Air Despatch, air drop, heavy drop or aerial delivery, makes use of a range of specialist equipment such as containers and platforms (pallets) to get stores and vehicles directly to the point of need, quickly, from the air, exploiting one of the characteristics of air power, immediacy.
Air despatch, or air dropping stores, is yet another of those subjects where the past is chock full of British military and industrial innovation but the present is hanging on by the skin of its teeth due to continued budget erosion and changing priorities.
Anyway, enough griping, start with an amusing video.
We might all laugh at the amusing incidents in the video but air despatch needs the utmost precision and skill, it can be very dangerous for personnel and equipment, as this video illustrates;
Those working in the front and back ‘office’ need perfect synchronisation, it is one of the most demanding tasks we might ask of the air and ground crews involved.
This post has been updated a few times in response to some excellent feedback from a number of posters on PPRUNE, Dragartist, Ancient Aviator and VX275, thank you gentlemen
A Short History
There is a rich history of UK air despatch, from Arnhem and the Rhine crossings to Afghanistan with all points in-between but probably the first significant air despatch carried out by the UK (and anyone) was in Iraq during the disastrous 1916 Defence of Kut Al Amara in Iraq by members of 30 Squadron, Royal Flying Corps some some RNAS seaplane pilots. This scratch force also included Henry Aloysius Petre, the founder of the Australian Flying Corps.
In the first few days of the resupply effort success was patchy, the first package of detonators fell onto enemy lines and the makeshift bags used would often burst. The effort subsequently went on to deliver 13 tonnes of supplies in 140 sorties over a couple of weeks. Stores included food, ammunition, tobacco, fishing nets, wireless set spare parts and even £10,000 in gold and silver coins. Food was generally free dropped but one request was for a millstone, the defenders having discovered a mill where enemy forces had removed the stone. The 70lb millstone could not be free dropped without damage and so a parachute and rig were made at Basrah from old aircraft fabric.
Although the air supply operation did not alter the outcome it marked the first time forces in the field had been re-supplied by air despatch.
Air despatch was used on the Western Front and in the inter war years developed by all the major nations in one form or another, building capabilities in line with parachute assault techniques.
The interwar years saw some development of parachuting in general;
In World War II air despatch was used by extensively and for British forces, notably in Burma in support of General Orde Wingate’s Chindit force. Whilst the military effectiveness of the Chindit’s is an ongoing debate what their operations did prove decisively is that ground forces could be sustained by both tactical transportation aircraft operating from austere locations and parachute air delivery.
The Douglas C47 Skytrain (Dakota in RAF service) was the preferred aircraft for air despatch for the allied air forces because it was stable at low level and its handling was not unduly affected by cargo loads being, literally, kicked out of the side door.
Fuel, ammunition, food, weapons and medical supplies were regularly dropped using simple ‘free dropping’ or with parachutes and woven basket containers. As the techniques developed the range of cargo expanded, live poultry and pigs were dropped and even eggs. US forces in Burma and India calculated the costs of these operations and whilst air landing was obviously the cheapest, free dropping was not much greater but parachute delivery was nearly $2,000 per tonne, compared with $50 per tonne for air landing.
The image below shows an RAF Dakota acting as both resupply and gunship!
In response to the needs of SOE in occupied Europe and the realisation that D Day would require significant air delivered supplies led to the creation of the Air Despatch Group, Royal Army Service Corps, in April 1944.
RASC Air Despatchers went on to support operations in mainland Europe.
Up until this point the containers were fabric bags or various sizes and configurations of wicker baskets
As volumes for air delivery operation in mainland Europe were expected to rise significantly more research and development was directed to the containers used for the delivery of stores by air dropping.
One such item of equipment was the CLE.
CLE’s went through a number of revisions and the MkIII’s were still in service 40 years after the end of WWII. CLE stood for Central Landing Establishment but eventually changed into Container Land Equipment and then Container Light Equipment.
CLE’s went through a number of revisions in size and construction with some specialised units developed for radio equipment for example. Dimensions were similar, 1.7m long and 0.4m diameter.
