Inspecting a CFM56 jet engine – Opening an Engine Cowl

October 2nd, 2011


CFM56 Jet Engine - aircraft engine maintenance

CFM56 Jet Engine - Credit: Wikipedia - David Monniaux

Imagine working on an Airbus A320, doing routine aircraft engine maintenance of a GE/SNECMA CFM56 jet engine. CFM is a combination of two major aircraft engine manufacturers: the French firm Snecma (SAFRAN Group) , and the U.S. firm, GE. This CFM56 jet engine is typically employed  in many current Airbus and Boeing aircraft, commonly used in many commercial flights. One of the primary factors behind the CFM56′s broad-based market acceptance has been its simple, robust design, giving it high reliability, durability and easy maintenance. In the video shown below, the exact sequence of tasks performed by an aircraft mechanic are explicitly shown by the manufacturer.  The takeaway from this video are the following points:

  • The absolute requirement for performing tasks sequentially, per the maintenance manual, is obvious
  • The need for a modest amount of physical exertion is demonstrated
  • A lot of detail work is involved in getting access to the engine accessory compartment
  • Provided each step is done correctly, this is not such a daunting task!


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California Aircraft Mechanic Schools

September 2nd, 2011

California aircraft mechanic schoolsMany California aviation maintenance training schools are recognized as being of excellent quality, and approximately 20 Aircraft Mechanic Schools are FAA certified in California.  California has a proud history of involvement in the aviation and aerospace industry, and hosts many outstanding institutions. Many unique civilian and military aircraft technology innovations have come out of the aerospace industry in California. California’s climate and an abundance of land for a host of civilian and military airports has for decades fueled steady growth in the state’s aviation industry. Also, it doesn’t hurt that California is populated by smart, forward thinking individuals who have repeatedly made a difference in the progress of aviation in the 20th Century.  On a list of the top 20 aviation maintenance schools in the U.S.,  California can boast of the following aircraft mechanic schools:

  • City College of San Francisco
  • Mt. San Antonio College
  • Long Beach City College
  • Sacramento City College
  • Orange Coast College
  • Chaffey College
  • Antelope Valley College
  • Reedley College

In California, one has a choice of the type of aircraft mechanic school to attend, and several school options are typically available to the budding aircraft mechanic. For instance, if you are living around San Diego, San Diego Miramar College would be a good fit for you. In the Los Angeles area, you have a choice of Crimson Technical College, Long Beach City College, or West Los Angeles College, among others.

California aircraft mechanic schools

Here is a table of the current FAA FAR Part 147 schools in California.


Aircraft Mechanic School NameCityWeb SiteContact
Antelope Valley Community CollegeLancaster

Antelope Valley College
Aviation Institute of MaintenanceOaklandAviation Institute of Maintenance

Aviation Institute of Maintenance
Chaffey Community CollegeRancho Cucamonga

Chaffey College
City College of San FranciscoSan FranciscoCity College of San Francisco

City College of San Francisco
College of AlamedaAlameda

College of  Alameda
Crimson Technical College/Redstone CollegeLos Angeles

Crimson Technical College

Gavilan CollegeGilroy

Gavilan College
Long Beach City CollegeLong Beach

Long Beach City College
Miramar CollegeSan Diego

Miramar SDMC
Mt. San Antonio CollegeWalnut

Mt. San Antonio College
North Valley Occupational CenterMission Hills

North Valley Occupational Center
Orange Coast CollegeCosta Mesa

Orange Coast College
Redstone CollegeInglewood

Redstone College
Reedley CollegeReedley

Reedley College
Sacramento City CollegeMcClellan

Sacramento City College
San Bernardino Valley CollegeSan Bernardino

San Bernardino Valley College
San Joaquin Valley College Aviation Maintenance Technology ProgramSan Joaquin Valley

San Joaquin Valley College
Solano Community CollegeFairfield

Solano Community College
Southern California School of Logistics School of AviationVictorville
West Los Angeles CollegeCulver City

West Los Angeles College
Wyotech Oakland (a branch of Fremont campus)


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Rivets and Airplane Maintenance

August 21st, 2011

Rivets and Airplane Maintenance

Junkers F 13

Junkers F-13 CH-59 displayed at the Aviation and Space Permanent Exhibition, Budapest. Photo: Attila Szabo, Curator

Universally taught at all aircraft mechanic schoolsairplane rivets are a time-honored method of attaching two metal surfaces together, for airplane maintenance.  Rivets are generally superior to welds when it comes to airplane maintenance.  Solid shank aluminum rivets first made their appearance in 1919, with the German Junkers F-13, which was the first civilian all-metal airplane. Also, the Junkers F-13 was the first aircraft to appear without spars. This innovative aircraft manufacturing technique has proven to be of lasting appeal through the ensuing decades, due to the inherent advantages of rivets for simplicity, cost, reliability and weight. An aircraft designer specifies rivet fasteners in their blueprints for the airframe, and will identify a certain rivet type by using rivet part numbers, a drawing symbol or a head marking. For airplane maintenance, it is essential an aircraft mechanic understand how to read the manufacturer blueprints and understand what type rivets are needed in a particular airplane.

