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[F-117A's undergoing depot maintenance and upgrades at Site 7, USAF Plant 42.(LMSW)]

F-117A Upgrades II


On October 16, 1996 it was published:

"The U.S. Air Force officials said it's F-117A Nighthawks are headed for an upgrade program intended to cut support cost and increase availability and possibly improve stealth characteristics. Known as the Single Configuration Fleet effort, the program is scheduled to begin in 2000 and service all F-117s by the end of 2004.
The F-117s now have more than one major radar absorbing material (RAM) and "a labor intensive access panel technology." The new program would address these issues with a single, optimized RAM coating, new leading edge technologies and advanced access panel technologies. An Air Force official said this effort is not part of a plan for the F-117 mid-life upgrade that Lockheed Martin Skunk Works, Palmdale, Calif., has been asked to develop."

On April 14, 2000 a gloss white F-117A was seen making several low passes and eventually landing at Skunk Works in Palmdale, Calif. F-117A #85-0816 was conducting a functional test flight after completing modification upgrading with new exterior low observables materials. The aircraft had received a white primer coating and was flown prior to the application of final coating of black paint.

Aviation Week published on May 15, 2000:

F-117 Gets Standard Stealth Configuration


Exhaust System

By far one of the most .....

In 1991, persistent problems with the unorthodox exhaust system led to a decision to fit a new type of engine exhaust system involving the use of a new bottom side to the shelf-like extension over which the exhaust passes. The modification involves the use of new heat shields, better seals, new airflow paths, and new high- temperature thermal protection at the edge of the exhaust system. Most of these changes were designed to improve the maintainability of the exhaust system, which had proven to be a persistent problem.

The high exhaust temperature also caused problems for the composite materials. The following was published in November 1993 by USAF.

""Achievement: A new high temperature composite material resin developed by Wright Laboratory's Materials Directorate is being used to solve a recurring heat damage problem on the fuselage trailing edges of the F-117A stealth fighter. Their AFR700B resin has increased the temperature capability of organic matrix composites by 150 degrees F to 700 degrees F and provides enhanced processability and, for the case of the F-117A, improves the aircraft's performance while maintaining its low-observable profile.

Background: Air Force aircraft performance requirements continually demand more of aerospace materials. They must be lighter and stronger while operating at increasing temperatures. To help meet these demands, researchers at Wright Laboratory's Materials Directorate have developed an improved resin, called AFR700B, that increases the maximum operating temperature for composite materials. The F-117A aircraft has fuselage trailing edges made from composite materials that were being damaged by exposure to high temperatures. Hot exhaust gases from the aircraft's engines were charring the trailing edges causing replacement of the composite material. Scientists and engineers from the directorate's Nonmetallic Materials Division worked jointly with the F-117 System Program Office at Sacramento Air Logistics Center (SM-ALC) and the USAF Advanced Composites Program Office to use the AFR700B material and correct the problem. The Materials Directorate supplied the AFR700B prepreg material to SM-ALC who fabricated the trailing edge parts. The parts were furnished to the Consolidated Test Facility for a flight test. The flight test proved the AFR700B parts performed satisfactorily and the SPO at SM-ALC accepted them for use on all F-117A aircraft.

Payoff: AFR700B resin offers aircraft designers an advanced lightweight composite material for high temperature applications. Using the resin for in-house fabrication of parts to solve a recurring heat damage problem on the fuselage trailing edges of the F-117A stealth fighter will save the Air Force at least $15 million in acquisition costs and $50 million in life cycle costs.""

In 1994, the team of engineers from Wright Laboratory's Materials Directorate and the Sacramento Air Logistics Center (SM-ALC) mentioned above received the first Lt. Gen. Thomas R. Ferguson, Jr. Award for Excellence in Technology Transition for AFR700B. Kenneth M. Johnson, Dr. James R. McCoy and Capt. Michael W. Holl from the Materials Directorate and Allegra D. Hakim, Richard B. Warnock, Anthony Brindisi and Dennis M. Conboy from SM-ALC collaborated to develop AFR700B. The award will be presented annually to the individual or team responsible for the most significant transition of technology from the laboratory to an operational Air Force system during the previous year.

The following was published in October 1999 by USAF Material Command.

