Back Ling-Temco-Vought XC-142A "Tri Service"
1964

Ling-Temco-Vought XC-142A

The XC-142 Tilt-Wing V/STOL program had its roots from the recommendations from a government advisory group in 1959. The group recommended that a full-size aircraft was required, with specific requirements for the Navy and Army. Beyond the obvious military applications of such a system, there were also many that felt that the plane could also have considerable civilian applications.

The group noted that all previous VTOL programs at the time had been built to illustrate a particular principle, and the fact that it could be accomplished. Few of these concepts had any operational military capabilities. Consequently, with the XC-142, it was decided that this system would be tested in an operational environment.

With that goal in mind, it was decided that the system would fulfill requirements for all three military services. Thus was born the first tri-service VTOL.

In 1961, a Request for Proposal was released, and in September, the proposal from Vought-Hiller-Ryan was announced as the winner. It was also announced that the Air Force would manage the program with the cost of the program to be shared equally by each of the services.

Vought Aeronautics Division of Ling-Temco-Vought was the prime contractor, with Hiller and Ryan serving as the major subcontractors. Vought subcontracted the design and fabrication of the empennage, aft section, engine nacelles, and wing to Ryan. The overall transmission system and selected components were subcontracted to Hiller, which was also responsible for the flap and aileron fabrication.

Compared to previous test bed experiences, the new V/STOL was a large aircraft with significantly optimistic performance goals, similar to those of the Army's DHC-4 "Caribou" transport.

The XC-142 grossed out at about 16900kg loaded with an empty weight of about 10780kg. The plane had a fuselage length just exceeding 17.7m, with a maximum height of 7.9m and a sizable wing span of 20.6m. The model carried a single tall vertical tail that provided 12m2 of area. The wings carried large trailing double-slotted flaps the entire length of each wing and were mounted high on the fuselage.

The bulky fuselage was designed to carry significant cargo, with the cargo compartment being 9.15m in length with a 2.1m height and width. That volume equated to about 32 full-loaded troops and gear, or four tons of cargo. In addition to that capability, there was also the ability to carry 370 litres of fuel. There was also a planned capability for auxiliary tanks which would greatly add to the range.

Power consisted of four 3080hp General Electric T64-GE-1 engines, mounted in nacelles on the wings, which were all cross-linked together. Each drove a giant four-bladed 4.7m Hamilton-Standard fiberglass propeller, the tips of each practically overlapping each other.

Later in the program, Hamilton Standard would provide an improved version of the propeller using the 2FF blade design, which featured a wider planform, rounded tips, and a more pronounced twist than the earlier 2EF blades. The goal of the new design was to improve aerodynamic load distribution and overcoming a static load problem.

The four engines also drove a fifth propeller, a three-bladed fiberglass type, in the tail through an interconnected gear and shaft train. Therefore, power was available to turn all five propellers when one, two, or three engines were shut down. The tail propeller rotated in a horizontal plane and was declutched and braked for cruise flight.

Tying all this power together was obviously an intricate and complicated setup. Through cross-shafting gearboxes, the rotation from each engine was brought together at the top of the fuselage. The power was then sent back to the tail rotor through a tail propeller shaft, into the tail propeller gearbox, and on to the variable pitch tail propeller.

The propulsion system of the XC-142 was definitely an over-powered situation. For example, the plane could lose an engine on take-off and still clear a 15.25m barrier in 122m carrying a 4500kg payload. Also, with all engines operating, the plane had a rate of climb at sea level of 34.5m/s. On a hot day, even with an engine out, the XC-142 showed a climb rate of 17.8m/s.

Control of the craft during the ascent stage was intricate to say the least with roll controlled by differential propeller pitch. Pitch control was accomplished by the eight-foot, three-bladed variable pitch tail rotor. Yaw control was provided by ailerons powered by propeller slipstream deflection, actually a second VTOL concept being employed in the XC-142.

The craft had a unique capability with the main lift system in that the wing was capable of rotating through 98 degrees instead of the expected straight-vertical position. The wing tilt mechanism consisted of two screw-jack actuators driven by a centrally-located hydraulic motor. The tilt was controlled by a variable rate switch on each collective lever, or by a constant rate switch. This allowed the plane to hover in a stationary mode in a tailwind condition.

The trailing edge of the wings carried three-section, double-slotted flaps in three sections, with the center and outboard sections operated also as ailerons. The flaps were programmed automatically with changing wing tilt, although the pilot had an override capability. Leading edge slats were used for stall suppression, and were mounted outboard of each engine nacelle and operated automatically as a function of flap position. The vertical tail was operated as a standard rudder-and-fin set-up, which supported the slab-type unit horizontal tail assembly.

