Title: Page born: April 01 2002

SENIOR TREND (FSD)

"Ben said 'Okay.' The rest of us said, 'Oh, shit.'" Original F-117A program manager Alan Brown on Ben Rich accepting the USAF's deadline of 22 months from contract to first flight of the F-117A.

On November 16,1978, Lockheed was awarded a contract for five full scale development (FSD) test aircraft under the code name Senior Trend. The Senior Trend aircraft came to be defined as a single-seat night surgical strike fighter, with no radar but a very comprehensive electro-optical system for aiming its weapons. Because it was intended to operate at night, and had no radar, there was no requirement for any air-to air capability. Apart from it's low observable (LO) design, its most unusual feature was associated with it's covert mission: the outer wings were removable, allowing the aircraft to be stowed inside a C-5 transport.

The C-5 would ferry the fighter and its support crew into a base (quietly and discreetly at night) within striking distance of its target.(Note: this was how many of the first aircraft were delivered to Groom Lake. In fact, the image to the right shows a crated up Senior Trend F-117A being loaded aboard at the Skunk Works in Burbank. This method was later abandoned in favor of aerial refueling during flying with the thought that by the time an aircraft was disassembled, transported, and reassembled the crisis would be over.) The USAF saw the Senior Trend aircraft as one that would be used singly or in pairs against a small range of targets. Not many would be needed, explaining the initial order of only 20 aircraft.

The five FSD aircraft were not prototypes, but test aircraft that after the initial testing phase could be upgraded and become part of the operational fleet. When the FSD's were flight tested, the data and design changes would be immediately implemented on the FSD's as well as any future aircraft to roll off of the production line.

For example, FSD-1 (#79-780) showed stability and control problems that did not show up during wind tunnel tests. This was rectified by enlarging and lengthening the tail fin, and changing the tail fin from a four faceted diamond shaped cross section to a six sided hexagon cross section. FSD-1 was modified after the 10th flight (August 6, 1981). It initially flew with the larger fins on Oct. 21, 1981. FSD-2 (#79-781) which first flew on September 24, 1981 was retrofitted with larger fins after four flights. During retrofit, a production nose assembly was also installed replacing the conventional nose boom it originally delivered with. FSD-3 (#79-782) was retrofitted with the new fins while still in the production jigs, and each aircraft leaving the Burbank plant after that had this change implemented into its airframe.

Although the honeycomb structure of the FSD's exhaust system successfully handled the 400degF. temperature change between it's outer skin and the inner skin, the super heated air consistently caused warping at the four inch deep opening at the rear of the platypus. Once the precisely faceted panels lost their shape, the RCS bloomed from some aspects-defying the whole purpose of the aircraft.

FSD-1 was fitted with large, experimental blow-in doors over the platypus exhaust system to see if they would help cool the engines' superheated gases. Eventually, it was found that an expandable , shingled structure would take care of the problem, resulting in the implemented complex exhaust system, incorporating sliding elements and quartz tiles to resist heat without changing shape.
Other design changes include: the current mesh screen covering the FLIR as opposed to the original faceted flat surface having holes-creating a hard "screen", testing of fixed leading edge slats in an attempt to improve lift and reduce drag, and a change in the trapeze bomb hoist among other things.

The USAF required that the aircraft carry at least 5,000 lbs. of ordnance or auxiliary fuel or both, added with the need to store these items internally if the aircraft was to keep it's low observable qualities, required that there be a large internal bay. Airframe and size limitations restricted engine placement to the fuselage. This resulted in the aircraft having a remarkably wide structure with engines and wheel wells placed outboard of the bay, and a more modest wing sweep of 67.3 degrees. (As opposed to the Have Blue's 72.5 degree sweep.) The increased wing area provided better lift for the heavier FSD while keeping with the shape of the hopeless diamond. The dart like appearance of the original XST's also gave way when the IR acquisition and designation (IRADS) was added. Made up of a downward-looking sensor (DLIR) under the fuselage, and the FLIR ahead of the cockpit, the IRADS's need to retain good downward visibility in the FLIR resulting in the nose of the aircraft having a steep, blunt shape. This feature added some to the FSD's observability, but not an amount substantial enough allow the overall observability.

Also, it was originally believed that the inward-canted tail fins on the XST's would help shield the upward facing exhaust system from aerial IR detection. In doing this, the fins actually channeled the hot exhaust gases straight downward below the aircraft, increasing the IR signature from below. The twin tail also required that each fin be mounted on it's own separate boom. Although the distance was insignificant in the XST's, the larger FSD's distance of approximately 11 feet across the exhaust system made this arrangement impossible. Therefore, the split tail was abandoned by the now familiar V tail. The new arrangement was placed at the end of a stronger lengthened center spine to increase it's distance from the exhaust. It was found that the V-tail actually disperses the exhaust gases better than the split tail.