[F-117A exhaust tiles.(AFMC)] "The Air Force Research Laboratory's Materials and Manufacturing Directorate at Wright-Patterson Air Force Base, Ohio, recently completed one of the most successful parts replacement projects on record.
Working with the F-117 System Program Office at the Sacramento Air Logistics Center, McClellan AFB, Calif., and the Air Force's Advanced Composites Program Office, also at McClellan, the directorate designed, developed and transitioned a high-temperature composite material system for operational aircraft which solved a recurring heat damage problem on F-117A's fuselage trailing edges. This composite increases the heat tolerance by 150 degrees Fahrenheit, improves performance and helps ensure a low-observable profile.
As aircraft become increasingly sophisticated, Air Force performance requirements continually demand more of the aerospace materials used to build them. These materials must be lighter and stronger, able to withstand higher temperatures and cost-effective. Materials and Manufacturing researchers supplied the composite material to employees of SM-ALC, who in turn fabricated the new trailing edge parts. Subsequent flight tests proved the composite parts performed satisfactorily and the program office accepted them for use on F-117A aircraft.
[(AFMC)] SM-ALC determined it could fabricate the composite parts in-house at a cost of about $5 million below the price estimated by an outside aerospace vendor. A total of 450 separate component parts were fabricated at SM-ALC using this technology, with the last component assembled in January.
Using the resin for in-house fabrication of parts to solve the recurring heat damage problem will save the Air Force at least $15 million in acquisition costs and a reported life cycle savings of $50 million.
This, and the fact that only one component has been returned for rework, makes the composite program one of the most successful parts replacement efforts on record. In addition, it earned the Lieutenant General Thomas R. Ferguson, Jr., award for excellence in technology transition.

-Mr. Pete Meltzer, Jr.
AFRL Materials and Manufacturing Directorate"

Structural Modifications

Besides the minor changes incorporated under the updates listed, some significant structural changes have been made. Winf root modifications were incorperated from the 24th aircraft and were subsequently retrofitted to all earlier F-117As. Aircraft number 781 lost one of its tail fins in flight on September 25, 1985. The cause was found to be flutter and a program was instituted to design a stronger unit. A new, graphite thermoplastic-composite tail fin was authorized in Augest 1986 and was first flown on ship # 784 on July 18, 1989. It was incorporated on the production line and, by 1992, retrofitted to all earlier aircraft. New composite bomb bay doors were added around the same time to allow simultanious drops of two weapons. (This had been impossible with earlier doors) Furthermore, life-limited skin panels are being replaced and webs are being retrofitted in a program scheduled to run from FY02/99 to FY02/04.

TSPR Depot Maintenance

[TSPR program emblem.()] On October 2, 1998 Skunk Works was awarded a $1.8 billion dollar maintenance contract for the F-117A. The cost-plus-incentive fee Total System Performance Responsibility (TSPR) contract provides for fiscal year 1999 through fiscal year 2006 and marked the beginning of an unprecedented government acquisition strategy to lower the total ownership cost of the F-117 fleet.. Under TSPR, the Skunk Works provides support in the areas of program management, engineering technical assistance, depot activities, logistics, spare parts administration/warehouse operations, subcontract management and field support to the 49th Fighter Wing at Holloman Air --more-- Force Base, N.M. The SPO retains core functions for program direction, requirements determination, contract management, budgeting/financial execution and product/service acceptance.

Under TSPR's Cost Plus Incentive Fee/Award Fee contract, the Skunk Works' achievements during fiscal year 1999 (Oct. 1, '98 - Sept. 30, '99) have been significant. The company scored 100 percent in its performance against incentive objectives or "metrics" in the areas of spare parts availability; timeliness and quality of depot-delivered modified aircraft; deficiency report response time and weapon system trainer availability. Five government entities-the 49th Fighter Wing-Holloman AFB, the Air Force SPO, Air Combat Command, the 410th Test Squadron and the Defense Contract Management Command-judged technical performance, management performance, subcontracting and customer satisfaction in order to determine the award fee. The Skunk Works achieved a grade of "Excellent" with a 98 percent award fee. Cost-effective implementation of TSPR also resulted in government savings achieved under a 50/50 cost share provision of the contract.

TSPR's success was especially evident during Operation Allied Force, when the Skunk Works, in support of high-tempo operations, filled critical F-117 spares requirements halfway around the globe as F-117s operated from deployed locations in Italy and Germany during the 77-day air campaign. Ross Reynolds, Skunk Works F-117 Program Manager, emphasized, "Skunk Works' logistics support was a major contributor in maintaining F-117 mission capability rates well within the Air Combat Command standard, even in wartime."

The following is an excerpt from the Oct 2, 1998 "Areotech News and Review":

"On October 2, 1998 the USAF awarded Skunk Works a $2,054,514,064 contract for F-117A maintenance. Representative Howard P. "Buck" McKeon's press secretary, David Foy, expressed the Congressman's support for the award.
"Congressman McKeon believes very strongly that the F-117A should be maintained by the Lockheed Martin Skunk Works," Foy said. "The Skunk Works built the plane and the workers there have the expertise that will be needed to maintain such a highly technologically advanced aircraft.""

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