Quote:
Originally Posted by CraigSca
Wow - had no idea each pre-flight check includes an alternate airport for landing - thought all of that was figured out on the fly.
I do have a quick question for you - you mentioned maintenance variances - how often do you fly with something wrong with the airplane (obviously, non life-threatening)? Do you ever fly with a lack of redundancy? Are you allowed to? I would assume there's something wrong with the plane the majority of the time (even if it's something that has nothing to do with its ability to fly), but I've often wondered to what degree are things broken on a plane and yet still pass "ok to fly".
|
You won't have an alternate for every airport all the time. And the alternate that you have for takeoff obviously wouldn't be the airport that you use at your destination. Third, the alternate that you file for your destination is mostly so you have a plan and are even legal to depart. If the weather is bad enough they are required. If you do need to divert, it often times is a mix of where the company wants you and where you can go. I've had my alternate change 3 or 4 times on 1 flight just so we could hold longer for the the destination airport. With weather, it's a very dynamic situation.
So here's the story with maintenance and broken stuff. It's extremely regulated. FAA regulations state that everything must work on an airplane for it to be able to fly. Everything that is, unless it's on one of 3 lists. Lists are created so that planes aren't grounded for coffee pots being broken. They are put together with the help of the manufacturer and approved by the FAA. If it's one one of these lists we might be able to go with it broken.
That's the short of it.
There are a lot of redundancies built into the plane. A lot. We have a list called an MEL for checking to see if a we can fly with a broken item, like an air conditioning pack (one of the most common) or auxiliary power unit (APU). This list has explicit instructions about what can be broken, what action needs to be taken and how it needs to be flown with said broken item.
Another list is the CDL. It has items that can be missing and still let us fly like gear doors. Same rules apply as above. The last is a non-essential furnishings list like a coffee pot, or floor trim that can be missing.
If any item isn't in the books its considered a no-go item. A gas cap would certainly be a no-go item. I don't want to see my fuel siphoning out of the wing as we go along.
So to answer your question, a lot. Some planes are better than others. Planes with more automation that tell you everything that is wrong with it have a tendency to tell you a lot. That can lead to a lot of nuisance write ups for things that there just doesn't seem to be an answer for. The auto pilot, or flight management system can be written up and deferred. And there can be certain items that are allowed 1 flight to take it somewhere for the purposes of getting fixed.
One of the more interesting/frustrating things happened many years ago. We were in MSP with a full plane and a jump seater in the cockpit. I was finishing up the final weight and balance for the plane and then we heard this hiss, like air rushing out of a balloon. It took a minute for us to figure out that the valve on the crew oxygen tank had failed and we sat there helplessly while all of our oxygen drained out. The tank was inaccessible, once it was gone, it was gone. The flight cancelled and we had to fly back to Cincinnati, at a pressure safe altitude of 10,000 feet.
Another was when I volunteered to take a plane from Denver to St Louis to help another crew out so they didn't get screwed. I was going there anyway. Come to find out that the issue was with the landing gear and the plane had to be flown with the gear locked and pinned in the down position. No passengers again, but we had to make a planned fuel stop because of bad weather in St Louis.
Most times you'll have 1 or 2 things deferred, they will be minor things generally. Even broken tray tables end up in the book. But sometimes you'll hear of someone who determined that they simply didn't feel safe flying the plane with whatever mechanical issue was involved, like a shattered wind shield as an example. One pane can be shattered, but the plane can be ferried to a base, but some guys still will refuse the plane. It can lead to big discussions with the company and the union. For the record, I've never had anything that I haven't been able to work out, one way or the other.