Their parachutes were colour coded so personnel in the ground could quickly identify their content without having to open them first, an ingenious but simple development.
Yellow; medical supplies
Light Blue; food and water
White; general stores
Green; signals equipment
Low powered lamps were used for night drops to aid location.
CLE could be carried in singles or bundles and launched from the side door or underwing racks, the latter a technique often used by the Halifax and Hasting aircraft.
The famous Welbike had a dedicated CLE
There was a lighting system used on the CLE for identification during night drops consisting of 4 small lamps mounted on a frame and powered by a battery. There were also experiments with smoke generators to highlight containers in the daytime. Most were painted in light colours, such as white, to aid recovery.
The containers provided much needed extra supplies to the lightly equipped Airborne Forces and were used post war, including Op Musketeer.
An oft overlooked but important requirement was the need to rapidly move CLE’s away from the drop zone. One device used was the folding airborne trolley, designed to fit inside a CLE, it was used extensively for both stores and medical evacuation.
Toggles were used to allow additional men to pull the trolley
There was also a larger version, the Airborne Handcart, used by glider forces.
Dakotas were used extensively for operations in Arnhem and supporting US forces in Bastogne.
Although vehicles were mostly air landed in gliders, some air dropping of vehicles did take place, they would be slung underneath the aircraft (Halifax, Lancaster, Hastings etc), making use of the crash pans under each wheel and the parachute developed for the airborne lifeboat. Other heavy items like artillery guns were also delivered using this method.
These were not entirely satisfactory techniques and after the war the ‘Paratechnicon’ was developed, a specially designed vehicle container that was mated with the fuselage of a specially adapted Halifax and dropped at the appropriate point.
It used inflatable ‘balloons’ and 6 or 8 parachutes to control descent. Although it was able to accommodate a payload weighing a little over 2.7 tonnes it was aircraft specific and following a fatal accident where one of the parachutes was caught on the aircraft, it was withdrawn.
The next major advance in air despatch came with the introduction of dedicated cargo aircraft with rear cargo doors and an up-swept tail, rather than modified passenger aircraft or bombers. Aircraft like the C-82 Packet, Fairchild C-123 Provider, Nord Noratlas and Blackburn Beverly for example, although slightly earlier aircraft like the Fairchild C-119 Flying Boxcar could be used for air despatch if the rear cargo doors were completely removed before flight.
1956, of course, saw Operation Musketeer, Suez.
3 PARA secured El Gamil airfield on the 5th November 1956 using 18 Valetta and 7 Hastings aircraft for personnel and 7 Hastings used in the heavy drop role. Although the Medium Stressed Platform was in service it was not cleared for the Bevereley and so the older ‘crash pan’ method had to be used for the 3 PARA vehicles and artillery guns, the crash pans being recovered from a number of museums in an echo of Black Buck many years later.
The introduction of the Blackburn Beverley in 1956 heralded a number of innovations including reversible pitch propellers for short field performance and reverse taxiing and cargo floor rollers but the main one was a large boxy body equipped with hydraulic clam shell doors and ramp. It had a payload of just under 20 tonnes but a very short range so typical air despatch loads would be in the order of 16 tonnes. The cathedral like cargo box was slab sided and large enough to carry large plant vehicles.
Relying on gravity and an upward flying angle, loads could me manually extracted with the parachute deploying only when the load was clear of the aircraft. As loads got heavier relying on gravity would not be enough and so parachute aided extraction was developed. This is dangerous because if the parachute deploys and the load gets stuck on the cargo floor there is a danger of causing a fatal stall.
The rear cargo doors and single cargo deck of the Beverly and Argosy provided an opportunity for a step change in heavy equipment delivery.
The Boscombe Stressed Platform (BSP) it was developed further into the Stores or Supply Stressed Platform deployed using an extractor parachute after which the main parachute opened.
Still in service, the MSP is 2.14m wide and 4.88m long, it can accommodate loads between 2.722 tonnes and 8.165 tonnes. They can also be daisy chained.
The HSP could be used with stores or vehicles to a maximum weight of just under 16 tonnes for Hercules and 19 tonnes for the Beverley. It was 2.6m wide and 7.5m long.
