Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Why Don't Anybody Build Airliners Out Of Steel?  
User currently offline747400sp From United States of America, joined Aug 2003, 3757 posts, RR: 2
Posted (8 years 1 week 4 days 8 hours ago) and read 6987 times:

I know this sound like a stupid question, but why nobody builds airliners out of steal? The 2707 and L-2000 both was design to be build out of stainless steal. If Boeing or Airbus start using steal instead of plastic or aluminum, they may have stonrger plane thats could take a collusion or hard landing, also they could last longer. MCI and Prevost build there buses using steal. Now an airliner is supposed to have a stronger structure than a bus, so it dose not make since to keep build these aluminum and plastic airliner. I do not care if it will burn more gas, a steal airliner is safer than the one we have today, and Boeing and Airbus should try it.

That's my opinion, and please tell me with grace?  Smile

51 replies: All unread, showing first 25:
 
User currently offlineMD11FR8Jock From United States of America, joined Nov 2006, 13 posts, RR: 0
Reply 1, posted (8 years 1 week 4 days 7 hours ago) and read 6972 times:

One word, WEIGHT!! Even though there are lots of merits for the strength, the weight difference would make most A/C unable to fly or so heavy that they would not be able to carry any pax or cargo. Even today Boeing and AB are beginning to use substantial amounts of composites that are in many cases just as strong as some types of steel yet weigh less than alum. On a side note both MCI and Prevost superstructers of their coaches are made of Aluminum (Got this from my brother that owns a charter company and runs both types of coaches) I hope this sheds some light on a very admirable idea.

User currently offlineEMBQA From United States of America, joined Oct 2003, 9364 posts, RR: 11
Reply 2, posted (8 years 1 week 4 days 7 hours ago) and read 6968 times:

Quoting MD11FR8Jock (Reply 1):
One word, WEIGHT!!

Second word.... CORROSION....!!!



"It's not the size of the dog in the fight, but the size of the fight in the dog"
User currently offlineLincoln From United States of America, joined Nov 2004, 3887 posts, RR: 8
Reply 3, posted (8 years 1 week 4 days 7 hours ago) and read 6972 times:

Ok... I'm not an engineer, but my dad is in Management for one of aviation's leading fabricated metal suppliers (and he's 2500 miles away, so fat lot of good that does for this thread)...

I think it all comes down to weight, resilliance, and how easy it is to work with

Aviation grade aluminum is a very light metal, and relatively easy to tool, and is plenty strong.

I'm not sure about the weight or structural integrety of stainless (and it depends on the "class" of that stainless, but from what I understand it is a major pain in the ass to machine-- special tools, special techniques, etc. which would likely be cost prohibitive and difficult to service.

Hell, I have my eye on a $1400 "entertainment console". The only difference I can tell between it and the $300 version is the one I want has welded stainless (and marginally different styling).

You mention that you aren't concerned if it burns a little more gas since it would be "safer". I would counter that there hasn't been an accident in recent memory* where a change from aluminum to any other material would have any appreciable impact on the survivability, not to mention that the odds of such a situation occurring are so slim the "cure is worse than the disease", so to speak.

If two planes are going to run into each other (or terrain) at full tilt, regardless of what the birds are made out of, it will NOT BE A GOOD THING--aluminum vs. aluminum, aluminum vs. steel. etc.... The sheer forces involved virtually gaurntee this (two objects coming from opposite directions at 400 miles per hour hitting would be a 800 mile per hour speed delta).

Lincoln
* - The two potential I can think of: The early British jet model had squared window openings, resulting in metal fatigue at the corners and failure, and the Aloha 737-200 that "peeled open"... I don't know that any other material would have had better performance characteristics in either of these cases.



CO Is My Airline of Choice || Baggage Claim is an airline's last chance to disappoint a customer || Next flts in profile
User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 4, posted (8 years 1 week 4 days 7 hours ago) and read 6972 times:
AIRLINERS.NET CREW
DATABASE EDITOR



To my knowledge, only two aircraft ever utilized steel as their primary airframe material:

The Budd RB-1 Conestoga:






...And the Fleetwings Seabird amphibian:





2H4





Intentionally Left Blank
User currently offlineFLY2HMO From , joined Dec 1969, posts, RR:
Reply 5, posted (8 years 1 week 4 days 7 hours ago) and read 6962 times:

Quoting 747400sp (Thread starter):
they may have stonrger plane thats could take a collusion or hard landing,

Strength doesn't necessarily equal safety. If you look at the car's made back in the 50's, they'd always survive almost intact after a crash because they were massive and very robustly built. But yet, in the inside, the passengers would be tossed around as rag dolls against the sides of the cars. Today's cars might seem flimsy in comparison, but they are safer because the cars frame and body panels are designed to take absorb energy on impact, therefore minimizing the energy transfer to the occupants inside.

