gallons are used, and then travels to Hong Kong, where liters are used and kilos are on the receipt. Getting these figures backwards or messed up can lead to serious consequences.

To keep all this straight, we have a fuel order form that we fill out once we've decided how much fuel to put on. Both pilots check the fuel slip before we give it to the fueler. Cathay pilots always order fuel in kilos and the trained, approved aircraft fuelers know this. Once the fueler has put the required fuel on board, he takes the fuel slip we gave him and writes down how many gallons or liters he put on, by taking the reading off his truck.

This is a picture of an excerpt of our fuel slip and shows the math formula we use to double check the fueler's job. If he fuels us in gallons, he writes the amount of gallons in the gallons section. If he fuels us with liters, he places those digits in the liters section. We multiply the amount of liters times the *specific gravity* of the fuel (fuel changes density depending on its temperature, so the fueler, who knows the specific gravity, gives us that number, something like 0.794) to get our uploaded amount in kilograms. If he used gallons, we first take that value and multiply by 3.785 to convert the gallons to liters, and then multiply by the specific gravity. We end up with the kilos we have in our tanks.

Both pilots check the math, and finally, we check the fuel gauge to see if it agrees with what we ordered. If the fuel slip math and the gauges agree, we are good to go. If the fueler put in wrong numbers or put the numbers on the wrong line, we'd catch the error by crosschecking our math numbers versus the numbers we are seeing on our fuel gauge.

In a famous accident in Gimli, Manitoba, Canada, Air Canada crashed a 767 onto a deserted runway because they got their fuel order wrong. They messed up the whole liters and gallons math. Normally, this would be no big deal, as their math error would be caught by crosschecking the fuel gauge. The trouble that day was that their fuel gauges were not working, and they were using a procedure where fuel was uploaded based on a previous known quantity. This is a perfectly acceptable method, but if it is used, the math better be right! You can read more about that accident here, and the amazing way the captain, a glider pilot as well, glided the aircraft to an injury free landing.

Another famous accident involving fuel, or the lack thereof, was an Air Transat Airbus A330. They developed a fuel leak and didn't catch it in time and ended up also doing an amazing job to glide the aircraft down to a landing in the Azores. You can read more about that accident here.

We've learned from other carrier's mistakes, and our procedures at Cathay help mitigate fuel problems caused by leaks because we check the fuel once an hour. The flight management computer, or FMC, gives us two readings on fuel: the amount we are calculated to have based on fuel burn, and the totalized amount from fuel sensors in the tanks. If the calculated value and the totalized value differ by a certain margin, we have procedures that help us figure out what the problem is, and how to solve it.

Ultimately, mistakes can and do happen because we are all human and machinery breaks down occasionally. Usually, mistakes come from carelessness or fatigue when running the numbers. Thankfully, fuel issues rarely occur and Cathay has made it a strong focal point to make sure we check and recheck our numbers when it comes to fuel.

TobyLaura.com

Metric flight levels

A reader asks, "I heard Chinese and Russian air space uses the metric system while most other countries use the imperial system of measurement. Is it alot of trouble converting the different system of measurement? I remember a Air Canada 767 having to make an emergency landing due to running out of fuel from wrong metric conversion. That won't happen with Cathay?" -- Tomcat1



Two great questions that I wanted to answer in my blog, one at a time. The first issue deals with metric flight levels and the second issue deals with metric fuel volume. I'll answer the flight level question below, and the fuel question in the next blog entry here.

Most of the time, you and I hear the captain come over the P.A. and say that we will be cruising along at 37,000 feet. Because he told us a value in feet, it makes sense. This is because ICAO, or International Civil Aviation Organization, the world standard on aviation issues, has deemed that altitudes and flight levels will be measured in feet. There are some nations though, that use metric altitudes and flight levels and don't follow ICAO rules and suggestions. CIS countries (former Soviet countries dissolved in 1991 that have names that end in "stan", like Uzbekistan) and Russia and China assign altitudes in meters instead of feet. The captain on a flight traveling from Moscow to Beijing might say we that we will be traveling at 10,600 meters. Huh? How high is that?

As a side note, there are altitudes and there are flight levels. In North America, below 18,000 feet is called an altitude, and 18,000 feet and above is called a flight level.**

The issue then becomes, when transiting the airspace of a country that uses meters, there has to be a transition from feet to meters for our assigned altitude. This occurs all the time and happened on my last flight from Anchorage to Hong Kong, as we passed through Russian airspace. Before we crossed into Russian airspace, we were flying at 38,000 feet, or flight level 380 (three eight zero). The American controller asked us what our requested flight level was in meters and we told him 11,600 meters. He then passed that on to his Russian counterpart, and when we crossed into Russian airspace, the Russian controller told us to climb and maintain 11,600 meters. This metric altitude is equivalent to 38,100 feet, so we climbed 100 feet.