The demand for higher weights and lower deployment altitudes (to stay below radar cover) meant supporting the platforms was no longer possible with conventional parachutes and a series of innovative sectional parachutes were developed by the G.Q. Parachute Company.
To improve accuracy for heavy loads and as a successor to the Ground Proximity The Ultra Low Level Airdrop (ULLA) was developed at Boscombe for use with the Beverley and C130, similar in operation to the US Low Altitude Parachute Extraction System (LAPES). The ULLA platform was a development of the Stores/Supply Stressed Platform (SSP)
As can be seen in the image above and video below (and the second one from the beginning), the parachutes are fully reefed (or opened) and the aircraft must fly very low, ULLA for example, required 10 feet + or – 5ft.
LAPES and ULLA left service with the USAF and RAF respectively by the end of the nineties, aircraft, equipment and personnel risk, coupled with a reduced demand meant it simply faded away in importance. The video at the head of this post shows a LAPES demonstration at Fort Bragg in which three people died as a result of the load hitting the tail of the C130 as it extracted.
The Medium Stressed Platform is still in service with the RAF but the other containers have been replaced with the Container Delivery System (CDS).
The Blackburn Aerial Delivery System, developed in the late fifties and early sixties in conjunction with the armed forces and GQ Parachutes, was an important milestone because it was an automatic system that allowed the payload to be released with the despatcher at a safe point, i.e. in front of the load. It also paid a great deal of attention to the safety of the aircraft and had a number of design concepts that are still used today.
Essential items were air dropped to the Task Force in 1982 from RAF Hercules aircraft and since then RAF Hercules have air dropped supplies for military and humanitarian aid disaster relief, the latest over Mount Sinjar in Iraq.
Although Air Despatch has a relatively short history in the major military powers such as the UK, France, Russia and the USA it is an enduring requirement to air drop supplies, although heavy drop of equipment and vehicles, less so, at least for the UK.
Post 2010 SDSR 47 Air Despatch Squadron RLC (47 AD Sqn) are now part of 13 Air Assault Support Regiment RLC (13 AASR), located at RAF Brize Norton.
Techniques and Equipment
Whether it is deploying relatively small door bundles to dropping an entire aircraft of humanitarian supplies there are many factors to consider.
Flying low reduces dispersion and increases accuracy, good for ground personnel that have to recover the stores, but it puts the aircraft at greater risk from ground fire and might in some cases alert enemy forces that ground forces are in the area.
Night drops improve aircraft survivability and reduce detection of the stores but can also be hazardous to those on the ground.
Different factors also apply if the drop is for humanitarian assistance, risk of the loads creating casualties as stores may drop onto people rushing to recover the food or water, for example. This happened in Timor when the Royal Australian Air Force conducted a HADR drop, a child lost their leg after a parachute load hit him. An air drop of supplies to the Yazdi refugees on Mt Sinjar had to be suspended because of risk of injury to them, difficult choices being made by the aircrew.
Stores and equipment hanging around in the air whilst they serenely descend means they are exposed to enemy detection and fire so the general objective is to get them on the ground as soon as possible, this also improves accuracy and reduces dispersion. However, some loads may be less resistant to higher velocity impact and so may have to use low velocity techniques.
Some stores can even be free dropped, without the aid of a parachute.
A catch all term for heavy loads such as vehicles, artillery guns, small boats and ammunition pallets.
The main piece of equipment used for heavy dropping (apart from the parachute deployment system and parachute(s)) is a pre stressed platform. Of the Supply, Medium and Heavy Stressed platforms described in the history section, only the 8 tonne payload Medium Stressed Platform remains in service
Even though it is a fifties design, the MSP is still a very capable piece of equipment with a number of advantages over the newer Type V, especially in its ability to load multiple items on a single platform, two light guns or light gun and Pinzgauer for example. This obviously reduces the number of aircraft required for a given force size.
