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Comment by trhway | Hacker News Reader

another option mentioned is to mount the missiles on the bay doors - opening of the door would put the seeker into the air stream as if the missile were on a wing rail. Sounds like a typical quick fix/patch :) Not sure why it is AIM-9, not something more long range. The role of F-117 is just to [stealthily] truck the missile and drop it. The other radars and control would guide it.

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A longer range missle would require an active radar to lock onto a target. That sort of negates the whole thing. The AIM-9 is a passive IR seeker that can aquire it's own target.

HARM missiles don't seem to be active and a special HARM derivative might be suitable. Something that may not have been made public.

https://en.wikipedia.org/wiki/AGM-88_HARM

Normal HARMs have hit radar emitting aircraft :

During the Gulf War, the HARM was involved in a friendly fire incident when the pilot of an F-4G Wild Weasel escorting a B-52 bomber mistook the latter's tail gun radar for an Iraqi AAA site. (This was after the tail gunner of the B-52 had targeted the F-4G, mistaking it for an Iraqi MiG.) The F-4 pilot launched the missile and then saw that the target was the B-52, which was hit. It survived with shrapnel damage to the tail and no casualties. The B-52 was subsequently renamed In HARM's Way.[4]

Hard to fit, probably. 5ft longer and 4x as heavy

From what I read the HARM (and all anti radiation missiles) wasnt particularly good at tracking a moving target. Especially another aircraft closing in fast that is manuverable.

As for IR missile options beyond the Sidewinder the US never really invested in any longer range IR missiles like the Soviets did as part of their overall effort to go big in IRST (which didn't seem to pan out all that well to my knowledge).

I think it did, if not otherwise because modern jets simply have stopped relying on their own radars, making long range IRST more important.

I have never read this. I always think of radar as a flashlight, because it's essentially what it is, except with electrons instead of photons.

When you have car coming from the opposite direction, with its high beams on, you can see it really, really well, even if you keep your lights off (passive HARM).

Microwaves are still photons!

I appreciate the correction - I don't really understand this at all. Physics 103 is where my knowledge of anything resembling science ends.

The difference is the challenge of imaging those wavelengths. You cannot just use a glass lens to focus a nice sharp picture onto an imaging sensor. Imagine that car is heading towards you, but you have to close your eyes and try to pinpoint its location by judging the shine of light through your eyelids.

Something like the Brazo (radiation tracking Sparrow) would've been nice.

Didn't exist at the time, but the AMRAAM doesn't require the launching aircraft to be using (or presumably even have) a radar. The launching aircraft just gives the missile the target's state vector before launch, which it could have gotten from another aircraft. The AMRAAM then flies to intercept the target, receives course updates if they're available, and then turns on its own radar when it gets close.

The state vector could even potentially come from an AWACS, although the angular resolution wouldn't be great. If the launching aircraft had an IRST system though, that is easily solved.

Incidentally, this basic capability is the present/near future of air combat. Modern but non-stealth aircraft hang back with their radars on. 50 miles or so in front of them are the AMRAAM equipped stealth aircraft getting datalinked targeting from the "quarterback" aircraft behind them. Tracks can be refined by having multiple radars observe the same target from different angles, and further augmented by the stealth aircraft's IRST system if it has one. The (stealth) launching aircraft can then immediately turn tail and run while the quarterback aircraft continues to provide midcourse updates to the missile.

This sort of datalinked network with aircraft up front with radar off, IRST on and launch capability feels like the future of BVR combat. Also add in an awacs to do IFF interrogation and declaring to the launchers as well.

It's really the present. This is a capability that exists and what is being trained now.

There are a number of variations on this play. The simple ones are:

1. Stealth (F-35/F-22) squadron keeps taking turns "illuminating" using radar and spot for each other, toggling radar on and off.

2. AWACS / ground-based radar / MIG-31M provides targets and stealth comes in close to take them out.

3. There is a concept that flips #2 - stealth comes in and looks for targets, a large transport aircraft is converted into a "missile truck" and ripple fires on target from a distance, WITHOUT having to illuminate - there are missiles called AWACS killers which are pretty dangerous to #2. Note that ripple fires implies missiles with multiple means of targeting.

