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Old Mar 1, 08, 11:51 am
Join Date: Feb 2008
Location: Mountain West USA
Posts: 436

Originally Posted by pogopossum View Post
It appeared like the mechanical issue was known prior to take off, but they declined to acknowledge until we were in the air. Conjecture, of course.
It could be that, but with something as big as the lavs, its doubtful they just ignored them. Now, they should have mentioned it to the passengers before boarding, but this is just me playing Monday Morning quarterback and there is a lot that could have been going on to preclude that.

A captain has to balance the needs of passengers versus the needs of the company and delaying a flight so that people can use the restroom 10 minutes before scheduled departure may not be realistic, especially on a shorter flight.

Its a damned if you do, damned if you don't situation.

As a passenger, you might think its not, but deboarding an aircraft is a big deal.

Once you let people off, they are free to roam. You'll have someone decide to go to the bathroom, then go get something to eat or just wander off. Then you are in the tough spot of either leaving without them or wait the indefinite amount of time before that one passenger hears the multiple announcements and wanders back to the gate. You leave, they are now mad because their flight left without them.

Now, it is possible they both broke in flight.

One thing about these new aircraft is that they are highly computer controlled and very electronic in nature. If the computer senses a fault, it can take just about anything offline. Often, when an aircraft is new, the software sometimes is a bit too sensitive and pulls stunts like taking systems out of service for no reason. I am not familiar with the systems of the EMB170, but it is possible that the computer just had a bad day and turned them or an associated system off, rendering the lav's unusable.

Fixing that problem would require rebooting the computer, which in an aircraft's case, requires shutting everything down and turning it back on after a minute or so.

Obviously, that's not a good option while in the air.

Originally Posted by sbagdon View Post
The way I'm reading this is that the crew knew the lavs were out, before closing the cabin door. If this were the case, is this a safety violation?[/I]
Not necessarily.

Every airliner has a book called the Minimum Equipment List or MEL as you will often hear it referred to. The MEL is a book of things on the plane that can be broken and it still be safe and legal to fly.

What an MEL allows an airline to do is maintain some semblance of an ontime schedule and to get the aircraft to a location where the maintenance can be performed. Not every outstation has parts, for example.

In the above case, it is quite possible that both lavatories can be inoperative and the plane still be legally dispatched (the a/c I fly can be dispatched with its only lav inop and when the blue juice freezes some nights, that's what happens).

This may also explain why the mechanic came on the plane. In most cases, to "MEL" an item requires a mechanic to come on board and perform certain actions that render the component unusable. He then makes an entry in the aircraft log noting that the lav's, in the above example, are inoperative.

Each MEL has a time limit for when it has to be fixed, ranging form 24 hours to 120 days, depending on how critical the part is. However, most reputable operators do fix the issues relatively quickly.

How many MEL's can an aircraft have?

Well, often there is no limit. Some operations can be precluded if certain systems are inoperative. However, at the end of the day, its up to the captain to draw the line and get some things fixed if its unreasonable.

How do you know how many MEL's your plane has?

Each MEL item must be clearly posted for the crew to see, so in most cases, stickers are placed in different places in the cockpit to denote each MEL. Many stickers means many MEL's.

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