sexta-feira, 19 de setembro de 2008

Stabilized Approach - Ready for Go-around?


*Land as soon as possible

In some circumstances, the role of airmanship and good judgment should be clarified.

Even in this situation – RED WARNING – procedures do not decide on behalf of the crew. The level of emergency and the time available should be evaluated. Crew good judgment and decision are based on the time available, the type of failure, the flight situation and the environment ( weather, characteristic of surrounding terrain, etc…)

Sometimes, the main reasons behind the procedures should be explained

For example, in case of TAIL PIPE FIRE
The crew must perform the following actions:

Shut down the engine
(MASTER switch ser to OFF)
Do NOT press ENG FIRE pushbutton


Because FCTM02.03

This would stop power to the FADECs and would stop the motoring sequence
The fire extinguisher must not be used, as it will not extinguish any internal engine fire.

As a first priority, the engine must be ventilated

“Follow the procedures” is NOT sufficient.
Not even the best procedures can be considered perfect. Extensively tested before implementation, SOPs are the outcome of a lot of expertise.
However, the environment is dynamic, and procedures can only provide baselines. Not ser of procedures can substitute for human intelligence and flight experience.

SAFETY = Safe aircraft + procedures + pilot’s competence as an ability to manage the expected and unexpected


Why do well trained and experienced pilots NOT always follow procedures?

By Clarie Pelegrin
Director Human Factors

For years, everybody has shared that same idea that safety will be guaranteed if pilots ares selected and trained, so as to strictly apply procedures.

The method was:
Tell them
Train them
Enforce them

To follow procedures.

When incidents or accidents occur, most of the time a non-adherence to procedures is mentioned. But this is not sufficient to explain accidents, because every day pilots do not follow procedures and this does not always lead to accidents.

In the aviation domain, the purpose of introducing procedures was to enhance safety in normal and abnormal conditions, by reducing uncertainty and thus risks. The rationale was obvious, and the benefits so blatant that the aeronautical industry has been using procedures for many years.
It is now undisputed that pilots shall adhere to the procedures designed for them. But real life is not always that simple.

The objective of this article is to understand the complete picture: good procedures design is important as well as appropriate explanations to ensure pilots have sufficient confidence in their skills and judgment to manage the situation.

Each procedure is designed as the best and safest way to do a given task. Flight deck procedures are the skeleton of flight operations. They are the structure and the organizations by which a pilot can fly and interact with the aircraft and other crewmembers.

Role of Procedures

Everybody knows the obvious role of procedures as a GUIDE for action ( individual and collective guide). It tells the pilot

What to do
When to do it

Sequence, order, synchronization

How to do it
Who should do it

Organised task sharing

What to observe and what to check
What type of feed back is provided to the other crewmember

But procedures also have additional safety functions, which sometimes are not taught and explained well enough:

They support:
1 – Situation awareness and anticipation
2 – Decision making by providing
3 - Error management
4 – Support risk management within complex and dynamic situations

Procedures implementation

Not everything is predictable, and there is no magic in procedures. Mismatches do exist between procedures and actions. Implementing a procedure is not a simple automatic process.
A procedure implementation is by nature different from the procedure itself: the first one is an action, the second one is an instruction. The procedure specifies the tasks, then the piot will have his/her own way for implementing the task.

Human performance is not stable, and can be impaired by a variety of factors such as fatigue, stress, workload or operational pressure. This can impair procedure implementation. This is why it is important to understand the triggering factors behind procedure deviations in order to minimize them.

Most of the time, crew action includes much more than what is written. It requires sophisticated mental functions such as:
1 – Understand the situation
2 – Understanding the procedure and its meaning
3 – Ensuring that all pre-conditions are checked
4 – Anticipating the expected results
5 – Ensuring that all actions requested by the procedures are performed in the right order, with good judgment and with food synchronization between crewmembers