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Scavenging a crashed 777: for a book

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Scavenging a crashed 777: for a book

Old 17th Sep 2014, 12:21
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Scavenging a crashed 777: for a book

Hi, I'm writing a book of fiction that involves a slightly damaged 777 that landed on a primitive island. I've been lucky to be in contact with a 777 pilot to get his input, but there are a lot of technical questions he doesn't know. Hopefully, some of you experts will answer my questions.

Appropriate title for an aircraft engineer?
One of the PAX is on the 777 in order to fix a 757 that is broken elsewhere. What is this person's correct title? Is it "Aircraft Engineer"? Or, Maintenance Engineer or something else? I'm assuming the person is about 35 years old and would be fairly knowledgeable regarding all the plane's systems.

Emergency radios on the raft - can you talk with them?
I know each raft has a radio set to 121.5Mhz, the question is if they just emit a homing signal or if you can talk to anyone else using one of these?

Galley hot water boiler
I'd like to use the hot water boiler as a pressure vessel to generate steam. My question is how large are these boilers (gallons) and how many a 777 is likely to have.

Cabin printer, cockpit printers
Are these regular 8.5 x 11 inkjet printers? Or dot-matrix? Or what? They would be valuable, at least until their ink ran out. Are supplies typically carried on board?

thanks!
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Old 17th Sep 2014, 21:24
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Appropriate title for an aircraft engineer?
LAME, Licensed Aircraft Maintenance Engineer, AMT Aircraft Maintenance Technician in the USA.

Emergency radios on the raft - can you talk with them?
No they beep only. This is called an ELT, there is generally one on the aircraft and others in emergency rafts.

Galley hot water boiler
Maybe a few liters, not sure about quantity in craft.

Cabin printer, cockpit printers
Probably 8 1/2 wide but it is on a roll with perforated seams. They are thermal printers.
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Old 17th Sep 2014, 21:41
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Thanks for the feedback.

Do you know if there is a hand-held VHF radio typically on the aircraft? I see the ground-crew with them, but does a unit remain on the aircraft?
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Old 17th Sep 2014, 22:08
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Typically not, yet on battery power a static inverter converts dc to ac and one ships radio may be operational.
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Old 17th Sep 2014, 22:27
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There are variants of emergency radio which do have built in microphones and allow voice on 121.5. The use of the option is not encouraged, as it eats battery life. Some variants of 777 may have them fitted. Most modern units transmit location (GPS co-ordinates) on 406 MHz also, although some still don't - the odds are that anything fitted to a 777 will.

Typical units:-

http://www.transair.co.uk/sp+Kannad-...egra-ELTs+4010

http://www.sportys.com/pilotShop/product/16431

G

Last edited by Genghis the Engineer; 17th Sep 2014 at 22:58.
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Old 17th Sep 2014, 23:58
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I like where your imagination is taking you Except 1 thing: B777's don't crash unless you make it crash

But to continue with your story, you'll have to decide how damaged it is (and what caused it), do you still have battery power (for a short time anyway)?
If so, you'll have radio.
BTW they say the battery lasts about 30mins on a flying/systems powered plane.

Coffee makers have a boiler of about 1ltr, depending on aircraft configuration there are about 10-14 on board. They run on electricity (unless you want to boil the water on a campfire )

Good luck
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Old 18th Sep 2014, 00:32
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Some more background:
- The plane doesn't crash, they try to land it with wheels up on the water and "slide" it up onto the beach. It mostly works, except for the tail section which fractures, but remains attached. Minimum loss of life.

- Some fuel remains, they didn't ditch it all. Possibly 1,000 gallons.

- Engines are DOA, but the RAT and APU should be functional, the engines remained attached and were shut down on impact, but they did take in quantities of seawater and beach sand. I don't expect them to be operational and I can't imagine the value of getting them to work.

- They have used the alternator and a bike from cargo to build a windmill. Doesn't produce much, but enough.

- They will have to figure out how to build a steam-powered electrical generation eventually. I'm figuring the boilers might work for that. I was hoping that the tanks used for water/waste could be turned into boilers, but it seems they are made of carbon-fiber? They don't seem to be aluminum or SS.

- Are the reservoirs used for oil and the fuel tanks made of carbon-fiber too? Any large containers that might be made out of SS?