Other features included the two small twin doors immediately forward of the V-tail where the parachute breaking system is located. (Even though the FSD's did not have the high sink rate of the XST's, the aircraft still landed at a speed of 180 mph plus. Landing techniques lowered the landing speed by 10 mph and the parachute is now only used in landings with high crosswinds or on shorter runways.) The FSD also had a tailhook to be used in combination with a portable arresting cable and two hoists that raises and lowers the munitions back up into the weapons bay and forward into the air stream respectively. (Note: this is the exact opposite of the landing gear that retract forward into the aircraft.)

FSD-1 was originally delivered unpainted (See earlier picture on this page) and was painted in a camouflage paint scheme for it's first flight. That was abandoned for the standard gray used on all four subsequent flight test aircraft. Ben Rich, head of Skunk Works, personally preferred the gray and would have delivered the entire run in gray, but chief of TAC, Gen. Bill Creech, wanted black since it would mask the faceting and their shadows during the day. "You don't ask the commander of TAC why he wants to do something. He pays the bills," later recalled Rich. "The Skunk Works plays by the Golden Rule: he who has the gold sets the rules! If the general had wanted pink, we'd have painted them pink."

The Groom Lake crew called the FSD's "Scorpions" because of its menacing aspect and forked tail. (Other names applied to the F-117A include "Black Jet" and "Cockroach".) Two patches appear to have been worn by the personal at Groom. One featured featured a standard T-38ish aircraft and a scorpion separated by a lightning bolt with "Scorpion FTE" (Flight Test Engineer) written below. This patch was specific to the FTE's for the program. Since they could not ride in the aircraft (F-117A's are single seat) , they rode in the T-38 chase. (which is why the T-38 is featured on the patch). Published reports that FTE stand for "Flight Test and Evaluation" are incorrect. The second features a Scorpion with "Baja Scorpions" written across. (The Baja supposedly refers to lower or southern Groom Lake where testing was taking place.) In all, about 40 patches are known to be related to the F-117A, including patches related to individual test programs.

Even the C-5 flight crews that picked up the completed Senior Trend aircraft from Burbank had their patch-a black circle with a white crescent moon and a large question mark. On a tab at the top of the patch was "DON'T ASK!," while another tab at the bottom carried the letters "NOYFB." (None Of Your F#@!*#% Business) A similar patch (although possibly not specific to the F-117A) was given to upper management under Ben Rich and is shown here to the right.

It must be remembered that the F-117A number came along later in the project. At the time other aircraft operated at Groom. These included the Red Squadron-a squadron of Soviet aircraft that the US government had "acquired". These flights where logged in the pilot's logs as YF-110, YF-113, YF-114, etc. The pilots of the Senior Trend aircraft logged in the next in sequence, the YF-117A for a lack of an unclassified designator. When Lockheed printed up the Dash 1 flight manuals, they printed F-117A on the front cover. Supposedly neither the US government or Lockheed wanted to pay the reprinting cost.

On June 18th, 1981, Lockheed test pilot Hal C. Farley lifted the nose of FSD-1 off of the runway at Groom Dry Lake and made the first flight of the F-117A. FSD-2 made it's first flight unpainted on September 24, 1981. FSD-3 was initially painted gray and made it's first flight on December 18, 1981. FSD-4 was delivered in early 1982, but remained grounded for RCS configuration until 7 JUL 82. FSD-5 made it's first flight on April 10, 1982 and was used for navigation/autopilot and avionics development.

On September 25, 1985 the left tail fin "fluttered off" of FSD-2 (#79-781) while doing a pull-up maneuver during a daylight weapons test at Groom Lake. As the black tail with its large white 781 fell to earth, the pilot, Maj. John Beesley, was unaware anything had happened (because of the computer compensation) until the chase plane told him. He brought the aircraft in for a safe landing, and was later awarded the Distinguished Flying Cross. Restrictions were placed on certain regimes of flight (high speed) and the all-moving metal fins were replaced by thermoplastic graphite fins. (This incident is on file because the whole test was being filmed, but the footage is still classified.) On July, 18, 1990 FSD-5 (#784) flew with the new rudders. (Possibly lifting the speed restriction) The last graphite rudder was fitted in 1992.

Current operating FSD's are operated by the 410th Test and Evaluation Squadron, 412th Testing Wing, Air Force Flight Test Center, Air Force Material Command at Palmdale California Plant 42.

Full Scale Development (FSD) Aircraft

FSD-1 (#79-780)

Made it's first flight on June 18th, 1981 at Groom Dry Lake Nevada. FSD-1 was used for most testing related to the basic air vehicle. It was delivered unpainted, but made it's first flight in desert camouflage. Was configured with the conventional nose boom, and small vertical fins. The small verticals were replaced after the 10th flight (August 6, 1981). It initially flew with the larger fins on October 21,1981. It was positioned by the gates at Nellis Air Force Base, Nevada on May 16, 1992. This was the first of the F-117A series to take up gate guardian duties.

