titanium bits

[yeehawfactor]

why is there not an effort to recycle used titanium bits? for as expensive as raw ti is, you would think that someone would be doing this, especially for cassettes.

[CNote]

Hmmm, I thought raw ti was pretty inexpensive. It is a very abundant material. I guess you are referring to the cost in extracting, processing, and machining it. My guess is that the latter two would be just as costly in recycling.

[Louis]

This whole Ti thing is kind of interesting. As cyclists we happily pay huge premiums for Ti parts.

Today at work (the local warplane factory) a guy who probably knows more about the aircraft design than just about anyone else out there (Daniel Raymer) told us that some aerospace manufacturers are eliminating the markup over aluminum they used to use when doing initial costing for Ti structure. It’s getting to the point that other than some additional manufacturing challenges, there isn’t that much cost difference in the long run. Of course, for airplanes the weight savings might have a bigger payoff than they would in cycling (lighter structure allows you to cram a few more passengers in the plane), but maybe not, considering how much money some gram-shavers are willing to pay.

Louis

[saab2000]

Louis,

Which airplane factory? I have a passing interest in airplanes and some fools have even decided that it is OK to let me fly theirs! And get paid for it!!! Outrageous!

Anyway, the future of commercial airplanes will involve a lot of composites. They are already coming. The Premier 1 is a composite airplane.

Airbus and Boeing also are using more and more composites. The main issue I see with its use is the ability to repair skin damage from a collision with ground equipment. Also, the odd problem catastrophic failure under pressure at 41000 feet is another issue.

Obligatory cycling content - We use a lot of composites in bikes and a lot of Ti!

[rwl]

Saab,

the sailplane folks are certainly leading the pack on composites. friends fly out here in CA/NV with a 'couple of hundred pound' experimental. I think the solo version dives at something like 400kmh (the 'daily flyer' is a ASH25) Personally, I won't fly with them in a Cessna!

[saab2000]

Sailplanes may be leading the pack in General Aviation, but that is a whole 'nuther world to what happens where people pay to ride on planes.

Certified transport aircraft have to prove that they will be safe for up to 30+ years of service and tens of thousands of cycles of pressurisation and de-pressurisation.

I have seen photos of sailplanes with impossibly long wings with an insane aspect ratio. They really flex. Of course, they are designed to.

Anyway, sailplanes and light single-engine planes are in a different universe than commercial airliners.......

[Louis]

Louis, Which airplane factory? I have a passing interest in airplanes and some fools have even decided that it is OK to let me fly theirs!

I'm a Structural Dynamics engineer at Boeing, here in St Louis (where we make the military stuff, F-15, F-18, etc.). If you want to fly one of ours you'll have to talk to the USAF or the Navy...

Louis

[saab2000]

I would enjoy very much flying one of yours. The airplanes are awesome! Unfortunately, I have a bit of difficulty with their mission.......

By the way, for anyone else who cares, I just fly 'em. People like Louis know a LOT more than I do about how they are built. It is pretty neat stuff what he does.

:beer:

[RichMc]

Nuts. When I was young enough to fly that stuff I had no problem with the mission. I had an appointment lined up to the Air Force Academy but they said my eyes were too bad to fly. Nuts. Now I've had lasik done and I'd qualify but I'm too old. Nuts. Guess I'll just ride my bike. No matter how thrilling flying hand gliders was it just can't compare with the ride of a F-15. Time and place is everything.

[dave thompson]

Rich: You could rent one of these, here: http://fighterjets.drakeandcavendish.com/MiG-25_Russia.php and here: http://www.flymig.com/

What a hoot! Lotsa titanium bits.

[BdaGhisallo]

http://www.mg.co.za/articlePage.aspx?articleid=199466&area=/breaking_news/breaking_news__international_news/

Hey Saab,

What do you make of this airbus losing its tail over the carribean? Your mention of increasing carbon fibre use in planes brought this to mind.

[saab2000]

I am remotely aware of this incident. Until a full investigation can be completed it is a bit imprudent to comment on this one. American Airlines lost a rudder in October of 2001 and this resulted in a crash. The pilot, not design or material, has been blamed officially. That airplane was also an Airbus. If it turns out that these incidents are related, Airbus could have a serious problem on their hands, at least with regards to the certification of the two aircraft types in question. Without really studying the facts it is hard to make a reasonable judgement on the merits or liabilities of composite structures.

I am not anti-Airbus. They are fine airplanes. Occasionally problems can crop up which engineers never anticipated when the aircraft were designed.

How's that for a non-answer!

By the way, I used the word "composite". This is not the same as carbon fiber, or at least not the same as we use it in bikes.