- Thanks for the details on the 121.5Mhz. My pilot friend that flies 777 mentioned he thought they had voice, I didn't know if he was mistaken or not. I guess my 777 will have those types of 121.5Mhz radios/beacons.
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Old 18th Sep 2014, 09:49
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Again, I like your thinking, mate
You're not stupid and doing the research, I hope we can help (don't count on me too much )

Watertanks (3 of on 777-300) are fibreglass
Wastetanks (2 of) are carbon fibre, so both are good for storage (although wastetanks???) or as floating devices.

The RAT might survive the impact/landing but only if it remains retracted (it deploys from the bottom of the plane).The RAT deploys automatically when both engines stop....so be aware.
Bare in mind the APU needs fuel to work (they use about 200+ kilograms per hour) the fuel pipe runs under the floor so you might want too leave that intact.

The oiltanks, sit on the engines, are made of casted aluminium, probably melts.....

O, and about the fuel; they dump it (jettison) and ditch the plane

I probably go too much into details and I keep thinking about a movie i.s.o. a book (hope for you one day they'll make a movie of it), forgive me for that.

And again, my beloved Triple doesn't fail
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Old 18th Sep 2014, 12:05
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Thanks for the clarifications. Too bad the APU uses so much fuel to run, that would be an easy win.

I wonder if the APU could eventually be converted to run off steam power? It's a turbine after all. Maybe with some modifications? Of course, the modifications would have to be made with a limited set of tools.
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Old 18th Sep 2014, 13:09
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Kenpimental - Hmmmm ... you do know this plot has been done before, in both book and film form, don't you??

http://media.apunkachoice.com/image/...mage-37157.jpg
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Old 18th Sep 2014, 14:31
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Yes, familiar with that. Of course, my plot is very different. I haven't revealed it completely. There is certainly not going to be any effort to make another airplane to fly people off the island. They are stuck where they are and must make the most of it.

And no, it isn't a version of, "Lost" either, though both happened on an island. The island is of no major significance. I plan on making the 777 more of a focus in this story. More McGyver than the impossibilities of Lost. Of course, there is an interesting twist, but that can't be revealed.
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Old 18th Sep 2014, 19:02
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Steam engine and bike alternator.... Not alot of current there. I'd go for the generators in the engine or APU. Then you might have enough juice to annoy everyone nearby with a spark gap transmitter. This is assuming the radios are inop.
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Old 18th Sep 2014, 20:24
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Well since the airframe is pretty much in one piece, the 406 ELT would have gone off and rescue will be within a day or two at most.

When I traveled a lot, I took a portable printer with me, maybe one of the pax did the same? Check the cargo, maybe someone was shipping a small diesel generator (they will run on jet A) if you want a more "McGyver" kind of thing, and a tight power budget to boot, have a box of thermocouples in the cargo. Strung together with any kind of a heat source and you can get some power.

Check out how the RTG's work in spacecraft like Voyager or even some Russian lighthouses worked for the idea.
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Old 19th Sep 2014, 00:00
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There is no hope of rescue. They are on their own. It's not exactly the world as it exists today. Sorry if that's confusing.

There are thermal printers on the plane. I believe there are two of them. I'm not sure about the stability of thermal paper, so it's probably a good idea for someone to bring a portable ink-jet printer.

I'm hoping to convert a gas-powered engine over to steam. I know it can be done. I have to figure out what kind of simple gas-powered engine would make sense in the cargo hold. It seems to be "cheating" to have a small diesel generator sitting on the plane ready to go. I want more McGyver than that.

Thermocouples seem a little forced. It would be pretty random for them to be on the plane.

Right now, I don't think I'll need more thank 1KW per day generation. A windmill will do that. They'll want a steadier power source than wind, which is why steam is the next logical step. Best case would be that steam could drive the APU, but that might require super high pressures and volumes that are difficult to generate McGyver style.

But thanks for the ideas! Please keep them coming.
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Old 19th Sep 2014, 01:10
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Don't overlook the possibility of 'scavenge finds', perhaps things from discovered crashed planes from a war in the past, or things that get washed ashore (can be tied in with a storm). Such things could fill in for items not available from the plane to make your story plans work. I'm a sucker for a good realistic story, kudos on doing the research!
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Old 19th Sep 2014, 02:21
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Thermal paper actually keeps for quite a long time if kept tightly wrapped, and stored in a cool dark place. I have some that is over 20 years old, and it's still usable.
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Old 19th Sep 2014, 17:50
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There will be plenty of intact pressure vessels all around the plane that can be used to store steam (engine oil tanks, potable and waste water tanks even made of fiberglas, and last but not least fire fighting tanks with a squib still under pressure).

