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Comment by sebzim4500 | Hacker News Reader

Isn't the whole point of an F-35 that it is really hard to track with radar?

Outside of combat missions, stealth aircraft have little widgets on them which multiply their radar signature. Stealth aircraft are meant to be stealth only in real combat missions.

Seems to be this thing discussed here,

https://en.wikipedia.org/wiki/Luneburg_lens#Radar_reflector

(caption: "Luneburg reflectors (the marked protrusion) on an F-35")

edit: Also here (with quotes from a US Air Force Avionics Technician):

https://theaviationgeekclub.com/these-devices-make-stealth-a... ("How Luneburg lens radar reflectors are used to make stealth aircraft visible on radar screens")

It can be.

I believe for “routine” training they’ll keep a radar reflector in them. Very little need to have stealth when bouncing around the US.

I was in a stealth fighter squadron. It really depends on the mission profile as to determine if the reflectors will be on the plane during CONUS training. If we're doing BVR 'tag' drills, they won't have them installed. If we're just putting butts in seats to keep certs current or maybe some air to ground training, then the reflectors will be installed.

Caveat, I was in the Air Force and I'm not too familiar with NATOPS which is what I believe the Marines would be operating under to determine SOP. I was not a pilot, but I was in operations and received the same briefings. My training was also from when we first got real stealth fighters and SOP has probably evolved a lot in the last decade.

What's most interesting about this story to me is... What sort of mishap would lead to an ejection with autopilot left functioning? That all seems very peculiar. Weird way to join the Caterpillar Club.

“The Caterpillar Club is an informal association of people who have successfully used a parachute to bail out of a disabled aircraft. After authentication by the parachute maker, applicants receive a membership certificate and a distinctive lapel pin. The nationality of the person whose life was saved by parachute and ownership of the aircraft are not factors in determining qualification for membership; anybody whose life was saved by using a parachute after bailing out of a disabled aircraft is eligible. The requirement that the aircraft is disabled naturally excludes parachuting enthusiasts in the normal course of a recreational jump, or those involved in military training jumps.“

https://en.wikipedia.org/wiki/Caterpillar_Club

Brought back memories of my dad's "induction" into the Caterpillar Club in 1962. When we cleaned out and sold my folks' house, I took a picture of his framed membership certificate; he often wore the lapel pin on civilian sport-coat lapels.

https://www.commondraft.org/Caterpillar-Club-certificate.png

Amazing. Thank you for that. Do you exist because he had an ejection seat?

> Do you exist because he had an ejection seat?

No, I was a little tyke at the time. (The story: https://news.ycombinator.com/item?id=33348425)

Dunno but if they dont find the aircraft it will be difficult to determine how it happened. My guess would be weird software. There might be something with the F35b's because there are a few crashes in the headlines.

Worst case scenario someone slaved it to a netowrk and stole it since the f35bs have VTOL.

It's really hard to track with active radar, which is why the first thing NATO does in a foreign country is bomb all TV and radio stations off the air. With passive methods it's no problem at all.

What do TV and radio stations have to do with active radar?

Nothing. That's the point. You don't need active radar with the right mix of broadcast stations and math tricks.

The other way around, it's easy to track these with passive radar which is why all radio emitters get bombed.

TV and radio stations can be used for passive radar. Passive radar is when you use existing radio sources as you illumination source and your radar system is listen-only. Stealth aircraft tend to be more visible on passive radar since passive is usually a longer wavelength that the aircraft was not designed for. You can even DIY a passive radar.

https://spectrum.ieee.org/passive-radar-with-sdr

You could use a focused receiver to look for TV signals being emitted from an object thousands of feet in the air over (say) the ocean off the coast of California. Since you know there is no TV station antenna floating in the sky out there you know you are getting reflected rf from a plane.

Your receiver is "passive" - it doesn't emit a signal - so the attacking enemy has to find it visually. If the enemy bomb all the TV antennas then you need to emit your own signal to generate the reflection.

It seemed like such a good idea at the time.

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