And even then, composites are even stronger than steel, and are lighter than aluminum in most cases. The only real benefit I would see is that steel is reltively cheap and easy to work on.


User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 6, posted (8 years 1 week 4 days 7 hours ago) and read 6962 times:

Quoting 747400sp (Thread starter):
I know this sound like a stupid question, but why nobody builds airliners out of steal?

Because it's a felony?  Wink


User currently offlineKl671 From Canada, joined Jul 2005, 141 posts, RR: 0
Reply 7, posted (8 years 1 week 4 days 7 hours ago) and read 6953 times:

First of all the metal is called steel.

The overiding reason steel is not used extensively for an aircraft's structure is weight. An all steel airliner would simply be too heavy.


User currently offlineHAWK21M From India, joined Jan 2001, 31702 posts, RR: 56
Reply 8, posted (8 years 1 week 4 days 2 hours ago) and read 6867 times:

Quoting 747400sp (Thread starter):
but why nobody builds airliners out of steal

Its reffered to as STEEL.
The reason for not using steel is Weight.You don't want things that fly to be heavy,as it'll require you to burn & carry more Fuel to carry that excess weight.Not Economical.
regds
MEL



Think of the brighter side!
User currently offlineMD11Engineer From Germany, joined Oct 2003, 14138 posts, RR: 62
Reply 9, posted (8 years 1 week 3 days 23 hours ago) and read 6820 times:

Quoting 2H4 (Reply 4):
To my knowledge, only two aircraft ever utilized steel as their primary airframe material:

You forgot the very first all metal aircraft built by Hugo Junkers back during 1915, the Junkers J1. Since back then aluminium was a strategic metal, he had to try out his folly using steel (Who would build an aircraft out of something as heavy as metal instead of wood and fabric?).
He also pionered the cantilevered "thick wing", giving it space on the inside for a strong spar, which did not need external bracing wire to hold it straight.
After he proved the concept, he got access to aluminium and build his later aircraft out of this metal

Jan


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 10, posted (8 years 1 week 3 days 22 hours ago) and read 6807 times:
AIRLINERS.NET CREW
DATABASE EDITOR




Quoting MD11Engineer (Reply 9):

Interesting piece of history there. Thanks, Jan.  Smile


2H4





Intentionally Left Blank
User currently offlineBlackbird From , joined Dec 1969, posts, RR:
Reply 11, posted (8 years 1 week 3 days 19 hours ago) and read 6748 times:

It's too heavy predominantly.

User currently offline474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9
Reply 12, posted (8 years 1 week 3 days 18 hours ago) and read 6731 times:

Many thousands of aircraft were built from steel, examples:

View Large View Medium
Click here for bigger photo!

Photo © Jean-Pierre Bonin



View Large View Medium
Click here for bigger photo!

Photo © Stephen Lane


Mild steel tubing was used to fabricate the frame of the fuselage, wings and empennage. It was then covered with fabric.


User currently offlineLightsaber From United States of America, joined Jan 2005, 13518 posts, RR: 100
Reply 13, posted (8 years 1 week 3 days 17 hours ago) and read 6700 times:
Support Airliners.net - become a First Class Member!

Quoting 747400sp (Thread starter):
I do not care if it will burn more gas,

Every added kg in an aircraft that doesn't ad value drops its purchase value by $500. Yes, that's the added cost, in a commercial airliner, of the weight.

Weight is break wear and tear.
Weight is range. You're saying build a plane with ~60% of the range of a competitor because you'll feel safer? Ugh... you won't be safer. At 200kts, its doesn't matter what material a plane is made from if you crash.

Since traveling by plane is already the safest way to travel, its not safety. Besides, carbon fiber/carbon-carbon planes will be able to take the dings and hits that cause so much concern with an Aluminum plane.