The magic in the design was probably in the intricate control system, a fully-powered irreversible type with artificial feel forces and powered by dual independent hydraulic systems. Dual cockpit controls, consisting of conventional rudder pedals, control sticks, and collective levers for all take-offs and landings, provided the highest technology of the system.

The XC-142 design also considered logistics implications, in addition to the VTOL design goals, with the tail rotor rigged to fold to the port side to reduce the storage length and protect against damage during a loading operation.

The first XC-142 was rolled out in early 1964 with its first conventional flight being made in September 1964, its first hover three months later, and first transition two months later than that. The Air Force extensively tested the XC-142's capabilities with cargo flights, cargo, and paratrooper drops, along with desert, mountain, rescue, and carrier operations.

In 1966, one of the XC-142s passed operational tests to prove the model in carrier operations. In quick succession, the plane accomplished 44 short take-offs and landings, along with six vertical take-offs and landings from the USS Bennington.

The carrier trails were accomplished using the number five prototype, which was crewed by both USMC, Navy, and Army pilots. The flight regime covered VTOL operations at a variety of speeds, which occurred at wind conditions from 10 to 55km/h. A large variety of wings and flap tilt angles were used during the testing. Also, there were landings accomplished with three and six degree glide slopes. In an amazing demonstration, the plane negotiated a 360-degree turn within the width of the flight deck. That same year, one of the prototypes was also tested in an overwater pickup operation. The plane lifted a man from a life raft to determine its capability for rescue and recovery. A standard Navy horse collar sling was attached to 38m of cable and then lowered through a floor hatch just aft of the cockpit. The tests proved that there were no problems with effects of the propeller downwash or slipstream turbulence.

The program called for the building of five prototypes, but cross-shaft problems, along with some operator errors, resulted in a number of hard landings causing damage to the complete fleet.

The most serious of the mishaps, resulting from a tail rotor driveshaft failure, caused three fatalities. The May 1967 accident took place near the Dallas, Texas, LTV plant and occurred in a heavily-wooded area where fire started after the impact.

The flight plan for the ill-fated prototype included a rapid decrease in altitude from 2440m to 915m, effectively simulating a pilot rescue under combat conditions. A nose-over at low altitude followed, from which the crew could not recover. The crash aircraft was XC-142 #1 which had flown 148 times at the time of the crash.

Other incidents included the following:

  • Aircraft #2 - On October 19, 1965, this craft experienced a ground loop causing extensive damage to the wing and propeller.

  • Aircraft #3 - On January 4, 1966, this model made a hard landing in the vertical mode. There was significant damage to the fuselage. The wing of this plane was late mated to the Number #2 for further testing.

  • Aircraft #4 - On January 27, 1966, an engine turbine failure caused the overriding clutch to engage, causing extensive damage to the wing, outboard aileron, the number two nacelle, aft engine shroud, and fuselage. It was later used by NASA for further research.

  • Aircraft #5 - ln December of 1966, a ground accident caused major damage to the fuselage, nose, wing, and propellers. The incident was caused by pilot error who failed to activate the hydraulic system, which resulted in no brakes or nose wheel steering.

The final decision on the disposition of the aircraft occurred during the Category II Operational Suitability Program, which was conducted at the Air Force Flight Test Center. The testing consisted of 113 flights, totaling 163.9 hours, which was accomplished between July 1965 and August 1967.

Three of the XC-142s also participated in a major operational test demonstration during the program, where the planes participated in demonstrations of VTOL, STOL, and movement of Jeep-mounted 106mm recoilless rifles, unloading of three-quarter ton trucks with towed 105mm Howitzers, dump trucks, and 450-kg A-22 containers.

For a typical XC-142 design mission, the plane could operate with a gross weight of 16900kg, including a four-ton payload. At that weight condition, the plane could take off vertically, cruise 370km near 480km/h, hover for ten minutes, and then land.

One of the limitations found in the plane, even though the overall test results were very positive, was an instability between wing angles of 35 and 80 degrees which was encountered at extremely low altitudes. There were also high side forces which resulted from yaw and weak propeller blade pitch angle controls.

Another XC-142 complaint was the excessive vibration and noise in the cockpit, when coupled with an excessively high pilot workload, and which presented a considerable challenge in the cockpit. The program was a considerable effort, with 39 different pilots flying the prototypes for a total of 420 hours.

The greatest national exposure the XC-142 received during its flight test program occurred when the #4 prototype participated in the 1967 Paris Air Show.

The technology contributions which were derived from the program were felt to have made the program worth its effort. In retrospect, it has to be assumed that if the mechanical problems experienced with the XC-142 could have been solved, the plane could well have achieved operational status.

The only remaining XC-142, #2, currently is on display at the Air Force Museum at Wright-Patterson Air Force Base near Dayton, Ohio.