FSD-2 (#79-781)

Made it's first flight unpainted on September 24,1981. It was originally configured with the conventional nose boom and small tail fins. It was retrofitted with larger fins after four flights. During the retrofit, a production nose assembly was also installed. The first SENIOR TREND RCS test flight on January 23 1982. This aircraft was used for weapons separation, anti-icing, flying qualities, and performance testing. It reportedly carried a White Playboy Bunny on the fin during testing. It was delivered to the US Air Force Museum at Wright Patterson AFB on July 17, 1991.

FSD-3 (#79-782)

Ship 782 made it's first flight occurred on December 18, 1981. It was used for acoustics and navigation system testing. Initially painted gray. Later painted black after the brief period with the US Flag on the underside. Currently being flown by the 410th Test and Evaluation Squadron at the Skunk Works in Palmdale, Calif. as a WSC Avionics Test Bed.

FSD-3 (#79-782) with the US Flag

Ship #782 was initially painted grey. However, later in Nov. 1983 the aircraft was painted with a U.S. flag motif painted on the underside. The reason for this-the aircraft was officially being unveiled to high ranking officials, including Secretary of Defense Casper Weinberger during a F-117A test force change of command ceremony at Groom Lake.

The above is the first photo of this paint scheme widely available to the public. This photo appears in "F-117 Nighthawk" by Paul Crickmore, published in July 1999. As with past photos of the F-117A, now that the first photo has been published, the author is sure that other photos of this scheme will soon appear in the public domain.

The upper surface was painted flat black with standard gray markings. The tail markings have been duplicated exactly in Mike Machat's "Lockheed Legends" painting. There was a 6" (not 6' like in the Goodall book and the drawing) white disk with a Lockheed skunk logo near the top of the tail. Below it, and spread out rather more widely than usual, were USAF and 782. The forward third (ending about 6" aft of the retractable blade antenna) of the underside was blue with 50 white stars. The stars were in even rows, except a few stars had to be nudged out of line to accommodate the DLIR window. The thirteen red and white stripes increased in width toward the aft end (Think "rising sun"). A camera pod under the right wing (to photograph weapon drops) was in the middle of one of the red stripes, and was also painted red.

The plane approached the reviewing stand from the south and banked to show it's top surface. As it reached the center of the crowd, the plane banked again to show the American Flag. The crowd went wild. It was a beautiful airplane, and kept its patriotic colors for a number of months before being repainted overall flat black.

FSD-4 (#79-783)

Initially delivered in early 1982, but remained grounded for RCS configuration until July 7, 1982. It was used for RCS and IR signature testing. Later used for avionics integration tests. During the early Senior Trend years FSD-4 had it's own patch-a red delta shape with the number "4" and a black scorpion superimposed over it. The shape was based on the wing of the plane. Currently being flown by the 410th Test and Evaluation Squadron at the Skunk Works in Palmdale, Calif. being a WDC Avionics Test Bed and testing low observables. This aircraft performed a flight demonstration and was on static display October 18th and 19th at the 1997 Edwards Air Force Base Airshow displaying "79 783 ED" on the tail.

FSD-5 (#79-784)

First flight was on April 10, 1982. Used for navigation/autopilot and avionics development. Currently being flown by the 410th Test and Evaluation Squadron at the Skunk Works in Palmdale, Calif. being a OCIP/RNIP Avionics Test Bed and testing Weapons Compatibility/Separation, Performance/Flying Qualities, Flutter, and Structural Loads. This aircraft performed a flight demonstration and was on static display October 18th and 19th 1997 at the 1997 Edwards Air Force Base Airshow displaying "79 784 ED" on the tail. The tires were all black, but the inside of the MLG (Main Landing Gear) wheel (which is usually white) was painted yellow, with a small, black 'Baja Scorpion' stenciled on the center 'wheel cap'.

"Pete's Dragon"

Contrary to some published reports, aircraft (FSD-4)#784 was not delivered with a color drawing of Elliot, the dragon from Disney's "Pete's Dragon" in tribute to Col. Pete Winters, the USAF site commander at Groom Lake. (Elliot remember was invisible to everyone except Pete.) Apparently, that aircraft was #787 and it was named for Pete Barnes. Barnes was assigned to fly IOT& E in #787. Also contrary to published reports, The Pete's Dragon artwork was not on the tail of aircraft-rather the night before Barnes's first flight (July 8, 1982), Brad Brown (a painter for LADC) painted a dragon design on the side of the aircraft, after hours, on his own time. Pete's Dragon also had it's own patch-a black shield with a green dragon and "Pete's Dragon" in red. Patrick Allen Blazek writes that the origin of the "Pete's Dragon" patch in part derives from the Walt Disney movie of the same name that featured an invisible dragon. The USAF crew chief for the aircraft was Clyde Fonner. To raise money for Fonner's retirement party, the patch was designed. Aircraft #787's first flight was in the summer of 1982 (With USAF acceptance on August 23, 1982.). It was used by test force as a defecto-FSD for initial operation test and evaluation. This IOT&E program has come to be known as the Dragon Test Team. (FOR MORE INFO PLEASE SEE "THE DRAGON" PAGE).

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