CR4 - The Engineer's Place for News and Discussion ®


Previous in Forum: Stageless Rocket Coming Out of New Mexico to an Orbit Near You   Next in Forum: New Photos of the Next Mars Rover
Close
Close
Close
11 comments
Participant

Join Date: Apr 2017
Posts: 1

Aircraft Assembly Line Thought

04/22/2017 6:04 PM

I have been studying the following simple case:

An aircraft assembly line is organized as a flow production process with a certain takt time. The total flow-time for assembly, painting and flight test is 25 days. The paint process takes 4-5 days, depending on the customer specific paint schema (due to cleaning, painting primers, base coating and customer livery and related drying times). The flight testing takes 7-8 days (depending on the weather conditions and issues that arise during testing). The delivery interval is 2 days. The assembly process starts with fuselage assembly in a fixed assembly tool and which takes 400 hours, to be performed by a of 10 people on average. The other assembly and test activities are much smaller and can be broken down in packages of 4 or 8 hours.

I would like to hear your opinions about the following questions:

  • How do you, in general, set up an assembly line in stations to optimally use all resources?
  • How many stations do you need in this specific case? Where do you perform the paint
    process in the flow?
  • What are the alternatives to plan the 400-hour fuselage assembly work package?
Reply
Pathfinder Tags: Aircraft assembly line
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United States - Member - Hobbies - Fishing - New Member Hobbies - Target Shooting - New Member Hobbies - RC Aircraft - New Member Engineering Fields - Aerospace Engineering - New Member

Join Date: May 2009
Location: On the road, USA
Posts: 2115
Good Answers: 66
#1

Re: Aircraft assembly line thought

04/22/2017 7:28 PM

First off, welcome to CR4®. Your not the first person to want to cut production time in aircraft production. But there comes a fine line between quality with reliability and mass production.

Are you willing to put your family on an aircraft that was mass produced with little or no quality assurance? Quality comes from time and development of a technique to produce a reliable aircraft. Your lifecycle could prove to be very short if you cut corners.

There's could be a price to pay for cutting corners.

Is this Rocket Science? Maybe the next thing to it.

"The assembly of aircraft is ......"

__________________
Confucius once said, “ Ability will never catch up with the demand for it".
Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 17984
Good Answers: 1038
#2

Re: Aircraft assembly line thought

04/22/2017 8:11 PM
__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Reply
Guru
Australia - Member - New Member

Join Date: Feb 2008
Location: Australia
Posts: 1714
Good Answers: 200
#3

Re: Aircraft Assembly Line Thought

04/23/2017 8:13 AM

Welcome to CR4 and you've startde with an ambitious question.

I would suggest that you need to research "Design For Manufacture and Assemble" or DFMA. This explains in some detail how you componentise a product into each and every assembly step and determine the time for that task/operation and the sequence that provides optimum output.

You need to run that in the quality and costing constraints that exist for you.

Once you have that process mapping, it is usually possible to sequence the work based on equipment utilised or assembly complexity as each component is added.

Tact times are then able to be "tuned" by adjusting which stage performs the tasks at the workstation interfaces.

I learned this in automotive industry. Refinement then gets into component design to make them easier to fit properly and so on.

Good luck.

__________________
Just an Engineer from the land down under.
Reply
Guru

Join Date: Apr 2010
Posts: 5280
Good Answers: 513
#4

Re: Aircraft Assembly Line Thought

04/23/2017 1:52 PM

Is this real or a homework problem?

Reply
Guru
United States - Member - Hobbies - Fishing - New Member Hobbies - Target Shooting - New Member Hobbies - RC Aircraft - New Member Engineering Fields - Aerospace Engineering - New Member

Join Date: May 2009
Location: On the road, USA
Posts: 2115
Good Answers: 66
#5
In reply to #4

Re: Aircraft Assembly Line Thought

04/23/2017 5:05 PM

sounds like homework to me. If it was real time, he'd already know the answers

__________________
Confucius once said, “ Ability will never catch up with the demand for it".
Reply
Guru
Engineering Fields - Aerospace Engineering - Member United States - Member - Army Vet in the aviation industry

Join Date: Mar 2008
Location: Bridgewater, Va.
Posts: 1688
Good Answers: 92
#6

Re: Aircraft Assembly Line Thought

04/23/2017 10:58 PM

There are some basic parameters that need to be defined before the questions you ask can be addressed.

