Earlier quoted context omitted.
The only person here that knows what they're talking about. Everyone's talking about calipers :/
I love that out of all the more complex ideas about what may have been used, it turns out likely to be a solid piece of metal with of a given thickness, couldn't get more simple than that.
FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
81–90 of 170 posts
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#82One 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…
This tool would be capable of performing that measurement with 0.001" accuracy. https://www.harborfreight.com/feeler-gauge-32-pc-63665.html Someone performing maintenance in their garage on an internal combustion engine would encounter the need to measure the same tolerances, for example, adjusting valve clearances. This is a common and accessible measurement task.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#83Earlier quoted context omitted.
If you're into 3D Printing, feeler gauges are also a great way to level your bed... move the extruder 0.04 above the bed at four points, stick your 0.04 feeler under it and adjust the springs until it touches the feeler. Voila, one perfectly leveled 3D printer bed.
Most people use a sheet of paper for this. I wouldn't use it to check the tolerances of an airplane part, but it gets you 99% of the way there.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#84Earlier quoted context omitted.
I love that out of all the more complex ideas about what may have been used, it turns out likely to be a solid piece of metal with of a given thickness, couldn't get more simple than that.
They're deceptively simple. If you want to get into the history of modern manufacturing, a lot can be written about the development of gauges of accurately known dimensions.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#85Earlier quoted context omitted.
They're deceptively simple. If you want to get into the history of modern manufacturing, a lot can be written about the development of gauges of accurately known dimensions.
I went down a rabbit hole of videos last yearish about the origins of precision (that should be a searchable phrase to get started).
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#86One 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…
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#87Earlier quoted context omitted.
The only person here that knows what they're talking about. Everyone's talking about calipers :/
Who even uses calipers for critical precision? Calipers are for dimensions machinists append with -ish, as in four thousandths-ish. Important dimensions deserve a micrometer, especially the feeler guage that just said you need to tell your boss to scrap a 737. Decent machine shops even have different classes of micrometer; there's the one you carry in your pocket, and then there's the fancy set locked up in your boss…
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#88I 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.
I worry a little more about theme parks that don't do winter shutdowns or might not have done the full shut it down for the winter procedure with sudden lockdown orders. The regulatory environment is also sketchier.
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#89Earlier quoted context omitted.
For small 4-6 seater general aviation aircraft it's hard (relative to a normal landing), but not at all unheard of. A modern 4 lane highway is more than wide enough, and very probably has a long enough straight section within range, to make for a relatively uneventful landing if you can get traffic to cooperate. You're absolutely correct though when it comes to larger aircraft. I rather doubt there are any examples o…
> I rather doubt there are any examples of an off airport landing of a 737 without significant damage to the aircraft. https://en.wikipedia.org/wiki/TACA_Flight_110
Since I love reading about these kinds of incidents and the best way to solve a problem is to claim it's impossible, I amend my claim to "I rather doubt there are two examples of an off airport landing of a 737 without significant damage to the aircraft." :)
Re: FAA issues emergency directive on 2,000 Boeing 737 NG, Classic planes
#90The title here should have "737 NG, Classic" not "737 NG Classic". As in "Boeing 737 NG and Classic aircraft", not "Boeing 737 NG Classic aircraft".