Often times, this transition is done outside of radar contact, meaning we are not on anyone's radar scope. The onus is on us to make the proper correction so we don't hit an oncoming aircraft going the other direction. To make sure this is done properly, we have a small chart that we always pull out, even though we know what it says, and it tells us the metric values and their equivalents in feet. Another nice little handy dandy thing in the 747 is a meters button on the instrument panel. When it is pressed, our digital altimeters show both feet and meters together, making this procedure a no brainer. However, we use the chart, even though we have a meters button, because we always set our altitude in feet, even in a metric environment. Why? Easy: The autopilot only takes inputs as feet, in 100 foot increments. In some situations, the metric equivalent could be right in between these 100 foot increments, at say 39,450 feet. If that is the case, do you set 39,400 or 39,500? So that every Cathay pilot is on the same page, we set the altitudes given us by the conversion chart, and keep meters selected on our altimeter to double check our altitude in meters. That way, the chart does the rounding for us and it's even less of a no brainer.

The great thing about no brainers? They are hard to mess up, so the procedure is safe and effective. Now, has the other pilot, in his 747, screaming along at 600 knots, coming right toward us in the opposite direction, has he set his altimeter correctly? Ha ha! To protect for that, there's TCAS.

TobyLaura.com

** A flight level is an altitude where altimeters are set to a standard barometric setting, 29.92 inches. In the U.S. and Canada, this is done at 18,000 feet and higher, so that below 18,000 is called an altitude and 18,000 feet and above is called a flight level. Other countries have different transition levels, where the pilots adjust to the standard setting (in Hong Kong, it's 9,000 feet) but the principle is the same. Closer to the ground, we want our altimeters adjusted for local barometric pressure, as this can affect what the altimeter reads. With the local pressure put into the altimeter, the more accurate it is at telling us our height above the ground. Air traffic control lets us know what this baro pressure is. Up away from the ground, to help everyone to be separated by perfectly equal amounts of accurate airspace, we set a standard of 29.92, keeping everyone's altimeter reading the same value, no matter what the local pressure is. Ground contact isn't a factor, and altimeters give us an accurate reading, not above the ground, but a standard plane, at 29.92 inches of mercury. This allows tight vertical spacing of aircraft, because with everyone's altimeter reading the same altitude above the same level plane, aircraft can safely fly more closely together.

Cathay Cargo: The Samaritan

Cathay Cargo made the news again with their help in partnering with Billy Graham's son Franklin and Samaritan's Purse to deliver donations from Charlotte, North Carolina to Chengdu, China. Cathay did the same thing last year with the same organizations to send aid to China after a terrible earthquake.

It's great to see my employer helping out in giving aid to other nations and partnering with Faith-based organizations. Here is the article.

TobyLaura.com

Newest Mac owner

Congratulations goes out to my dad, the newest Mac owner in my family and the most recent to see the light about cruddy windows. He already had a monitor, keyboard, and mouse, so he went with the Mac Mini, the most affordable way to get a Mac. It's just a tiny box that has a lot of USB ports on the back so you can plug in your monitor and accessories, and viola: new Mac.

The new iMac's are sexier, but the Mac mini is no slouch and allows for more versatility. It's going to take him a little while to get used to how easy and comfortably a Mac runs, but a steep learning curve can be fun, too, if he looks at it like an adventure, where new computing tricks lay just around the corner.

He was fed up with all the garbage that windows is: "Program not responding", "Program has performed an illegal operation", "End this program now?", "Your virus software is out of date", "A new software patch is available." And on and on. He was ready for something that just works. He wanted to find a computer that could run windows and Apple software on the same machine. He found it, in the new Mac mini.

Intrigued? Learn how easy it is to switch from windows to a new Mac and why, here. The Apple store is here.

TobyLaura.com

Lowepro Slingshot 200

One of my passions is photography and I've collected a sizable amount of 35mm and digital photo gear from Nikon over the years. I also have a decent Olympus 35mm system from my dad, that includes the OM-2 and OM-4 with several lenses, and an old Canon AE-1 and lenses from my grandpa. I used to do Mamiya medium format, but have since sold that off. I'd like to re-ignite the medium format flame, but that is for another post, and lots of money later.

