Aerospace Blog

Deployment aboard an aircraft carrier usually lasts for six months - as long as nothing extreme happens and you don't get extended, which can happen from time to time. For the first three months, you act like a robot, just doing your job and not thinking about home too much because you know there's still a long way to go. Then, when that three-month mark hit and you're on the second half of your deployment, something clicks in your head and the countdown begins. It isn't so bad until the fourth month and you're just two months from the end.

People would always have a countdown on their computers. A lot of people would start talking about the first thing they were going to do when they got back, or their plans for when they went on leave. This is also the most dangerous time on deployment. Because people are thinking about their homes and families, their heads are somewhere else than where they need to be – concentrating on their jobs.

This applies especially to people working on the flight deck. That's easily the most dangerous part of the ship to work on. The last month is the worst because you just want the deployment to be over with. You start getting anxious about being home and what's happened during the last six months. For most part, you have no idea what's happened in society since you've been away. You've missed out on what movies have come out, new music, and family stuff that wasn't the most urgent in letters from home

These are just some examples. The sailors who have it the worst are the ones with a new baby at home that they've haven't seen yet. All you hear them talk about is how they can't wait to see their kid and spend time with him or her.

Finally, the day comes when the deployment is over and you're pulling in to the pier. You have to be in your dress white or dress blue uniforms and man the rails. This is a ceremonial thing - to put on a display and look our best, I suppose When you pull in, you can see a huge gathering with everybody's family, from mothers and fathers to wives and sweethearts waiting for their loved ones on the pier. They have all kinds of signs up saying "Welcome Home" and things like that. It's a great feeling to be home finally, and to know that you made it back alive and in one piece from a deployment where, usually, someone else didn't.

Editor's Note: Click here for Part 1 of this multi-part series.

While you were in port and not on duty, you made sure to get off that ship as soon as possible. After being onboard an aircraft carrier for anywhere from two weeks up to two months, you were just itching to get off. A lot of people would take tours of the surrounding area; the ship had a good system for setting up different kinds of tours. You would sign up for them before the ship even pulled into port. They were so popular that they filled up fast and usually sold out.

Sailors who didn't take a tour would still just get off the ship and explore the area. They'd go shopping for all kinds of souvenirs, either for themselves or their families. I always tried to make sure I did both. Family members always appreciated that kind of stuff - well, at least mine did. I also enjoyed the local cuisine. Some of the best food I've ever eaten was in these coffee shops and really nice, family-owned restaurants.

The owners loved us because we'd go in groups as large as 15 people and take over the restaurant. We'd celebrate, enjoy life, and blow off steam and a lot of money. We'd do some drinking, of course, and smoke Cuban cigars. If your squadron or ship division allowed it, you were allowed an overnight liberty pass - which means you didn't have to go back to the ship by 9 or 11 at night. You would get a hotel room and could stay out all night, if you wished, as I did when we were in Venice, Italy.

Unfortunately, the party in port never lasts. Soon enough, it's time for the ship to pull back out to sea. Usually, the first day back to regular operations is slow and boring because you really just want to be back in port. But that goes away after a day. You could definitely call it a Monday.

The food on an aircraft carrier was a real experience. For the most part, it was like playing craps in Las Vegas. You never knew what you're going to get. For special meals, they would broadcast what they're serving. When they did that, however, the lines would be extremely long. Sometimes, you'd wait an hour in line for food.

There were four serving lines in all. Usually, two lines on one side of the ship would be serving something different than the other two lines, so you did get a variety. There were some certainties about the food for sure. You knew they'd be serving chicken and serving rice, and that every third piece of rice was rock-hard. We'd always joke around and say that the chicken was sea gull. The food was all right, though. It wasn't like home cooking, of course, but it was ok. It could have been a lot worse.

Editor's Note: Click here for Part 1 of this multi-part series. Parts 4 will run tomorrow on 8/5/08, right here on CR4.

When you're out to sea aboard an aircraft carrier, you get to see some amazing things, especially weather-wise. Once, we sailed right under a rainbow. It was misty and cool, but there wasn't a pot of gold at the end! Personally, I enjoyed the sunsets at sea the most. The colors of the clouds and skies were truly spectacular. I can still say that the sunsets on land don't come close to the ones at sea.

I remember being down in Australia during the winter when the storms were extremely intense. The whole aircraft carrier rocked left and right like it was a toy. Waves crashed ten feet over the bow. These waves were huge! Still, the best sleep I've ever had was when the ship was rocking like that. There's nothing like sleeping to the rocking of the sea. Of course, not everybody would agree with me on that - especially the sailors who got seasick.

Watching a lightning storm at night was another great sight. The water lit-up when the lighting stuck the ocean. Sometimes, the lightning would travel along the surface of the ocean as if it was surfing. Some other things you saw at sea were the marine life, especially whales and dolphins. I remember looking down from the flight deck and seeing a whole school of hammerhead sharks. It was times like that when you hoped the ship wouldn't sink! It was a privilege to see these animals - and not in a zoo or aquarium.