Quoting FLY2HMO (Reply 5):

And even then, composites are even stronger than steel, and are lighter than aluminum in most cases. The only real benefit I would see is that steel is reltively cheap and easy to work on.

 checkmark  There is only two areas in a plane where steel makes sense. The first is the landing gear (nothing takes shock loads better than steel). The second is in the engine (there are cases were the lightest way to make a component is steel).

Otherwise, for strength you need "moment of inertia" in an aircraft frame. In other words, volume of material. Due to how thin everything must be, shape must be used to prevent buckling, not material strength as much. That is one reason why the composites are the future of airliners.

Heck, they are even starting to make cars out of aluminum to save gas/improve performance. This of an airplane as a bus version of a ferrari.

Just to put it in perspective, a steel plane would cost about $5k more per flight than an aluminum plane. Would you really pay $100/ticket more just to have a plane out of a material you like than no aerospace engineer would want to touch? If we wanted to work with steel we would have become civil engineers. You do know the difference between civil engineers and aerospace engineers? Civil engineers make the targets.  duck   Wink


Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlineScooter01 From Norway, joined Nov 2006, 1213 posts, RR: 8
Reply 14, posted (8 years 1 week 3 days 16 hours ago) and read 6684 times:
Support Airliners.net - become a First Class Member!

What about being magnetic? What would happen in case of a lightning strike?


"We all have a girl and her name is nostalgia" - Hemingway
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 15, posted (8 years 1 week 3 days 15 hours ago) and read 6661 times:

Why don't we skip one layer of unnecessary complexity and simply build the passengers out of steel. Then we could build airplanes out of eggcrate because it wouldn't matter! I think a 747 made of eggcrate, filled with steel passengers (who would obviously need less clothing/luggage) would weigh less than the standard model.


Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineFlametech21 From United States of America, joined Sep 2006, 47 posts, RR: 0
Reply 16, posted (8 years 1 week 3 days 15 hours ago) and read 6660 times:

Weight, Corrosion, other factors make it uneconomical.

Airliners have many steel parts inside of them, just not on the fuselage skin. As an aerospace engineer you would just choose the right material for the job. Many different materials make up an aircraft including aluminum, steel, carbon-fibre, plexiglass, titanium, and many others.

Steel might be "strong", but we're talking about 50 ton turbine powered monsters that somehow have to get airborne. I have a better chance of getting killed in a car wreck on the neighboring I-635 then crashing in a plane on the runway. Besides, in a wreck aluminum has compressibility properties that absorb much of the impact. And carbon-fiber is lighter, stronger, and just as safe as it shatters, making the aircraft's structure take the brunt force of the impact, but saving the passengers inside from being crushed, like in aluminum.

My point is that steel is just to damned heavy for fuselage skin. If steel were light enough to fly, then the M1 would be an airplane, not a tank.

Lightning strikes are a non-issue, the fuselage skin is either connected to or is itself an electrical ground. Lightning passes right through it on it's journey to the ground, leaving the aerostructure relatively unharmed.  airplane 



They build them to a higher standard at Long Beach!
User currently offlineScooter01 From Norway, joined Nov 2006, 1213 posts, RR: 8
Reply 17, posted (8 years 1 week 3 days 15 hours ago) and read 6651 times:
Support Airliners.net - become a First Class Member!

Quoting Flametech21 (Reply 16):
Lightning strikes are a non-issue, the fuselage skin is either connected to or is itself an electrical ground. Lightning passes right through it on it's journey to the ground, leaving the aerostructure relatively unharmed

..and right through sensitive electonics and people touching any STEEL parts??



"We all have a girl and her name is nostalgia" - Hemingway
User currently offlineSaintsman From United Kingdom, joined Mar 2002, 2065 posts, RR: 2
Reply 18, posted (8 years 1 week 3 days 14 hours ago) and read 6642 times:

Aluminium will conduct electricity as well as steel

Lightning strikes are a non issue.


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17170 posts, RR: 66
Reply 19, posted (8 years 1 week 3 days 14 hours ago) and read 6630 times:

Quoting SlamClick (Reply 15):
Why don't we skip one layer of unnecessary complexity and simply build the passengers out of steel. Then we could build airplanes out of eggcrate because it wouldn't matter! I think a 747 made of eggcrate, filled with steel passengers (who would obviously need less clothing/luggage) would weigh less than the standard model.

