Worrisome state of aircraft maintenance - big things count too
I wish I hadn’t started to write this blog. What I found out while researching it scares me.
Earlier this week, my colleague, Charlie Leocha, wrote about the sorry state of aircraft maintenance. He postulated, in a nutshell, that all of those broken reading lights, torn seat cushions and malfunctioning headsets might point to a larger systemic problem with airline maintenance programs in the era of airline cutbacks.
During my days as an airline employee, I often heard the term “MEL,” short for Minimum Equipment List. It was a nebulous term for me — I kind of knew that it meant an aircraft could fly with certain items out of service, but I naively thought it was stuff like the coffee pot or maybe some minor onboard item.
Or maybe I was just in denial.
What I found in the following list, which is approved by the Federal Aviation Administration for the Boeing 757, is unsettling. Of course, there are caveats and “if X then Y” provisions with many of the MEL items, but some of the systems or items that can be inoperative or malfunctioning are:
1. Fuel tank quantity indication system
2. Windshear alert system
3. Ground proximity warning system
4. Traffic Alert Collision Avoidance System (TCAS)
5. Thrust reversers
6. Engine fire detection system
7. Fuel tank pumps
8. Passenger emergency oxygen system
9. Ice detection system
10. One of the windshields in the cockpit can have a crack in it (go figure)
They say a little knowledge is a dangerous thing. To me, the non-pilot, the complete list seems to stop just short of saying the flight can try to take off with one of the wings missing.
This stuff goes way beyond reading lights.
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4 Responses to “Worrisome state of aircraft maintenance - big things count too”
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Gee thanks, David! I feel much better about flying…….
The MEL isn’t as frightening as you might think. Sure, a lot of things can be inoperative and you can still be legal for flight. I know there are people that would shout “I don’t want anything wrong with the airplane when I fly” but they also don’t want to pay the extra $1000 per flight it would take to make sure there were enough parts, mechanics and spare airplanes around to make that happen. So we get an MEL, Minimum Equipment List, to give approval for some items to be inoperative for a limited number of days.
The items you mention with some explanation:
1. Fuel tank quantity indication system
If you know how much you started with, and know how much the engines are going to burn, then fuel tank quantity indicators are not necessary. This is usually done by meetering fuel in from the truck, or you ’stick’ the tank, which measures fuel while you’re on the ground.
2. Windshear alert system
We flew for years without one, and if it’s failed any pilot worth his stripes will be able to recognize when the potential for wind shear exists and stay away from it. That’s standard procedure anyway and the detection system is really just a last-ditch backup for looking out the window, radar, training and experience.
3. Ground proximity warning system
see above…you have to know where you are in relation to the ground, and the GPWS is just a backup for common sense.
4. Traffic Alert Collision Avoidance System (TCAS)
this is a backup for ATC, and looking out the window. We flew for years without this system, too.
5. Thrust reversers
All airplanes are certified for landing without reversers. All landing distance tables assume the reverser is not used. It’s just helps save the brakes.
6. Engine fire detection system
There are two loops to detect a fire. one can be inop, the other will still work
7. Fuel tank pumps
Two in each tank and even if both fail the engine will suction feed.
8. Passenger emergency oxygen system
Not even needed if you stay down low in the atmosphere. If this system is inop the flight can be dispatched at 10,000 feet and no one will ever have a problem.
9. Ice detection system
only if you are going to fly in areas where ice isn’t forecast
10. One of the windshields in the cockpit can have a crack in it (go figure)
The windshield is actually 9 layers thick, in three major sections. The crack can be in the outer most pane, which is the heating element. The pressure panels would then still be intact and functioning normally.
See, it’s not as bad as you think.
Thanks, LARRY.
AS USUAL, WONDERFUL EXPLANATION WITH EXPERTISE.
Regarding the thrust reversers, I read somewhere that some airlines were trying to discourage their use after landing to save fuel. I know I have been on some recent flights where only braking was used to slow us down.