The trick, when you have more than a point and shoot, or digital SLR with one or two lenses, always becomes: How do you carry it all? The simple answer is: You DON'T. Like Ken Rockwell advises here, if you carry everything, you'll end up using none of it and just get frustrated with a sore shoulder. I have to echo Ken's comments. The more we take, the less focused we become. The hardest lens to use, in my opinion, is a superzoom that does everything, from wide to telephoto. These lenses, like the 18-200 or the 18-135 or the 28-300, let you zoom all over the place, but don't do any one thing extremely well. They also don't allow the photographer to focus on one perspective or one focal length, so all the photos tend to be random and lack much thought. It's much easier, especially for the beginner, to use just one lens with one focal length, like a 50mm or 28mm. After those are mastered, then move on to the superzooms.

The camera bag is the same way -- carry it all, and it is too cumbersome and you end up shooting nothing, or take too little, and you miss a lot of opportunities. Small bags, like the Lowepro 140, is a small bag for our D40 and one we use for vacation shots, but doesn't allow me to carry the lenses that I want to carry. My goal was to find a bag that could hold three, maybe four lenses, and my camera, the Nikon D700. I own too much to carry it all and decided I'd pick four lenses to carry all the time: 17-35mm, 50mm, 80-200mm, and a small fisheye for fun.

Backpacks are stupid because they have to be set down on the ground to get into them, and are targets for thieves. I don't want to be on vacation with a huge bag on my back that screams, "Nerd." I also didn't want a shoulder bag because they can cause too much discomfort after carrying it a while, and can slip off when I bend over or twist. Small bags won't hold enough. Fanny packs, like the ThinkTank system are great for pros, but again, scream nerd if you are just walking around on vacation or on a photo shoot. I was in a quandary as to what to do.

My wife finally pointed out the Lowepro Slingshot 200. It's a hybrid bag that can fit all I want into it and more. It's like a backpack, but can swing around to your chest to get into it (so it doesn't have to be placed on the ground). It's like a shoulder bag, but has a much better strap to disperse the weight. It's also a lot more roomy than a fanny pack. I've loaded it up and it feels really great over my shoulder and back, and I don't look like a nerd (at least according to me!). Here's a quick product video of it and shows how it can be slung around to your chest to access the bag:




If you are looking for a great bag that will carry a decent amount of equipment, isn't too big, isn't a backpack, is easy to get into and out of, and doesn't cost an arm and a leg, check out the Slingshot 200. I got mine from Adorama and got free shipping. I highly recommend Adorama. I ordered the free 7-10 day shipping on Saturday, and it came the following Wednesday via UPS. They don't charge sales tax and have the best selection of all kinds of gear, as good as anyone in the U.S. I won't say here how much I've spent over the years at Adorama, but it's many thousands and I've never had a bad deal from them yet.

Let me know what kind of camera bag you use. You can also read more about the Slingshot here.

TobyLaura.com

Mulching

Laura and I got lots of mulching accomplished this week. I got into one of those rhythms where I feel real productive and wanted to get something done. I think it was because I only got 2 hours of sleep the night before, coming home from work, and got giddy. Either way, it was good to get the mulching finished. Laura was a great big help because she was the spreader of the mulch to make it look nice, and I was the brute force to move it where it needed to go.

We have a lot of mulch on our property as it goes around several trees and all around the perimeter of the house. Three yards of mulch set us back $38 a yard at Kurtz Brothers. We buy it in bulk there and they have great prices and are only a few miles away. We borrow a pickup and make a few runs to get it once a year. If you live in Columbus, Ohio like we do, I highly recommend Kurtz Brothers. They have three locations, good prices, and are helpful and friendly.

I ordered one yard and then came back and got two more in one trip. Two yards of mulch in a one ton pickup takes up the entire bed! The guy used a huge front-end loader to fill the bed and then asked if I wanted a little bit more. I told him that I'd take whatever he'd give me, and boy, he dumped it in. I probably got more than two yards on that load, and that's another reason I like buying mulch at Kurtz.

The mulch looks great and I love how mulch can transform an old, destroyed yard from winter, and turn it into a warm pleasant place to look upon. It's just window dressing, but it sure makes the place look a lot sharper.