1) What kind of aircraft is being manufactured? Piper Cherokee, B747, A380, F-35, CH-53K helicopter, ultralight?

2) What is the estimated initial volume and projected volume growth?

3) Where is the manufacturing to take place? US, Zanzibar, Cambodia, EU? Laws, labor force, availability of automation, and energy costs help define methodology.

4) What components are to be ordered from OEM specialty companies? Engines, subsystems, avionics, etc?

Only when these questions are answered can one begin to define the manufacturing processes required.

And you're wrong about your initial premise. "The assembly process starts with fuselage assembly in a fixed assembly tool" is no longer valid in some manufacturer's production scenarios. Many commercial manufacturers are now assembling using modules like the shipbuilding industry has been doing for many years. Predefined modular sections (cockpit, passenger section, empennage, etc, complete with wiring and other accessories) are manufactured in separate assembly lines, even in different countries with different manufacturing requirements, and married into the main assembly line at the appropriate time.

And welcome to CR4.

Hooker

Reply
Power-User

Join Date: Dec 2016
Posts: 203
Good Answers: 5
#7

Re: Aircraft Assembly Line Thought

04/24/2017 10:41 AM

The paint process takes 4-5 days

Nope! Having worked for the lazy B ranch (Boeing) a plane is painted in less than 24 hours and this includes forced drying.

People get the wrong idea about a place like Boeing. Nothing is made there unless its an R&D project. Its an assembly point.

I worked procurement QA where we had to be at the manufacturing site to assure the items being produced were to specification. This assured that when the parts arrived to Boeing stores that quality inspection would have already been performed.

However there were still problems. The tear away elastic inlet cover on the ALCM cruise missile (one of my vendors) was being torn on installation on the assembly line. I flew to Seattle to review the installation process and found the girl who was installing the covers (trend analysis showed the problem to be on a given shift) had long fingernails and was tearing the cover when it was being stretched over the inlet.

We had her trim her fingernails and i had special elastic gloves made out of the same material that the cover was made of and the problem was solved.

Point is that even if the product meets specification before its shipped that operations downstream can affect the outcome.

__________________
formally known as texasron
Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 11263
Good Answers: 133
#8

Re: Aircraft Assembly Line Thought

04/24/2017 12:14 PM

I don't suppose you could learn anything from looking in how McDonald's puts a burger in a bag? Assembly line there too, pretty much optimized. I would not expect too much from attempting to launch a Big Mac, though.

__________________
If it ain't broke, don't fix it. Just build a better one.
Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18073
Good Answers: 314
#9

Re: Aircraft Assembly Line Thought

04/25/2017 2:58 PM

A brief overview: first off,

1.) Define all your processes.

2.) Bring in task specialists for all the processes, from start to finish (quality control, manufacturing, material scientists, ????)

2a) Define the short falls and mitigate them

3.) Bring in outside contractors to develop and support the processes

3a) Paint lines

3b) Any type of specialized equipment needed such as ovens, curing ovens, autoclaves

3c) Jigs/fixtures and tooling

Now, once you get a preliminary process established, you can start with the logistical support of the processes with suppliers, vendors, etc....

__________________
phoenix911
Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 11263
Good Answers: 133
#10
In reply to #9

Re: Aircraft Assembly Line Thought

04/25/2017 3:16 PM

#4 - be flexible, there is no religion to the fabrication floor. An assembly line based upon dogma is likely to fall short of the glory of Dog.

__________________
If it ain't broke, don't fix it. Just build a better one.
Reply Score 1 for Off Topic
Participant

Join Date: Jun 2017
Posts: 4
#11

Re: Aircraft Assembly Line Thought

06/28/2017 4:59 AM

Can I please ask when the fuselage arrives is it semi fitted for wiring or completely empty? This can have a huge impact on the time taken to manufacture. From the times i have worked on the A380 FAL the fuselage parts arrived in the jig with major cabling looms etc fitted and needing only to be connected at the section joints.

Painting came after flight testing and right at the end pretty much so that it was as pristine as possible for customer hand over (except the tail as this allowed you to see the customer from the point of exiting the marry-up jig).

Reply
Reply to Forum Thread 11 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

dj95401 (2); Hooker (1); James Stewart (2); Just an Engineer (1); MTJB-Engineering (1); phoenix911 (1); Rixter (1); ronc (1); SolarEagle (1)

Previous in Forum: Stageless Rocket Coming Out of New Mexico to an Orbit Near You   Next in Forum: New Photos of the Next Mars Rover

Advertisement