How surface-to-air missile can be fired unintentionally not deliberately

I don’t have first-hand knowledge of how an anti-aircraft system works, but my theory is that the attack was partly automated. Keep in mind that the plane was delayed by about an hour on the tarmac, so that may be a factor.

If the plane was cleared for take-off, this would have been coordinated with the defense forces, who would’ve been prepared for a civilian plane leaving Tehran. This was probably sent via a take-off window, so the plane being delayed on the tarmac missed the window.

Keep in mind also that the US had scrambled fighters from the UAE, and so there was a possibility of intrusion on Iranian airspace. So, a delayed plane outside of the take-off window may have looked like a radar-dodging fighter to an automated anti-aircraft system.

Possible explanation from a thread[0] on reddit:

> I am wagering an educated guess here that the technical difficulties on the plane were transponder related. If the defense missile systems the Iranian use were set up with auto interrogation, which is a fairly common thing, and the plane had issues with their transponder, which also happens then it is possible that the defense system cued the commercial flight as hostile or suspect and either launched a missile at the plane (not sure of Irans capabilities and limitations with their missile systems in regards to auto-fire) or an inexperienced operator with weapon release authority pressed a button to shoot a missile at what his system was telling him was a bad guy.

> Missile systems have a series of electronic breaks (think buttons that open and close relays allowing the missile firing voltage to reach the igintor) and mechanical breaks (think keys that have to be inserted and turned to the live/fire position). As the threat level increases the operators automate more of the process by closing these breaks. This makes for a faster response time to any threat the system identifies.

> So was it possible that an Iranian missile system was set with the minimum number of breaks/automated in a way a missile could have been inadvertently fired? I would say absolutely this is plausible given the attack a few hours prior with an expectation of an American response.

[0] https://www.reddit.com/r/worldnews/comments/embvsd/pentagon_...

You're not going to like this but ...

1) Militaries routinely lock-on to passenger airliners for practise.

Russia is rumored to cancel the missile launch far into the sequence, though sometimes they goof up and it fires.

2) Airlines knowingly route over war zones to save fuel, and usually only stop after a shootdown, like the MHA flight over the Ukraine.

Without going into geopolitics or minimizing any deserved outrage over it and response to it, there's a reasonable case of thinking this in terms of consequences of concentrating power. Specifically, consider thinking of this in terms of accidental discharge rates.

You arm one person in a room and tell them not to shoot, and it's almost a guarantee they won't. Try this with 10 people and it's still extremely likely they won't. With 100 it's still a good chance nothing will happen. At 1,000 I'd get nervous. But keep concentrating this force over time and a shooting becomes a guarantee. Arm 31,000 police officers and wait a year and you'll see either 23 revolvers or 434 semiautomatics go off accidentally. These are all seasoned professionals and it still happens to them as a matter of statistical certainty.

So back to the incident - you can get lost in tracing something like this to the trigger man, and their immediate firepower locality but the larger perspective is that risk and danger is directly tied to policy decisions that created these conditions. Training, aptitude and fire discipline is all over the charts in any military force and if history tells us anything, it's not a stretch to call it an accident.

NYPD handgun study including accidental discharges [PDF]: https://www.ncjrs.gov/pdffiles1/Digitization/145560NCJRS.pdf

It's not impossible for SAM sites to incorrectly set a target. During the Gulf War an RAF Tornado was shot down by a Patriot missile that had incorrectly targeted the aircraft. Not long after, a US F-16 pilot reported he was targeted by a Patriot site as well, but the missile was not launched. In 2003 an F-18 was shot down by a Patriot, killing the pilot.

Most countries have their own IFF (Identify Friend or Foe) codes in their transponders. Civilian planes also have transponders that identify them as non-threats, but that is not fail proof (MH17, the 1988 Iranian incident, etc).

The best analysis I’ve read is here: https://www.thedrive.com/the-war-zone/31791/lets-talk-about-...

Summed up as: older technology, possibly manned by reservists on the final hours of the graveyard shift, nervously watching a radar screen for a counter attack from an enemy known to use electronic trickery resulted in a missile being launched at a misidentified target.

It is not hard if you are stressed.

A U.S. Navy ship, the Vincennes shot down an Iranian airliner in 1988 by accident.

It seems obvious to me that the proposition is that the plane was misidentified or otherwise somehow accidentally targeted instead of some other target, either by human error or by a not-well-enough-supervised automated system - not that the firing of the missile was unintentional. I.e. they are not claiming that somebody accidentally hit the fire button with their elbow, I think.

Nothing in that says the firing was unintentional. It specifies the TARGET was accidental.

>US media reported it had been mistakenly shot down by Iran.

Looking at the video and comparing this to videos of UAV's being shot down with Stinger shoulder mounted surface to air missiles it looks very close to identical.

I don't think this was a big missile system like the Patriot or anything. Airlines have checklists and back-n-forth with air traffic control to set their transponder and any air traffic control worth anything would be keeping track of any heavy aircraft leaving their airports which there are reports that no call of trouble was mentioned by the airliner so that means they've already reviewed the ATC tapes.

It could have been an abnormally nervous missile platoon in possession of stingers (or similar) told to be on the alert for air to ground attacks and maybe something spooked them or they were targeting the airliner like others have mentioned and someone pulled the trigger unintentionally.

It seems unlikely that they meant to shoot down a civilian airliner right above Tehran.

It's possible that they were on high alert for fear of an American retaliatory air strike and misidentified the plane.

It seems reckless to have kept the airspace open and civilian planes flying in those circumstances, though, because, well...

This is one of the things that concerns me about things like CIWS/Phalanx, which is a short-range turret gun system for navy vessels.

It has a mode which, when enabled, says "if you show up on my radar and do not have a friendly beacon on you, you are going to get a kilo of tungsten through your center of mass and we're not going to bother asking questions of any human first."

The use case is to prevent another Cole incident, but configuring a weapons system in such an autonomous mode means that you're in a mode where unintended deaths are acceptable, and that makes me very, very concerned.

i think the general understanding/current story is that it was fired deliberately, but not at that target.

I guess we'll all find out the official version of the story in the days to come.

It's possible the person who fired it thought the airliner was a US military craft. It's also possible it was intended to be fired at something else, but targeted the airliner by mistake.

Note that surface-to-air missiles are likely to target heat sources, and it seems like the engine of the airliner, a significant source of heat, may be where it was struck.

I'm not convinced. I have a theory that when the US killed Qasem Soleimani Iran looked over to Russia for a nod of approval. Once they got the nod (yeah, we'll back you in a proxy war) Iran went ahead with retaliation against the US and simultaneously put Trump in a position where he will most likely denounce any responsibility to defend/aid Ukraine. Setting the stage for round 2 Ukrainian invasion.

1. Russia puts mercs in Crimea to sow unrest.

2. Russian mercs drive unrest.

3. Unrest drives Russia to annex (liberate) Crimea.

4. Obama sanctions Russia.

5. Russia helps elect Trump.

6. Trump lifts sanctions against Russia.

7. Trump endebted to Putin.

8. Iranian tensions ratchet up.

9. Trump has a hard on for killing Iran.

10. Trump has an aversion to confrontation with Russia.

11. Putin puts Trump in a position to renounce responsibility to defend Ukraine (world peace).

Putin has set the stage for the US to turn Iran into ISIS: The sequel and simultaneously weakened Ukraine.