What is a Standard Operating Procedure (SOP)?
A look at Standard Operating Procedures and why they are used.
What is a Standard Operating Procedure?
The term SOP is an abbreviation for a Standard Operating Procedure. SOPs are a framework of common procedures set out by an airline which supports pilots in operating a commercial aircraft safely and consistently. SOPs provide step-by-step instructions for how to carry out a task or procedures. It has been suggested that SOPs are specific to routine tasks, but in aviation, they equally apply to rare emergency situations.
Many industries use SOPs to ensure that tasks or operations are completed correctly and in a specific order. It also ensures that the task or procedure is carried on in the same way consistently by many different people.
In aviation, and specifically for pilots, Standard Operating Procedures (SOPs) serve a number of purposes such as:
- Ensuring that aircraft is flown correctly in accordance with the manufacturer’s guidelines
- Promote adherence to the manufacturer’s and airline’s operating philosophy
- Promote operational safety
- Promote operational efficiency
- Utilise aircraft resources and functionality appropriately
It also allows any pilots from the same company who may not have flown with each other before (or they may even have never met each other), to fly together as a crew. Adherence to SOPs means each pilot knows exactly what they and the other pilot should be doing in any given phase of flight. This is particularly important when working for a large airline with hundreds or perhaps thousands of pilots.
Different types of SOPs
The following are different types of Standard Operating Procedures:
A memory flow of arranging switches and levers in the correct position for a particular phase of flight. For example, it is normal that the PM / PNF (Pilot monitoring or Pilot not flying) will complete the before start flow and then read the before start checklist which the PF (Pilot flying) will respond to.
A call or acknowledgement of an event. For example, most EASA airlines have to acknowledge an automated callout of 1,000ft which would be followed by PM / PNF stating whether they are stable or not for the subsequent landing.
A procedure that requires completing with certain criteria. For example, in visible moisture below 10 degrees pilots will be required to taxi and take off with engine anti-ice systems on.
SOPs can also be developed as time goes by to incorporate improvements based on experience, accidents, near misses or innovations from other manufacturers or operators to suit the needs of a particular organisation.
SOP design covers both normal and non-normal operations. For example, they dictate how the take-off should be flown whilst also providing guidelines for how to respond to an engine failure.
SOPs should not be designed to be too detailed and exhaustive as this can over complicate the process which may require a high level of attention and mental capacity at the expense of other tasks. However, they should also not be be too vauge or relaxed to the point that the crew have too many options to decide between as this may lead to the SOP being incorrectly applied.
If a pilot is not conforming to SOPs. he/she can be expected to be challenged by the other pilot. Failure to respond appropriately to 2 or more SOP deviation calls by the other pilot will lead them to assume you have become incapacitated and will take control of the aircraft.
When would you not follow an SOP?
However, there may be an occasion where it is preferably or vital to ignore or not carry out an SOP. This would normally be in an emergency situation. An example of this would be continuing to land the aircraft below the operating minima where the pilots had not become visual with the runway as they had an uncontrollable cabin fire. In this case it would be safer to continue with the landing despite it being against the rules (or SOPs) to do so.