The problem is the boiler itself not blowing up. I would use a hydaulic piston as the boiler enclosure.

Course there are also all kinds of stuff in the shipping containers in the hold including tyres under pressure which could power the many micro-turbines like engine starter motors etc.

I bet if you managed to buy a scrapped B777 (Asiana) you could ship it to an island and populate it with volunteers to sort these questions out pretty damn quick.
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Old 19th Sep 2014, 17:58
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Q1: Are there fire-fighting equipment on the plane? If so, of what form?

Q2: How big is the hydraulic piston you're talking about? If there are hydraulic pistons, then I think a primitive steam engine might be possible using them?

Q3: Are there any tools that you'd expect to find on a plane in the normal course of events? I'm assuming there aren't any - except for what the AMT is bringing with her to fix a 757. A hacksaw is going to be vitally important to their future...

I'm here at the Smithsonian and there is a museum which shows all sorts of old steam generators, electrical generators and early inventions. Good material!
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Old 20th Sep 2014, 15:34
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I used to operate as a flight mechanic, this could be a charter aircraft, you would have a Maintenance REP (flight mech) on board with a portable personal tool box in a main deck closet and a FAK, fly away kit in one of the belly holds. This has contained in the past several sections of flexible hose, a 60 tonne jack, pipe swaging kits and sections of pipe. And a few belly cans full of every part (mostly electronic boxes) that if failed could ground an aircraft. This is done to allow a charter service to be anywhere at anytime w/o ground support. they are commonly used by sports teams, oil companies, cruise lines, casinos the big business right now is the military.
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Old 20th Sep 2014, 19:14
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re: APU
I've been told that 1,000G of fuel is about 15 hours of APU operation. If there is no ability to stretch for let's say a week or two, then it isn't worth the effort to run. Anyway, it produces way more energy than they need at this point. The only feasible long-term method is to use steam power with the APU, and I agree, it would take a huge boiler for that. I don't think anything existing on the plane could be repurposed for that.

re: RAT
Would the RAT deploy if the captain shut down the engines? He does it just before they hit the water. I think the RAT is plausibly the best thing to use for generation once they reach a little more sophisticated stage of development.

re: saltwater immersion
In this scenario, the plane is not immersed/floating in seawater. It's more like it is a powerboat blasting through shallow water/bottom as it rides up onto the shore. It isn't in the shallows for more than 5-10 seconds - so I'm going to pretend that nothing was really damaged by the saltwater except the engines.

re: aircraft gennys
I think there is some confusion. I'm talking about using the 28V AC alternators that are driven by the engine as backup power. I believe these are 300W at 2300 RPM. I'm not talking about the IDG - those are heavy duty 120KVA alternators that spin at 24K.

re: power conversion/inversion
I realize the APU has to also be removed from the plane to get the output to be converted to something that will work with portable electronics and AC tools. I do have an AMT on the airplane (for a good plot reason). She will be able to use her docs on her laptop to figure out the bits and pieces.

re: ditching?
Why is that so far fetched? If Captain Sulley could have ended the flight of his Airbus right onto a gently sloping beach, don't you think he would? Anyway, I do have a pilot who currently flies 777s reviewing the book and he didn't mention anything wrong with this scenario. I think it is because he's reading what I wrote and you're assuming something about what I wrote. Maybe I'll publish those portions on this forum if that will help.

re: charter flight
It would be a big change in the plot/characters to go with a charter flight. I'm hoping that I can use the excuse that there is an AMT on board who is headed to fix a 757 and is bringing along a decent set of tools to make sure they can.

re: hacksaw
Things get a lot more complicated without a way to cut SS/Alum up. One option is to have it in the cargo hold. I'm a sailor, and I know that whenever I travel to my boat, I'm bringing all sorts of tools/replacement parts. All it takes is for some passenger who is scheduled to spend a week on a boat somewhere in the Caribbean to be bringing some badly needed tool to the skipper.

re: Sat phone/406 EPIRB/GPS
These won't work as there are no satellites in the sky. Help is not around the corner. There is no rescue being staged, no one is coming for them. They are on their own.

Last edited by kenpimentel; 20th Sep 2014 at 19:41.
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