Think about a departure when your tire deflates during the climb.
Now that you know... what is the best course of action? Returning to the departure station, or continuing on to destination?
In the old, non-computer, planes, you wouldn’t have known about the leak until landing, then you would land with a flat tire at destination. More than likely without incident... other than a surprise tire change.
But what if that destination happens to be a remote location, say 11 hours flight time away, and there's only one plane flying in and out daily… what happens? You ground operations until you can fly another plane in with a couple new tires. A huge economic impact. A huge impact to customer service and people's lives.
Note 1: A "couple" tires? Yes, the tire next to the deflated tire needs to be replaced too.
It makes economic and operational sense to return to landing at the departure station, get your tires changed and then press on. There are always pros and cons to every decision. Since you can’t dump fuel on the A330, you'll end up doing an overweight landing. Not a big deal.
Note 2: With an overweight landing Airbus recommends to perform an automated landing using managed speeds.
Performance charts indicate using medium brakes (verses low or high) leave plenty of landing distance even without the tire and associated brakes. But you will have overheated brakes during an overweight landing. You will have to wait until the brakes cool—delaying your departure by a couple hours.
Note 3: Maximum temperatures for departure is 300 degrees centigrade.
What's the problem with returning to the departure station besides a few overheated brakes?
A 17 hour duty day for the flight crews. With a return, this could push your next departure well into the next morning. Is it possible to be rested and your best for the second attempt at the journey? What if another more serious situation were to occur after an extended delay? Does the FAA's pending rest regulations take into account a departure, an emergency, a return, followed by a delay and a second departure? Is there a different level of fatigue with a departure and flying for 17 hours, than a departure, a return and continuation? The real question is how much rest did you have going into a night like this?
Being rested for your flight is essential. It's about being safe and responsible to yourself, your fellow crewmembers and your passengers. You never know when the unusual is about to happen, be prepared for it! Be rested!
Note 4: 17 hours awake = an alcohol level of .05.
Interesting fact: Did you know it’s possible to be awake for 24 hours without ever seeing the sun?
Life is an exhausting adventure when you're a pilot. What's the longest duty day you've ever flown? Mine was with Tower Air... 27 hours!
On a side note: What do you think I said to my Captain after we declared an emergency and returned for landing touching down at midnight?
Enjoy the Journey?
Was that your Lagos emergency? Glad it wasn't more serious.ReplyDelete
I was once a passenger on a B747 that blew tires landing at Montreal, it needed all 4 tires on one bogie replaced. And another that had an in flight shutdown, and an L1011 that had an engine fire on take off. They were scary, but the crews were well trained and had it all under control.
Interesting post. I'm guessing your problem was with MLG wheel #8 which is showing 65 psig while all of the others are at 240 +/- 5.
It's interesting to learn about all of the operational factors that go into the continue-vs-return decision. As a purely technical matter I'd think it would be OK to continue (an opinion I do NOT extend to the BA crew that flew California to England on three engines a few years back).
Question for ya': Are those the post-landing temps above the pressures? I guess it makes sense that the low-pressure wheel has the most elevated temp (1,335F - wow! "Glow in the dark" stuff).
I assume that you declared an emergency 'cause that's the only way to get the airport to roll the equipment, and given the risk of fire from the brakes, you sure do want the fire brigade standing by. Did you calculate an expected stopping distance and inform them for positioning purposes? Can you even do that?
As to what you said to the Skipper...was it, "Happy New Year"?
Good job by all. Thanks for sharing.
Fascinating info, Karlene. I'm SURE what you said to your Captain was 'I'm enjoying this journey!' :-)ReplyDelete
Yes D.B. that's why we had to return. There was a bit more to the adventure, but what happens in the flight deck stays in the flight deck. Sometimes. :)ReplyDelete
We weren't sure if ours would hold together or not. But it did. And stopped nicely.
Thanks for your comment.
Hi Frank, yes...that's it on the wheel. We could have continued and had an extended stay in Lagos. But that would have really messed up the operations. Do we make decision on operations? Yes. It all goes into the decision making process. But safety and landing at the nearest suitable airport is essential. Not this case.ReplyDelete
Safe. Safer. And unsafe, can be up for debate. And may make an interesting post one day.
There were a few more issues...but I'm working on the answer right now. We had a little gremlin in the MCDU. Thankfully it was clear conditions.
Those numbers were glowing the brakes down below. The mechanics said they never saw such heat. I think they blow fuse plugs around 900-1000 degrees.
All the airlines I've worked with mandated that anytime we do an overweight landing we roll the equipment. I think it just makes good sense. We didn't tell them where we would stop, because we kept her rolling to get her off the runway.
If we had something more serious, they (fire trucks) normally sit aside the approach end and then drive with the plane until she stops. This time, they just waited at the other end.
Thanks for the comment!
Neat post Karlene! Did you end up continuing the flight eventually? I find it interesting an airplane that big can't dump fuel. Can you land just below max takeoff weight safely or do you need to burn a little off? And what's the ref speed at that weight? Thanks again for sharing!ReplyDelete
Thanks Daniel! We departed at 245 that same morning. Pushing our 18 hour duty day. One of those nights I was "lucky" to have slept just before.ReplyDelete
It is amazing that you can't dump. And yes... she can land. I found out more interesting things on landing overweight... more to come on that next week.
Great post KP! Thanks for sharing. Glad it turned out to be uneventful.ReplyDelete
Thanks Chats... but the plot thickens. I've learned a lot since this event. More to come next week.ReplyDelete
Great post, Karlene! Still coming to terms with the fact that a wide-body like the 330 can't dump fuel!!?? As always, your posts are educating and informing aviators - From the Ground Up!!ReplyDelete
Allow me to comment. Fuel Jettison system is required by regulations if an aircraft does not meet the performance gradient requirements for an approach climb and go-around with a weight equal to max takeoff weight minus the fuel requirement of 15 mins for aircraft to return back after takeoff.
A330 meets this requirement, hence the fuel jettison system is optional on this aircraft.
Thank you for sharing this information! Interesting. I didn't realize that it was "optional." So... could the max takeoff weight be increased and have the "optional" dump system installed? Why else would they put that in? Does anyone have a configuration such as that?Delete
Jettison system could be installed by operator as deemed fit. In this case, it's an option that operator takes a call.ReplyDelete
I cannot verify but I'm told that Emirates has it on its A 330 and the Thai on A330-300
Interesting! Maybe the plane has so much power for the range... companies don't need it? None of ours can dump fuel. Thanks for the added information.Delete
af447 type pad, I read your post. Interesting, but not sure I agree with everything...such as thrust levers. But then we can't all agree on everything. Your hours on the plane are amazing. But then the thrust levers, while I first thought the same thing... confusing... isn't a design flaw, is more a need to understand them... and then they work great. The situation with the accident you mentioned, I believe that pilots only know what they know. This is a central theme in my book, Flight For Control. We need "more" training for these automated planes, not less. Thanks for reading. Looking forward to reading more of your stuff too. Fly safe!Delete