To be honest, I have to defer to the engineers here who know a lot more than I do.

My specialty is in flying airplanes. I know a bit about them and how they function (duh.....), but I am not an engineer. They know a LOT more than I do about material limitations and fatigue.

Louis?

[PanTerra]

I'm a Structural Dynamics engineer at Boeing, here in St Louis (where we make the military stuff, F-15, F-18, etc.). If you want to fly one of ours you'll have to talk to the USAF or the Navy...

Louis

I want to commend you Louis for working in that noble field, keeping our boys safe and in the air. Thanks. :hello:

[Tom]

So, one day I'm riding past a little local strip where there's a bunch of ultralights, a skydiving outfit and a few Cessna 152s when there comes up this ungodly noise from behind the trees. There was clearly some enormous vintage internal combustion engine revving up and then down the strip came an old green single engine beast with a greenhouse cockpit about ten feet behind the prop. Clearly everything in front of the cockpit was motor, and I don't know how big the propeller was but it was very, very large in proportion to the plane. This thing shot off the ground and howled away.

I asked my ultralight flying co-worker about it and he said that it's an old Russian trainer, it was used to train jet pilots. I guess it was about the hottest thing with a propeller and it would be cheaper for them to crack that up if they couldn't handle the performance. Very cool. He doesn't know how the guy that has it came into it. If I were a pilot I'd sure like to take that thing out and see what it could do.

[zap]

Saab, it was later found that Airbus was also at fault for that crash in NY in '01. Airbus knew of potential problems with the carbon layup at and around the attachment points for the vertical stabalizer and did not advise its customers in a conspicuous manner prior to this incident.

Don't know if proper inspection of this area would have uncovered any cracks on this particular plane, but when dealing with unexpected forces, a solid composite structure is good to have.

Are the wings for Airbus' new jumbo plane the largest composite structure ever made?

[saab2000]

From what I understand (and this is limited by the fact that I have not read the whole report) the pilot, upon entering some wake turbulence from a preceding aircraft, manipulated the rudder pedal to such a degree that the load limitations of the rudder were exceeded.

Thus it is the pilots fault. HOWEVER......., many airplanes have this issue and if I were to step on the rudder in my current airplane with full force at a speed of, say, 250 knots I would probaly rip the rudder off and we would all....... well, lets not go there. Let's just say that it would be a CNN "Live Event".....

While the report says the pilot is to blame, it is not to be said that Airbus is without fault. I simply do not know enough about the accident to make a conclusion. Also, the report says one thing. Accident reports are made from data which is pieced together from the Flight Data Recorder, the voice recorder and the wreckage. Nobody survived this accident so there is nobody to tell their side of the story directly.

I blame nobody. We need to use accidents as tools and learn from them. Hopefully someone can improve something to avoid this happening in the future. Knocking very hard on wood here, there are fewer accidents today because of what we have learned from accidents in the past.

My last airplane had a rudder-limiting device which was speed sensitive. Full deflection was not possible at high speed. Why this is not the case on all aircraft is a mystery to me.

As to the wings of the A-380, well,I think they are still aluminum. Not sure though. Wings must be quite flexible on a plane like this.

Again, I must say "ask the engineers". They know much more than I do about this sort of thing.

Not trying to kill a good aviation argument, but I am not going to comment on this here anymore. If anyone is curious they can PM me. But this is a cycling forum after all....... :D

[BdaGhisallo]

Hey Saab,

Is there much that really frightens you when you are in the air? Does wicked turbulence ever spook the pilots? Sure you are in control of the plane and you log many more hours in the air than any passenger ever would, but have you ever had it so bad that you started to sweat a little?

And what about flexing wings on passenger jets? I always get a little unnerved when I can see the wings flexing a touch. How much should one reasonably worry? You always hear about alu bike frames not flexing when really fatigued but just snapping - or at least in the early days of them. Has anyone's wing ever cracked significantly at its juncture with the fuselage?

I know flight is extremely safe, but the consequences of that one unlikely failure are pretty catastrophic compared to others forms of mass transit.

Cheers.

[saab2000]

Pilots have respect for the elements. I have only seen turbulence one time that I would call frightening. And it was over as soon as it started. Lasted about 30 seconds.

In my opinion the greatest single danger to a passenger airplane (other than the pilot - no joke) would be thunderstorms. I mention pilots because the root cause of most accidents can be traced to pilot error.

Think of turbulence as nothing other than wavy air. If you are on a boat, it is not absolutely still, is it? Well, neither is an airplane. Not the same thing, but not all that different.

Flexi wings? Has anyone ever seen one come off? Didn't think so. The flex needs to be there. If they were absolutely rigid then they would break off. The fueselage is pretty rigid, but not the wings.

