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Assume a passenger aircraft were left undercover for a very long period, perhaps thousands of years, in a damp, arboreal environment. How much of it would survive? Which parts would remain intact, and which parts would decay? What would it take to get it airborne again?

How long could it reasonably survive for, and still be recognisably an aircraft?

Edit

Assuming that it couldn't be flown, how long could an airframe (i.e. just the metal and glass) last, in less than ideal conditions, without mothballing or deliberate preservation, such that an ordinary modern day person could look at it and be able to easily recognise it as such? It might be an irredeamable wreck, but it would be recognizably an aircraft.

Futher Edit (context)

For those interested in further context about the question, this is in regard to a fantasy novel I'm constructing called The Weapon Child.

superluminary
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    How much protection does the aircraft have? A simple cloth sheet covering it, or is it shrink-wrapped with a tough, opaque plastic? – Frostfyre Jun 21 '16 at 15:32
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    Left in a hanger and abandoned. Think Gatwick Airport in 5000 years. – superluminary Jun 21 '16 at 15:33
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    If you're dealing significantly in a post-human world, I would suggest taking a look at the Life After People series. – Frostfyre Jun 21 '16 at 15:54
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    @James and superluminary: I think I found my new favorite resource for material life expectancy: Life Expectancy Table. Apparently, the hangar would have collapsed within about 250 years. – Frostfyre Jun 21 '16 at 16:09
  • @Frostfyre Awsome find, I shared it in [chat] – James Jun 21 '16 at 18:12
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    "Recognizable" by an ordinary person who has seen a picture of an airplane? Or by an expert archaeologist? – Nate Eldredge Jun 21 '16 at 20:15
  • Some items can be preserved under extraordinary circumstances. Have you considered preserving like this rather than basically out in the open? – Kys Jun 21 '16 at 20:33
  • Recognisable by an ordinary modern day person, such that you might see the cockpit, the nose cone. It might still be standing on its landing gear. Probably covered in vegetation, but not buried or disintegrated. – superluminary Jun 21 '16 at 21:10
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    The trick is finding an enclosure that doesn't collapse on top of the aircraft within those 5k years. Arboreal environment implies moisture. The aluminum frame will be mostly powder in 5k years. – JS. Jun 21 '16 at 21:21
  • @Frostfyre I would imagine the plane would rather survive the cover of cloth or tough, opaque plastic – Roland Jun 21 '16 at 21:46
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    Hangars aren't where people store planes long term. The desert is where one stores a plane long term. – Aron Jun 22 '16 at 03:07
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    IF you somehow stored the airplane on the surface of the moon, there will still be a recognizable structure after 5000 years (all the rubber, seals and fluids will have boiled away very early). It is thought the landing stage of the Apollo moon landers will still be recognizable millions of years into the future if undisturbed. – Thucydides Jun 22 '16 at 03:28
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    Just a little personal note: I work in a team which restores a ~60 year old aircraft to airworthy shape. It has accumulated less than 2000 flight hours (pratically brand new) and stored in pristine conditions including recurring maintenance for more than half of its lifespan. Still it requires hundreds of manhours to get it into the air again. – Bowdzone Jun 22 '16 at 07:28
  • @Frostfyre - That is indeed an excellent table. – superluminary Jun 22 '16 at 10:13
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    @Aron - The aircraft hasn't been stored. This is the moment the protagonists realise they're not in Kansas anymore. – superluminary Jun 22 '16 at 10:17
  • I could not help but think of the book The World Without Us [1] by Alan Weisman. Maybe that's standard repertoire to questions with the post-apocalypse tag, but maybe it's not, so I did not want to leave this unmentioned. [1] https://en.wikipedia.org/wiki/The_World_Without_Us – bers Jun 22 '16 at 12:35
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    It would be a pile of white powder. – user_1818839 Jun 22 '16 at 20:17
  • @BrianDrummond - Interesting. Do you have a source for this? – superluminary Jun 22 '16 at 22:20
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    @superluminary None in text form. Just various aluminium (and related alloy) components in my possession, only 1-2% of that age, making annoyingly steady progress towards that form. – user_1818839 Jun 23 '16 at 10:21
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    Unless your hangar is built like the Great Pyramids, it will have long collapsed onto your plane and the plane will have been exposed to the elements for thousands of years. It will be hard to find it among the plant life that's taken over. – Johnny Jun 23 '16 at 18:17
  • I don't get it why someone would phantasize about a 5000 year old plane, but the question is very relevant for believers of atomic energy, as they intend to safely store nuclear waste for even much longer time frames – Roland Jun 24 '16 at 10:09
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    You can make nuclear waste into solid glass stored in stainless steel or copper alloy containers, and store it in Pyramid like enclosures in desert dry conditions. None of these (except desert storage) are realistic for a large aircraft. If the Pu has been removed in reprocessing, to recycle in breeder reactors, the remaining radioactivity falls below the original ore in about 500 years. Different magnitude of problem. – user_1818839 Jun 24 '16 at 11:15
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    @Drummond The point is that up to now no working solution exists for nuke waste. Even with encapsulation in glass pearls in a concrete barrel in a deep mine shaft the stuff will not withstand the required ages. Let alone a plane in a simple hangar – Roland Jun 24 '16 at 15:09
  • @Roland : That is true. Every step of the process has been tested - reprocessing to shorten the active life, recycling the Pu, vitrification, mine shafts, pyramid building. But there isn't the political will to put the steps together. – user_1818839 Jun 26 '16 at 10:19
  • I'd say, adjust your timescale in a major way. Are you married to 5,000 years? I would say this: first figure out what it is you want: 1) intact plane, able to be flown with restoration, 2) People who barely remember that we had flight...things like that, then adjust your timeline, not reality, to fit that. More can happen in 100 years than you think. It likely doesn't take thousands to achieve whatever goals you have. – Erin Thursby Dec 27 '16 at 20:35

