Strategic Brigade Airdrop
An Army brigade, which contains about 3,250 soldiers and 3,450 tons of equipment, is airdropped and airlanded in two phases. During the first phase, aircraft must be able to drop roughly 2,500 troops and 1,350 tons of equipment within a limited amount of time. During the second phase of the operation, the remaining 750 personnel and 2,100 tons of equipment are delivered to a landing zone. Without the initiatives, it would take a C-17 SBA formation about 25 minutes longer than the Army's requirement for the airdrop.
At the beginning of World War II the airborne concept was that parachute troops should be used as assault units to seize and hold airheads for air-landing troops. As stated in FM 31-30, published in May 1942, this doctrine regarded parachute troops as the "spearhead of a vertical envelopment or the advance guard element of air landing troops or other forces." This concept of airborne warfare envisaged the capture of suitable landing areas by small detachments of parachute troops, who would hold the airhead until relieved by either glider- or airplane-landed reinforcements. Actually, this concept never became the basis for major US Army airborne operations during World War II.
American airborne division structuring had been originally based upon the doctrine of using parachute troops only as an "arrowhead' to prepare the way for glider- or airplane landings, hence the original divisional organization called for one parachute regiment to two glider regiments. The advantage of parachute troops over gliders in getting the maximum number of men on the ground in a minimum of time, as well as the smaller number of aircraft and the shorter troop carrier columns needed for parachute troops, had impressed airborne planners. Consequently, for both the Normandy and Holland operations the 82d and the 101st Airborne Divisions had a ratio of three parachute regiments to one glider.
Yet the days of the glider were numbered, for American experience with glider troops in World War II had proven so disappointing that Army Ground Forces concluded that in the postwar Army gliders should be used only for the transportation of cargo. By the time the Korean war began, the glider regiment had disappeared completely. But the concept of a two phased assault, in which parachutists seize an airfield so that fixed wing aviation can then land a second echelon of equipment remained in the Strategic Brigade Airdrop, with C-17 cargo planes eventually performing the function initially envisioned for the rather less successful cargo gliders of World War II.
Strategic Brigade Airdrop is the most demanding airborne operation driving organic airlift capability. C-17s have assumed this mission from the retiring C-141 fleet. With the successful validation of dual-row airdrop capability, the C-17 fleet will be fully mission capable for this requirement upon delivery of 120 aircraft. The airdrop requirement, therefore, is less demanding than the overlapping MTWs and does not drive force structure.
This operational task requires additional airborne communications and generally launches on short notice, requiring rapid and close mission planning and coordination with the user. The Strategic Brigade Airdrop also produces an intense MHE requirement to support the rapid rigging and onload of airdrop platforms at the staging site. Such intense activities create a significant operations security (OPSEC) challenge. These airdrop aircraft must be able to fly in a non-navaid environment, conduct formation air refuelings, and participate in formations of up to 100 aircraft. Finally, crews and troop commanders need near real-time situational awareness of the battlefield and communications with ground forces in order to react appropriately to the dynamic character of combat operations.
Air refueling enables Strategic Brigade Airdrop - taking airborne troops from CONUS garrisons and air-dropping them directly into the combat zone. Air refueling puts the 'rapid' in rapid global mobility, allowing airlift and deploying combat aircraft to fly direct from the CONUS to the AOR without delaying at en route bases.
The Army and Air Force jointly satisfy the Defense Planning Guidance requirement for forcible entry into non-permissible environments through Strategic Brigade Airdrop (SBA). The SBA is the responsibility of the XVIII Airborne Corps and is a division ready brigade task force, capable of rapid response time, surprise and rapid build-up of combat power, while reducing risk to air assets and providing operational flexibility. The mission of the SBA is to seize an area and establish a lodgment for expanded combat operations, as necessary. An SBA could be employed as part of a larger combat operation or as a stand-alone mission to accomplish a Non-Combatant Evacuation operation or show of force. The C-17 is the aircraft of choice for the SBA due to its outsized cargo carrying capacity, unlimited range due to air refueling, and short landing capability.
The SBA delivers - via airdrop (echelon A) and airland (echelon B) - a brigade-sized Army force of the 82d Airborne Division directly from CONUS (whenever possible) to any target area in the world. When performed solely by the C-17, the SBA consists of 53 airdrop (Alpha Echelon) and 46-48 airland (Bravo Echelon) sorties to deliver the XVIII Airborne Division's Ready Brigade-Medium. Items contained in the echelon B include some items that are too large to airdrop, such as tracked and other vehicles from the Immediate Ready Company (IRC). Ultimately, the force package will be tailored to a specific mission, with the Division Ready Brigade (DRB) medium the optimum force for planning.
