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Comment by smoyer | Hacker News Reader

Many plane's "noses" are non-metallic so that the front-facing radar can be placed at the front of the aircraft. The ones I've seen are often fiberglass and are pretty weak. Breaking the plastic has very little impact on the ability of the aircraft to fly (compared to sucking a bird into an engine for instance).

The USAir flight that ended up in the Hudson river was disabled by striking a flock of Canadian geese (https://en.wikipedia.org/wiki/Chesley_Sullenberger)

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There are a few good shots of the Delta BOS->SLC flight that made an emergency landing in Denver after encountering a hailstorm en route: http://www.dailymail.co.uk/news/article-3193043/Captain-s-co...

Wow! ... I'm assuming the pilot had no radar and (almost?) no visibility. The glide path antennas and receivers must have been intact but I'm not sure I'd have the nerve to trust a blind, hands-off landing in a damaged aircraft!

The way ILS is set up, all the delicate stuff is on the ground. Imagine two long, thin lobes of radio coverage (like two imaginary cigars) that overlap slightly in the middle. If you can pick them both up you are on the glide slope. If you can only pick up the top lobe you are too high, and if you can only pick up the bottom lobe you are too low. This means the equipment on the plane is very simple (fits into a single-engine aircraft) - if you can pick up the signal at all then you are good to go. In theory you could even use an omnidirectional receiver, although I would guess that they are somewhat directional just to enhance rejection of spurious signals.

But yeah, landing in a hailstorm with very little visibility is never real fun, but it's what instrument-flight ratings are there for.

With the disclaimer that I've only flown small aircraft, every flight I've taken in fog, snow, heavy rain, etc. has still had a small window of visibility before the wheels touched the runway. With that windshield, could he tell? It looks like the side windows might be less occluded, so I guess you'd still get some visual reference (though not whether you're "lined up").

I don't know the equipment nor Delta's Operational Specs, but Denver has Cat II, Cat IIIa and IIIb approaches to four of their northerly runways. Cat IIIb permits landing with an RVR (runway visibility) of 300 feet and an "alert height" (somewhat similar to a decision height, but not regulatory) of 35 feet.

If you're going to put an airplane down with no forward visibility, finding a 150' wide runway with CatIIIb/c minimums is probably the best you can do.

Links to KDEN's navigation data are on this Airnav page: http://airnav.com/airport/KDEN

I never noticed that that guy's name is "Chesley". I wonder how often he gets people thinking that's a typo for "Chelsey" or something of that nature.

Canada geese

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