17 Answers17

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Your time frame is way, way too long.

Aircraft are incredibly complex machines; let's review a few of the failure points.

Fluids:

  • Your first failure point is likely to be fuel. OK, technically the batteries would drain out first, but if you have fuel you can get those recharged in most cases. Your limits look to be around 12 months to 2 years (jet fuel is probably less).

  • Hydraulic Fluid. This stuff is under intense pressure and in the course of a couple years those seals are going to fail...now you can't steer, or move the landing gear.

  • Oil. It goes bad too, but it takes longer, if the oil was perfectly fresh and in a completely closed system it could hypothetically still be good.

All of the fluid systems are going to fail in the first couple of years.

Electrical systems:

  • Wiring is sensitive, any parts not covered in plastic are going to cause you problems...rodents sometimes like wire too...odds are over your time frame something will move in for at least a while. If not, contact points will be the first to corrode. Unattended the wiring is likely failing after 20 years (give or take).

  • There are a whole lot of systems in a plane, all will fail inside of probably 25 - 30 years. Navigation will be shot (no satellites), air systems for cabin pressure, lights, etc., etc.

Mechanical Systems:

  • Over your time frame...nothing survives except perhaps the remnants of a few larger pieces of metal.

  • Odds are the hangar falls on top of the jet anyway...

  • Moisture is bad, and persistent. It will get through the hangar roof and eventually make it collapse. Even if it somehow doesn't land on your plane it will allow more water to hit the jet...increasing the decay rate.

In short, there is absolutely no way someone is going to find a flyable jet 5000 years later. Even if the thing were vacuum sealed and stored in a dry underground cave in the desert somewhere it would still not be flyable.

Community
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James
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  • Could it still be recognisably an aircraft? Wings? A tail? – superluminary Jun 21 '16 at 15:50
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    @superluminary Under some set of ideal conditions (which your scenario is not) it is possible, I mean if gold jewelry from the Minoan civilization can survive that long odds are we could package up a jet to last that long too...it wouldn't be functional but it could probably still be recognized as a jet. – James Jun 21 '16 at 15:52
  • "Odds are the hangar falls" This is exactly what I was thinking. But I was trying to figure out a time frame for that to occur in a country that doesn't have a lot of natural disasters. – Frostfyre Jun 21 '16 at 15:53
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    You forgot that even if the airplane somehow magically survives, 5000 years later, who will know how to fly it? Might want to compare Do planes have keys? and What stops planes from being stolen? on [aviation.se], except I recall seeing something more similar to Is there no physical security in space, other than being in space?... – user Jun 21 '16 at 15:53
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    @MichaelKjörling Good points, and you could go one step farther and ask... what are the odds they even know what a jet is? – James Jun 21 '16 at 15:54
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    @MichaelKjörling It's more of a Statue of Liberty/Planet of the Apes type of moment. – superluminary Jun 21 '16 at 15:57
  • @James Good point; I suppose my comment was directed largely toward the OP's "What would it take to get it airborne again?" and "Could it still be flown?". – user Jun 21 '16 at 18:39
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    Yeah, even in the "vacuum sealed in a cave" scenario, even if the fluids had been removed, the seals would be worthless after that long. At an absolute minimum, you'd have to replace all of the seals and fluids for it to be flyable. You'd also have to find someone able to operate such ancient technology. :) Consider that only 2,000 years ago, the horse-drawn chariot was the pinnacle of non-water transportation technology. – reirab Jun 21 '16 at 19:13
  • I doubt jet fuel is actually less stable than gasoline as you suggest, but it certainly wouldn't last centuries. – Random832 Jun 22 '16 at 17:37
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    @Random832 jet fuel is intermediate between gasoline and diesel. The lighter the petroleum fraction, the harder it is for bacteria to eat it. Diesel (heavier than jet fuel) goes bad quite fast in storage unless mixed with bactericidal chemicals. So jet fuel will indeed go off faster than gasoline. – nigel222 Jun 23 '16 at 11:16
  • @nigel222 Ah, bacterial problems hadn't occurred to me - I had assumed that the process of going bad was chemical as it is with gasoline, and had to do with how volatile it is. – Random832 Jun 23 '16 at 13:52
  • An airplane have hundreds of power supplies, and those psus used by every circuit, sensors, computers, motors, pumps, will will likely fail in a timespan of few decades, If one of those systems goes bad, it will probably, result in the whole thing being useless. Electrolytic capacitors will be the first to fail as their fluids dry out or leak. When they leak it will also corrode other components. In the timestamp specified even the copper on every electronic board will corrode. Without the controller boards, flying is out of question. Not to mention other parts that will fail sooner. – Vitim.us Jun 23 '16 at 16:16
  • Maybe the problem is the time frame is too short. Maybe his protagonists need to find a fossilized cassette tape, or a petrified electric guitar. – TMN Jun 24 '16 at 16:40
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When people wish to mothball expensive equipment for possible use later, they perform a specific set of operations intended to remove the most sensitive parts from the environment.