Junkers F13

Credit: Wikipedia - Avion Junkers F-13 en el Deutschen Museum

Rivet heads come in various sizes and head styles, including

  • Universal
  • Countersunk
  • Flat
  • Round

By convention, rivet sizes increment in steps of 1/32″. Rivet diameters range from 3/32″ to 1/4″.   Stock rivets are usually cold formed from aluminum alloy that has been annealed. These rivets are usually called “Manufacturer’s Heads”. Common types of manufacturer’s heads are Universal Head rivets and Flush Head Rivets (Countersunk Rivets). A common Universal Head rivet is designated as rivet type MS20470, which is the most common, and strongest solid aluminum rivet. It is used in internal airplane structures, where a protruding head is not significant. On external aircraft surfaces, a countersunk rivet becomes essential. The following video gives some fundamentals of flush head riveting, and is very instructive! These are key points to keep in mind for airframes and airplane maintenance.

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Aircraft Mechanic Schools – check out Embry-Riddle Aeronautical University

August 16th, 2011


aircraft mechanic schools - Embry Riddle Aeronautical University

Embry-Riddle – a good choice for an aircraft mechanic school

If you want to get a top-notch education at an aircraft mechanic school, check out Embry-Riddle Aeronautical University. Located in Daytona Beach, Florida and Prescott, Arizona,  Embry-Riddle has a proud history of involvement in America’s aerospace sector. Embry-Riddle’s distinguished history is described in the following passage from the 2010 Embry-Riddle catalog:

“On Dec. 17, 1925, exactly 22 years after the historic flight of the Wright Flyer, barnstormer John Paul Riddle and entrepreneur T. Higbee Embry founded the Embry-Riddle Company at Lunken Airport in Cincinnati, Ohio. The following spring the company opened the Embry-Riddle School of Aviation, coinciding with the implementation of the Air Commerce Act of 1926, which required, for the first time, the certification and medical examination of pilots. Within three years the school had become a subsidiary of AVCO, the parent of American Airlines.  Embry-Riddle remained dormant during most of the 1930s, mirroring the casualties of the Great Depression, and the Lunken Airport operation was phased out. By the end of the decade, however, World War II erupted in Europe and the demand for skilled aviators and mechanics grew significantly.  Embry-Riddle’s second life was about to begin.

In South Florida, Embry-Riddle opened several flight training centers and quickly became the world’s largest aviation school. Allied nations sent thousands of fledgling airmen to the Embry-Riddle centers at Carlstrom, Dorr, and Chapman airfields to become pilots, mechanics, and aviation technicians. Some 25,000 men were trained by Embry-Riddle during the war years. After the war, under the leadership of John and Isabel McKay, Embry-Riddle expanded its international outreach while strengthening its academic programs.  With Jack R. Hunt as president, in 1965 Embry-Riddle consolidated its flight, ground school, and technical training programs in one location by moving northward to Daytona Beach, Florida. This move, which proved to be a moment of singular importance, was made possible by Daytona Beach civic leaders who donated time, money, and the use of personal vehicles. The relocation signaled the rebirth of Embry-Riddle and the start of its odyssey to world-class status in aviation higher education.”

Embry-Riddle accepts aircraft mechanic students for traditional training as an A&P mechanic. Unlike many other schools, Embry-Riddle also is a significant aeronautical university, where a student can obtain either a bachelor’s degree in aeronautics, or graduate schooling beyond this.  Students obtaining an education at Embry-Riddle often have a leg up in the job market, upon graduation. But don’t take my word for it, check out .

Embry-Riddle – one of the best aircraft mechanic schools

From,  a list of important points to know about Embry-Riddle is presented.  One point mentioned bears repeating, namely that the major airlines hire more alumni from Embry-Riddle than from any other collegiate aviation program! In the field of aircraft mechanic A&P certification training, Embry-Riddle has listed some of the advantages of training in their school. See

Embry Riddle Aeronautical University

As an example of the training a student accomplishes at Embry-Riddle aircraft mechanic school, see the following video of the Maintenance Hangar at Embry-Riddle Aeronautical University.