The SBA consists of an Alpha Echelon (airdrop 2,500 troops and 1,350 tons of equipment) and a Bravo Echelon (airland 750 personnel and 2,100 tons of equipment). Under the current CONOPS, the Alpha echelon would assault, seize and secure an area for the introduction of the Bravo Echelon. Ideally, this concept targets an area capable of handling up to four aircraft on ground simultaneously (maximum on ground - MOG) for a total of 46 aircraft in a 20-hour period.
Time constraints for the SBA are as follows:
- P-hour is first airdrop aircraft time over target.
- P+30 minutes is last echelon A aircraft airdrops load.
- P+4 hours is first echelon B aircraft lands at target area.
- P+24 hours is last echelon B aircraft lands at target area.
Target area characteristics included short, austere areas; likely with no organic air traffic control or cargo handling capability; were not compatible with C-141/C-5; and ideally should possess at least a maximum on ground (MOG) of four C-17's. Airfield selection, requirements, and SBA composition will be METT-T (mission, enemy, terrain and weather, troops and support available, time available) driven.
A Small, austere airfield (SAAF) is an unsophisticated, short airfield, incapable of C-141 or C-5 operations. It is usually in a forward operating area. SAAF's may have various surfaces including paved (prepared) or unpaved semi-prepared compacted surface (dirt, gravel, sand) runways and are typically limited in one or a combination of the following: material handling equipment, fueling capability, maintenance facilities, taxi ways, navigational aids, and parking space for aircraft ground operations.
A subset of a SAAF, an Semi-prepared runway (SPR) is an unpaved runway that has been prepared to safely support required aircraft maneuvers. The amount of engineering effort required to prepare an SPR depends upon the planned operations (i.e. number of landings), type of aircraft, the existing and required weight bearing capacity, and the existing soil and weather conditions. Runway preparation could take from a few hours to as long as several days. Consideration should also be given to periodic maintenance and resurfacing of an SPR during operations.
A distinction was made between a paved and an unpaved SAAF, based on the joint service common definitions and the fact that the personnel and equipment demands to insert an SBA in a semi-prepared (dirt, gravel runway) are greater. The definition for a "Semi-prepared Assault Landing Zone (ALZ)" is relatively close to the joint service agreed upon definition of an SPR.
There are significant challenges in delivering the Bravo Echelon to a single semi-prepared runway (SPR) within the 20-hour window, a capability the C-17 had yet to demonstrate as of 2002. The yet-to-be-resolved issues include the ability of SPRs to support the weight of the C-17, the inaccuracy of takeoff and landing data, and the inability to predict the ability of targeted SPRs to support intended operations. While these issues have not yet proven insurmountable, they do provide formidable challenges which will require a concerted effort by all agencies involved in order to make the Strategic Brigade Airdrop Mission a credible deterrent and one which military commanders will be willing to employ.
While there were no documents as of 1998 which contained a specific written requirement to insert an SBA into a SAAF, the Defense Planning Guidance (DPG) implies a requirement to be capable of such by its direction to provide a certain sized force anywhere within a defined timeline. There is an implied requirement, based on the verbiage in the DPG, to insert an SBA into a paved SAAF. This requirement can be met in the future with the current SBA assumptions/ planning factors as a guide, given sufficient C-17 aircraft. In the interim, it required reliance on C-141's for personnel airdrop and a portion of the equipment airdrop, as well as an intermediate staging base (ISB) from which C-17's shuttle the remaining airland portion. This concept is outlined by the JIPT for SBA to perform an SBA from FY 9704 to FY 0404. Use of an ISB is a short-term response since it was the only viable alternative available (ISB use introduces a greatly increased timeline outside of the SBA requirements and adds additional complexity and risk to the operation).
There is an implied requirement, based on the verbiage in the DPG, to insert an SBA into an unpaved SAAF - a Semi-prepared runway (SPR). However, based on the 1998 resources and time constraints, this could not be met with C-17 and/or other airlift at that time.
Based on previous testing on a semi-prepared runway, the time requirement to prepare a site could take from several hours to several days. This was not within the time line established for an SBA. Given the shearing force of C-17 braking and its effect on the runway surface, an SPR will have to be shut down for periodic maintenance. Because of the ambitious time line for the airland portion of the SBA (46-28 airland sorties within 20 hours to close the force within 24 hours; this equates to 26 minutes per aircraft to land, unload, refuel if needed, and takeoff), it was determined that there is no time to stop operations to perform runway maintenance. Engineers questioned the availability of an SPR that can accommodate at least a maximum on ground (MOG) of 4 aircraft.
Runway preparation and maintenance that exceeds the Rapid Runway Repair capabilities of the DRB force would require additional equipment be added to the SBA and heavy dropped. This equipment could come from either the airborne, light equipment company attached to the 82d Airborne Division (618th EN CO) or one of the two combat, airborne engineer battalions (27th and 37th EN BN's) under the 20th Engineer BDE.
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