CMH-17 Coordination Meetings & Tutorials

  • The next AM Coordination meeting is scheduled for April 19 - 20, 2022. Registration available here
  • The next PMC Coordination meeting will be summer 2022 (dates and location are TBD).

CMH-17 Tutorials


Tutorials are held contingent on interest and instructor availability. The decision to hold or cancel the tutorials will be made one month before the workshop. The following tutorials are available. Note that the Certification and Statistics Tutorials typically occur concurrently. Attendees may only register for one. The Damage Tolerance course is taught at a different time.  

Certification Tutorial


The Aircraft Structure Certification and Compliance Tutorial (updated in May 2016) includes safety awareness curriculum developments in Structural Engineering, Manufacturing and Maintenance. Attendees will gain an overall understanding of aircraft certification and substantiation and will benefit from opportunities to interact with other attendees. The tutorial complements and extends the topics in CMH-17 Volume 3, Chapter 3 by providing added content depth. The tutorial emphasizes the following:

  • Structural substantiation and proof of structure of type design 
  • Production support
  • Manufacturing defect disposition
  • Continued operational safety

Additional material will discuss newer industry engineering guidelines and regulatory guidance and policy published since 2011, such as the following:

  • Bonded repair size limits
  • Damage threats
  • High energy wide area blunt impact (HEWABI)
  • Fatigue and damage tolerance


Statistics Tutorial

Printable Statistics Tutorial Outline

In support of Handbook objectives, the handbook includes methodology for performing a number of engineering processes associated with the design, manufacture and continued operational safety of composite materials.  These processes use rigorous statistical analysis requirements to confirm acceptability. These statistical procedures are sometimes intricate and confusing to individuals that are not familiar with them.

This tutorial is a comprehensive treatment of the CMH-17 methods for statistical analysis and their importance to proper development of design information. Students will participate in an interactive session on the CMH-17 statistical methods, including practical example problems.

Students will receive a copy of CMH17STATS. Students need to bring a laptop computer with Microsoft Excel to participate in the interactive sessions, as they will be focused on using the specialized software available: CMH17 STATS and HYTEQ.

Lecture: Statistics for Allowable Generation
Understanding A- and B-basis values and related statistical tests This section focuses on the concepts of A- and B-basis values, what they represent and why they are important. Students will leave with a clear statistical understanding of A- and B-basis values, and an in-depth appreciation of the significance of these values in engineering applications. In addition, a user-friendly flowchart that outlines the material property basis value generation process used by CMH17 Stats will be presented. The flowchart, which was jointly created by Statistics Working Group and Data Review Working Group, emphasizes engineering rationale while ensuring statistical validity.

Interactive Tutorial: Statistics for Allowable Generation (Includes Practical Example Problems) 
This interactive tutorial section will include practical example problems on how to compute engineering basis values as outlined in CMH-17. The CMH17 STATS program computes A- and B-basis values as well as other statistics. The use of engineering judgment in interpreting the software results in arriving at a final decision will be discussed.

Lecture: Equivalency Data Analysis

Understanding material equivalency and acceptance testing (material specification limits).  This section focuses on the concepts of equivalency testing, including the null hypothesis, Type I and Type II errors, the test statistics and the power of the test. Students will leave with a clear understanding of the purpose and criteria for material equivalency and acceptance testing. A modified co-efficient of variation approach for the purpose of generating interim basis values and specification limits will be explained and discussed.

Interactive Tutorial: Equivalency Data Analysis (Includes Practical Example Problems)
This interactive tutorial section will include practical example problems on how to compute equivalency test statistics outlined in CMH-17. HYTEQ (HYpothesis Testing of EQuivalence) computes the hypothesis test results for equivalency data. The use of engineering judgment to interpret the plethora of equivalency test results in arriving at a final decision will be discussed.

* Agenda and content is subject to change.

Bonding Tutorial


Structural Adhesive Bonding Materials and Processes Tutorial

Structural adhesive bonding is an area of startling complexity contained in a tiny seven thousandths of an inch-thick ribbon. This tutorial will attempt to clarify why structural adhesive bonding has a frequently unacceptable level of surprise, rarely good. These surprises can continue throughout a bond’s life cycle, not just development and manufacturing.

Many failures of bonded structure are the result of misunderstanding issues associated with bond processing, whether during original manufacture, field support, or repair. This tutorial covers bonding materials commonly used, and the processing they require to create successful bonded structure.

One of the central difficulties with structural adhesive bonding is that there appears to be at least one conspicuous (and perhaps even reasonable) exception to almost every rule or guideline considered. Rather than trying to provide absolute guidance in such an environment, the tutorial will attempt to provide counsel on what to do with the variety of answers, some contradicting each other, already found in the literature.

The tutorial is presented from the perspective of Materials and Process Engineering. While many areas of expertise must work together well to achieve bond system success, M&P has central responsibility for providing a good bond.