S.Markman & B.Holder "Straight Up: A History of Vertical Flight", 2000

LTV XC-142A

Technical data for XC-142A

Crew: 2, passengers: 24-44, engine: 4 x General Electric T-64 turboshaft, rated at 2095kW, wingspan: 20.6m, length: 17.8m, height: 8.0m, wing area: 49.7m2, empty weight: 10250kg, max speed: 667km/h, ceiling: 7620m, range with max fuel: 756km, range with max payload: 370km

Comments1-20 21-40
Gary Schreffler, e-mail, 26.07.2017reply

I have color a 8mm home movie of the XC-142A launching from the Saratoga (CVA-60). After launching, it made a couple of passes before departing for Rota. Very cool stuff!

Anonymous, 03.05.2020 Gary Schreffler

Gary - any way of sending me a quick video online of that? I'm the historian of the USS BENNINGTON CVS-20 and she did her initial testing for carrier ops aboard BENNINGTON in May of 1966 prior to her trip to the Paris Air Show in June of 1967.

Joe Pires. Jkpires@atmc.net

Thanks in advance. 🇺🇸🇺🇸🇺🇸🇺🇸⚓️⚓️⚓️⚓️

reply

Lawrence Getso, e-mail, 29.12.2016reply

I also was on the east side of the lake and was with the others who ran in through the muck to reach the crash site. There was nothing anyone could have done at that point. It was sad situation and still haunts me to this day.

Clint Spooner, e-mail, 18.05.2015reply

Regarding Pete Bitar's comment, take a look at NASA Langley's "Greased Lightning" the 10 engine (electric) which has distributed lift as well as computer implemented stability control. If made in a full sized aircraft, might be a practical application of the XC-142 tiltwing principle.

Shaun Jester, e-mail, 11.05.2015reply

Family legend says my father, Charlie Jester, was new to the program and volunteered to operate the winch on his last flight. I've never read these comments before today, 48 years after the accident. Thank you to all who have posted! I'd be glad to correspond with any other family members or LTV folks who have stories to share. shaunjester@yahoo.com

Pete Bitar, e-mail, 27.04.2015reply

What a great aircraft. I wonder, if one was able to get the original drawings and update everything with modern control systems, computerized systems management (to lighten the workload in the cockpit), and modern materials to lighten overall aircraft weight, with more efficient engines, could it fly again and be a real competitor? I believe so, but it would take a big commitment of funds and time. It'd be a great tribute to, from all I've read, a great team of people that sacrificed so much to make it fly in the first place. Modern tech could solve the problems that killed it then.

Joseph Engle, e-mail, 05.01.2013reply

I remember the day the 142 went down. My mom picked me up from Paul Keys elementary school in Irving, and told me my dad, Joe Engle, was OK, but there had been a crash. Being the son of a test pilot, I'd gone to a number of funerals for pilots, but never a memorial for three in one day.

The crash deeply affected my dad, especially the loss of Stu Madison. Along with Bob Rostine, if you saw one of them, you saw the other two.

Bill Moore, e-mail, 03.05.2020 Joseph Engle

Hi Joe,
I am not sure if you are my cousin, but if your dad was a pilot in the F-8
and the A-7 programs, your sister is Mary Ann and your mother was Ruth Moore, I live in Asheville, NC and would like to hear from you.
Bill Moore

reply

eflatguy, e-mail, 20.12.2012reply

Stu Madison was one cool dude.
I was in scouts with his son.
I remember him being a real trickster, while giving a lesson in navigation and compass usage.
After a while, he revealed the magnet he had palmed in his hand.
That was fun.

Bart van der kallen, e-mail, 25.10.2014reply

Hi all,
Great story's to read.
Sorry for my bad englisch.
Ist there anybody who have THE drawning of THE plane.
I'm startet to build a rc scale plane .
THE software is already there. A prototyp is already flying ((semi-scale)YouTube)

i want to build a wooden model in a scale of 1:7

Thank u very mutch .

Bart

Ed Flinn, e-mail, 28.07.2010reply

I was an aero engineer ~ propeller performance specialist ~ on this project from 1962 until the program was canx. John and Mary Ann Omvig and their two children were our next door neighbors and Lake Arlington water skiing buddies with our young families. Such a terrible loss, all three extraordinary aviators. John was a survior of jet fighter crash on a carrier in the Korean war.