The MSP is not compatible with the floor of the C130J or A400, both of which use the Dash 4a Cargo Handling System from AAR Corp. With the C130K now out of service the Medium Stressed Platform has bee rendered obsolete. Unless the UK purchases a compatible platform, it is out of the vehicle heavy drop business.
The US DoD contracted with Triton Composites in 2003 to develop a composite platform called the Triton Composite Airdrop Platform (TCAP).
The current Type V metal platform used for low velocity airdrop (LVAD) is expensive because of its heavy and complex modular design. Triton Systems Inc. proposes to develop a lightweight, low cost, environmentally-friendly composite airdrop platform (CAP)to replace both the current Type V and DRAS platforms. The approach is to engineer advanced thermoplastic composite (TPC) materials based on Triton’s extensive experience in the transition of metallic structures to cost-effective, structurally-efficientpolymer matrix composites. Triton will explore a range of composite platform designs, ranging from inexpensive, single-use, throwaway platforms, to platforms that will provide a greater level of durability and reusability than the current Type V. Low costfiber, matrix, and core materials, and affordable manufacturing methods will be employed. Triton has teamed up with a current Type V and DRAS supplier to develop this future generation composite airdrop platform. The developed composite airdrop platforms can be used to improve mission effectiveness for Future Combat System LVAD missions. These platforms would also benefit humanitarian relief work involving airdrop of food and other supplies. Meeting thedifficult impact and durability requirements would allow the validated composite constructions to be applied to other missions requiring lightweight, damage-tolerant materials.
It does seem to have progressed beyond development though.
The current market leader for heavy drop platforms if the Type V from Capewell, available in a number of configurations and dimensions. It was developed to replace the A/E 29H-1 (LAPES) and the Type II (LVAD) airdrop platform.
It comes in a variety of sizes and capacities from 8ft long to 32ft and can carry up to 19 tonnes although ramp limits might limit the payload (16 tonne single load, 25 tonnes multiple load on the A400M for example)
Capewell also make a smaller platform called the Multi Drop Platform that can carry a 1.36 tonne payload.
Others include the Zodiac DRAS platform and the Aeronet PD8/PD9 platforms, the latter of which was recently used by the French in their operations in Mali.
The Russians have an interesting approach to heavy drop, rocket assisted parachutes and dropping with the crew inside!
Although things might look a bit threadbare for the UK in the vehicle heavy drop department at the minute, boats are another matter entirely.
In 2010 the MoD placed a contract with Babcock for the Small Boat Aerial Delivery System (SBADS).
Babcock is currently delivering 186 units of its innovative aerial drop system, SBADS, to the MoD. The system has been designed by Babcock’s Integrated Technology team to deliver small rigid and inflatable hulled boats safely to the ocean from military transport aircraft. It was selected by the MoD after competitive trials, in which it out-performed other air-drop system solutions.
The modular system features a novel deceleration mechanism that can be adjusted to control deceleration rates on impact with the water, to avoid damage to the payload on landing. A unique, patented, twin V-form flexible sheet provides low deceleration and hence low landing forces initially, and then higher deceleration to prevent payload submersion.
The system is modular to handle larger payloads, or to enable a variety of payloads to be dropped, from life rafts and medical equipment containers to boats over 12ft long with outboard motors fitted ready for action. The modules are designed to be compatible with the Hercules and Airbus A400M or other aircraft equipped with the standard 108 inch cargo handling system, and could easily be modified to suit other aircraft. The modules can be fitted with floats to allow recovery and re-use during training exercises, or can be configured to sink during operations.
Babcock has developed a manufacturing process for the SBADS using a range of purpose designed welding jigs and fixtures that ‘standardises’ production, to enable rapid delivery while maintaining quality. 186 SBADS units are to be delivered to the MoD by February 2011. Approximately 90 have been delivered to date.
Also in service with the UK, Norway and the USA is the Airborne Systems Maritime Craft Aerial Delivery System (MCADS) and Small Boat Modular Platform (SBMP) that uses the PRIBAD and PURIBAD platforms although these may be replaced with SBADS.
Smaller items can be packed and despatched from the aircraft side doors as paras exit but of course, they have to fit. They usually weigh between 30kg and 300kg.
