What Southern Hospitality and Humidity
Have in Common?
Southwest Hot & Cold Air!
Beauty Truly Skin Deep?
What’s in a name like “Southwest Airâ€?
Moisture and humidity; that’s what!
And when it comes to what makes common sense, I think it will be easy to see the following makes …dollars and sense.
Consider for a moment the adage which says; “…what you don’t know won’t hurt you.â€
But, be that as it may; “What you can’t see can and will bite you.â€
Take for instance the cold sweat of condensation on the OUTSIDE …EXTERIOR of your favorite McDonald’s soft drink.
You can see that can’t you?
Of course you can.
Why? Because its surface is visibly exposed for your inspection.
But can you see the interior skin of an aircraft’s cabin? No, of course you can’t.
But, because the moisture from the warm moist air (inside a McDonald’s cabins) can be seen on the outside of the cup’s exterior surface …due primarily to your cup’s contents …or, what’s on the inside of the cup …there is a cold which sets up a relative differential temperature necessary to produce or exceed the dew point.
Turn this example inside out and think of this in terms of the physics at play inside an aircraft’s cabin.
In this case, the cup’s exterior now becomes the cabin interior’s skin surface which …unlike the cup …can not be as easily observed not detected.
Therefore, in regard to the origination and formation of cracks in the skin surfaces of an aircraft …reverse the scenario above, and this process whic involves relatively warmer moist cabin air is no longer that which can be seen on the outside …but rather a matter of fact …a hidden one at that.
And just because you can’t see it; that doesn’t mean its presence and affects should be ignored.
Because the interior skin surfaces of an aircraft are all well covered over under various degrees of inter-woven, layers of cabinetry, insulation, plumbing, heating and cooling ducting, wire bundles, escutcheons, equipment and various other interior fixtures.
What can be easily seen is primarily the exterior skin, but corrosion …unlike beauty is not always skin deep …it is ugly to the bone …a consideration which is primarily an inside …out …hidden consideration.
What is seen is often too late …especially when the power of the pencil whipping comes into play …as a forsaken matter of a horribly over looked consideration of time and money …when such practices are given place in allowances ahead of safety.
Aside from the chances that safety is overlooked …God forbid that we should look back to a time when Air Tran was operating under a different name which suffered under a low esteem for safety checks regarding the shipping of spent oxygen canisters …what might be going on with Southwest Air’s Boeings?
The practice of Pencil-Whipping checks is one consideration. The …Let’s don’t and say we did mentalityâ€ is a slippery slope …similar to Value Jet’s mid air explosion …a demise which led to repackaging the entire company in a face lift called “Air Tranâ€ … fines not withstanding.
The intervals between the deeper inspections are most likely the prime consideration, though, because it is not practical to tear out the interiors to check the skin throughly …vs. thoroughly …from the inside out …in spite of the fact that there are ultrasound and x-ray inspection techniques which exist to do the checks from the exterior skin surfaces.
However, it may be the case that cabin interior and corrosion inspections which could cover the formations and originations of cracks from the inside are for the most part …checks which may not be an ordinary part of the normal interior cabin inspections.
So if …not removed nor included to accomplish interior skin inspections in the inspections which have shorter periodic intervals …I.E.; the A B and C Checks …such more in-depth opportunities must wait and rely on longer spaced-out interval inspections such as given and afforded in the D Checks.
However, high duty cycles where rapid temperature variations are a routine part of an overworked airframe …are or should be a consideration of any periodic and routine set of comprehensive maintenance intervals …just like the FAA historically mandated TBO (Time Before Overhaul) items which are routinely changes out in clock work fashion according to the number of gear cycles …the number of flap and actuator cycles and the like.
However, unlike the numerous mechanical systems whose historical life cycles are tracked with a degree of rigor which would make any CPA or accounting firm proud …condensation cycles are most likely not a part of any maintenance schedule …let alone a consideration whose adherence has a standard to follow …outside of what dictates normal routine priorities focus within the guideline of what practices’ esteem have to date provided.
Don’t sweat the small stuff? Be careful, it’s not all small stuff.
Some small things pack a powerful bite.
Good luck and have a safe flight!
All the best,