Port visits were a break and a relief that everybody looked forward to. Kind of like an oasis in a desert. You finally got a day off and could truly relax and blow off steam. Like I said before, you don't get a day off while you're at sea. Usually, a ship is in-port for three days on average - four if you're lucky. Still, you'll usually have duty for one of those days. There were usually three duty sections for a squadron.

Duty is when you have to stay on the ship and do a watch, guard duty, or serve as military police (we called it shore patrol). It's usually an easy day, especially if you don't have a watch because all you might do is just hang around in your shop and clean up real quickly. Or, you basically do nothing and watch movies, read a book, or whatever you want as long as you stay on the ship. A lot of people would catch up on sleep. You also had to muster (usually every eight hours) just so the watch commander could take a head count and make sure you're still on the ship.

You did not want to miss that or be late to a watch . . . because then you're in trouble. If you did, usually as a punishment they'd make you strip and wax your workshop floor, or they'd give you somebody else's watch. And port was something you didn't want to misss.

Editor's Note: Click here for Part 1 of this multi-part series. Parts 3 and 4 will run next week, right here on CR4.

After watching part of a recent PBS series called "Carrier", I thought it might be a good time to blog about my own experiences in naval aviation. While serving in the U.S. Navy, I spent more than a year and a half of my life aboard aircraft carriers. And while I have to admit that the PBS series was good with the facts, it left out some things about the everyday life of sailors.

For starters, everyday that you're out to sea is like a Monday. No days off. You're 12 hours on working and 12 hours off - either sleeping, working out, relaxing, reading, or whatever else you enjoy before going back to the grind. When you're working, the schedule varies. Because I worked on aircraft - F-18s to be exact - there's not a lot to do if nothing is wrong. Don't misunderstand me, though. There's always work to be done. Military aircraft require frequent inspections, and you're always making sure that your shop is clean or that your personal qualifications are up-to-date.

Just like the wind, things change quickly aboard an aircraft carrier A lot of times, after a full day of flying missions, the jets come back with problems. That's when the pressure goes up (a lot) to have them fixed. Things also depend on the shift you're working and the ship's flying schedule. For the most part, flight ops were during the day, which meant that the night check did most of the maintenance. The day check was usually responsible for making sure the jets were working – and that the squadron had enough functioning planes for the day's missions.

Aboard ship, we always said "it's Ground Hog Day!" That was true for the most part since everything was repetitious. When you were off work, you tried to do different things to keep you going. For example, while in your berthing (where your squadron slept and living space), you would kick back with the fellas (women had their own separate areas) and just play cards. Spades was always a favorite. Usually, people formed tight-knit groups and would hang out, just socialize, or go to the gym together.

It was nice to unwind, but there was never enough free time. Usually, when your shift was over, you just wanted to shower and go to bed since you were so tired. So in reality, you might be lucky to have three or so hours to yourself. The rest of the time, you were sleeping, showering, or eating. But there were also times you get to see some amazing things aboard an aircraft carrier.

Editor's Note: Click here for Part 2 of this multi-part series.

The aeroelastic analysis of laminated composite wings is vital to the prevention of failures induced by oscillatory motion. The aeroelastic instabilities will change, however, when a crack has initiated in a wing structure and must be accounted for by adjustment to the structural and dynamic model.

An aeroelastic normal mode analysis greatly depends on the free vibration modes of the wing. To achieve accurate results, a new Dynamic Finite Cracked Element (DFCE) (refer to Chapter 2) is implemented. From the previous chapters, both the DFE and DFCE both show excellent accuracy for preliminary coarse meshes.

Composite wings consist of two types of bending-torsion couplings: geometric and material. Geometric coupling originates from an offset of the centre of gravity (CG) axis from the elastic axis (EA), where material coupling arises from material anisotropy. Geometric or material couplings can cause flutter instabilities in a wing. Wings modeled as beam assemblies can produce various couplings.

Since the incentive of this chapter is to study the aeroelastic flutter and divergence of a defective wing, only bending-torsion couplings are considered. To achieve purely bending-torsion behavior in a composite beam or wing structure, specific laminate stacking sequence must be considered (i.e. symmetric or unidirectional unbalanced laminates). The beams used in this chapter, to approximate a wing, are assumed to be based on classical laminate theory with solid rectangular cross-section and unidirectional plies.

In Figure 5 (refer to http://www.aeroway.ca/CR1.html), much like the divergence speed plot, the flutter speeds tend to be sensitive to ply angle and crack ratio. When the crack ratio is gradually increased from no crack up a/b =0.6 a drop in flutter speed is observed for most ply angles, except for the unidirectional plies set in the region of 96 degrees to 146 degrees. In this region, a flip flop in this trend is seen, where the flutter speed increases with a larger crack.

The influence of a static crack on a laminated composite wing is significant in both the free vibration modes as shown previously in (http://www.aeroway.ca/CR1.html) and on the flutter and divergence speeds observed in this blog. A reduction in the divergence speeds occurs when the crack size is increased for most unidirectional ply angles considered. Whereas, the flutter speeds are observed to increase in specific ranges of ply angles.

The V-g method has proven to be an excellent method for the extraction of the flutter speeds and readily extended to more complex formulations particularly ones that include unsteady flow.

AerospaceSteve