F-4 (Phantom) at Davis Monthan AFB
F-4 (Phantom) at Davis Monthan AFB

Aerial view of Davis Monthan AFB
Aerial view of Davis Monthan AFB

During mothballing, sensitive equipment like engines and electronics are removed, fluids are drained, and less sturdy equipment (e.g. cockpits) are covered.

Airline companies have a similar facility nearby in which they store retired aircraft.

The US Navy has a facility for retired ships at which they perform similar operations.

The US Air Force Museum's display aircraft are similarly stored. Their preservation is such that by restoring the electronics, engines, fluids, and other components would make (most of) those aircraft flight worthy.

I would assume that using these techniques could significantly extend the time that the airframe could be restored to flight worthiness by many decades certainly. However, I doubt if this would extend to centuries.

Even if it did, who would know enough to do the work and where would the parts and supplies come from?

Robert Harvey
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Jim2B
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    An aircraft stripped of "electronics, engines, fluids and other components"? Pretty much what does that leave, besides the airframe itself? – user Jun 21 '16 at 18:42
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    @MichaelKjörling It's not like the airframe is completely worthless, but certainly a long way from flyable. – called2voyage Jun 21 '16 at 20:31
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    Sounds like making a mummy! Drain the Pharoh's fluids, remove components, keep covered, park for 4K years. – JDługosz Jun 21 '16 at 21:25
  • Serious question relating to your photo, which shows the landing gear deployed, and wheels chocked to stop it moving. Won't this give the tyres flat spots? Or are they assumed to be replaced on refurbishment anyway? – Criggie Jun 22 '16 at 02:18
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    The rubber on tires will be decayed after a few years anyway, so replacing them would be a standard operation. It's just easier to move the airframes around if they still have wheels, so often the tires are left on. You can tow a vehicle at low speeds on pretty terrible tires. – Thaeli Jun 22 '16 at 05:37
  • @Ian - I'm assuming, after such a long time, that the landing gear will be largely buried by accumulated leaves, animal faeces, and other material. – superluminary Jun 22 '16 at 22:27
  • If the Wright brothers had been given restricted time travel to study the stripped-out fuselage of a modern Cessna, don't you think it would have saved the world a decade or two of experimentation? Even better if the propellor and corroded wreck of an engine were still in place. If nothing else, knowing for certain that something is (was) possible makes re-inventing it a lot easier. – nigel222 Jun 23 '16 at 10:49
  • Worth noting that "mothballed" aircraft are not left entirely defunct of maintenance and care: it's just dramatically reduced. They are still given some attention to ensure they don't become damaged – Jon Story Jun 23 '16 at 15:07
  • @nigel222: Gasoline engines had not developed sufficient power-to-weight ratio to make a plane fly fast, and most modern aircraft designs would be incapable of flight at speeds that would be achievable. Further, there's a critical difference between modern aircraft and the Flyer: In a modern aircraft, if one stalls at altitude one will gain speed until one either recovers or hit the ground very fast. If the Flyer stalled, it would descend largely uncontrollably but slowly. The Wright Brothers stalled quite a few times before they got good at flying, so survivability was important. – supercat Jun 23 '16 at 17:22
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    As I understand it, the Wright brother's successful plane design had to due with 3 recent inventions. 1. aluminum block internal combustion engine (dramatically improved engine thrust to weight ratio), 2. wing warping as a control mechanism (invented by Wright brothers), 3. wind tunnels to test designs (also invented by Wright brothers). Without all three of these then they could not have built an airplane at all. – Jim2B Jun 23 '16 at 18:26
  • @nigel222, the basic principles of flight were known at the time. The Wrights' contribution was 1) realizing that the popular formula for wing curvature was wrong, and 2) experimentally designing a wing that would work with their intended aircraft design. Studying a Cessna might have eliminated the two-year gap between the barely-controllable Flyer I and the practical Flyer III (the Flyer I's elevator was too small and too close to the center of gravity), but it really wouldn't have accelerated the rest of their work. – Mark Jun 23 '16 at 21:45
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In 5,000 years it would not be recognizable as an aircraft. There are good answers already with respect to the aging of the aircraft proper.

