Posted on 11/05/2018 6:45:54 AM PST by BenLurkin
Indonesian investigators, the plane’s manufacturer, Boeing, and the U.S. National Transportation Safety Board are formulating a more specific inspection for Boeing 737 MAX 8 planes related to the airspeed problem, Tjahjono said.
“If there are urgent findings to be delivered, we will convey them to the operators and to the manufacturer,” he said.
Lion Air has said a technical problem with the jet was fixed after problems with the Bali to Jakarta flight. Investigator Nurcahyo Utomo said investigators need to review maintenance records, including what problems were reported, what repairs were done including whether components were replaced, and how the repairs were tested before the 2-month-old plane was declared airworthy.
“Currently we are looking for the cause of problem,” he said “Whether the trouble came from its indicator, its measuring device or sensor, or a problem with its computer. This is what we do not know yet and we will find it out,” he said.
At the meeting with family members, Tjahjono had said that information downloaded from the jet’s flight data recorder was consistent with reports that the plane’s speed and altitude were erratic after takeoff on its final flight. Searchers are still trying to locate the cockpit voice recorder.
(Excerpt) Read more at ktla.com ...
Time to look to see if the same supplier provided pitot tubes to Boeing.
I said the very same thing on Airliners.net. I wonder if both Airbus and Boeing need to look at re-engineering the whole pitot tube design, especially given pitot tube’s susceptibility to clogging due to foreign objects and ice.
I thought these newer jets were supposed to have multiple sensors for redundancy.
AF447 was 10 years ago. there are literally thousands upon thousands of these things in operation every hour of every day; if it was a defective design, planes would be crashing twice a day.
it’s going to turn out to be a maintenance issue. this device gave ample warning it was about to go out, and the the discount airline discounted them all.
My only aviation experience is as a passenger.
Having said that...
I thought modern jets had old-time pneumatic (air tube) pitots in addition to the new-fangled electronic ones, as backup.
The idea was (I thought) to always have a set of the most basic instruments as a backup using the oldest and known reliable mechanical technologies.
Is that wrong?
ours or theirs?
In the case of AF447 it was more a case of bad piloting.
High humidity in that area and then at altitude they froze over - however - checklist calls out pitot heat ON. There are other means to check what’s going on with airspeed indications and how to over ride.
-— Airbus had problems with pitot tubes that led to the crash of Air France flight 447. -—
I just watched a video report of this crash. The pitot tubes did freeze up as the plane passed through a storm. This freezing is not unusual and would have cleared itself in a minute or so. This caused the 2 flight officers to take improper “corrective” action which led to the plane stalling and plunging into the sea. The captain was on break and out of the cockpit.
The real cause of this disaster was the appalling errors of the two crew members in the cockpit. One was pulling the stick back to pull up the nose while the other was pushing the stick down to gain speed. They didn’t look at their instruments or realize that they were counteracting each other. By the time the captain got back to the cockpit it was too late. This accident was completely preventable.
https://www.youtube.com/watch?v=r5LUGaW6TyE
Did Mujibur put gum on the static port thinking that he was plugging a hole?
Rumor has it the Co-Pilot did climb out and try to pee into the tube to melt the ice, but couldn’t because the cover was left on. He then came back inside the plane to ask the pilot if he should take the cover off. The pilot said yes, then the plane crashed.
They do. That’s why things often turn out to be a little more complex than armchair observers on the internet think.
Every competent pilot I know knows a pitch/power relationship for climb and cruise speeds. And if the airspeed indicator does not match what they know is a normal relationship between what the indicator says and what they have for pitch/power, they rely on experience.
I had an airpseed malfunction on a T-38 years ago, and landed it quite safely and easily by relying on that relationship. (And the white rocket will eat your shorts in a moment if you ever let the airspeed sink below what is recommended.)
Airbus had a very aggressive pitot tube replacement program after AF447.
There was only one crash, AF447, but many reports of erratic air speed indications in A330/A340 aircraft.
We don't know yet if there have been any other reports of erratic airspeed indications on other B737 Max aircraft.
LOL
My 5.5 years in aircraft instrumentation knows that most airspeed indication problems are caused by the pitot tube heater not working. But this was in a warm climate and I don’t think they got very high where the air would be cold, so maybe not in this case.
I can’t recall the details (and leaving for work), but I recall a report of wasps nesting in a pitot tube.
I agree with others’ comments re maintenance problem: There were warnings and they were not heeded, defect or not.
-PJ
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