Man I'd love to see those eggcrate turbines. Big grin



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineLehpron From United States of America, joined Jul 2001, 7028 posts, RR: 21
Reply 20, posted (8 years 1 week 3 days 12 hours ago) and read 6605 times:

Steel on average (as there are many variants of the stuff) is about 3 times heavier than Auminum based materials. If structural weight goes up, either fuel or payload goes down without having to redesign the engines.
Quoting 747400sp (Thread starter):
I do not care if it will burn more gas

You won't have to, you'll have either less payload or less range because the damn thing is heavy.
Quoting 747400sp (Thread starter):
but why nobody builds airliners out of steal? The 2707 and L-2000 both was design to be build out of stainless steal.

Those were meant for supersonic flight. When an object goes past sound, air compresses so much that the temperatures and pressures rise like crazy. Concorde was made of aluminum and went to Mach 2, if faster then aluminum woud melt, hence the use of steels and titanium based alloys. Yes they would have been heavier and it would cut down their range, but they are not and should not be compared with regular airliners.
Quoting 747400sp (Thread starter):
If Boeing or Airbus start using steal instead of plastic or aluminum, they may have stonrger plane thats could take a collusion or hard landing,

Airplanes are not designed to crash, they are designed to fly. Air crashes don't happen that often, the newsmedia brightens this aspect a bit, giving the impression of unsafe flying. They are not like cars that have airbags to protect people from thier own stupidity or by those that are stupid. Pilots have years of training before they are certified to carry people.

Quoting 747400sp (Thread starter):
a steal airliner is safer than the one we have today

What is your confidence in the idea of 'steel airliners' based on?

[Edited 2006-12-09 23:23:34]


The meaning of life is curiosity; we were put on this planet to explore opportunities.
User currently offlineCosmicCruiser From United States of America, joined Feb 2005, 2255 posts, RR: 15
Reply 21, posted (8 years 1 week 3 days 10 hours ago) and read 6538 times:

Quoting 747400sp (Thread starter):
stonrger

stronger

Quoting 747400sp (Thread starter):
collusion

collision

Quoting 747400sp (Thread starter):
steal.

steel

Quoting 747400sp (Thread starter):
dose not

does not

Quoting 747400sp (Thread starter):
since

sense

Quoting 747400sp (Thread starter):
keep build

keep building

Quoting 747400sp (Thread starter):
Why Don't Anybody

Why doesn't anyone


User currently offlineAirframeAS From United States of America, joined Feb 2004, 14150 posts, RR: 24
Reply 22, posted (8 years 1 week 3 days 10 hours ago) and read 6531 times:

Quoting CosmicCruiser (Reply 21):

Cut the dude some slack, I think he is hearing impaired/deaf like I am...so his english skills are not top notch like hearing people's skills are...

American Sign Language and the english language is not the same.



A Safe Flight Begins With Quality Maintenance On The Ground.
User currently offlineFr8Mech From United States of America, joined Sep 2005, 5645 posts, RR: 15
Reply 23, posted (8 years 1 week 3 days 9 hours ago) and read 6526 times:

Quoting Flametech21 (Reply 16):
Lightning strikes are a non-issue, the fuselage skin is either connected to or is itself an electrical ground. Lightning passes right through it on it's journey to the ground, leaving the aerostructure relatively unharmed.

Apparently you have never seen the results of a lightning strike on an aircraft. Sometimes little damage, sometimes major damage. Certainly not a non-event.



When seconds count...the police are minutes away.
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17170 posts, RR: 66
Reply 24, posted (8 years 1 week 3 days 9 hours ago) and read 6518 times:

One important point here, and it was covered a bunch of replies back but I would like to repeat it, is that it doesn't matter what you build the plane out of with regard to collisions. Two objects colliding at airliner speeds are going to suffer major damage no matter what they are made of.

"If the black box can resist a fall from 30000 feet, why don't they build the whole plane out of black box material?"