The failure that caused the crash was the fracture of a funk strut on the tail prop control rod. As the ship began to pitch over, the pic (apparently)decided he had a horizontal tail aoa problem (all moving horizontal stabilizer /elevator)thus elected to go deeper into conversion to vertical flight ~ the tail prop had gone hard-over in the nose down direction with catastrophic results. There was some speculation that had he elected to accelerate to wings down conventional flight the he might have recovered...but not likely. After the crash we had one of the ships in the structural test lab at LTV, with vibration generators on just about every control system. It soon became obvioius that the funk strut assembly was readily excited in its natural frequency by many normal modes of the ship...clear failure modes. In hind sight, and by today's standards, the program should have had far more structrual dynamics testing before flight.

Mark Peterman, e-mail, 23.04.2011reply

Shaun Jester, his mother Sue and sister are all still missing Charles. Shaun and I are friends from grade school /boy scouts. My father (also LTV at the time) and I have always loved Shaun and Sue. We were 45 years old when Shaun finally told me about how they were notified that tragic day. It was an emotional moment and apparently one that he had not confided outside the family (not even his wife) until that day. Shaun now works for another defense contractor in Ft. Worth and Sue is glad he is not a test pilot! I was way too young (b 1963) to have met Charles and only know of him through his family and some photos. Since Shaun and I still see each other (he is my brother in Christ and Scouts!) if anyone has any information about Charles they would like to send their way, drop me a line please. I will see him again next week.

Doug Sheldon, e-mail, 28.04.2011reply

I was stationed at Edwards, AFB (F-111 program) during the same time frame, mid to late 60's, as the XC-142 test program. The Army's equivalent to a USAF flight control specialist was a drone MOS. An Army Spec 5 was assigned to base A&E squadron for the XC-142 and I joined him a few times on work assignments when there wasn't much F-111 activity. The XC-142 was a hydraulic nightmare. But, what a challenge, as were many of the one of a kind aircraft at Edwards.

Bob Madison, e-mail, 07.06.2011reply

My son, Stu's nephew, alerted me to this site; it's snswered a number of questions that have lingered in my mind. Another LTV pilot had told me (at my brother's younger daughter's wedding) that it was a "pin" failure that caused the tail rotor to go to full pitch. So LTC Chubboy's more detailed explanation is especially appreciated.

james, e-mail, 09.08.2011reply

Where are the other four a /c now? The ones that crashed.

Catherine Hardesty Lugo, e-mail, 14.11.2013reply

My dad, Ed Hardesty, was a test pilot at LTV during this time

Jesse P. Jacobs, Jr., e-mail, 28.05.2010reply

Ross Beedle wanted to know which XC-142A was on the USS Saratoga in May 1967 flying off the carrier going to Rota Spain. I was the Test Director & I know it was Airplane #4 the last three numbers on the tail were 924 It is currently at the Air Force Museum, Wright-Patterson AFB, Ohio. I am Colonel Jesse P. Jacobs, Jr. USAF (Ret).

Joe Pires, 03.05.2020 Jesse P. Jacobs, Jr.

Tail number on aircraft that was tested aboard BENNINGTON CVS-20 in May of 1966 was 25925. Was flown by the Captain of our ship Rodney Howell.

I'm the historian for the USS BENNINGTON CV /CVA /CVS-20 and its PACT organization.

Jkpires@atmc.net

reply

Tom Humphrey, e-mail, 19.07.2010reply

I was a LTV flight test engineer working the A-7 program but knew most of the LTV test crew that worked the XC-142A. Emailers T Morrow and Robert Chubboy were correct on the names of all three crew members killed on the fatal demonstration flight. John Omvig was the co-pilot and Charlie Jester was operating the winch in the aft section. Jester did not have an ejection seat. As I recall Stu Madison ejected as the aircraft pitched over passed -90 degrees. John Omvig ejected from the inverted aircraft just before impact with the ground. All the LTV test pilots were top notch professionals. Stu Madison though was one cool customer and it was well known that he was John Konrad's (Director of Flt Ops)golden boy and was headed for greater things. It was a terrible trajedy

T Morrow, e-mail, 08.01.2010reply

The pilots on the fatal flight were Stu Madison,
Charlie Jester, & John Omvig

rudager, e-mail, 28.12.2009reply

I'll tell you who was in the tail of that contraption..

SOMEONE WITH GIANT F*CKING BALLS

I mean damn, what were they thinking!?

Jim Wilson, e-mail, 07.11.2009reply

I was 18 and driving on the East side of the lake when the aircraft went down. Myself and Martin Herndon waded through the Willows and Marsh and I was one of the first to arrive until now I didn't know the Captains name but always wondered who was in the tail section of the aircraft.

Richard Elston, e-mail, 15.07.2008reply

I remember the crash in May 1967. One of the other crewmember's last names was Jester. I was friend's with his daughter.

1-20 21-40

Do you have any comments ?

Name   E-mail


Virtual Aircraft Museum


All the World's Rotorcraft


Back AVIATION TOP 100 - www.avitop.com Avitop.com