The Pentagon Has Two Choices for Light-Attack Planes
An expert in counter-insurgency aircraft explains the options
In mid-2015, after a bruising battle on Capitol Hill over the future of close air support, Air Force Chief of Staff Gen. Mark Welsh directed exploration of a future attack aircraft, notionally designated A-X.
Up until then, there had been no equivalent to the A-X program that developed the A-10 Warthog, because the F-35 was intended to replace the A-10 by this time. As a result, none of the advance work required for a new aircraft program has been done. The direction by Welsh caught both the Air Staff and Air Combat Command (ACC) somewhat flat-footed.
Fortunately, substantial work has already been done with respect to light attack aircraft, with respect to ACC’s OA-X concept, the Light Attack Armed Reconnaissance (LAAR) program for the USAF, the Light Air Support (LAS) program for the Afghan National Air Force, the Imminent Fury project and the Air National Guard test program for light attack.
Since the release of the OA-X enabling concept, which covered turboprop light attack aircraft, substantial advances have been made. The EMB-314 Super Tucano (or “A-29” in its U.S. and Colombian designation) has been sold to another 14 nations from Ecuador to Indonesia.
The Air National Guard successfully completed a test program with the AT-6B, which incorporated much of the A-10’s fire control system.
Textron built the Scorpion demonstrator in record time, and the U.S. Air Force stood up its first A-29 squadron, the 81st Fighter Squadron at Moody Air Force Base, with aircraft destined for Afghanistan. The Navy’s Development Group (DEVGRU) wrapped up the Imminent Fury project with the Super Tucano and subsequently borrowed two OV-10s from NASA, and outfitted them to participate in a combat demonstration, called Combat Dragon II.
Above — the T-6A Texan II as a training aircraft. U.S. Air Force photo. At top — a Colombian Super Tucano deploys flares. Andres Ramirez/Wikimedia photo
With potential Air Force interest in light attack aircraft, a number of manufacturers have put forth existing and potential products for consideration. These vary over the full range from fully operational aircraft to paper designs. There are a number of potential candidates in varying states of development, only two of which are currently viable.
The A-29 Super Tucano and AT-6C Coyote are the most advanced aircraft developmentally. The AT-6B is a fencer, benefiting from commonality with the A-10C and AT-6C and a very robust communications and data array. The A-29 is a bruiser, with a higher, heavier airframe and a slightly heavier stores load. Both use the PT-6A-68 turboprop delivering 1,600 shaft horsepower.
Both aircraft, combat loaded, are comparable in power-to-weight ratio and wing loading to a combat-loaded P-47D. Both meet all requirements of the Buy American Act — unit costs are $11-14 million per unit, combat equipped, for a squadron-sized buy with support and training devices.
The A-29A Super Tucano is under production in Jacksonville for the Afghan Light Air Support program. Approximately half of the 20 aircraft have been delivered to Moody, where they are being used to spin up Air Force crews in preparation for training ANAF personnel. DEVGRU also used this aircraft for Phase I of Imminent Fury. LAS-configured A-29s lack the comm, datalink and crypto capabilities of U.S. aircraft, are equipped with a mil std 1553B databus, and use less capable sensors due to export controls.
The A-29 is the most widely deployed modern turboprop light attack aircraft in the world, with the most experienced users being Brazil and Colombia. Almost 200 aircraft have been produced with another 200-plus aircraft on order. Colombian air force crews have extensive combat experience, including with precision-guided munitions, due to their use against the FARC.
Brazil has used them extensively for counternarcotics, reconnaissance and counter-air operations. The aircraft are in service worldwide from South America, Africa and Asia.
The aircraft is certified to carry rockets, free fall munitions, air to air missiles (AIM-9L class), air to ground missiles (AGM-65 class), and laser-guided bombs including the Enhanced Paveway II. The 1553 Databus does not allow for employment of satellite-guided munitions. The A-29 has U.S. government airworthiness and weapons certificates.
An AT-C Texan landing in Glasgow on July 3, 2014. Mark Harkin/Flickr photo
The AT-6C is a derivative of the T-6B with hardpoint wings, an uprated engine and avionics from the A-10C, including the Central Interface Control Unit which provides the primary mission systems for the AT-6C.
The AT-6C uses a modified A-10C Operational Flight Program, leveraging all of the A-10’s stores management, datalink, map and helmet mounted cueing system interfaces.
Commonality with the T-6B is over 70 percent. There are two prototypes, one production validation aircraft, and one LRIP aircraft on the production line. The aircraft underwent a two-year evaluation at the AATC in Tucson, and was judged to be an “operationally effective and suitable light-attack and armed reconnaissance aircraft.”
The AT-6C carries almost as much fuel as the A-29 despite a smaller airframe, and has accomplished weapons tests with the GBU-12/58 Paveway II, guns, guided and unguided 70-millimeter rockets and Mk-81/82 bombs.
