i believe it's pronounced Prang!
Posted on 06/15/2019 10:29:53 PM PDT by CondoleezzaProtege
United Airlines said one of its jet blew “multiple” tires on Saturday upon landing at Newark Liberty International Airport. Flights were delayed by more than five hours at the busy United hub airport that serves the New York City area.
The tires on the left landing gear of the Boeing 757 blew after Flight 627 from Denver landed at Newark around 1 p.m. said the Federal Aviation Administration.
United Airlines said some customers had minor injuries and that they refused medical attention.
(Excerpt) Read more at cnbc.com ...
When a major manufacturing company has a problem like the 737MAX the investigation will eventually reveal a lot of embarrassing stuff. History has proven that the worst thing a company can do is to try to do anything that would appear to impede the investigation. Take your hit & learn from it. Boeing is going to go through a period where everything they do or fail to do will will become fodder for the Media. And that will partly be do to the execs pushing to reveal this stuff.
There are always line workers and line supervisors who know the real deal. Internal investigations eventually find out that “somebody knew” and “somebody higher up was told and did nothing”. For the next few years Boeing will be more or less an open book— until the next senior management group has to learn this hard lesson all over again.
Has been the cause of a crash, including other factors, in the past.
VERY rare. Probably already addressed to not happen again.
I doubt this was it. Maintenance issue or a hard landing would be my guess.
Sheesh, is the pilot ex Navy or something? That looks like he (?) tried an arrested / carrier landing with an airframe and gear not set up for it...
While I seem to be on a flight to somewhere every few weeks, I have very little connection to the aircraft industry. However, I have a few questions concerning aircraft tyre operation and since I see there are some smart Freepers commenting here who do have that insight, perhaps somebody could comment on my musings…...
Here’s my question…. In flight, a tyre is at standstill and once it hits the runway, it has to hit its required rotational speed virtually instantly. If a large aircraft with 54 inch diameter tyres lands at 225 mph, this means that the tyre rotational speed goes from zero to a bit over 1,400 rpm almost instantly. That level of rotational acceleration would present a horrendous design problem for other types of ‘rotational equipment’ such as a large fan impeller but far less so for an aircraft tyre due to its lighter weight and the elasticity of the material. Regardless, at the moment of touchdown, the tyre will be grossly distorted due to the incredible acceleration and the force of the aircraft as contact is made with the tarmac. My guess is that about 99% of the amount of degradation that an aircraft tyre sees over its lifecycle happens in the first few seconds of touching the tarmac on a landing. Would that be about right? This being the case, has there ever been thought given to having the tyres already rotating to match ground speed before the plane lands? Would that not be a good thing to do? I can’t imagine that it wouldn’t be a good thing and I’m wondering why it’s not done….. i.e. cost, another maintenance item, extra weight, risk that something could fail and lock a wheel up, somebody’s assessment that tyres are already well within their limitations when accelerated from zero etc.?
The other thing I’m wondering about is this…. I haven’t really paid that much attention before but when a pilot lands, is the objective to do an initial slight ‘touch’ (a kiss between the tyres and the tarmac) to get the wheels rotating before the rest of the landing is done? It would seem that this might happen naturally anyway since there always seems to be a bit of a bounce before the wheels are in permanent contact. This would seem to me to be a good idea since putting all the weight on a tyre that’s already distorted due to the rapid acceleration would be far more likely to have a tyre blowout.
Thoughts?
That kiss is a bounce and it is almost impossible to not bounce a little. If you don’t bounce at all it is called “slick” landing which is the nirvana of landings. It happens so rarely that you remember those landing where “slicked” it.
I would suggest that a ‘slick’ landing is likely more conducive to tyre blowouts than a ‘kiss’ landing... at the moment of contact, I would imagine that at the contact point, the rubber will increase significantly in temperature. Once the wheel is spinning in free air for even a second or so, it gives the surface a chance to cool and when dealing with rubber, this has to be an important consideration.
I’m wondering if the tyre pre-rotation isn’t done because of gyroscopic effects. If the wheels are all turning, this might make it far less likely that a pilot could do a last second correction.....
i believe it's pronounced Prang!
>..has there ever been thought given to having the tyres already rotating to match ground speed before the plane lands? ... I can’t imagine that it wouldn’t be a good thing and I’m wondering why it’s not done…
Tried and discarded. Rims were designed that caused wheel rotation when lowered into the airstream. But the rotating wheels became powerful gyroscopes the pilot had to overcome during approach and landing. Became a control issue. Too dangerous!
I think the reason is obvious. If the wheels had electric motors and they were spinning and the tires impacts at angle slightly off the runway axis, which happens all the time, think about what would happen.
In a hard landing you would expect the rear Landing Gear to take the hit, not the Nose Gear.
I cannot fathom how that damage happened unless they came in with the Nose down and the Nose Gear hit the Runway first.
When JetBlue had an issues where the Nose Gear did not rotate forward on an A-320, the Pilot landed with no apparent damage to the plane.
I don’t see that as a problem at all.... certainly no worse than the wheels starting at zero rpm. For the record, it wouldn’t need to be electric motors in the wheels that got them spinning... that can be achieved other ways as well.
However, I do buy R1b’s point about gyroscopic effects ‘before landing’ causing control issues. It would be interesting to have some history of what was all tried when that was looked at.
Oh goodness, no - you would be surprised at the amount of repairable damage.
Not cheap, but certainly do-able.
Putting words in someone's post that were not there is pathetic.
Yea asking a question for clarity is pathetic. /s
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