Secretary of Defense Rumsfeld and Gen. Myers (the new Chairman of the Joint Chiefs) just had a press conference regarding the U.S. response in Afghanistan.
They also mentioned that two C-17 aircraft were going to airdrop aid and relief supplies, including 37,500 food packets (presumably MREs).
They mentioned the problems with such aid in Kosovo, and that some of the drops then were “less than successful.”
These new drops, they said, were from high altitude, but did NOT involve the use of parachutes. A reporter asked how supplies could survive a high-altitude drop with no parachutes, and was told that some new methods have been developed.
My own thoughts are: even if reinforced, what can survive a fall from 30,000+ feet? What about anyone unfortunate enough to be at the drop zone? Are they using retrorockets?!
Well a object reaches its terminal velocity in only 1000-1300 ft. After that the height dropped is more or less negligible. Assuming a design which was stable in freefall it could probably have a impact speed of as low as 90 mph, but if not as high as 180 mph.
My best guess is it used a design like the Mars Landers. Some kind of protective bouncy ball stuff. Impact --> bounce --> roll. I am curious to know the exact details as well though.
The following Norwegian defense department site http://www.fkn.mil.no/bp99/eng/artikkel/17drop6.html
has a report of a drop of a 600 kg pallet of food supplies to the ground without a parachute. The drop is from a C-130 aircraft from a height of 60m and a speed of 250kph. Although this is a low altitude drop, the load also has a substantial horizontal velocity.
This World Food Program site http://www.un.org/News/Press/docs/1999/19990917.wfp1053.doc.html
mentions another trick “The WFP has deployed a Hercules C-130 to drop 350,000 plastic 200- gram packets of high-energy biscuits, which are packed in such a way that they float and circle as they fall to ensure a soft landing. It is a less dangerous operation than the conventional airdrop and does not require a special drop zone.”
And this Army site http://www.quartermaster.army.mil/oqmg/Professional_Bulletin/1997/Winter/cdsppf.html
describes the standard Container Delivery System and mentions a newer type of container. “This container, known as the TRIAD, consists of a heavy-duty cardboard container similar to a CONEX insert, type-8 nylon, a static line and no parachute. Meals, Ready to Eat (MREs) are typically sent in this container for resupply.”
I also recall being told of a method for precision cargo drops without parachutes that involved, IIRC, some poles. I forget how it worked but it was clever and perhaps it could be used for high altitude drops as well.
And, a lot of the stuff they are dropping (dry goods and blankets) aren’t really hurt by hard impact.
There are a lot of ways to slow something down without a parachute, btw. The streamer was mentioned. you can also design something so that aerodynamic loads will cause it to spin like a helicopter, creating a high drag.
The terminal velocity of an object is determinted by its weight and the total aerodynamic forces on it. Large, light objects don’t fall very fast, especially if they are designed to be aerodynamically ‘dirty’. A large flat package full of biscuits and blankets might have a terminal velocity slow enough that it’s essentially floating down like a big piece of paper.
Since I posted, I also thought of the Mars Lander type of airbag approach. However, I still wouldn’t want to be under it when it lands. In any event, since the SecDef and Gen. Myers seemed not at all concerned about civilian danger, I’ll bet that Yeah supplied the answer, at least regarding MREs. More from the Army site listed above:
Finally, Sam and CaelNCSU, if you’ve ever seen a pallet of MREs, they are anything but light. I was picturing a large, massive cube hitting the ground at several hundred mph. Thousands of individual, loose MREs would be a different story, with a far lower terminal velocity.
Having dropped a few things from airplanes (and before anyone asks - such droppings were legal and/or accidental but harmless) the weight vs. shape has a lot to do with how things fall, and how they hit. Usually, it’s been a camera I’ve dropped out of an open cockpit airplane. I have them on safety tethers, so they don’t get caught in vital aircraft bits and can be retrieved. One time use cameras fall slower, spin in the air, and tend to “float” in the airstream. Solid cameras, like a 35mm, tend to plunge straight down like a rock. Were it not for the tether I’m sure the two types of cameras of about the same size but very different aerodynamic characteristics would also have very different landings.
As a general rule, the larger the volume for a given weight, the slower the fall and softer the impact.
