Should I stay or should I go?
My cell flashed the number of a dear friend who just returned from a trip out west. She’d been incommunicado for a week and I needed a girlfriend fix. I quickly answered her call.
“So,” she said in the way she starts every conversation. “I’m buckled in the front of the cabin as the plane pushed back from the gate. (She is convinced that any row past about ten on an airplane is a certain death wish–never mind reasoning with her on this point, believe me, I’ve tired.)
I yawned. A week away and that’s the headline?
She took a quick breath and continued. “The pilot came over the loud speaker and reported that they had a broken switch and needed to call maintenance.”
A malfunction. I perked up. Keep going girl.
And she did. “So,” (I warned you) “I thought to myself, does he mean switch like a light switch for the bathroom or the kind of switch that keeps the landing gear from moving up and down?”
My shoulders rolled back allowing my chest to expand. I postured like a proud parent. Yep, that’s right, my friend knows about gear safety switches.
I stretched a minute to relish in her technical savvy and then started thinking about what she really wanted to know.
Can any equipment be malfunctioning on airplane without making it unsafe to fly?
A twinge of guilt bubbled in my gut as I flashed back to the incident of the broken window shade (Monday’s post) and thought about airplanes’ minimum equipment lists. (MEL) The detailed document that allows airplanes to dispatch with inoperative and malfunctioning equipment not having impact on the safety of the flight.
Just in case you’re wondering, no, the crew doesn’t flip a coin, or shake a magic eight ball to decide what items fall into this category. Each airplane has a comprehensive FAA approved MEL listing all equipment that can be inoperative for an airplane to be airworthy. (Think of the MEL like a hall pass from the principal, it can get you to a lot of places in the building as long as you have the documentation and follow the rules)
An airline will develop operation and maintenance procedures for each item on the MEL using guidance from the airplane’s manufacturers recommendations and engineering specifications.
When a flight crew discovers any malfunctioning equipment, they will check to see if the item is included on the MEL. (For example it might surprise you to know that a clock is required equipment to fly under instrument flight rules–in the clouds)
If the inoperative instrument or equipment is not on the MEL, then the airplane is grounded until maintenance can be performed
But if the item is on the list (your golden hall pass) then the pilot, or more likely a mechanic, can deactivate or remove the inoperative equipment.
Next, they must post a placard, an aviation label somewhat like a post-it, marking the equipment “INOP”.
The final step does ultimately reside in the pilot’s judgement. If the captain confirms that the inoperative equipment presents no hazards to the flight, then the plane is cleared to fly.
There is one caveat however. The inoperative equipment cannot be placarded indefinitely. (A pass with an expiration date) The regulations state the MEL only permits operations for the minimum time necessary for equipment repair. And emphasizes that the operators, in this case, the airlines, must have the equipment repaired or maintenance deferred at the aircraft’s next required inspection. (They don’t let you drive for very long on the spare)
So after careful deduction, I figured the crew on my friend’s flight found refuge in the MEL, departed and flew her safely home.
Hail the MEL.
After taking a moment of silence, any guilt from the broken window shade no longer haunted me. After all, I wasn’t sitting in the exit row.