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Impact of Aging on Airplane Maintenance

August 12th, 2011

As an aircraft mechanic, airplane maintenance is sometimes not covered in adequate detail in aircraft mechanic school. In all aircraft, there is an aircraft life cycle, which can be described as  the “bathtub curve“. The overall reliability of a system or component through out its life cycle involves three phases:

  • infancy/break-in
  • useful life
  • wear out

This is shown in the accompanying figure, adapted from The Australian Transport Safety Bureau.

Airplane Maintenance Bathtub Curve

Source: ATSB (2008)

During the very early flight years of an aircraft, the failure rate decreases over time, as many failures are due to material flaws or problems in manufacture. This phase is less relevant when considering aging aircraft. In the useful-life phase, failures due to initial flaws gradually decrease while failures due to wear-out gradually increase. Therefore, the average number of failures remains relatively constant throughout the useful-life phase. During the wear-out phase, failures will increase as the product reaches the end of its useful life.

The FAA has in place a system of continuing airworthiness.  When it fails, the consequences might be dramatic.  Here is an example of what happens when manufacturer bulletins for maintenance are not fully known.  In Australia, in December 2000 and April 2001, Ansett Australia’s fleet of Boeing 767 aircraft were taken out of service,  because of problems in the Australian airworthiness system.

In 2000,  Ansett’s  fleet of Boeing 767 aircraft was among the oldest in the world. These aircraft were used on relatively short domestic flights, and had accumulated a large number of flight cycles. The Ansett fleet of Boeing 767 aircraft was grounded, not once but twice, because some fatigue damage inspections had not been carried out.  In June 1997, Boeing introduced an Airworthiness Limitations Structural Inspection Program for the Boeing 767 aircraft. This program was part of the damage tolerance requirements and was designed to detect fatigue cracking in susceptible areas that had been identified through tests and in-service experience. There was a Boeing requirement to carry out some of the inspections before 25,000 cycles.  However, Ansett staff  did not originally recognize this requirement and at the time of the “Airworthiness Limitations Structural Inspection” program introduction, some of the Ansett Boeing 767 aircraft had already flown more than 25,000 flight cycles . In June 2000, further inspections at 25,000 cycles were introduced by Boeing. These inspections included the Body Station 1809.5 bulkhead.  Ansett initially did not act on these inspections.  In fact, some aircraft had developed dangerous cracks in their wing front spars. Read the rest of this entry »

FAA Airframe & Powerplant A&P Certification Exam Details

July 31st, 2011

A & P certification

How does one obtain an FAA Airframe & Powerplant  (A&P) license?

An A&P certification is issued by the Federal Aviation Administration (FAA), which allows a mechanic to legally work unsupervised on aircraft.   Before taking the required FAA A&P test, you need to obtain some related experience to become eligible.  This experience can be accomplished by one of three possible routes.

  • You can obtain traditional training from an FAA approved, Part 147  Aviation Maintenance Technician School.  Usually, this training lasts 18 months to about 2 years.  Then, after graduation, you take the FAA tests to become A & P certified.
  • You can obtain military training.  Depending on your military occupational specialty code, you can be eligible to test for either the airframe or powerplant certification, sometimes both.   Visit your local FAA FSDO office to get cleared for the test. To see the complete Military Occupation Specialty (MOS)  list, see the Airmen Certification FAA document.
  • You can obtain work experience. This can be done by working under an FAA approved repair station or FBO under the supervision of a certified aircraft mechanic.  This route requires 18 months per certificate or 30 months for both certificates.   All of your work experience must be thoroughly documented with your pay stubs and log book entries (signed off by the supervising aircraft mechanic), and/or a notarized letter from your employer or other proof that you actually performed the required work .  You then need to visit your local FAA FSDO office for an interview.

Traditionally, after graduating from an aircraft mechanic school,  taking the FAA aircraft mechanic test series is the next step on your way to an A&P license.  To improve understanding of its aircraft mechanic tests, the FAA has issued a useful test guide, entitled:

FAA-G-8082-3A, Aviation Maintenance Technician—General, Airframe, and Powerplant Knowledge Test Guide

which is available online at:

This test guide provides needed information, preparing you to take one or all of the three FAA aircraft mechanic  knowledge tests.

The FAA has a sequence of three tests, identified as follows:

TEST NAME                                                                TEST CODE

Aviation Maintenance Technician—General                     AMG
Aviation Maintenance Technician—Airframe                    AMA
Aviation Maintenance Technician—Powerplant                AMP

For any of these tests, the minimum passing score is 70 percent. If a passing score is not obtained, a particular test can be re-taken, with certain restrictions. Detailed test information is provided in the FAA-G-8082-3A document.