A technique called ‘South East Container Despatch’ is also used to deliver small bundles from the side door of a C130 that uses a small plywood ramp intruding into the slipstream.
One on the ground they are de-rigged and the stores moved.
Container Delivery System (CDS)
Container Delivery System (CDS) is the most common system, used by pretty much everyone that air drops supplies
It uses a lightweight 48″ square plywood ‘skidboard’ onto which is mounted a layer or two of cardboard honeycomb energy absorbing material, other sizes are available but the 48″ square skidboard is compatible with the widely used Capewell Center Vertical Restraint System (CVRS).
The load or load bag is rigged to the baseboard and the parachute attached. This is usually a time consuming break bulk process, transferring from one land pallet to the skidboard, as mentioned in the previous post, the worlds of land, sea and air logistics have yet to fully converge.
After rigging and checking they are transferred to the aircraft
Dropping (in single or two rows) is initiated by cutting a webbing retaining strap or using wireless release mechanism and the loads simply fall out of the back as the aircraft pitches up and a static line deploys the parachute. A number of variations exist that use different packing materials and for different loads. Small loads can be deployed as door bundles and CDS bundles are generally no more than 1 tonne but can include quad bikes, small boats and light engineering plant.
Personnel on the ground then recover the stores, most of the time the pallet will land the right way up, but not always. Because the skid boards do not have forklift slots, the job on the ground cannot be assisted with mechanical handling equipment, unfortunately
A parachute extracted delivery method for Container Delivery System (CDS) bundles has been developed and deployed the USA.
Accuracy and speed of delivery is said to be much improved with dispersion reduced by two thirds.
If the stores are robust they can be free dropped like this example from the RAF in Ethiopia, Operation BUSHEL in the early eighties.
The RAF delivered over 14,000 tonnes of food aid using this method, a method pioneered in the 1972 Nepal famine relief operations. In recognition, 47 Air Despatch Squadron Royal Corps of Transport won the Wilkinson Sword of Peace.
In 1993 the RAF tested a systems called Snowdrop from GR Woodford Co that combined two sachets into a single pack, one sachet containing a dehydrated stew and the other, a vitamin and mineral rich fruit drink. These were packed 24 to a carton and when the carton entered the aircraft slipstream it would break up and allow the sachets to fall to the ground. Read the patent here
The US Operation Provide Hope in Bosnia in 1993 depleted war stocks of USAF air drop equipment and cost in excess of $30m, none of the equipment was recovered.
In response, a system called Tri-wall Aerial Delivery System (TRIADS) was developed.
TRIADS is very simply, a cardboard box that is launched into the aircrafts slipstream at high altitude where a tether rips open the box, allowing the individual food or water packets to fall to the ground. These packets were initially MRE’s but have since evolved to the Humanitarian Daily Ration or HDR.
TRIADS was used to deliver 2.5 million HDR’s during initial operations in Afghanistan in 2001 for Operation Enduring Freedom. Because they are deployed at high altitude the aircraft is not placed under the same risk as for low level free drop methods.
Each C-17 can deliver up to 14,000 HDR’s using TRIADS.
There is still some risk for people on the ground, not least from the plywood skidboard, which makes its use unlikely in some situations
The latest US development is Humanitarian Operations Packaged Essentials, or HOPE, package. Each contains a water pouch and energy bar. A single C-17 could drop 125,000 HOPE packages in a single pass and dispenses with the cardboard box completely.
As part of the US Low Cost Aerial Delivery System (LCADS) the U.S. Army Logistics Innovation Agency (LIA) developed the Freedrop Packaging Concept Project (FPCP) for use in Afghanistan.
Ultra Low Level Extraction
Although not strictly air dropping, a transport aircraft can land, slow to taxi speeds and simply roll cargo pallets or vehicles off the ramp. This minimises time on the ground and doesn’t need anything but the most basic of rigging. The cargo, usually on 463L pallets or equivalent, is simply picked up by ground forces and the aircraft flies off.
