Knowing your aircraft’s limits

By Brent Crow

We all have our limits when we fly—but do you know your aircraft? How can you ensure that its limitations are not exceeded or that configuration changes were successful? The answer is: Limitation Operation Indication (L.O.I. for short). The acronym, L.O.I., can apply to any configuration, power change, or system operation, when a logic check may need to be performed. It’s the perfect tool to put in your pilot’s “bag of tricks”.

As an example, let’s walk through using L.O.I in the process of deploying flaps:

Limitation

Start by ensuring that the airspeed limitation for the deployment of flaps will not be exceeded. Are you in the white arc of the airspeed indicator? Are you certain that you can keep the airspeed under the limitation? If so, move to “Operation”.

Operation

Make sure you have your hand on the correct lever, switch or handle in order to make the operation occur. Are you correctly selecting the proper position (for instance, flaps to 25 degrees versus 45 degree position)? If so, then move the flap handle to the appropriate position. (FYI— for gear and perhaps spoilers it is a good practice to keep your hand on the handle until you have verified the gear indication is correct, or until the spoilers have been stowed).

Indication

Now, confirm that you have a positive indication that the operation actually occurred. For flaps, a quick glance at the wings can verify the flaps deployed to the proper position, and that they are not asymmetrically deployed. When applying this to landing gear, don’t forget those 3 green lights on the panel. For configuration changes, there is always going to be some sort of aerodynamic change with the aircraft that can help you verify that the operation of the configuration change was successful. When deploying flaps, there is almost always a pitch and airspeed change that you will have to anticipate.

Be careful because you can be your own nemesis. You drop flaps because you are 8 knots below max flap operating speed and then the aircraft pitches up. You counter with an overly-aggressive counter pitch in the nose-down direction. This causes the airspeed to jump 10 knots and now you find yourself exceeding the limitation. Oops—time to squawk the aircraft and make a safety report!

To recap, Limitation Operation Indication (L.O.I) ensures you :

• Properly check control function prior to the flight so there is less likelihood of a loss of control accident

• Don’t land with the gear up

• Never operate the wrong lever, switch or handle

• Catch malfunctioning equipment early

• Don’t exceed operating limitations