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# Page 101 of 434

ASD-STE100 Simplified Technical English

## Rule 6.6 Make sure that no paragraph has more than six sentences.

Paragraphs divide a text into logical units and help keep the reader's attention. If paragraphs are
too long, they cannot have this function. Do not put different topics in the same paragraph. If a
paragraph has more than six sentences, divide it into two smaller paragraphs. This structure will
make your text easier to read.
Example:

| STE: | Description of the fuel manifold (refer to figure 10001) |
| --- | --- |
|  | The fuel manifold (1) has these primary parts: |
|  | - Two motorized fuel shut-off valves (referred to in this manual as a "shut-off |
|  | valve") |
|  | - A pressure transducer (2) |
|  | - Three fittings (10), (13) and (15). (one paragraph, 1 sentence) |
|  | The shut-off valve operates in the valve body (21). The valve body (21) has: |
|  | - An aluminum alloy ball (27) |
|  | - A retaining ring (31) |
|  | - Two seals (26) |
|  | - A spring (25). (one paragraph, 2 sentences) |
|  | The spring (25) holds the ball (27) in position to prevent internal leakage. The |
|  | preformed packings (18), (2) and (30) are installed on the seals (26), the shaft |
|  | (28), and in the valve body. They prevent external leakage. One of the two seals |
|  | (26), on which the spring (25) operates, has the function of a relief valve. It |
|  | operates when the pressure applied in the opposite direction is more than a set |
|  | value. (one paragraph, 5 sentences) |
|  | The actuator assembly (4) is of a rotary type. A DC motor, which has a permanent |
|  | high-speed magnet, supplies power to the actuator. Micro-switches in the actuator |
|  | de-energize it at the end of travel. They also send signals to the fuel control panel |
|  | to show the operation condition of the valve. A micro-relay controls the direction of |
|  | shaft rotation and an electrical connector connects the actuator assembly to the |
|  | aircraft electrical supply. (one paragraph, 4 sentences) |
|  | The pressure transducer (2) is installed downstream of the shut-off valve (in the |
|  | RH engine line). The fitting (10) connects the pressure transducer (2) to the fuel |
|  | manifold (1). A lockwire safeties the pressure transducer (2). The pressure |
|  | transducer (2) has an electrical connector that connects it to the Fuel Management |
|  | System of the aircraft. (one paragraph, 4 sentences) |
|  | Three fittings (10), (13), and (15) connect the two shut-off valves and the pressure |
|  | transducer (2). They attach the fuel manifold (1) to the aircraft structure. |
|  | (one paragraph, 2 sentences) |
|  |  |

reader to understand.

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# Page 102 of 434

ASD-STE100 Simplified Technical English
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# Page 103 of 434

ASD-STE100 Simplified Technical English

## Section 7 - Safety instructions

Summary of the rules
Definitions
How to write safety instructions
Rule 7.1 Use an applicable word (for example, "warning" or "caution") to identify the level of
risk.
Rule 7.2 Start a safety instruction with a clear and accurate command or condition.

## Rule 7.3 Give an explanation to show the risk or possible result.

Definitions
Safety instructions tell the readers that procedures or work steps in procedures can be dangerous
or cause damage. Usually, descriptive writing does not include safety instructions, unless these
instructions are quoted text, or a descriptive text that includes safety risks.
The words and definitions that follow agree with the specifications for technical publications that
are applicable to aerospace and defense:
- A warning tells the reader that there is a risk of injury or death.
- A caution tells the reader that there is a risk of damage to objects.
  It is possible that other industries or domains use different words or categories for safety
  instructions.
  If you use different words (for example, "danger," "attention," or "notice") or graphical
  symbols, always make sure that the content obeys rules 7.1 thru 7.3. For more information,
  refer to:
- International Organization for Standardization. (2018). Occupational health and safety
  management systems — Requirements with guidance for use (ISO 45001:2018).
- American National Standards Institute. (2024). ANSI Z535 series.
- International Organization for Standardization. (2024). Graphical symbols — Safety
  colours and safety signs — Parts 1 thru 4 (ISO 3864).

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ASD-STE100 Simplified Technical English
How to write safety instructions
Rule 7.1 Use an applicable word (for example, "warning" or "caution") to identify
the level of risk.
Use a word (for example, "warning" or "caution") or, when applicable, a symbol, to immediately
show your reader the level of the related risk.
Examples in STE:
All examples in this section are in uppercase letters, but STE does not give rules for
formatting. Refer to the applicable specifications for technical publications, style guides, and
other official directives.

| WARNING: | BEFORE YOU FILL THE LIQUID OXYGEN SYSTEM, PUT ON A FACE MASK AND |
| --- | --- |
|  | PROTECTIVE CLOTHING. LIQUID OXYGEN CAN CAUSE IRRITATION OF THE |
|  | RESPIRATORY TRACT AND EYE IRRITATION. |

| WARNING: | BEFORE YOU FILL THE LIQUID OXYGEN SYSTEM, PUT ON A FACE MASK AND |
| --- | --- |
|  | PROTECTIVE CLOTHING. LIQUID OXYGEN CAN CAUSE IRRITATION OF THE |
|  | RESPIRATORY TRACT AND EYE IRRITATION. |

### PRESSURE REGULATOR IS SET TO ZERO. THIS PRECAUTION WILL PREVENT

### DAMAGE TO THE UNIT.

| CAUTION: | BEFORE YOU OPERATE THE GROUND TEST UNIT, MAKE SURE THAT THE |
| --- | --- |
|  | PRESSURE REGULATOR IS SET TO ZERO. THIS PRECAUTION WILL PREVENT |
|  | DAMAGE TO THE UNIT. |

- If there is a risk of injury or death, use a "warning."
- If there is a risk of damage to machines, tools, or equipment, use a "caution."
- If there are the two levels of risk together, use a "warning."
  Examples:
  Non-STE: CAUTION: EXTREME CLEANLINESS OF OXYGEN TUBES IS IMPERATIVE.

| WARNING: | BEFORE YOU FILL THE LIQUID OXYGEN SYSTEM, PUT ON A FACE MASK AND |
| --- | --- |
|  | PROTECTIVE CLOTHING. LIQUID OXYGEN CAN CAUSE IRRITATION OF THE |
|  | RESPIRATORY TRACT AND EYE IRRITATION. |

In the non-STE example, the safety instruction is a caution. But if you know about oxygen systems,
you also know that oxygen mixed with other materials can cause explosions. Because there is a
risk of injury or death here, you must identify this safety instruction as a warning.
Compare the wording in the two safety instructions. The non-STE safety instruction is an abstract
sentence and only makes a general statement. The warning in STE gives clear and correct
information about how to decrease the risk of explosion. The warning contains the words
"explosion," "injury," and "death" to make the reader clearly understand how important this safety
instruction is.
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