But what of the environment? Rain will damage the aircraft by rot and rust. Ice will cause stress, opening small cracks. The weight of ice and snow can cause structure failure and collapse. High winds can lift the aircraft and pull weakened pieces off, or the jarring of the aircraft falling when the wind gusts subside could collapse things too. A flood every 500 years doesn't sound unreasonable, so now its full of mud and debris. Or parts float, other parts don't, and the airframe is stressed. If the water is flowing, parts can be torn off. You get the idea. Nature is a tough place.

In addition to weathering, generations of trees and other plants would grow through it, tearing it apart. It would be buried by rotting vegetation and leaves. A fire in the area (once in 500 years does not sound unreasonable) would surely burn away or thin the aluminum sheeting. Remember - after a century, the airframe is full of tinder and it likely sits in a forest. Trees will fall on it.

Of course no one would know the plane was there. Otherwise it would have been salvaged long before and utterly destroyed. So the most you're likely to find, if you happen to look in the right place, are lumps of rusted metal buried deep underground in a forest. Or whatever the area looks like 5000 years in the future.

Tony Ennis
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Thanks for the hilarious question. Might I rephrase like: do you know of many buildings or constructions of a couple of centuries old without any kind of maintenance, that is still recognizable? Let alone operational, in case of a machine?

Let's look at some examples. You talk about a hangar. Just consider your house. How much wear and tear do you see after say 5 years of no maintenance? Paint falling off. Corrosion, wood rot, dirt. After some 20 years of no maintenance or cleaning, it might well be overgrown with plants. You want to add two zeros? Nothing might be left all.

Let's look at climate. Here in Northern Europe, everything might be wiped out by the next ice age, think of an ice glacier of thousands of meters high pushing from the north. Ice ages appear roughly every 10,000 years, and the last one ended about 10,000 years ago, so the next one will most probably be within your time frame of 5,000 years.

Then infra structure. A plane is nothing without infrastructure, like runways, communication, trained personel, fuel of a precise composition, and maintenance. Lots of parts have maintenance schedules based on time, like a checkup every month, or six months. Suppose that after some extreme time frame a part may be in perfect condition, e.g. a turbine blade. If it is not checked up regularly according to its maintenance schedule, it cannot be certified for operation. So in case it might "work", it is useless from the point of certification. Who would risk his life just to "try out" if it would fly?

I mentioned runways. I remember having seen an asphalt road literally disappeared after being abandoned for some 20 years.

How about robbers? I would guess that within a few years the plane would miss essential parts due to robbery. The pyramids prove that even a tough cover will not stand robbery.

Nice question anyway.

Update:

Yesterday, I unpacked my old record player. You know, from before the compact disc we had those vinyl records? Now, my record player was wrapped in plastic when I moved, and stayed wrapped for perhaps 20 years. Was it operational? In principle, yes: motor, plateau, levers, pickup element, wiring, hinges, cables, even my self-built pre-amp worked. Only one part failed: the rubber belt between motor and plateau was, hum, melted, or, transformed. It was broken in pieces, and most pieces were like peanut butter, or tar. A few pieces could be lifted and removed, other pieces had literally be scraped away. I did not manage to get all sticky tar and rubber away.

Ok, I did get the thing to work with an improvised belt, cut from an old bicycle inner tube, a recent one. But this reminded me of the question about the 747. Just cut the requested timeframe of 5,000 years by a factor of 200 and possibly essential rubber parts may detoriate to a point that it is hardly recognizable.

The moral of the story is that you do not want to try such old equipment. I wanted to try the record player because some people here got renewed interest in vinyl records. But why? Records got dust and ticks, and sucked. Compact disc, a huge improvement, sucked too. Digital music on my hard disk, or the cloud, is much better. Same for airplanes. Even now the 747 is considered to be outdated: too much noise and pollution. Let alone after the next couple of generations of aircraft. Even if the old museum stuff could be flown, you do not want that. Really.

Update may 2021. Middle/end of Corona Covid-19 pandemic.

More than half of all airplanes worldwide have been grounded now for about a year. As the severity of the pandemic decreases, air traffic is started up again. Experts warn for technical problems because of this mothballing which was only a small fraction of 5000 years.

At 9 january 2021, a Boeing 737 from Sriwijaya Air crashed in the Java Sea (Indonesia) 6 minutes after takeoff, killing 62 people. Experts call as probable cause: storage with no flights for 9 months, and taken back into service too fast.