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Sallie Mae Career Training Smart Option Loan for Aircraft Mechanic Schools

July 24th, 2011

Sallie Mae loans at aircraft mechanic schools

The Sallie Mae Career Training Smart Option Student Loan is one option for financing your attendance at  aircraft mechanic schools. It is one example of what is generically referred to as a private student loan. You can apply for this type of loan at:

Sallie Mae designed this online application to be quick and easy for you to complete. Before starting, we recommend you (and your cosigner, if applicable) have the following information handy:

Sallie Mae application information for aircraft mechanic schools

From the Sallie Mae website, this is the information you will need to apply online for the career training smart option loan:

  • Permanent address and current address, if applicable, along with previous address information
  • if you’ve lived at your permanent address for less than one year.
  • Social Security numbers of both the student and the cosigner, if applicable.
  • School information, including GPA and academic period of enrollment.
  • Loan amount requested, as well as other financial aid you expect to receive.
  • Employment information.
  • Financial information, including monthly mortgage or rent payments.
  • Name and contact information for two personal contacts (not required for cosigners).

There are several advantages to a Sallie Mae Smart Option Loan, which Sallie Mae describes on their website.

“By making interest payments while in-school and taking advantage of the Smart Option Student Loan’s shorter repayment term, you can save over 25%  on your total loan cost compared to a traditional private student loan with deferred payments and a 15-year repayment term.”

Favorable rates – “2.25% APR to 9.11% APR” (at the time of this writing)

No penalty for prepayment

“Applying online is easy – it only takes about 15 minutes to apply and get a credit result”

24/7 online account management ”

As with all loans, there are also disadvantages.

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Understanding Airplane Rivets

July 21st, 2011
Airplane Rivets

Airplane Rivets

Universally taught at all aircraft mechanic schoolsairplane rivets are a time-honored method of attaching two metal surfaces together, with a lasting attachment. Rivets are superior to welds.

In many non-aviation situations, a “pop rivet” can be attached to fasten two surfaces, using a pop rivet gun. The general idea is to use a rivet with a “shank” and a “mandrel”. The pop rivet gun pulls on the top of the mandrel, exposing the shank.  As the shank expands, continued pulling on the mandrel clamps the two metal surfaces together. Continued force from the pop rivet gun then snaps off the mandrel head, at a pre-fashioned break point. When the rivet head comes off, it makes a “popping” noise.

The following video shows conceptually what happens as one attaches a pop rivet. Note especially what happens to the mandrel and shank as the rivet is formed.

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How a Turbo Fan Jet Engine Works

July 18th, 2011
Turbo Fan Jet Engine

Turbo Fan Jet Engine

Any definition of an aircraft mechanic job would involve engine maintenance. The Turbo Fan jet engine has revolutionized the modern aircraft industry, because of its high efficiencies and power output.  First, here is a video illustrating the main components  of a jet engine.

Shown below  is a video animation of a duel spool, high bypass turbo fan commercial jet engine. In a turbo fan jet engine, Newton’s Laws of Motion , in this case
Force = mass x acceleration
are obeyed, as you can see.

Shown below is a brief video, explaining  how a modern high-bypass turbo fan jet engine works, from . This CFM56 turbo fan jet engine powers the Boeing 737(300-900) , the Airbus A340 (200-300), and is also used with the Airbus A320 family of airplanes.

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Financing Aircraft Mechanic School

July 15th, 2011

At a typical aircraft mechanic school, tuition and other expenses might be $15,000 to $35,000 once all the required coursework for FAA certification is completed. Students can meet all the FAA knowledge and experience requirements with one to two years of training in any of over 170 FAA Part 147 certified aviation maintenance schools. Room and board alone often is in the range of $8,000 to $10,000 per year.

So how is one to finance this debt? Fortunately, scholarships and financing plans are usually made available at most aircraft mechanic schools. Nearly all students receive some sort of financial aid, and sometimes up to 2/3 of students receive either a scholarship or a grant. Often, in excess of 90% of the students receive a loan, usually in the range of $5,000 to $15,000.

Technical college students, who are seeking student loans, need to complete the Free Application for Federal Student Aid (FAFSA), available online at The FAFSA document is the starting point, allowing a determination of what student loans one is able to qualify for, in addition to grants that could be available, based upon your financial need. You can complete the application for free at the FAFSA website. When considering loan financing, it is very important to make sure you are attending a federally accredited institution. This can be checked at “The Department of Education Database of Accredited Postsecondary Institutions,” at the website . From this database, one can determine if an aircraft mechanic school is accredited, and the date of accreditation.

Some financial aid opportunities include Federal Pell Grants, Federal Stafford Loans, Alternative Student Loans, Federal Parent Loans for Undergraduate Students (PLUS), and also Veteran’s Training. Read the rest of this entry »