"There are no stupid questions, but there are a lot of inquisitive idiots."
25 SlamClick : Even if the airplanes were not damaged the passengers would end up as a homogeneous layer of miscellaneous protein matter at the forward end of the t
26 Flametech21 : Let me rephrase that. From a pilot's standpoint it is a non-event. I realize that it can cause various degrees of structural damage, almost always le
27 Post contains links 747400sp : The MCI D 4500 is Cor-Ten steel from the floor up and the G 4500 frame is all stainless steel. I got this from, WWW.Busmag.Com/PDF/MCIG4500.pdf, look
28 Kaddyuk : Because then the only people who could touch it would be Avionic engineers and only GOD knows what sort of Mayhem would Pursue!
29 Post contains images HAWK21M : So its the same out there too.I thought it only occured out here. On the topic....Efforts are being made to make Aircraft more lighter & strong enoug
30 Xv408 : The design problems often faced by engineers is stiffness and fatigue life rather than absolute strength. Hence aluminium being used in preference to
31 747400sp : Take in mind that the XB-70 and B-58 Hustler was made with a honeycomb stainless steel structure.
32 Post contains images Lehpron : What temperatures? I just said faster, while that could be anything from Mach 2 to infinity, aluminmin melts around 1200F and those temperatures do n
33 HAWK21M : Whats the Progress with Composites,Temperature resistant wise. regds MEL
34 Post contains links Xv408 : At Mach 2, the peak temperature is around 120 deg C. At mach 3, it is around 340 deg C. Aluminium's creep properties start to degrade at around 140 d
35 777236ER : We wish. Crashworthiness keeps structures people awake at night.
36 Post contains images Lightsaber : 9G crash requirement. Trust me, you have not known engineering pain until you've had to scrap a design because the weight of the wires takes you out
37 B2707SST : Both aircraft were to be built from titanium alloyed with small amounts of vanadium and aluminum. Stainless steel is too heavy and aluminum loses str
38 ThrottleHold : Amen. Signed, The grammar gremlin.
39 Post contains links and images Lehpron : Took me a while to figure it out: For some reason, I expect planes that survive say a belly landing to be repaired and reflown. I don't know how ofte
40 777236ER : The structures people do quite a lot of work on crashworthiness, both on individual parts to ensure they meet the regulations, and as a concept to in
41 Pygmalion : And all the pax would be facing the back of the aircraft.
42 Post contains images Starglider : For the XB-70, conventional sheet metal skins, reinforced plates of various constructions, and sandwich or composite panels were designed and evaluate
43 Prebennorholm : If we strip down a modern airliner, even a "plastic bird", and sort the different components by material from which it was produced, then we will find
44 L-188 : One other issue is that the softer Aluminum takes a rivet easier. The Budd Conestoga went with welds instead of rivets. Over time those welds began to
45 AAden : [quote=MD11FR8Jock,reply=1]One word, WEIGHT!! Even though there are lots of merits for the strength, the weight difference would make most A/C unable
46 747400sp : Not to get off subject, but are passenger rail cars still made of steel.
47 Post contains images B2707SST : Not necessarily; the structural construction method depends on the properties of the material being used. Stainless steel seems suited for honeycomb
48 Starlionblue : Older ones are. Newer high speed cars are normally made of aluminum to save weight. I believe one of the myriad reasons for the failure of Acela Expr
49 Starglider : True, depending on the design of the airframe. Current SST studies focus on a cruising speed of Mach 1.6 to 2.4. Perhaps using fuel as a heat sink, a
50 Bohlman : I thought that gold, silver, and diamond were all better conductors? Anyway, something I didn't see mentioned was the fact that the reason people die
51 Starglider : Apart from the SR-71, which flew but had a structure that leaked, the Boeing and Lockheed SST designs may have had simpler structures but never flew.
Top Of Page
Forum Index

Reply To This Topic Why Don't Anybody Build Airliners Out Of Steel?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Thrust Levers Out Of Sync In Picture? posted Sat Nov 18 2006 06:25:35 by Jawed
Why Does The Tower Give Out Altimetric Reading posted Fri Nov 10 2006 02:58:14 by YULspotter
Speed Of Air Out Of The GE-90-115's Back End posted Sun Sep 10 2006 01:47:24 by UAL747
New Caterer For KLM Out Of Sao Paulo (GRU)? posted Thu Jun 8 2006 22:52:50 by TOGA01
Running Out Of Runway posted Sat Jun 3 2006 21:46:23 by Tarzanboy
Can You Make A A330 Out Of A A340? posted Fri May 5 2006 17:51:39 by KrisYYZ
Out Of ETOPs Range? posted Wed Mar 29 2006 20:39:12 by XXXX10
Why Don't Piston Engines Shift A La Automobile? posted Mon Jan 9 2006 23:29:23 by UAL747
Who Services An A/c Out Of Its Home Base? posted Fri Aug 26 2005 03:19:37 by AJet
Strange AA Departure Out Of ORD posted Wed Jun 2 2004 19:27:05 by SpeedbirdHeavy

Sponsor Message:
Printer friendly format