After a period of no flights for 9 months, the plane was inspected, approved, flown from storage in Surabaya to Jakarta on 14 December, and resumed passenger service the next day. After 132 flights, it crashed at 9th of January. See https://www.nytimes.com/2021/01/13/world/asia/indonesian-plane-crash-mothball.html and https://www.telegraph.co.uk/news/2021/01/13/indonesian-airliner-crash-may-linked-plane-grounded-nine-months/

So, even if the plane "looks good" after just 9 months of careful mothballing, it may not be safe to fly. Let alone when it does not look good after being left abandoned in a hangar for five thousand years.

Roland
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    I agree with you, but one counter-example are the pyramids. Good luck getting a plane in one, though. – JS. Jun 21 '16 at 21:23
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    Exactly. The oldest ones in Egypt are hardly 5000 years old. So a plane in a pyramid would have a chance of surviving time, but in a hangar???? And the question was about a damp, arboreal atmosphere, that would exclude a pyramid. – Roland Jun 21 '16 at 21:26
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    One trick would be getting the plane in/out while keeping everything else out. Critters and mold would wreak havoc before the airframe corroded to powder. Probably be under 300 tons of bat guano after just 500 years. – JS. Jun 21 '16 at 21:34
  • @JS After 500 years the tires will be non-existent, crumbled to dust, so how would you move the plane in/out that hangar? Or did I miss your point? – Roland Jun 21 '16 at 21:39
  • "Ice ages appear roughly every 10,000 years, and the last one ended about 10,000 years ago" Does that mean we are going to be in another ice age soon? – John Odom Jun 22 '16 at 22:03
  • @Roland Uh, speaking of pyramids and damp, arboreal environments, there's the Mayan pyramids. It hasn't been 5,000 years yet, and most of them are in ruins. Time does a lot of damage, especially when you add water and plant overgrowth to the mix. – HopelessN00b Jun 22 '16 at 22:19
  • @Roland - Possibly a Mayan pyramid? – superluminary Jun 22 '16 at 22:21
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    @JohnOdom - Good point about the ice ages, but we can assume, for the sake of argument, that Ice ages are not an issue in this context. – superluminary Jun 22 '16 at 22:23
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    There are quite a few buildings in Europe of Roman construction, still in use. During the dark ages the (wooden) roofs rotted and collapsed but the (brick or stone) walls did not. If the walls were in a useful place when civilisation was renewed, the locals just put a roof back on it and moved in. (More often these walls were in the wrong place, and got dismantled to build new walls where they were wanted). – nigel222 Jun 23 '16 at 10:58
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    @JS the pyramids are not intact after 2000 years. The outer stone has been stripped off, the gold cap is long gone, and the contents of tombs are mostly gone. Stone is pretty durable (but still subject to erosion) but a 747 is made of much, much less durable materials. – Greenstone Walker Jun 24 '16 at 02:38
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    @JohnOdom: geologists indeed expect the next ice age within 100 to 1,000 years to begin. Some argue that by then, people might value the current "global warming" for a less cold climate then. – Roland Jun 24 '16 at 09:57
  • @nigel222 roman buildings still in use had lots of maintenance, repairs, and the original question assumed no maintenance. You little cheater :-) – Roland Jun 24 '16 at 10:00
  • @GreenstoneWalker My understanding is that the outer stone and gold cap were stripped off my men, not nature. I'll leave it to OP to determine whether than falls within the constraints of his/her question. – JS. Jun 27 '16 at 18:10
  • @Roland Roman construction received maintenance during certain periods, but many were also left unmaintained for long periods of time. Not quite cheating on Nigel's part. The roads, especially, were still useful a very long time later even if not maintained and that would have been a better argument than their buildings. Their roads were constructed way better than ours. Of course, an airplane is not going to hold up as well as a Roman-built road, nor like their concrete buildings, so your answer still stands. – Loduwijk Feb 26 '18 at 15:39
  • After ~132 flights, I'd think that either something was already a problem (from before mothballing) or something got screwed up after mothballing. If a plane were put into service too quickly, I'd think that a catastrophic failure would occur sooner rather than later. (NOTE: I'm not an aviation expert, I have watched air disaster documentaries.) – elemtilas May 23 '21 at 17:44
  • @elemtilas You might become even more expert if you read also from aviation experts selected by well-regarded newspapers. This case was also cited by a well-regarded dutch engineering society (KIvI) and supported by an aviation professor at TU Delft. The point is that you cannot just "look" at the (remains of) a plane and decide to fly with it. Even after one test flight it might still not be safe to fly. – Roland May 25 '21 at 10:14
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Plastic hoses, insulation, tires (already mentioned), cable sheathes, anything made of plastic would be useless in such a time frame.

