# How accurately can the USAF drop cargo? **URL:** \ **Category:** Factual Questions\ **Created:** [April 9, 2017, 6:21am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103 "2017-04-09T06:21:43Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [April 9, 2017, 6:21am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/1 "2017-04-09T06:21:43Z")
I’m excluding rotary winged craft for obvious reasons. I’m thinking of crews kicking stuff out of the back of a C130 or a C17, can they, say, land something inside a Baseball Diamond? ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [April 9, 2017, 6:52am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/2 "2017-04-09T06:52:16Z")
Interesting. They have Joint Precision Airdrop System which is reported to be accurate to 164–246 ft. > **[Joint Precision Airdrop System](https://en.wikipedia.org/wiki/Joint_Precision_Airdrop_System)** > > The Joint Precision Airdrop System (JPADS) is an American military airdrop system which uses the Global Positioning System (GPS), steerable parachutes, and an onboard computer to steer loads to a designated point of impact (PI) on a drop zone (DZ). The JPADS family of systems consists of several precision airdrop systems, ranging from extra light to heavy payloads. JPADS is used in conjunction with mission planning software that resides on a laptop. The function of this mission planning software... ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [April 9, 2017, 7:02am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/3 "2017-04-09T07:02:03Z")
I guess it would depend on altitude, winds and so forth - harder to drop stuff while you’re getting shot at, natch. But if accuracy is the sole factor, sure, no problem. Just drop the stuff from low altitude, near-stall speed to reduce the drift as much as possible, shouldn’t be too hard. These days they even have [GPS-guided drop pods](https://en.wikipedia.org/wiki/Joint_Precision_Airdrop_System) to land a payload within a ~75m radius of a set of long/lat coordinates. Might be a little wide for landing it inside the diamond itself as I understand the word (that is to say, within the space outlined by the 4 bases) but the ballpark is no sweat. ETA : ninja’d ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [April 9, 2017, 8:34am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/4 "2017-04-09T08:34:18Z")
My dad flew C-141s in the Air Force. I was with him once when he had to go into his squadron office to get something. We passed the squadron trophy case, and there was a light in it that had been crushed by something. I asked my dad what it was. To answer the OP, pretty darn accurately. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 9, 2017, 2:36pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/5 "2017-04-09T14:36:05Z")
If you’re not too concerned about the cargo \*staying \*in the diamond you can use LAPES: [M551 Sheridan Low Altitude Parachute Extraction System (LAPES) - YouTube](https://www.youtube.com/watch?v=dgg3iRaVnbw) . There are a number of fun, and some not so fun, videos of this delivery method being used. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [April 9, 2017, 7:13pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/6 "2017-04-09T19:13:15Z")
The minimum size drop zone for a single airdropped platform is 600 yards wide and 1000 yards long. That’s with normal cargo parachutes during peacetime and using the Computed Air Release Point. This is for safety purposes, however. They routinely come within 100 yards of the intended point of impact, and more often within 50. Anything within 25 yards is scored as a STRIKE, so I would say that 25 - 50 yards is an achievable goal. Landing within the infield is possible. Landing within the ballpark is routine. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [April 10, 2017, 12:37am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/7 "2017-04-10T00:37:25Z")
If the cargo was explosives … couldn’t they hit home plate? ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [April 10, 2017, 1:02am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/8 "2017-04-10T01:02:27Z")
> [@watchwolf49](#): > > If the cargo was explosives … couldn’t they hit home plate? Not consistently. The most accurate precision guided munitions can reliably land within a 5 meter radius only 50% of the time. That’s a large circle, and half the time it will miss outside that circle. Actually hitting the plate will be as much luck as anything. The plate will surely be destroyed regardless, of course. But not because the munition itself actually impacted it. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [April 10, 2017, 1:03pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/9 "2017-04-10T13:03:57Z")
> [@Bear\_Nenno](#): > > Not consistently. The most accurate precision guided munitions can reliably land within a 5 meter radius only 50% of the time. That’s a large circle, and half the time it will miss outside that circle. Actually hitting the plate will be as much luck as anything. The plate will surely be destroyed regardless, of course. But not because the munition itself actually impacted it. Ah … thank you … that’s not as near as accurate as TV told me is was … ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [April 10, 2017, 2:10pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/10 "2017-04-10T14:10:56Z")