The following day, we bought three Flowering Pear trees to replace some dying trees in our yard. They were a great deal from a nursery going out of business just down the road. We are hoping the city will take down the dying trees for free, as they are close to the road, and save us the trouble. Once the old and dying trees are gone, these Pears will line the back of our property that butts up to another road. The Flowering Pear trees' bulbs are huge and it is all Laura and I can do to move them. I rolled them into my wheelbarrow to move them and the bowl of the wheelbarrow bent and got disfigured a little. I'm really looking forward to moving them again into the holes I dig for them. I'm sure it will all be worth it once we get them planted.

TobyLaura.com

Emergencies high over the Pacific

Have you ever wondered what would happen if you were a passenger on a long flight over the Pacific and something terrible happened? I know I have, and like most of us, we probably envision treading water for a long time, or sitting in a life raft because the water is too cold for survival. (In the North Pacific in the winter, the water is survivable for about four minutes without protection or a lifeboat.) Fortunately for today's passengers and crew, this possibility is quite remote, thanks to many modern conveniences like excellent communication equipment, well designed and highly reliable aircraft engines, and safety procedures that are well thought out.

I can think of three major emergencies that we as pilots can plan and prepare for, that if the safety procedures are followed, are completely survivable, even when there are thousands of miles of ocean below the airplane.

These are: Fire, Engine Failure, and Cabin Depressurization.

There are many other things that could go wrong, but they are not as severe as these three biggies. Bigger than these, like the wings falling off, either usually don't happen or aren't survivable anyway, so why plan for or worry about them?

An onboard fire is probably the worst of the big three because it can quickly escalate from harmless to deadly in just a few minutes. Recall all those warnings about tampering with the smoke detectors that you hear prior to departure? Yeah, those are deadly serious -- no pun intended. The cargo compartments will seal themselves shut in the event of a cargo compartment fire to starve it of oxygen and fire suppression systems like Halon extinguishers take care of the rest of the fire. The cabin is a bigger problem because unless the fire is in a galley or lavatory trash can, it requires people like flight attendants to fight it. There have been several major fire disasters because the cabin caught on fire, like this Air Canada DC-9 and this South African 747 Combi (A combi 747 is one where the back half of the plane is cargo, and the front half is set up to carry passengers.) I'm sure that the lack of passenger smoking on planes has saved many lives.

But what about the cargo planes, like the one I fly? The cargo section of the main deck of the 747 is cavernous and there is no way to have enough Halon to put out a fire on that type of scale. But surely we have a way to fight it while it's three a.m. over the Pacific or Himalayas, right? The answer is yes, and it's actually a better system than in the passenger versions of the 747. Because we don't have to worry about keeping 400 people alive down below us, we depressurize the entire airplane while wearing oxygen masks, to starve the fire of oxygen. When we get a fire warning, we put on our oxygen masks and raise the cabin altitude to 25,000 feet, where there isn't enough air to burn an open flame. Once the fire is out, we lower the cabin back down to five or six thousand feet and take off our masks. It's a simple system that should prove to be very effective, however, I hope I never need to test it.

Along those same lines, another major problem that we can deal with effectively is cabin depressurization. If our plane can't maintain pressurization, then we can't maintain consciousness and everyone goes to their final sleep. Contrary to what some believe, aircraft don't carry large tanks of oxygen to allow people to breathe, they simply pack air into the cabin to provide pressure similar to sea-level pressure. See, the ratio of oxygen in the air, 21% is the same at sea-level as it is at 40,000 feet, there just isn't enough pressure in the atmosphere to breathe it in at high altitudes. Aircraft don't have to constantly supply oxygen, it is already there at 21%, they just have to make the pressure available for us to be able to breathe. They do that by taking high pressure air off the engines and sending it into the cabin. The cabin's "altitude" is controlled by how much of that pressurized air we let out, with a special valve called an outflow valve. As the valve opens, the pressure in the cabin lowers, and as the valve closes, the pressure gets greater inside the cabin. At high altitudes, we need lots of pressure to maintain breathable air, so at cruise, the valve is mostly closed.

When that system fails, or a hole gets blown into the side of the cabin, we lose all our pressure. The masks drop and provide air for a little while, but only for a few minutes at high altitude. We have to descend down to more breathable air, but doing that increases our fuel burn dramatically. On our Cathay 747's, we first descend to 14,000 feet, until all the oxygen in the masks are depleted, and then we descend to 10,000 feet, where everyone can breath normally. Our fuel burn will be around 50% more down at 10,000 feet, so if we are out over the Pacific, our destination is off the table. We will have to go to an en-route alternate, decided upon by using our point of no return, or PNR, described in the last blog here. Again, we always have to have enough fuel when we depart, to have a depressurization at any point along our route, and still be able to reach a suitable alternate.