I bought a car made in 1960. When I bought it, it was 40 years old, and had literally been driven by a little old lady less than 30,000 miles and kept garaged. Immaculate! I thought it would be a great car. We had failure after failure of plastic parts - brake hoses cracked, door handles snapped off, wires shorted out, vacuum hoses leaked, seat covers tore when someone sat down on them. Finally had to junk it.

LarryL
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  • This is very interesting. So all the plastic fabric and foam components were rotten, but the car still looked like a car? – superluminary Jun 22 '16 at 17:22
  • Yes. I'm sure if you search, you'll find lots of stories by enthusiasts who restore old cars. People are still finding classic vehicles in barns and suchlike. Rubber rots first, then the plastics and fabrics. But a car can still be easily recognised after a century of abandonment provided it's out of the rain. – nigel222 Jun 23 '16 at 11:06
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The future visitor will find a layer of aluminum-oxide dust, some metallic copper, possibly some recognizable plastic bits... underneath layers of iron oxide or whatever the building was made of, underneath a considerable amount of earth and vegetation.

Careful, high-tech archaeology would reveal the likelihood of a building. The aluminum, and exotic metals in 4 places and tungsten or depleted uranium in one, would hint of being a 4-engine-on-wing airplane.

Flying it would be out of the question.

Harper - Reinstate Monica
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  • So you would anticipate complete disintegration. My (ill-informed) understanding is that aluminium is highly reactive with water, but that once a thin layer of oxide has formed, it acts as a weather shield which prevents further oxidation. I'm guessing that this effect would not be sufficient to protect the aluminium alloy components over the timescale. – superluminary Jun 23 '16 at 09:42
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    @superluminary The oxide coating on aluminium is not quite perfect. In a damp environment it does gradually corrode. In a desert climate, not (or very slowly). In wet old England there are lots of 80-year-old aerials still cluttering up the chimneys. They'd stlll be usable, but they no longer transmit (black and white!) TV on those frequencies. – nigel222 Jun 23 '16 at 10:37
  • @nigel222 - the tv aerial analogy is very apt. – superluminary Jun 24 '16 at 08:12
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As others have mentioned the plane would certainly be unflyable - working components, plastics and electronics would certainly degrade over that long (most likely even with preservation).

However to answer the second part of the question more precisely, given a storage location that did not collapse and was reasonably weather tight the plane could certainly still be recognizable. Think of King Tuts furniture which is over 3000 years old. Even if the structure becomes brittle and collapses you would still have wings lying on the ground beside a fuselage.

(For location, I am thinking of an underground airbase if the entrance caved in and left the rest sealed.)

user21984
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Considering that it has been stored in a dry environment, in a closed place that doesn't collapse in that timeframe, I think that it will still be recognized as a flying object. Think about the antikhythera mechanism, that has been at the bottom of the mediterranean sea for over 2,000 years and after a large and meticulous study, using advanced technologies, scientists have been able to establish not only what it was used for, how it worked, and aprox. date of construction of the artifact, but also detect and design the missing parts (and allowing to make a replica that works).

The Antikythera mechanism is an ancient Greek analog computer and orrery used to predict astronomical positions and eclipses for calendar and astrological purposes decades in advance.

Loduwijk
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Santi
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    I hadn't heard of the antikhythera mechanism. That is indeed interesting. – superluminary Jun 23 '16 at 09:46
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    The quesiton says "damp arboreal environment". How do you get "dry" out of this? – GreenAsJade Jun 25 '16 at 13:12
  • You can't get much damper than the bottom of the mediterranean, where the antikhythera mechanism was found. By comparison a damp arboreal environment is dry. – pojo-guy Feb 26 '18 at 19:00
  • the Antikythera mechanism was in an anoxic environment, oxygen will corrode the plane to nothing in 5000 years. – John May 23 '21 at 14:48
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Supplementary answer. I watched a documentary about a few enthusiasts who wanted to salvage a WW2 plane that had ditched in the wilds of Northern Canada during the war. Their (crazy?) plan was to get it airworthy again and then fly it out using the frozen surface of the lake it was next to as a runway.

They almost succeeded. It took several months of maintenance to get the engines running again. Various parts had to be replaced - rubber in particular had perished. Also all the fluids - oil, fuel, hydraulic. Sadly, something caught fire during their take-off run. The pilots got out uninjured, but the fire utterly destroyed the plane.