If no runway exists the aircraft can still fly at very low altitude (less than 10m) and offload cargo pallets, bundles or vehicles using a number of low or zero altitude extraction systems in which the cargo is dragged out of the aircraft by drogue chutes or arrestor wires.
Vertical descent speeds are very low but the cargo will have the same horizontal speed as the aircraft which will need retarding.
Little used now due to decreasing demand and risk issues.
To improve survivability aircraft are forced to drop at night and from higher altitudes and speeds, this results in dramatically reduced accuracy and dispersion of loads. Using GPS guidance and parafoil type parachutes loads can also be launched some distance from the target point.
Various US and NATO studies looked at the issue of precision airdrop and combat operations in Afghanistan and Iraq have accelerated developments.
The SPADES system from Dutch Space used a steerable parafoil, the Firefly. It could deliver a 1,000kg payload within 50m of the target from stand off distances and high altitude with the Dutch MoD being the launch customer.
This Cassidian (Airbus Defence, I think) as is the Paralander. The German Luftwaffe have used the Paralander in Afghanistan where it was cleared for use on the C-160. A Paralander can deliver up to 1,000kg loads 26 nautical miles (50km) from the launch point.
Payloads go from 90kg to 4,500kg
Looking at these videos what is interesting is that some of the designs use a parafoil parachute to get to within the drop zone after which it is collapsed (or de-reefed) and a conventional round parachute deployed for the final journey to earth. The last video in the group also shows a vehicle being dropped using JPADS.
Less well known but equally critical is the JPAD Mission Planning software which is run on a standard ruggedised Panasonic Toughbook laptop and is used to collate data about the payload, weather and other variables to ensure the correct drop point is selected.
The PADS system from QinetiQ (and now Capewell) is with standard freefall parachutes to hugely improve accuracy and reduce dispersion. To verify weather conditions a drop sonde is used that relays atmospheric information back to the mission planning software which uses the data to calculate the optimum release point.
For a detailed overview of PADS, click here
The video below shows an RAF Hercules dropping supplies in Afghanistan, CDS and PADS in action. The second video is an overview from QinetiQ
The RAF video also shows one of my hobby horses, the lack of containerisation and materials handling vehicles meaning that the 20 personnel had to work all night to recover 60 tonnes of rations, that is for another post.
A recent innovation with the JPAD’s precision air drop system is using a small UAV launched from the cargo aircraft to precision drop the sonde. The USAF have carried out a number of proof of concept trials with the Silver Fox UAV. The UAV flies ahead of the cargo aircraft so that it does not have to fly over the drop zone as it does when manually dropping the sonde.
No amount of precision can help though, if the ground conditions are such that enemy forces have access to the drop zones, as this recent video from the Middle East shows
Whilst the Container Delivery System (CDS) is robust and effective it is expensive so unless the equipment can be can be returned it is a significant overhead and in many cases, the packaging will cost more than the contents.
In Afghanistan, the threat of IED’s and operations in remote locations meant aerial supply went through a renaissance but if overland logistics was difficult and dangerous going forward (the reason for air dropping) then it would be just as difficult and dangerous going in reverse. The reverse supply chain for CDS equipment also meant there would end up being a significant and expensive stock holding of parachutes, bags and securing items at remote forward locations. These locations had enough on their plate without managing CDS equipment and so the need arose for a much cheaper, single use system.
LCADS gets the components needed for low altitude air dropping to about $100 by using low cost materials such as woven polypropylene parachutes and rigging. Not having to recover the parachute and other materials simplifies logistics planning a great deal.
Out of LCADS came the Low Cost Low Altitude (LCLA) system.
The Low-Cost, Low-Altitude (LCLA) aerial resupply programme required system that allowed supplies of up to 75kg to be dropped from low altitude low speed aircraft (fixed wing or rotary).
LCLA bundles are small and designed to be handled without mechanical handling equipment, between 110kg and 250kg and can be dropped from smaller aircraft like a CASA 212.
US forces used the LCAD/LCLA system extensively in Afghanistan.
All types of equipment for all types of requirement, high, low, medium, low velocity, high velocity. cheap and cheerful, heavy and light or high precision.