What Do the AECMA Guidelines Say?


June 2000

What Do the AECMA Guidelines Say?

CIDMIconNewsletter Katherine Brennan Murphy, Center Associate

In the General Introduction to the AECMA Guidelines, the authors explain the need for simplified English:

Even though English is more and more the international language of aerospace, certain facts must be faced:

  • English has many forms depending on the nationality (or region of that nationality)
  • And even the “purest” English, with all regional dialect or jargon removed, can be difficult to understand if the grammar or word usage is too complicated.

They go on to describe AECMA Simplified English as “a controlled general vocabulary and a set of writing rules.”

Vocabulary Guidelines

In addition to the basic words in the vocabulary, each organization adds what are called Technical Nouns or Manufacturing Processes that are unique and well defined within that organization. Each vocabulary entry lists the word and its required part of speech. It also states whether the word is allowed or not and what substitutions are acceptable if the word is disallowed.

For example, the word “test” is approved as a noun but not as a verb. After the entry for test, you learn the following:

BEFORE: Test the system for leaks

AFTER: Do the leak test for the system.

OR: Do a test for leaks in the system.

The writer must also use the approved meaning for a word. For example, the word “follow” means “come after” rather than “obey.”

BEFORE: Follow the safety instructions

AFTER: Obey the safety instructions

The standard also restricts the forms of verbs and adjectives. For example, a writer must not use the -ing (progressive) form of verbs.

After looking at these few examples, you can immediately appreciate the difficult task of compiling a dictionary for an organization.

Style Guidelines

The style guidelines are more in tune with what any experienced technical writer would expect. Even so, following them can be a difficult process. Here are the major style rules:

  • Make your instructions as specific as possible.BEFORE: Different temperatures will change the cure time.

    AFTER: Increase the temperature to decrease the cure time.

  • Do not use noun clusters of more than three nouns.BEFORE: The nose landing gear uplock bolt is…

    AFTER: The bolt that attaches the uplock to the nose landing gear is….

  • Use an article or a demonstrative adjective (this, these) before a noun.BEFORE: Lift up assembly and put in box.

    AFTER: Lift up the assembly and put it in a box.

  • Use only infinitive, imperative, simple present, simple past, and future verb forms.
  • Use the only the active voice in procedural writing and as much as possible in descriptive writing.
  • Keep to one topic per sentence.
  • Do not omit words to make your sentences shorter.
  • Use a tabular layout for complex texts.
  • Use connecting words to join consecutive sentences that contain related thoughts.
  • Keep procedural sentences as short as possible (20 words).
  • Write only one instruction per sentence and use the imperative.
  • Write more than only one instruction per sentence only when more than one action is done at the same time.

Examples from Caterpillar

Before: Clean the element and cover.

After: Clean the element and the cover.

OR: Clean the element and cover the element.

Before: Take a measurement of the clearance.

After: Measure the clearance.

Before: Do the parking brake efficiency test.

After: Test the efficiency of the parking brake.

Note that different “flavors” of Controlled English make different choices. In the AECMA standard “test” is noun; at Caterpillar it is a verb. This difference underscores the need for each organization to create definitions that work well in their particular environment.

Example from Boeing

Here is an example of “before” and “after” from Boeing’s Simplified English. Between the before and after statements is the checker output that gives advice (known as a “critique”) on how to revise the text so that it complies with the Simplified English standard. If the checker detects nothing wrong with the sentence, the checker output just says “No errors found.” Jim Hoard has included brief comments that identify the standard in square brackets. These comments are not, of course, part of the checker’s critiques.

Before: Position truck shield under main gear truck and mark locations on truck where truck shield clamps will attach.

Critiques: Two instructions-possible error.

[Only one instruction is allowed in a sentence, unless the actions are performed simultaneously.]

Unapproved prepositions: under. Use: below, in, less than. [The preposition “under” is proscribed in SE. Alternatives are offered in the critique. You can choose one of them or rewrite the sentence to avoid a preposition altogether.]

Missing articles-truck shield, main gear truck, truck. [The English articles are to be used wherever they are appropriate in normal discourse. Telegraphic style is proscribed.]

After: Put the truck shield below the truck. Make a mark where the truck shield clamps attach.

Humorous Rewrite

Many people have read the article “Cat Bathing as a Martial Art,” by Bud Herron, published in the Saturday Evening Post. When I was teaching the engineers at Tektronix about Simplified English, I “obeyed” the guidelines to rewrite this article. Unsurprisingly, this rewrite took me four hours, and I had to look up every word in the approved dictionary. This experience certainly increased my resolve to put an authoring tool in place before implementing a version of Controlled English!

Please look on our Web site
to see before and after versions of these critical instructions. Both pieces are copyrighted and used by permission. CIDMIconNewsletter