So after 70 years in Arctic weather, a plane is just about capable of being repaired.

nigel222
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  • Interesting. What did it look like before they attempted to repair it? Was it recognisably a plane? Were the wings attached? – superluminary Jun 23 '16 at 09:35
  • Oh, definitely a plane in one piece. Pranged undercarriage and wrecked propellor blades from being ditched in the wilds. The fuselage was (allegedly) still flight-worthy though they never got it back in the air. The engines all worked after being dismantled, overhauled, re-lubricated, rotten non-metallic items replaced. – nigel222 Jun 23 '16 at 10:12
  • Here's the video. Hard to believe the video was made 20 years ago ... http://www.pbs.org/wgbh/nova/military/b29-frozen.html – Mark Lakata Jun 23 '16 at 18:03
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    It was the Kee Bird : https://en.wikipedia.org/wiki/Kee_Bird – Mark Lakata Jun 23 '16 at 18:04
  • northwest Greenland, not northern Canada – smci Jun 23 '16 at 22:16
  • Linked in from the Wikipedia for the Kee Bird is the successful resurrection of a P-38 "Glacier Girl" after 50 years under the ice. – gowenfawr Jun 24 '16 at 12:50
  • Kee Bird's engines had to be replaced completely, not "got running again". – Jamie Hanrahan Jun 24 '16 at 17:44
  • I stand corrected. It was a good few years ago when I saw it. Memory said that they rebuilt the engines. Confabulation of what they do with a classic car, I guess. – nigel222 Jun 25 '16 at 17:21
  • Fun! They got the engines "running again". The engineer would say: "useless, if the parts are not maintained and re-certified appropiately, the thing would not operate within specs". Luckily the pilots escaped the fire this time, but I would guess nobody would be so stupid to risk his life trying to "run" an amateurishly resurrected bigger machine like a 747 – Roland Jun 27 '16 at 11:37
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While natural materials like wood and metal might survive 5000 years in a usable state, there is no way any kind of plastic will survive that long. None of the types of plastics produced have thousands of years lifetime (not even hundreds of years) as a product requirement, and even if they had it is not clear that this would be possible to adequately test for.

hlovdal
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  • The plastics would be gone, but what about the aluminium airframe? Would that still be recognisable, or would we just have a mound of dust and animal droppings with trees growing out of it? – superluminary Jun 22 '16 at 17:21
  • Does plastic degrade even when stored in dry darkness? – Michael Jun 23 '16 at 14:33
  • @Michael Depends on the plastic and on its accidental and deliberate impurities (the latter are known as fillers and plasticizers). Chances are that the seats and trims will fall apart quite fast, the aerospace-safety-critical components less fast. But I doubt even those will last centuries. – nigel222 Jun 23 '16 at 17:34
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There's no way it could survive 5000 years. At this time scales the material diffusion becomes significant, and this will (at least) cause electronic systems death, because some conductors will short-circuit. And without electronics, an aircraft is not usable for flights. Also, we may assume that the temperature will not be constant, so the number of stretchings of the aircraft body will cause severe "metal fatigue" and other destruction.

Display Name
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    But would a modern day human be able to look at it and say "yes, that was an airliner"? – superluminary Jun 22 '16 at 10:20
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    @superluminary, he brings up a good point with thermal expansion and compression. Even if nothing fell on it and you kept animals out the stress of that many years of movement against bolts/joints/welds would tear the body apart. Some of the most basic metal parts assuming they hadn't completely oxidized/corroded might still be there, but no a modern human wouldn't be able to say "yes that was an airliner". – Ryan Jun 22 '16 at 23:12
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    @ryan I don't think 5000 years of thermal cycling will cause a fuselage to completely disintegrate. Develop cracks that render it nonviable for flight, certainly. Wings fallen off and back broken, possibly. But in a desert climate (damp slowly corrodes aluminium) I think it would still be very recognisable as an airliner. Also that a genius engineer from 1900 might be able to re-invent quite a lot from its wreckage (such as the jet engine). Even more so from a less advanced plane such as a pre-war turboprop or an early 707. – nigel222 Jun 23 '16 at 10:27
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    @nigel222, even deserts don't stay stable over that time period, 5000 years ago the Sahara got more rain then it does today. I'm sorry but after 5000 years of deterioration it's not going to be recognizable as a plane. – Ryan Jun 23 '16 at 15:48
  • @ryan desert as in low humidity environment. Climate change may happen, but there are places that have been arid (not rain-free) for thousands of years. Central Australia is an example. Need data on how fast Aluminium decomposes in such an environment, agree it won't last forever or for a million years. My gut feel is that 5000 is possible. – nigel222 Jun 23 '16 at 17:26
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     You state that your 747 will be sitting in the hanger for 5000 years. I'm afraid that this won't work - the hanger won't last for that long. While the plane is made mainly of Aluminum and won't rust apart, the hanger certainly will completely deteriorate long before the 5000 years are up, exposing the plane to the elements.

      Thousands of years of rainwater pounding against the surface, bits of collapsing hanger, hail, strong winds throwing around whatever debris may be in the area, and any other storms that may or may not happen over 5 millennia will be certain to put holes in your plane. As other answers have stated, all plastics and rubber components will be junk. However, any parts made of iron within the plane that normally wouldn't be exposed to moisture can and will rust over the thousands of years of being exposed to moisture. Another thing to consider is the freeze and thaw cycles, which will pry apart any important moving bits, and pretty much wreck the important systems on your plane.

