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That’s pretty cool. I’d assumed there would be something similar to the run-away truck ramps you see on steep grades — basically a deep gravel pit. However, act
by mrexroad 9mo ago
That’s pretty cool. I’d assumed there would be something similar to the run-away truck ramps you see on steep grades — basically a deep gravel pit. However, actually thinking about it, something along the lines of a gravel pit would likely cause significant damage to engines (not to mention risks created by engine damage) but also seriously impede emergency services.
- marcosdumay 9mo agoGravel flies. You can't have it anywhere near an airport runway. (Some planes have no problem with it, though. You can make even the entire runway of gravel if you only fly those.)
- andkenneth 9mo agothe distinction here is mainly jets vs props.
- stackghost 9mo agoGravel will happily fuck up a prop just as much as a turbine; it's more about ground clearance. The engines on modern airliners are quite low to the ground, which is why they tend to ingest gravel kicked up by the nose gear.
- CGMthrowaway 8mo agoWhat's the ground clearance of a flying piece of gravel! (in a gust of wind for example)
- stackghost 8mo ago>What's the ground clearance of a flying piece of gravel! (in a gust of wind for example) I'm not sure I understand the question you're asking. "Ground clearance" refers to the space between the thing and the ground. Airliners are low-wing monoplanes with the engines slung underneath the wings, and aft of the nose landing gear. The tires at the nose can kick up gravel which not only dings up the underside of the fuselage but can also get sucked into the jet intakes. There's only about 2 feet of clearance between the engine cowling and the ground. Compare this to a C-130 Hercules which is a high-wing monoplane with turboprops, which is designed to handle some degree of unprepared surfaces. The prop tips are never less than about 5 feet from the ground. Or, compare to a Piper Cub which has much less prop ground clearance but has the prop mounted forward of the nose landing gear so it's much less likely to encounter gravel. "What is the ground clearance of a flying piece of gravel" is... not really a question that makes sense to me.
- spockz 8mo agoI expect that “How high does a pebble get clear of the ground?” is what they meant to say afaict.
- CGMthrowaway 8mo ago"gust of wind" flying gravel not limited to nosewheel kicks
- Animats 9mo agoThese overrun areas aren't that long. This trick is used where there's not enough room for a long overrun area. The high drag has to start fast. With the styrofoam/pumice material, the wheels quickly drop all the way to the hard bottom of the arresting material, and then plow forward, dissipating energy by crushing pumice. With something more solid, the wheels may skim the surface for a while before digging in.