I have been wondering how dangerous flying is going to be when when / if it comes back and all these planes come out of storage. Mechanical things just sitting around is some times far worse than them being in constant use.
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FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
21–30 of 170 posts
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#22Interesting that the vast majority of 737s were flying so frequently that this was not found earlier. For their entire 20-ish year service life, those planes are never left idle long enough for this part to rust! Amazing. Goes to show how popular and successful the 737 line is.
This is true of all airplanes, not just the 737. They're so expensive that they all need to be in use continuously.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#23Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#24One of the inspection checklist items: Measure the clearance between the flapper bushings at both locations on each engine bleed air 5th stage check valve. If the clearance between the flapper bushings is a minimum of 0.004 inch (0.102 mm) at both locations, the engine bleed air 5th stage check valve at that location has passed this inspection. I knew that aviation engineering dealt with tight tolerances, but boy, it…
They've had calipers for literally thousands of years. I used to be involved in some intermediate gunsmithing work, and we had these tools called 'dial calipers' which have a little gauge you read and you can measure extremely precise things. We used it for getting cylinder diameters or clearances that needed that degree of precision. I can only imagine that in aviation, there are even more advanced tools, especially…
Boeing used to be a well respected company. At least until the merger with McDonnell Douglas, which turned it from an engineering driven company to a financial engineering company.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#25The official PDF document is here: https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf... I always wondered what the proper terms was for an airplane crash, and now I know: "forced off-airport landing"
Not necessarily. A "forced off-airport landing" could also be the result of an engine failure beyond gliding distance of an airport. Or engine fire, medical emergency in remote area, etc. There are many emergencies that could force an aircraft to the ground, off-field. Not all off-field landings result in an accident, or "crash". From our own regulations, NTSB 830 "NOTIFICATION AND REPORTING OF AIRCRAFT ACCIDENTS..."…
I think it would be rather hard to land a plane off the airport without substantial damage, especially when talking about larger ones.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#26Interesting that the vast majority of 737s were flying so frequently that this was not found earlier. For their entire 20-ish year service life, those planes are never left idle long enough for this part to rust! Amazing. Goes to show how popular and successful the 737 line is.
This is true of all airplanes, not just the 737. They're so expensive that they all need to be in use continuously.
Yeah I'm sure most commercial airliners are the same. Apart from maybe the Super-Heavies; I hear that there are dozens (hundreds?) of 747s and A380s sitting around doing nothing currently because they're too expensive to fly.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#27One of the inspection checklist items: Measure the clearance between the flapper bushings at both locations on each engine bleed air 5th stage check valve. If the clearance between the flapper bushings is a minimum of 0.004 inch (0.102 mm) at both locations, the engine bleed air 5th stage check valve at that location has passed this inspection. I knew that aviation engineering dealt with tight tolerances, but boy, it…
If it's a gap between two parts that they're measuring, that's as simple as a feeler gauge: https://en.wikipedia.org/wiki/Feeler_gauge . The set pictured there looks like it goes down to 0.05mm.
The only person here that knows what they're talking about. Everyone's talking about calipers :/
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#28One of the inspection checklist items: Measure the clearance between the flapper bushings at both locations on each engine bleed air 5th stage check valve. If the clearance between the flapper bushings is a minimum of 0.004 inch (0.102 mm) at both locations, the engine bleed air 5th stage check valve at that location has passed this inspection. I knew that aviation engineering dealt with tight tolerances, but boy, it…
They've had calipers for literally thousands of years. I used to be involved in some intermediate gunsmithing work, and we had these tools called 'dial calipers' which have a little gauge you read and you can measure extremely precise things. We used it for getting cylinder diameters or clearances that needed that degree of precision. I can only imagine that in aviation, there are even more advanced tools, especially…
I really struggle to understand how you could have used the term "well-respected" here. It ain't muscle memory, this was done deliberately. Could you explain how you can refer to Boeing being well-respected after the 737 MAX fiasco? Maybe I am missing something.
[edit] remove a word
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#29Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#30Interesting that the vast majority of 737s were flying so frequently that this was not found earlier. For their entire 20-ish year service life, those planes are never left idle long enough for this part to rust! Amazing. Goes to show how popular and successful the 737 line is.
And this may be obvious to some, but why does use inhibit rust?