The U.S. configuration used by the Air Guard is fully compatible with night vision devices, and includes SATCOM, SADL and a Gentex Scorpion helmet-mounted sight. It has a MIL STD 1760 databus instead of the 1553B and is fully compatible with GBU-38/54 and GBU-39 weapons, although they have not been tested. The aircraft lacks U.S. airworthiness and weapons certifications.
The OV-10X is a now-defunct proposal from Boeing. A proposal was delivered in 2009 for the LAAR program that would have required a buy of 100 aircraft at $20 million per aircraft. But subsequent follow-up in April 2015 revealed that Boeing is not tooled for new-production aircraft, and that there are no existing airframes suitable for modification.
The existing OV-10 inventory is in such poor condition that DEVGRU took two years and $30 million to locate and return two aircraft to serviceability for the Combat Dragon II program. These particular aircraft are NASA-owned OV-10s, designated OV-10G+, that have been partially upgraded with new engines and a 12-inch EO/IR ball.
The aircraft has no mission system, no 1553B or 1760 weapons architecture, but it successfully employed APKWS II guided 70-millimeter Hydra rockets in combat. Its remaining weapons certifications are left over from Vietnam. There is no viable path to a new-build or remanufactured OV-10.
The KA-1 Wongbee is a variant of the KT-1 trainer, built by Korean Aircraft Industries. The “KO-1” is operational with the South Korean military as a replacement for the Cessna O-2 Skymaster. It is more correctly an armed trainer modified for observation of forward air control missions, and external stores are limited to marking rockets, gun pods and AIM-9. The aircraft has no mission systems or sensors and no databus architecture.
KT-1C was proposed as a light attack aircraft, but remains a paper aircraft with no flying prototype. As envisioned, the KT-1C would have five stations to carry gun pods, free-fall munitions and rockets. It is advertised to have aircraft self-protection and a centerline FLIR ball.
The KT-1B is a more advanced version of the basic aircraft in service with Indonesia, while Turkey operates the KT-1T and Peru the KT-1P.
A Textron AirLand Scorpion in July 2015. Tim Felce/Wikimedia photo
The Textron Scorpion is a twinjet airframe with a modular payload bay that Textron has marketed as a potential light attack aircraft. The aircraft is a demonstrator rather than a prototype and has been tested to four Gs (dry). No weapons tests have yet been conducted.
The aircraft was designed for endurance with a long, high-aspect wing and is probably not suitable for use as a traditional attack platform with the current wing arrangement. Textron expects the unit costs for a combat-equipped aircraft to be $20 million per unit, but an armed, rewinged prototype remains in the future. Scorpion lacks a U.S. airworthiness certificate and weapons certifications.
The Air Tractor 802U is an armed variant of a U.S.-built cropduster sold to the United Arab Emirates as a light attack aircraft. The aircraft modification consists of adding guns and hardpoints to the 802B, resulting in a “COIN” aircraft with no ejection seats or mission systems.
The aircraft has been evaluated by ANG aircrew and in a study conducted by the Navy Postgraduate School, with exceptionally poor results. The NPS study was terminated when a prototype aircraft was heavily damaged in a landing mishap.
While the 802U is still technically for sale, marketing efforts effectively stopped when the chief test pilot was killed in an 802 accident.
Visibility is poor, the handling characteristics are marginal, and the aircraft is severely underpowered at combat weight. U.S. and Australian mishap data on the 802 family show a pronounced trend towards loss of control at slow speeds and there are documented cases where a stall will result in an unrecoverable flat spin.
The aircraft cannot conduct diving weapons deliveries and has poor flight characteristics above sea level. It has no weapons database architecture, no mission system and has not conducted weapons release and certification in the US.
The AT-X/FT-X are proposed combat aircraft derived from the USAF’s T-38 replacement, the T-X. They are intended as the successors to the F-5A and F-5E programs, and are also expected to serve in U.S. and foreign militaries. No requirements for these aircraft have yet been written and the performance specs of the T-X competitors are unknown.
A Textron AirLand Scorpion at the 2014 Royal International Air Tatttoo. Airwolfhound/Flickr photo
Cost and maintainability
There is no reliable cost data for the Scorpion, because the aircraft is a demonstrator only with no sales or bid history. Textron quotes a per-unit cost on the order of $20 million, but this is not backed up by any contract bid. The OV-10X is defunct, the KA-1 is merely an armed trainer, and the 802U is so manifestly unsuitable as a combat aircraft that no cost information is relevant.
The only two aircraft ready for commercial sales that are actually light attack aircraft are the AT-6C and the A-29. Both competed for the LAS contract, with bids that were very close with respect to price.
