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One of LTV's pre-Rutan transport studies that built on the XC-142 experience was the P916 proposal, with monocyclic pitch control. Notice similarity with the XC-142 wing.

As a preamble to his SOFTA proposals, Burt Rutan proposed this superimposed view of the LTV C-142 and the Bell/Boeing V-22.

Model 208 Plenum fuselage, blown slot lip, tandem wing

Model 209 Advanced, two-rotor tiltwing

Model 212 Tandem stopped rotor, turbofan for cruise

Model 213 Single stopped rotor, turbofan for cruise

Model 215 Tandem wing, skirt for Super-STOL, rocket assist

Type:special operations transport studies

Type:

Program:

Powerplant:not determined

Significant date: 1991

In 1991, Burt Rutan studied a series of transport proposals under contract with LTV Aircraft Products Group of Dallas, Texas (LTV) for the U.S. Army's SOFTA (Special Operations Forces Transport Aircraft) program. After SOFA, ATT and ATTT (AT3) this program was the latest in a series of special operations transport programs initiated by the Air Force and the Army. L.T.V.'s involvement in the program is kind of surprising since at that time the company had ceased working as a main contractor for a few years and was now known mainly as a subcontractor, notably as the airframe builder for Northrop's B-2 bomber. However, the Vought archives indicate that the company was involved as early as 1987 in the special ops transport studies, working on the SOFA and ATT requirements.

SOFTA called for an aircraft with the capability to penetrate into unfriendly territory in a clandestine manner and to inﬁltrate/exﬁltrate/resupply Special Forces teams or equipment at an unprepared site. Low observability was "desired" and payload should amount to 5,000 pounds, consisting of 14 fully-equipped troops or other small package size containers."The earliest studies conducted circa 1990 attempted to evaluate the potential of an upgraded C-142 design to meet the SOFTA requirement. On May 23, 1991, LTV contracted with Scaled Composites to prepare a preliminary design study and a prototyping plan for a proposed Special Operations Forces Transport Aircraft (SOFTA). Of interest is the fact that Burt Rutan had worked on LTV's original XC-142 back in 1965, and one can imagine that the new challenge of working from that initial work and adding his acquired expertise to it must have been particularly interesting to him.

All designs done by Scaled for LTV for the SOFTA requirement carried the name TIDDS (obviously the inhouse name for the program) and were signed by Burt Rutan himself. The first three months’ activity for the design study consisted of development of conﬁgurations that could satisfy the mission requirements. This portion of the study was intended to allow the maximum freedom to explore new methods to meet the mission. Working with a minimum number of constraints, a large variety of configurations were explored. Twelve concepts were presented by Scaled during a mid-term presentation at LTV on 1 August 1991. Those preliminary configurations included the following:

Model 208 Plenum fuselage, blown slot lip, tandem wing
Model 209 Advanced, two-rotor tiltwing
Model 212 Tandem stopped rotor, turbofan for cruise
Model 213 Single stopped rotor, turbofan for cruise
Model 215 Tandem wing, skirt for Super-STOL, rocket assist
Model 216 Tilt tri-rotor
Model 217 Counter-rotating rotor, tail sitter
Model 218 Dual aft rotor, tail sitter
Model 219 Single rotor, X-wing, tail sitter
Model 220 Dual rotor, tail sitter
Model 222 Direct lift engine turbofan
Model 223 Capsule-delivery/recovery turbofan

Separate pages for each of these designs will be created soon. One can assume that the missing designations (Models 210, 211, 214, 221) might have been allocated by Rutan to studies he decided not to submit to LTV for various reasons (not practical, not quite compliant to the requirements, etc.)..

On 7 August 1991, LTV provided a downselect to six of the twelve conﬁgurations. Scaled responded with a second preliminary design study report including further refinement and performance estimates on the Models 209, 213, 215, 216, 220 and 223. The presentation of those six conﬁgurations, including refined performance and weight estimates was provided in a report to LTV on 27 August 1991. Finally, on 16 September 1991, LTV requested that the remaining portion of the design study consider only Models 215, 220 and 223.. Interestingly, all the Scaled reports pertaining to SOFTA appear in the Vought Archive with the title "Design study for the XC-142 for Special Operations Forces", possibly as a decoy to conceal the nature of their contents.

Although LTV singled out three designs and Scaled fixed a precise calendar for the rapid prototyping and delivery of a demonstrator there is no guarantee that a demonstrator was actually built, and if it was, there is no telling which of the three design was chosen. However, it is believed that there is a definite connection between SOFTA and the DoD's SENIOR CITIZEN program, and if so, the Model 223 flying wing seems the most likely candidate. Of interest is the fact that both "Senior Citizen" and Scaled Composites have the initials "S. C.", and that several details seem to coincide, but this is all speculation and there is no actual evidence that the SENIOR CITIZEN prototype (if any) was the same as the Scaled/LTV SOFTA prototype (if built).

Population: one demonstrator possibly built, model unknown

Need:

The capability to penetrate unfriendly territory in a clandestine manner and to infiltrate/exfiltrate/resupply Special Forces teams or equipment at an unprepared site.

Design mission:

Penetrate 1000 NM into unfriendly territory (no payload) and exfiltrate clandestinely an Army Special Forces “A” Team of 12 personnel and 500 pounds of equipment, 4,500 total payload, and return 1000 NM to the Forward Operating Location.

Design requirements:

STOL required — 1000 to 1500 foot over 50 foot obstacle at an unprepared site.
VTOL desired — at objective area, 4000 density altitude, 95° day, 4500 pound payload.
Payload — 4500 pound (design)*, 10,000 pound (overload)
Combat radius [Mission radius of action] — 1000 NM, 100 to 500 foot altitude, 300 to 400 knots.
Self-deployment Range — 2400 NM, best cruise altitude/Mach.
Signatures — low to moderate**.

In all cases, the aircraft are assumed to be sized to the mid-mission hover requirement.

*other document states "5,000 pounds (14 fully-equipped troops or other small package size containers)".
**other document states "Low observability desired".

Crew: 2

Main sources:

MID-TERM REVIEW - Configuration Presentation - Preliminary Design Study
SOFTA Rapid Prototyping Plan (Volumes 1 and 2)
Scaled Composites Report No. SCIR 91-009, August 1, 1991.
Preliminary Design Study
SOFTA Rapid Prototyping Plan
Scaled Composites Report No. SCIR 91-010, August 27, 1991.
FINAL REPORT - Preliminary Design Study
Special Operations Forces Transport Aircraft (SOFTA)
Rapid Prototyping Plan
Scaled Composites Report: Report No. SCIR 91-012, October 15, 1991.

These documents can be found in the LTV archives at the University of Texas in Dallas.

Although the author of this site is the one who found out about the above reports, he extends his deepest gratitude to sublight, who made it possible for these designs to see the light of day.

Scaled inhouse reports are not meant to go public and are therefore quite rare. These provide a unique glimpse at the company's design development, rapid prototyping plan and schedule of operations.

Model 216 Tilt tri-rotor

Model 217 Counter-rotating rotor, tail sitter

Model 218 Dual aft rotor, tail sitter

Model 219 Single rotor, X-wing, tail sitter

Model 220 Dual rotor, tail sitter

Model 222 Direct lift engine turbofan

Model 223 Capsule-delivery/recovery turbofan