4. Drones can play the role of finding targets and recon-by-fire too.

The AMRAAM requires a fairly powerful transmitter -- usually a radar -- to send it those datalink updates.

We've already had a JSF launch a missile from an Arleigh Burke over the horizon and guide it all the way to the target.

This stuff that was science fiction a decade ago is now reality.

Painting targets with lasers by ground troops was one of the main ways to target without radar and was an approach for many stealth missions for decades. Though to what degree over alternatives today, I would not known.

Laser painting is still THE way to target in a contested (No GPS environment). The SU-25 basically has no TV/IR targeting capability in practice (though it's been developed) ALA the A-10, Javelin, etc.

I don't fully understand why - whether it's a technical, expense, or reliability hurdle.

At least our aircraft can self-designate though, they don't require a laser on the ground.

So can the SU-25, it has a laser pointer in the nose (ignore if you mean former Soviet bloc by "our"). My point is that a lot of US aircraft use TV/IR targeting frequently, whereas Russian ones don't have that capability except on the higher-end bombers/fighter-bombers (e.g. SU-34, and it's still rarely used with TV/IR guidance). I don't understand if this is a cost, tech, or reliability issue.

Furthermore, self-designation is useless when an aircraft is doing close air-support and can't tell apart friendlies from enemies, which is an extremely common scenario.

I meant US, I'm far less familiar with soviet bloc aircraft.

Dropping LGBs in close air support isn't a thing. There are other tools for that. Target designation with a laser designator isn't something that anyone is going to do in a danger close CAS situation.

It's a common practice for Russia. They just did it a bunch in Syria.

>There are other tools for that.

Not really, artillery is going to have the same problems if not more. Unless you have a Reaper, Apache, or Spooky on station.

Not necessarily. An AAMRAAM derivative could have used passive radar homing. After all, if an AWACs is the target, it's emitting huge amounts of signal on well know frequencies.

In fact, the Soviets had AWAC hunter teams using exactly this type of missile. They figured (correctly), that sacrificing a squadron of planes to blind NATO would be a fair trade. The number of E-3s in NATO were limited, and extremely expensive. The R-27 had radar homing variants with a range around 70km. This would require the launching aircraft to get very close to the AWACs and it's protective escort.

The Russians have continued this with the R-37, which has a range of up to 400km. They plan on targeting AWACS, tankers, ECM aircraft (JSTARS) and other high value aircraft. All of these are slow, easy targets for a fighter.

I recall reading that the AIM9 is/was very easy to integrate into a plane and can almost be improvised in the field to work.

Only if the missile's seeker head had a clear view of the target. The missile is blind if tucked inside a weapons bay. So integrating it into the f-117 would not have been as simple as bolting a rail to the wing.

Why can't it seek just seconds after dropping out from inside?

You have to uncage the seeker head in order for it to track. You would be just dropping it with the seeker pointing forward and hoping that the missile locks onto it with a limited view. The seeker is uncaged normally when you are tracking a target before you fire it. The pilot would have no idea if the missile would track when dropped.

Can't this be solved (for a new aircraft) by having a similar seeker on the aircraft (IRST) and letting the missiles tap into that, so that it can sort of "see" while in the bay, and you can be more or less sure that once deployed it will actually track?

Perhaps that's exactly what IRST does...

I imagine the likeliness of hitting yourself with it would go up dramatically if that was the case.

If the launching aircraft has an A2A radar, newer versions of the Sidewinder can use LOAL (lock on after launch) because their sensors are so sensitive. The radar cues the seeker head prior to launch, so it knows where to search. Missile is launched, seeker head acquires target, boom.

Mounts on the bay doors might have infringed on space requirements for other weapons that would be used more frequently. IIRC, the F-117's primary payload was 2 2000lb bombs, so cutting that in half for a mission that might not be very common would be a hard to sell tradeoff.

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