> [@Bear\_Nenno](#): > > Not consistently. The most accurate precision guided munitions can reliably land within a 5 meter radius only 50% of the time. That’s a large circle, and half the time it will miss outside that circle. Actually hitting the plate will be as much luck as anything. The plate will surely be destroyed regardless, of course. But not because the munition itself actually impacted it. I thought the Paveway series of laser guided bombs were somewhat more accurate than that- like a CEP of 3-4 meters or less in good conditions? Either way, if you’re aiming at the pitcher’s mound, a circle that is entirely within the base paths is something like 45 feet in radius, which is about 13 meters, which is well within that 5 meter CEP listed above ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [April 10, 2017, 2:35pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/11 "2017-04-10T14:35:58Z")
> [@Bear\_Nenno](#): > > Not consistently. The most accurate precision guided munitions can reliably land within a 5 meter radius only 50% of the time. Is that even with someone nearby painting the target with a laser? Or is that another Hollywood myth? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [April 10, 2017, 2:42pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/12 "2017-04-10T14:42:10Z")
> [@Robot\_Arm](#): > > My dad flew C-141s in the Air Force. I was with him once when he had to go into his squadron office to get something. We passed the squadron trophy case, and there was a light in it that had been crushed by something. I asked my dad what it was. > > To answer the OP, pretty darn accurately. I’m not getting this at all. What kind of light? What was it crushed by? What was your dad’s answer to your question? How does this tie in to “pretty darn accurately?” ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 10, 2017, 3:26pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/13 "2017-04-10T15:26:46Z")
> [@Bear\_Nenno](#): > > Not consistently. The most accurate precision guided munitions can reliably land within a 5 meter radius only 50% of the time. That’s a large circle, and half the time it will miss outside that circle. Actually hitting the plate will be as much luck as anything. The plate will surely be destroyed regardless, of course. But not because the munition itself actually impacted it. > [@watchwolf49](#): > > Ah … thank you … that’s not as near as accurate as TV told me is was … > [@bump](#): > > I thought the Paveway series of laser guided bombs were somewhat more accurate than that- like a CEP of 3-4 meters or less in good conditions? > > Either way, if you’re aiming at the pitcher’s mound, a circle that is entirely within the base paths is something like 45 feet in radius, which is about 13 meters, which is well within that 5 meter CEP listed above > [@scr4](#): > > Is that even with someone nearby painting the target with a laser? Or is that another Hollywood myth? LGB’s get pretty good. We’ve all seen the YouTubes of the bomb hitting a practice tank on a practice range dead center. The real world of combat contains more variables. The guy aiming the laser at the target is looking through some kind of scope and putting the crosshairs on the target. How precisely is the laser beam aligned with those crosshairs? How steady is his aim over the 30 seconds the bomb’s in flight? What happens if he takes hostile fire during that time? Is the target stationary or moving? Moving in a smooth straight line or jerking madly back and forth while zooming & stopping in an effort to evade? The guy dropping the bomb is supposed to drop it into a “basket”, an imaginary funnel that ensures the bomb has the steering capacity to make up the difference between where it would dumbly fall and where the laser spot wants it to seek. Did the pilot do an excellent job: nuthin’ but net? Or did she drop a rim shot that’s just barely in the basket? Recognize also that the basket changes size and position each time the target changes direction or speed. A drop can validly begin in the basket and then the target suddenly take a hard right turn and the basket slides out from under the falling bomb. The basket calculation makes assumptions about the unknowable winds between the airplane and the ground. How close are those assumptions to actual conditions? What about the bomb? How well calibrated are the one-time use electronics? Any loose wires? Did a bug get smashed on the laser seeker window on the way to the target? Are the fins on exactly straight or is one a bit bent or crooked? Are the batteries in good enough shape to last all the way to the target or will they crap out halfway there? What about the rest of the environment? Is it full of smoke & dust or fog or is it clear? How