Air India Learns: Composite Aircraft Advertised “Lightweight” Is ‘Stealthy’; “Fuel Saving” Is ‘Cloaked’

News Analysis: Air India Learns: Composite Aircraft Advertised “Lightweight” Is ‘Stealthy’; “Fuel Saving” Is ‘Cloaked’ since “Manufacturing” may be at odds with “Marketing” where it involves Commercial Airline Manufacturers.

Beyond the varied inherent problems in Carbon/Carbon Composites (as ‘Rain in the Plane’), there is also the problem of strength to highly stressed areas of an aircraft such as the “Wing Box” where it merges into the fuselage. Other areas such as the wing interfaces (hard points) with engine pylon nacelles may require additional support for strength. The list goes on and on.

Where strengthening is required, ‘Doublers’ made of Carbon/Carbon Composite can be fabricated. In many cases, Stainless Steel or Titanium is required for maximum strength. ALL of the ‘Doublers’ add weight; much more than many ‘Marketeers’ will admit to customers.

Fuel burn increases occur, with the added weight of structural enforcements, subsequently added in production. The vaunted: “5%”, “6%”, “10%”, “12%”, or “15%” Fuel Savings, touted by some airframes, is an illusion in many cases.

Since Carbon/Carbon Composite Construction FOR COMMERCIAL AIRCRAFT, is with a very short history, it is likely such aircraft can be expected to be written off in a much SHORTER LIFE SPAN. Metal aircraft have decades of life-span confirmation. They are not subject to deterioration from Solar Ray degradation of the metals (as are the adhesives used in Carbon/Carbon Construction). Furthermore de-lamination of the plies (due to stressing over time) weakens the fabrication significantly.

The Ethiopian Airlines Battery Fire, which was widely disseminated in the press, demonstrates another shortcoming of Composites: Heat. Allegedly, the Airframe rebuilt, in purported secrecy, the area that was damaged. “Why the concealment?” many airlines ask. 

Lastly, Composites do not dent; they fracture when hit. Any Landing Gear Failures will demonstrate the “Shattered Egg Shell Principle” as  Composite Aircraft Fuselages hit runways. 

From a Manufacturing perspective: If an Airline wants Longevity, Reliability, and Safety (LRS), Metal Constructions cannot be beat; a long History demonstrates this simple fact.

Alleged “Light-Weight” Construction is an also-ran in the ‘LRS’ Evaluation of Airline Aircraft to Purchase.

What materials may be suitable for Warfare Environment “Expendable” Military Aircraft is not necessarily the best for the travelling public in Commercial Airliners.

Reality.

Reference: http://seattletimes.com/html/businesstechnology/2023756440_boeingairindiaxml.html

Emirates Airline Gives Engineering Trainees a Unique “Hands-On” Learning Experience

News Analysis:  Emirates Airlines Engineering Trainees are getting a One-of-a-Kind Opportunity to better comprehend elements of Aircraft Construction. This build activity, albeit, rudimentary, nevertheless provides the impetus for ‘Seeds of Thought’ to germinate by the students. Required of good Aircraft Engineers is the ability to understand Systemically not only what has been built [Airbus A380, for example] but moreover, HOW IT WAS BUILT.

Learning about some of the Inherent ‘Frailties’ of Composites: The trainees “Drilling Problems” as well as many other Aircraft Industry known: i.e., Delamination due to stress; Adhesive degeneration caused by Solar Radiation Exposure at ‘Cruise’ [thereby leading to possible delamination]; Severe Carbon/Carbon Surface Abrasion due to particulates in the air (sometimes more severe due to Volcanism) and [U.S. B2 Bombers Constant Maintenance Problems from particulates]; Cracking ‘like an Egg Shell’ when merely bumped [let alone “Belly Landing” due to faulty Landing Gear]; Questionable LONG TERM Repair Integrity without using an ‘Autoclave’ as in Initial Construction by the “Air Frame”; Composites do not last as long as metals due to the aforementioned; Non-Metallic Thermal Behavior leading to constant “Rain In The Plane” Conditions.

In the United States, Beech Aircraft, several year ago sold their Stylish-Designed “Starships” to the public. Reportedly in the Press, due to inherent problems with composites, ALL of their “Starships” were re-purchased from their customers and the aircraft were Scrapped [due to allegedly Potential Legal Liability]; Production of the Starship, of course, ceased. “Rain in the Plane” was Newspaper Reported to be severe. Beech Aircraft Company is to be commended for not putting the public at risk. One can  read about this “Starship” Project, and its unfortunate end, using the Internet. This Aircraft History is not discussed by those parties selling Composite Aircraft.

The “Gain” of using Composites to the Airlines is “Lighter Weight” vs. the MANY ‘Frailties’ inherent in  that material. Some forget that “Metal’s Behavior Is Predictable” [due to its long and reliable usage in Aircraft Construction]. This should be realistically evaluated by Airlines.

Emirates Airline, with its trainees learning about the aforementioned Attributes of Composites, as well as other aircraft related subjects is to be lauded for its “Out-Of-The-Box” Thinking. 

Reference: http://gulfnews.com/business/aviation/emirates-builds-its-own-aircraft-1.1253041