The current cost estimates for purchasing turboprop light attack aircraft can be drawn from existing contracts for the Super Tucano. The typical contract is for a small package of aircraft (less than a squadron) and include training devices, simulators, two years of support and a robust spares kit. In 2004, the Colombian air force bought 25 Super Tucanos for $235 million, plus another $89 million to cover purchase of the EO/IR sensors.
In 2013, the Light Air Support contract, covering 20 aircraft, was negotiated for $421 million. While the individual aircraft, combat equipped with EO/IR ball run about $14 million, the support contracts, training devices and spare parts are accounting for a third or more of the total contract cost. The Colombian contract remains the largest contract executed to date outside Brazil.
U.S. government data on maintainability is drawn from the Air Guard Light Attack Test for the AT-6B and the Navy’s Imminent Fury program for the A-29. At this time, the I.F. reports remain classified. Within a year, additional baseline data may be obtained from the A-29 LAS aircraft at Moody.
The Air National Guard test program was a congressionally-directed evaluation that ran for two years. From the executive summary:
The AT-6C proved to be a very rugged and reliable platform, flying 183 out of 184 effective scheduled test sorties. The test team also flew the aircraft to Texas dry lake, near Nellis AFB, Nevada and performed FARP operations while on the lakebed. Additional austere field operations were successfully demonstrated at Truth or Consequences airfield in New Mexico. The aircraft was successfully evaluated for dust intrusion mitigation and assault strip (graded, level, graveled surface with some small ruts) performance. The maintenance man hours per flying hour (2.5) and costs per flying hour ($350) were impressive and unmatched by aircraft in the current inventory providing similar combat capabilities.
The fuel consumption of the turboprop aircraft is extremely low. The AT-6C fuel consumption at JEFX 10 averaged around 350 pounds per hour for all phases of flight. The A-29 uses the same engine with a different prop, and has demonstrated similar economy.
By comparison, an F-15E will use 390 pounds of fuel in six minutes at idle.
The Super Tucano. Photo via mashleymorgan/Flickr
The Super Tucano is the aircraft with the most operational flight time. Weapons used by the aircraft include the AIM-9, free fall munitions up to 750 pounds, and LGBs in the Paveway or Enhanced Paveway class (Colombia only). Rockets in the 70-millimeter or 66-millimeter class may be carried in seven or 19-tube launchers.
The aircraft has two internal .50-caliber guns with a total of 500 rounds of ammunition. Because of the lack of a 1760 databus, modern GPS-aided munitions are not compatible.
The AT-6C has dropped or tested more weapons than all other types of light attack aircraft combined, but lacks U.S. weapons certificates. Weapons successfully dropped or shot from the AT-6 include the Mk-81, Mk-82, GBU-12, GBU-58, AGM-114, 70-millimeter Hydra rockets and three varieties of guided rocket — APKWS II, GATR and Talon.
External gun pods have been fired in air to air and air to ground applications; the pods take up two of the six stations and hold a combined total of 800 rounds of ammunition. The aircraft is compatible with AIM-9X, GBU-38, GBU-54 and GBU-39, but none of these weapons have been tested for carriage or release.
KA-1 is capable of employing 70-millimeter Hydra rockets only.
The incorporation of a rocket-and-guns loadout means that field rearming by the aircrew is a real possibility. In the Jaded Thunder 10-1 exercise, the Navy validated its light attack concept using an armed A-29 for CAS and FAC(A). The aircraft repeatedly demonstrated rapid turns at Creech Air Force Base, as summarized in an after action report.
From two austere locations, with as little as 40 minutes between events, the aircraft was maintained, refueled, reconfigured between ISR and strike configurations, rearmed with multiple loads of rockets and guns, and launched / recovered during day and night operations. FARP evolutions were limited only to the Creech AFB fuel truck timelines, but were always accomplished in under 20 minutes from touchdown to launch.
Incorporating organic refueling with fuel bladders by Imminent Fury maintainers would have cut each of the FARP evolutions from 20 minutes to 7-10 minutes.
Absent a new development program, the AT-6C and A-29 are the only viable, short-term options for purchase in the immediate term.
Scorpion also has promise, but the aircraft remains a demonstrator without a finalized design configuration and is not in the same class regarding affordability. The A-29 is deep in a production run that will run more than 400 aircraft while the fourth AT-6C is in the production queue.
In short — there are no other suitable aircraft, jet or turboprop, suitable or available for procurement in the next two years.
Col. Mike “Starbaby” Pietrucha was an instructor and electronic warfare officer in the F-4G Wild Weasel and the F-15E Strike Eagle, amassing 156 combat missions and taking part in 2.5 SAM kills over 10 combat deployments. As an irregular warfare operations officer, Pietrucha has two additional combat deployments in the company of U.S. Army infantry, combat engineer and military police units in Iraq and Afghanistan.