      Essentially, your plane will be an artifact of a long lost era, nothing more than a bit of metal - that, and a home for whatever animals may be living in what was once a gloriously large plane.

X-27 is done with the network
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I guess the thing is how "fantasy" is your fantasy novel? No reason why a magic field couldn't have sustained it for 5000 years, or some as yet not invented stasis field.

Still, the question makes it sound like you're after realism so maybe that isn't helpful! :-)

Peter Cliff
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  • In this context that wouldn't work, but perhaps in another book :) – superluminary Jun 24 '16 at 08:10
  • A little lore: in the Drift World, magic always seeks the harm of the wielder. It's something that's used rarely, and usually at significant personal cost. An example of this is the seeker arrow. It always points towards one's heart's desire; be that wealth, or love, or opportunity; with predictable consequences. There are no "magical fields", or anything fluffy like that. – superluminary Jun 24 '16 at 11:38
  • Yes, this is a weird contrast to the usual plot of finding ancient artifacts. The magical weapon, the only thing that can save the world due to being forged thousands of years ago with forgotten magical knowledge; the alien spaceship lurking millions of years in a space graveyard; the evil abominations returning from their eons of slumber; the extra-dimensional beings who watched the birth of the universe ... – BeniBela Jun 25 '16 at 20:16
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Complicated mechanical equipment degrades with startling speed. A car that has been sitting in a garage for as little as six months probably won't start. After five years, the work of a day can get it back on the road (assuming good tools, fresh fluids, fresh fuel, new batteries, available replacement parts). After a fifty years in a field in a wet climate, cars become an unrecognizable pile of rusted metal. (but aluminum is different)

Hangers are usually just a thin metal shell over steel supports. It's unlikely a structure like that would survive a thousand years in a moist climate. I'd expect a normal hangar to be completely erased after a few hundred years in a jungle-like climate.

If you're interested in the process of decay here's a bit about the degradation: (shortening the timeframe to 5 years when things start to become problematic)

  • The fuel needs to be flushed (airplane fuel is less subject to the chemical degradation than gasoline, but after this time I'd expect enough water accumulation you'd want a full fuel system flush before trusting your life to this vehicle.)
  • Rubber hoses bushings and seals have begun to degrade. After five years the process has started so there are would be minor leaks and failures of rubber components. After a hundred years rubber will basically have turned to dust. (I've had 30 year old rubber crumble in my fingers like ash)
  • Batteries have leaked and are unusable. (all batteries have to be removed and new ones acquired, leaked acid must be cleaned up, contacts cleaned and sometimes replaced)
  • New tires. Tires in the landing gear will have gone flat and then been crushed by the weight of the plane (this could happen in as little as six months)
  • Hydraulic fluid has taken up water and needs to be flushed. Questionable if the systems will still hold pressure after five years.

The good news though is that if the hanger was built to last it could maintain integrity. (Think of Buddhist temples that have lasted thousands of years in the jungle). The plane itself being made of aluminum would be recognizable basically indefinitely. Aluminum oxide creates a very strong protective layer which basically prevents it from rusting away. I'd expect to see a recognizable fuselage and wings of a plane even after a thousand years.

jorfus
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We are of course intrigued by a long-term storage Jumbo Jet, but this the line of thinking would not be much different if it was replaced by, say, a bicycle, over a time frame of about 50 years. It will not be usable too.

a4android
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Roland
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Aluminium has no fatigue limit. This means that as the aircraft structure is subjected to many successive loads, no matter how small, it is guaranteed to suffer fatigue and fail.

Assuming it isn't destroyed by chemical corrosion as others have rightly pointed out, you must consider the loads to which the plane is subjected over a period of thousands of years. For example, if the plane is stored deep underground the temperature will be roughly constant but on the surface fluctuating temperatures will cause thermal stress, which over many cycles will start to cause failures. 5000 years makes for about 2 million day-night cycles, which should be enough to break off those parts subject to the highest stresses. Being exposed to the elements—snow, wind, etc.—would add large loads and speed the process considerably.

My best guess is that the wings may break off, the structure supporting the landing gear may fail and the plane collapse to the ground, the airframe may crack up around all windows, etc. I am obviously not an aircraft engineer so I don't know for certain which parts will be most stressed.

user25972
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Also remember that the windows are plastic. Once the plasticine leaks out, they will become very brittle. Then the flexing of the aircraft frame will crack and, eventually, destroy the windows. The wings, unless supported would eventually droop to the ground. The landing gear is pretty robust but it is bolted onto the frame. I think that those mounting points will go.

I think that, if you are lucky, after 5000 years, you will have a sagging aluminum tube with holes in it, resting on the ground.

ShadoCat
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