I’m watching Apocalypse Now on the tube and having a mild flashback. 
It happened during the scene where the river boat is attacked with arrows and spears.
Sometime between '65 and '67, while in Viet Nam, I was standing on the boat deck of my ship (LPD-5) watching the Hueys return and leave during an operation. On the bottom of one I saw what looked like an arrow sticking out of the skin. I said to the Marine I was bullshitting with “hey, Red, that looks like an arrow in that chopper over there” (we called them “choppers”, not “helos”). He said “It is an arrow. Once in a while a **** scores a hit”. I can’t remember the name he said, but he told me they were mountain people.
We were off the Mekong Delta at the time, IIRC.
Anybody know, for sure, of any arrow-shooting Viet Nam natives who didn’t especially care for invaders in their country?
Peace,
mangeorge
WAG here.
Since bows and arrows go all the way back to prehistory, any primitive culture develops spears and archery gear and knives as they seek ways to extand their reach or tearing abilities.
Any tribe in the jungles not supplied by the forces (friend or foe) with more modern equipment, might have nothing better to use.
Alternative WAG.
Maybe it would have been the silence/stealth of using the bow and arrow approach to keep from getting return fire.
Note–the armored vests used by troops in Vietnam did not stop arrows.
Hence the use of crossbows by the VC. The crossbows and the quarrels ( not arrows–arrows from a regular bow, quarrels from a crossbow) were manufactured from crashed airplane parts. Bowcords were made from control wires, & the frame of the bow was sketched out on the aluminium sheets of the structure. The sketched out sections would be snipped out with tinsnips or other simple cutters, & then bent into shape. Quarrels were made in the same way, in one piece, with all-metal vanes in place of feathers.
Learn something new everyday. I thought they were called “bolts”
“bolts” is also accepted usage.
mangeorge, perhaps it was the Hmongs? Or the “Yards”? Many of the mountain tribes worked with the U.S. military, so I was surprised to see your post. Maybe one of the Hmong warriors was feelin’ frisky one day and was showing his friends how accurate he was…
Most of the indigenous mountain peoples (most notably the Montagnards, also known as “Yards”) hated the Vietnamese - both North and South. They did, however, work with the U.S. troops in an attempt to rid their territory of VC/NVA forces. Many U.S. servicemen “went native” to earn the trust of these tribes.
In addition, many of the mountain warriors became “mercenaries” and worked with U.S. units all over the country. They usually brought their entire families with them when they moved around the country - made for some interesting and creative logistic operations at times.
I think the arrows are also significant in that there is a similar scene in Conrad’s “Heart of Darkness”, the book which inspired the film. In the book they are steaming up the Congo in the last years of the 19th century when they are attacked with arrows by people hiding on the banks of the river.
I was going to ask for a cite, Bosda Di’Chi of Tricor, on the use of crossbows in Vietnam. But then I thought, what the heck, I’ll have a look.
Here’s one for sale, but it’s made of wood, not parts from crashed aircraft.
Wooden crossbows have been common weapons throughout SE Asia for several hundred years, and as far as I know, they’re still in use for hunting in remote regions. Despite of their primitive construction, they are bad-ass weapons, having pulls of up to 150 lbs. and capable of sending a broadhead bolt through a human body. Most arrows, like those seen in “Apocalypse…” are small, thin bamboo sticks without heads more suited to shooting small birds than killing enemy soldiers unless poison is used. I’ll have to check my crossbow literature for details.
Goggle “Rung Sat”
Sometimes called the Forest of Assassins.
Charlie used crossbows as well, and Americans spent a lot of time in the Delta trying to clean out the Rung Sat.
There was a very famous “sniper” in the Forest that the LRRP’s and Seal’s called Geronimo.
Yes, Hmong. That’s it. It must have been from a crossbow. Whatever it was, it was strong enough to penetrate the skin of the Huey. The crew probably left it there as a way of saying “Neener, neener”. 
Ok, I took a look at Desmostylus’s link and I’ve got a question for anyone who can answer. How does the firing mechanism on it work? It looks to me like just a T-shaped piece of wood. Is there a part missing?
Wearia,
Yeah, the upper part of the T acts like a shortbow used “gangsta’ style”. It is strung with a cord, which is held back and released by the lower part of the T. The cord is not shown, and it is not strung as it is quite stressful for the weapon.