Things which scare pilots:
1. Collision warnings with no visual contact. A collision is almost always fatal.
2. Getting into a corner with regards to being surrounded by thunderstorm cells.
3. Periodic simulator checks!!! :D
4. Hydraulic problems
5. Electrical problems
6. Fire and smoke

Things which are fairly routine - or at least scarier to passengers.
1. Turbulence
2. Coming in over water. Getting lower and lower over water seems to freak people out. Getting lower and lower over buildings does not. The buildings will scratch the airplane worse than the water.

[BdaGhisallo]

Saab,

I must say that your last sentence tickled me. I never thought of a plane getting "scratched" as you imply! Gave me a great chuckle.

Living in Bermuda, I have always enjoyed the landing approaches over water, especially when you can see the faces of the guys on their fishing boats below!

Cheers. Thanks for the reassurance. It's always nice to have.

Geoff

[saab2000]

Next time you get nervous, just remember that the pilots have families too. We want to get home safely just as much as you do!

We refer to damaging an airplane as "scratching" or "bending" them. I have never done either. Don't intend to either. Worse than a scratch is "balling one up". This is the bad kind, resulting in the proverbial "CNN Live Event"........

Just remember, I want to get home too. So do all the other pilots.We all have families too. That is a pretty good motivator to do it safely.

[D-Squared]

Louis,
Why do you call them War Planes and not Peace Planes since they are built to preserve the peace.
D2

[PanTerra]

Louis,
Why do you call them War Planes and not Peace Planes since they are built to preserve the peace.
D2

That might get confusing to some people. However, with the term "War" plane factory, I think we all knew immediately what he was talking about. Someone might think a Peace plane is something akin to the PEACE-Mobiles of the 60's, a VW bus painted up with big psychedelic flowers. As an Air Force pilot, what do you call them, or what is the convention at SAC there in
Omaha?

I have heard of warplanes, warships. You just never hear peace planes or peace ships. Sounds more like PC terminology. I do remember the PCs wanting to use "peace" officer as opposed to "law enforcement" officer. Peace just sounded "kinder and gentler." Just gets me all warm and fuzzy. Here is a "Peace-plane":

[Louis]

D*D - see you PM inbox for a response.

Louis

[Dekonick]

If you think landing in an airplane is frightening - try landing in a helicopter with a Vietnam era pilot, at night, in the wind, on top of a 10 story building...

Its perfectly safe with a good pilot but boy does it make you think about your will and life insurance...

[PanTerra]

If you think landing in an airplane is frightening - try landing in a helicopter with a Vietnam era pilot, at night, in the wind, on top of a 10 story building...

Its perfectly safe with a good pilot but boy does it make you think about your will and life insurance...

I recently bought the DVD of "Final Countdown." One of the 'special features' on the DVD is the interview segment on the pilots that flew in the movie. That alone was worth the purchase price.

[Kahuna]

I have heard of warplanes, warships. You just never hear peace planes or peace ships. Sounds more like PC terminology. I do remember the PCs wanting to use "peace" officer as opposed to "law enforcement" officer. Peace just sounded "kinder and gentler." Just gets me all warm and fuzzy. Here is a "Peace-plane":

Hah! That's not a peace-plane.

THIS is a peace-plane...

http://airlinesgate.free.fr/photos/continental/n77014b.htm
http://airlinesgate.free.fr/articles/nyc2000.htm

[PanTerra]

Now that's a peace plane.

[coylifut]

from Honolulu to Portland Oregon that got temporarily lost in the mountains North of Vancouver WA. The captain and first officer ultimately got in an argument over who had control of the airplane. The captain instructed the flight engineer to to disable the cockpit voice recorder.

After a long battle, the Captain was fired.

[Louis]

An old pic from the Boeing web site:

"F-15E Strike Eagle Flies Northern Watch Mission

An F-15E Strike Eagle flies through the clouds over eastern Turkey in support of Operation Northern Watch. The F-15E is deployed to Incirlik Air Base, Turkey, from the 48th Fighter Wing at RAF Lakenheath, England. The aircraft are helping enforce the no-fly zones over northern Iraq."

I think the Kurds probably think of this one as a peace plane also. (FYI, those big things under the wings are fuel tanks, and it looks to me like all the armaments are air-to-air stuff, which makes sense if it was "enforcing the no-fly zone.") I'm hardly a war-monger, but when I see and hear one of those things do a Viking take-off, where the pilot pulls back on the stick right after he gets weight off wheels, and just goes straight up until the plane is just a speck in the sky, it's pretty cool.

Louis