Streamers and such have been mentioned - but simply making an individual MRE package larger and flatter without increasing the weight of the meal itself you will have a package that will fall slower and hit with less impact. So you drop the MRE’s as individual meals instead of in entire pallets. As mentioned, blankets, clothes, bandages, and so forth are not likely to be hurt by impact. Medicines that might be damaged by impact may be packed inside blanket bundles to provide necessary cushion. Sure, a few will get lost in the rocks and bushes, but it’s better than killing refugees that you’re trying to help. Heavier items can be put into packages with different aerodynamics that will slow their descent. After all, it’s not how far it falls but how it hits that counts.
Another thing I was wondering: how are people on the ground going to know what it is? The ration they showed on TV was labeled in English and didn’t look much like food, and you certainly wouldn’t want to mix up the food and the medicine. If I were an Afghan now and something fell out of the sky I’d probably be afraid to touch it. Are there still enough aid workers in there to make sure people actually get the stuff?
They are also dropping large numbers of leaflets, probably pictographic in nature (given the high levels of illiteracy in Afghanistan). I’d imagine those could get the message across, if anybody thought to do so.
It wouldn’t surprise me if the psywar folks in their flying radio stations were also giving instructions - this “food aid” is a major weapon, as well as a good thing to do.
I would imagine that, in addition to the already-there English writing on it that they’ve added both pictures and Afghani instructions. Yes, there are a lot of illiterate people in the country, but there are also a fair number of educated folks as well. Odds are that in any sizable group of refugees there will be some folks who read.
I have an additional question about this topic: Why?
I wondered at the PURPOSE of avoiding parachute use. I assumed it was probably because of some issue with unwanted sightings of the drop sites. Perhaps mean, bad Taliban leaders rush off to shoot down parachutes or steal whatever hits the ground, thus leaving the Afghanis without food after all.
However, if the loads are being slowed down by streamers, helicoptering their way to ground, etc. this purpose would be defeated.
I read a report on the humanitarian daily rations (HDRs) last night, I think from Reuters (no link, sorry). The HDRs were described as weighing only about two pounds, being wrapped in heavy plastic, and being aeronautically designed so as to “flutter” on the way to the ground. Evidently some engineers put some serious thought into these things. My first reaction was the same thing – if we’re going to try so hard to avoid civilian casualties, how can we then go and drop forty thousand cans of soup on their heads from 60,000 ft??
The rations (according to the report) are also noteworthy in that they are designed to be utterly inoffensive. No meat, no pig, no cow, and nothing anyone else could think of that would make anyone unwilling to chow down. They mainly consist of rice and vegetables. This sounds terribly bland to me – I mean, it’s not going to be a gourmet meal in any event, but I guess it’s better than slap on the belly with a wet fish.
Pumpkins make a really cool impact but nothing compared to that of a cabbage hitting from 1000+ ft. Cabbages fragment into what looks like 1000s of pieces convering 100-200 feet Lead shot filled tennis balls make excellent toys in freefall. You can throw them back and forth in the air. Cars have a slower freefall speed than expected. I personally have never fallen next to a car but have seen lots of video… The result is a pancake looking car.
According to people I know who’ve seen the drops of these kinds of packages, when food was dropped into the northern “no-fly” zone, several people were hurt and killed when large food bundles landed precariously, shifting and falling onto the people trying to get at the contents. Since then, the new design has been thought-up, and when it’s dropped, the load fragments progressively, falling as unit for a distance, then breaking into smaller units and beginning to spread out, then finally breaking into individual units, spreading still further, thus ensuring a fairly uniform dispersion, while keeping the drop fairly locallised, and preventing any serious injuries by getting too much of the load in one place.
It also allows for a faster, and therefore safer for the aircraft, drop run.
The packages are yellow to make the easy to see on the ground.
Each package contains 2200 calories, which is about what most Western men eat in a day, and is about twice what most Afgans get in a day. From the above link:
Not all that bland, and I’m sure these little packages are going to be quite popular.
Efficiency. A parachute isn’t free and it takes up space and lifting capacity that could be used for more supplies. Why bother if you can do without ? Designing the package to act as its own parachute, that’s a very neat little piece of engineering.