I’ve seen it in a Vietnam era film, or two - your unit is totally overrun and the only hope is to hit the deep bunkers and call bombers or artillery to hit your own position.
I don’t know if it ever happened in reality but is there a word or phrase that describes that situation, it would be a handy metaphor for something I have to do?
I believe it is called, or has been called a “Broken Arrow” over the radio to call in CAS on your position in such a situation. Not sure if that is the phrase you are looking for tho.
Yup the term was used during the Battle of Ia Drang:
The Israeli army has a similar concept known as the Hannibal Directive:
Thanks guys, that took 3 minutes. Pretty cool 
Broken Arrow was a code word designed to prioritize missions/assets in support of the unit in danger of being overrun. It didn’t necessarily say where those fires would be relative to the normal distance cushion for safety. If you want a mission within those distance, like right on top of you, it’s “danger close.”
It could also be referred to as Maxim 20: “If you’re not willing to shell your own position, you’re not willing to win”.
It has happened many times. Several people have received the Medal of Honor for doing this. John R. Fox and Brian Thacker are two great examples.
“Broken Arrow” was (and still is) used as a code word for certain nuclear weapons incidents. If you’re having a Broken Arrow event, the USA is having a bad day.
Technically, “danger close” means that there are friendlies within 600 meters (or more for larger artillery) of the coordinates that you’re calling a strike on. You wouldn’t say “I need an airstrike, danger close” to have someone bomb your position, you’d say “I need an airstrike at coordinates X, danger close” to remind them to please do a good job and hit the target at X because if they miss, they’ll hit good guys.
But, I can’t think of any phrase that means “fire on my position” and the public has taken “danger close” to mean that. It would probably work for the OP.
As a bit of trivia… Apparently the last time a Broken Arrow was called was during the Battle of Ia Drang in 1965, but that’s not the last time a “we’re getting overran” call went out. 5th Special Forces and MACV-SOG had a different code word, “Prairie Fire*,” which meant the same thing as Broken Arrow. I don’t know how many times it was used, but it wasn’t exactly rare with those guys because they liked to take like 8 dudes out and observe the enemy from an arms length away. In 1971, a Prairie Fire emergency happened to two different teams in the same area on the same day.
*This can be confusing because MACV-SOG border hopping recon operations into Laos and Cambodia were also code named “Prairie Fire.”
I swear I have seen this situation in a movie set in the Vietnam War.
The base is being overrun by a night assault and the Colonel is on the radio calling in artillery to wipe out the enemy forces. We only hear his side of the conversation:
“Yes, I am aware that those are my coordinates. I think that’s my call, don’t you?”
the situation being described isn’t exactly the Ia Drang “Broken Arrow”. It’s isn’t a “Bring all the help you can or we’re screwed.” It’s more like “We’re all dead either way, so let’s try to take the bad guys with us.” It is calling in air strikes or artillery strikes on your own position because that happens to be where the enemy forces are, and just maybe you can figure out a way to survive that but if not, it isn’t like you were going to survive anyway.
Perhaps you’re thinking of this scene from Platoon. At 1:43 into the clip, the Captain says “For the record, it’s my call. Dump everything you got left on my pod.”
I defer to anyone with more recent or better experience than myself, but …
I wonder if “broken arrow” is or ever was actually a generally recognized code phrase meaning “fire on my position” or “we’re being overrun”.
It may well have been used that way for one specific operation. And it sure could have been used in a movie or even two.
But I doubt it was ever a general phrase. Anybody got a good cite, even to personal experience?
When I was doing a research on Vietnam War, I checked out lots of forums just in case I could find some people talking from personal experience. And what I found out about broken arrow is that it was established prior to WWII and today is used as a code word in Iraq. So based on these broken arrow code wasn’t used only in one occasion. I guess it became a general phrase long before Vietnam war. But still, I’m not sure how reliable these sources are. So, all in all what I just said is an assumption.
Thinking back to the movie, various books, and my own training.
I think Danger Close is the call to cover dropping stuff on your own position. If you are having to shell your own position you likely aren’t observing niceties of normal call for fire procedures so whether that call is made or if it is more “I need mortars on my coordinates, NOW!” is open.
“Broken Arrow” was more a general call that a unit was in danger and needed priority on all available air support. Col Moore wasn’t calling for fire on his positions, he needed aircraft to pound the enemy forces that were engaged or moving to engage him. He did not want ordinance dropped on his position and the only strike that hit his position was the friendly fire incident as depicted in the movie. These would have been considered “danger close” and that specific call would be made to alert everyone friendly troops were near the strike zones.
There’s another line after that, Final Protective Fire (FPF) that is machine gun and mortar fire right at the edges of your own lines (say within 100 meters) to provide another curtain of bullets and shrapnel the enemy has to get through. We were taught those were all pre-planned fire coordinates with your artillery and mortar support. In addition, you’d give the platoon machine gunners pre-assigned sectors to sweep with fire regardless of seeing an enemy. That call is something like “Fire FPF!”
After that, there’s the “it’s all gone to hell plan.” In the movie “We Were Soldiers,” that’s what B company 2nd platoon (the troops who chased the Vietnamese soldier into the brush and got cut off) has in place when they are essentially being overrun at night by Vietnamese soldiers moving through their position looking for them. It’s the last chance roll of the dice. With luck, you are dug-in (even a hasty, 6 inch deep position is going to help tremendously) or at least prone. People standing and moving make much better shrapnel catchers than folks hugging dirt so while your odds aren’t great, they are a hell of a lot better than not calling in fire.
Ever watch the great Stanley Kubrick film Paths of Glory? Of course that situation was a tad different (a selfish & crazy WWI French general orders the shelling of his own trenches just to get the men to climb out and attack forward).