reflective is the target? How much scintillation (flickering & bouncing) is there in the laser reflection? How bright is the laser spot as seen by the seeker compared to its minimum detectable brightness? Real bright, kinda bright, or flickering above and below the minimum threshold? How many other laser spots are there flying around the sky given that every gunned vehicle in modern combat has a laser rangefinder? When you add all that up you see there are a lot of ways the 100% perfect outcome from a munitions test might fall short in the real world. You can broadly divide these issues into ones that incrementally degrade accuracy by a couple meters and those that trigger gross errors of dozens or hundreds of meters. Bottom line: when somebody quotes a, say, 5 meter CEP you have a lot of hits much closer than that, some right around there, and a smattering waay out in the distance. CEP is used in attack planning to decide how many shots it’ll take, _on average_, to take out some number of targets over some number of attacks. Q: What does a .250 vs. .300 batting average say about the guy’s very next at-bat? A: That he’ll either get a hit, a walk, or be out but we’re not sure which it’ll be. Not much more can be said with any certainty. Likewise CEP isn’t a property of \*a \*drop. It’s an average property of hundreds of drops. ---
**Author:** ![SanDiegoTim](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SanDiegoTim](https://boards.straightdope.com/u/SanDiegoTim)\ **Post date:** [April 10, 2017, 5:32pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/14 "2017-04-10T17:32:40Z")
During the siege of Khe Sanh the C-130’s were extremely accurate. However the cargo was not dropped from altitude. The aircraft, to avoid landing and being exposed to fire, used a parachute to drag the pallets out the ramp and onto the tarmac. They were just a few feet off th ground. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 10, 2017, 5:59pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/15 "2017-04-10T17:59:14Z")
See post #5. 🙂 ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [April 10, 2017, 9:25pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/16 "2017-04-10T21:25:14Z")
> [@Robot\_Arm](#): > > My dad flew C-141s in the Air Force. I was with him once when he had to go into his squadron office to get something. We passed the squadron trophy case, and there was a light in it that had been crushed by something. I asked my dad what it was. > > To answer the OP, pretty darn accurately. > [@Gary\_T](#): > > I’m not getting this at all. What kind of light? What was it crushed by? What was your dad’s answer to your question? How does this tie in to “pretty darn accurately?” The light was used to mark the center of the drop zone for a cargo drop at night. They managed to drop a pallet right on it, crushing it. I’d put that in the trophy case, too. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [April 10, 2017, 9:58pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/17 "2017-04-10T21:58:49Z")
> [@Robot\_Arm](#): > > The light was used to mark the center of the drop zone for a cargo drop at night. They managed to drop a pallet right on it, crushing it. I’d put that in the trophy case, too. Gotcha. Thanks. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 11, 2017, 7:39am UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/18 "2017-04-11T07:39:54Z")
> [@PastTense](#): > > Interesting. They have Joint Precision Airdrop System which is reported to be accurate to 164–246 ft. > [Joint Precision Airdrop System - Wikipedia](https://en.wikipedia.org/wiki/Joint_Precision_Airdrop_System) How much do these cost? I wonder if the parachute and guidance system are recovered after a drop? ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [April 11, 2017, 4:37pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/19 "2017-04-11T16:37:11Z")
> [@Reply](#): > > How much do these cost? I wonder if the parachute and guidance system are recovered after a drop? Over a quarter million. Though that cost is probably skewed by the costs associated with RnD and the limited number of systems built. I’m sure it will come down a bit. Yes, they are recovered after a drop. Even regular parachutes are intended to be recovered after every drop. There are disposable cargo parachutes now, which are the only ones that don’t have to be turned back in. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [April 11, 2017, 4:54pm UTC](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103/20 "2017-04-11T16:54:00Z")
Cite for stated cost: > **[Air Transportation: Smart Parachutes Dominate The Drop Zone](https://www.strategypage.com/htmw/htairmo/20140522.aspx)** > > The US Army recently ordered another 110 JPADSs (Joint Precision Airdrop System), which cost $273,000 each JPADS kits are attached to pallets of supplies to provide GPS and mechanical controls that guide the direction of the descending parachute for... $273,000 [Next page](https://boards.straightdope.com/t/how-accurately-can-the-usaf-drop-cargo/784103.md?page=2)