And finally, there is the little matter of engine failure. Do any nervous flyers ever worry about that? I didn't think so :o) No, it seems everyone's fear is engine failure, especially when traveling over such huge expanses of water. The good thing about the 747 is that it comes with four engines, so there is little chance of major trouble. But even superb aircraft like the 777 that only has two engines doesn't cause much concern for alarm as engine failure is so remote. These engines are not like a car's engine. They are millions of dollars worth of precision, and because they rotate, there are very few parts that wear like engine parts wear, and their maintenance is much improved over the maintenance you and I give our cars, for sure!

However, with that said, failures do occur, and when they do, pilots need to be ready for them. Much like the last blog entry described about PNR's here, we have a three engine PNR, where if one fails prior to a certain point, we know we'll need to return to a certain airfield, and if it fails beyond that point of no return, we will be able to continue to another airfield. This is because we now may not have the fuel to continue to our destination.

Why? Because we actually burn more fuel with three engines than with four. It sounds counter intuitive, but think of it like this: When we go from four to three engines operating, we now have less thrust. Less thrust means we can't maintain the same altitude, and have to descend a few thousand feet. This is because the higher we fly, the more thrust it takes to keep all that weight up in the sky and when we lose some of that thrust, we start to slow down. If we lost an engine and didn't descend, we would slow down beyond the speed at which our wing would be able to maintain lift, and we would stall -- where the wing can't produce enough lift for the weight it is having to carry. The trouble is, when we do descend, we burn more fuel and that is why losing an engine will actually cause fuel troubles. Also, I believe the synergy affect applies here, too. The thrust from four engines is better and more efficient than the increased thrust of three, making up for the lost engine, if the aircraft maintains the same weight and altitude.

So, I write this to give you a little bit of insight into what we plan for in the 747 as we get ready to cross large expanses of inhospitable terrain, either mountains or oceans. When crossing the United States, there are so many airports to duck into if trouble pops up that there isn't much planning to do. But when there are vast distances between places of refuge, proper planning is essential. Never fear, as even with the three biggest troubles that can occur, there is always enough fuel to get to a suitable landing field, because if there wasn't, we wouldn't be taking off in the first place. Cathay doesn't pay me enough to take that type of risk!

TobyLaura.com

Point of no return

Now this blog entry could be about the interest rate on your bank account, buying things at Cord Camera, or even a scary movie. The point of no return conjures up thoughts of entering an old, spooky house, with cob webs, knight's armor, and paintings on the walls where the eyes follow you as you slink down the long hallway, and pipe organ music playing demonic chords. That could all be true, but I want to talk about what the point of no return has to do with crossing large bodies of water, like the Pacific, while flying (enter more creepy pipe organ music).

Even though the term point of no return sounds ominous, and nervous flyers might think it would be one more reason not to fly, it really has everything to do with safety. On a typical flight from Hong Kong to L.A. as we fly across the Pacific, we depart the Japanese coast and head out for the West coast of the U.S. Because there is only water beneath us, or because there are limited airports available to us along the Alaskan Aleutian Islands, we come to a place in the sky where we no longer can return to the airports in Japan based on the amount of fuel we have remaining.

On our flight plan, we have lat/long coordinates that tell us when we've passed the point of no return, based on two airports, say Narita in Tokyo, and Vancouver. This point is often not equidistant between the two cities because of how the winds will affect a turn-around. However, we have this point of no return, or PNR, calculated for us so that in an emergency, we don't turn back toward an airport we can't get to based on fuel remaining. Prior to reaching the PNR, we tell ourselves that if we lose an engine, we will return to Tokyo, and once we've passed the PNR, we will continue to Vancouver. We always have enough fuel to get to one of these en-route alternate airports, or ERA's. We can't depart on our trip unless we have the fuel at any point along our route to get to a safe landing airport, and the PNR helps us to make a better decision on where to divert in an emergency.

The PNR is also helpful because the two airport choices may not be as friendly as Tokyo and Vancouver. They may be Cold Bay (shown on the left) and Shemya, both in the Aleutian Islands. Neither are wonderful places to visit, especially in the winter time, but I'd rather divert to Cold Bay because Shemya is a postage stamp in the middle of the North Pacific. The PNR is important because even though we may want to go to Cold Bay, if we've passed the PNR, it's hello balmy Shemya for us.

TobyLaura.com