AceReport

Just like LO16 back a few years that flew the entire TATL flight to burn off fuel. Many planes can take off quite a bit heavier than their Max landing weight due to fuel so they in fact have to either burn off or dump it.

I would also speculate that since PDX is a bit slower traffic wise and seems to be well equipped for an emergency situation (as most major airports are) that having it land there rather than SFO where a closed runway would lead to major delays was a wise operational move.

Moderator2

The respected Aviation Herald's posting on the incident: Incident: United B739 at Newark and Portland on Feb 25th 2018, burst tyre on departure

Wayside

Aircraft are certified to land at maximum takeoff weight. It requires an inspection to be returned to service but landing overweight is an option in any emergency. Some aircraft have fuel dump capabilities which can help get underweight but I believe the dumping is designed to help the aircraft meet engine out climb gradient requirements as well. Landing overweight certainly increases runway length requirements and this is all factored as the crew works through the abnormal procedure.

mduell

Or land and take the inspection.

jmastron

That's true, and there are incidents where that's the right thing to do, but a blown tire seems like a case where you'd want to land as light as possible. From a poster here who knew someone on the flight, it sounds like they also moved passengers around to put the center of gravity as far back as possible (without risking a tail strike).

mrswirl

Not an expert either but I suspect that a blown tire on takeoff is about like a blown tire on the highway - concerning of course, but hardly a critical emergency. If they're already in the air and climbing to cruise altitude then it is probably better to continue on, burn fuel and lighten the aircraft and prepare for an extended nose-up landing than turn back immediately. Sounds like the crew did a great job in bringing the plane down safely.

drewguy

Except that you can't really keep driving the car with a blown tire (run flats excepted) but you can keep flying the plane.

TA

With a blown tire, as others suggested above, yes you do want the weight down, so burn off the fuel and get to the destination while you're at it. All else during mid-flight and approach I would say is the same as in normal circumstances and would have little to do with the tire once the continuing decision is made, so additional fuel is not a concern. Then on landing, I would think they kind of have "1 try and better get it right", because once that bad tire hits the ground, you're not wanting to go around again and again necessitating much more fuel than usual...

chermorg

One thing I haven't seen mentioned a lot here is that this was a flight to a hub airport. Not a UA hub, but a hub airport where AS likely has maintenance they can use. If this flight were destined to, say, a smaller airport such as RNO or similar, they may very well have diverted to SFO or turned back.

EWR764

The blown tire at EWR would not have had an impact on fuel burn, and provided everything else was normal (e.g., no debris ingestion into an engine, gear stowed normally, etc.) the flight would proceed just as any other, with the same concerns vis-a-vis alternates, contingency fuel, go around, etc. The only issue I could see would be if the crew elected to perform a missed approach to allow the tower a visual inspection of the gear, but if it deployed normally, locked with three greens, I don't think that would be necessary, either. Plus, it was dark in PDX at the time the flight landed.

On landing the objective would be to keep the nose off the ground as long as possible to bleed off speed, hence moving some pax around for CG purposes (it was not a full flight), but this would be the case no matter where the aircraft landed, whether it was EWR, SFO, ORD or elsewhere. The decision to continue to PDX was no doubt made in concert with the crew, a maintenance controller and UA dispatch. In this case, PDX was a good decision, as it resulted in a safe landing, passengers getting to their destination, and a quick return to service for the affected airplane, planned for today after a ferry to SFO for tire alignment. In fact, it would appear that this decision was made primarily for customer convenience (after ensuring no safety of flight issues) since if UA wanted to avoid a possible ferry and extended period of time out of service, it very well could have sent the airplane to SFO right off the bat.

PDX is a 737 line maintenance station for UA, so changing tires and inspecting the nose gear there is a non-issue. However, since both nose gear tires were replaced, the a/c will not be returned to revenue service until the wheels are aligned.

Even at smaller stations, UA often stocks high-mortality parts (like tires) for common aircraft types and, if it the station does not have a UA mechanic on-site, will contract with a local FBO or ground handler for mx support as needed.

Insulator-King

I never realized that the front tires needed to be aligned. Learn something new....

goodeats21

Agreed. I love it when our friendly experts check-in with info...

TA

chermorg

That's good to know - they likely didn't care about going to PDX because they have the MX facilities and the manpower to fix it there (albeit they were unable to align the tires). I did not know this about PDX being a line mx station (and could've looked it up but meh).

tuolumne