Aerospace Careers: Fluid System Lab
The Fluid System Lab is a specialized facility that supports every
research and support aircraft flown at
NASA's Dryden Flight Research Center.
The mission of the Fluid System Lab is simple: design, manufacture,
modify, and repair all aircraft fuel,
pneumatic (nitrogen), and hydraulic (fluid) plumbing systems on aircraft
and in ground support equipment in
support of all flight operations carried out at the center.
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| Wheel well on B-52 depicting fuel, hydraulic, and pneumatic
systems. |
What are Fluid Systems?
Fuel, hydraulic, and pneumatic systems in an aircraft are composed of
many feet of metal and rubberized hoses, tubing, lines, pumps, and related valves
and regulators. These systems furnish pressurized fuel, hydraulic fluids,
and nitrogen throughout the aircraft to operate the engines, the flight
controls, the landing gear, and other vital components. Lines carrying pressurized
nitrogen also provide measurements of altitude, attitude, and air speed
to cockpit instruments and also to research instruments on the ground in
the Dryden mission control rooms.
Without pressurized fuel, hydraulic, and pneumatic lines a modern
aircraft could not fly, nor would there
be hydraulic or pneumatic-driven power to operate the majority of the
systems aboard the aircraft. The
proper function of the fluid and pneumatic systems on an aircraft is vital
to its operation and safety of flight.
Requests to initiate repairs, modifications, or creation of a fluid system
are originated by maintenance personnel, systems engineers, or research
project engineers. The requests can also come from contractors and other
agencies working jointly with NASA in a research project or flight support
operations. Once initiated, the work requests are processed through the
Dryden Aircraft Maintenance Branch for final approval and coordination.
 |  | | Hydraulic test stand tester | AGE Units and SR-71 |
Materials
Hydraulic and gaseous systems must withstand test pressures of up to 12,000
pounds per square inch (PSI) and operate routinely at pressures of about
3,000 PSI, so they must be made of durable materials. Most flight-qualified
hose and line fittings, valves, pumps, and regulators are made of titanium,
stainless steel, strong aluminum, and brass. Non-flexible tubing and lines
are also made of the same materials. Flexible lines are usually made of
rubber-like synthetic materials, with some wrapped in a protective flexible
metal mesh to increase the pressure limits and also to protect the lines
from contamination and damage.
Aircraft Ground Equipment (AGE)
The Dryden Fluid System Lab is also responsible for the design, repair,
and modification of fluid systems in all of the AGE units used on the
flightline and in the hangars. AGE units are the self-contained portable
pieces of equipment used to provide ground power to an aircraft, provide
ground test capabilities on the aircraft, and furnish fluid and pneumatic
power during all pre- and post-flight aircraft operations.
Fluid system pressure and safety requirements for AGE units are the same
as those on the aircraft they
support; therefore AGE maintenance and operational standards must be
equally as high.
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| Oil flow visualization on F-18 aircraft nose |
The System Simulator
One of the most unique pieces of equipment developed by the Dryden Fluid
System Lab is a hydraulic test stand tester. It is used to test and validate the
accuracy and readiness of the many AGE hydraulic units used on the various types
of aircraft flown at Dryden. The portable tester has actual hydraulic and pneumatic
systems, complete with valves and pressure regulators that simulate real aircraft
systems.
The ability to check an AGE unit before it is rolled out to an aircraft
prior
to a flight can save considerable time and expense, and may save postponing
an important research mission.
Recent Projects
Among the most visible projects associated with the Dryden Fluid System Lab
have been designing and installing the pressure source systems used to
release oil-based dyes and smoke in aerodynamic flow visualization studies
during research projects gathering aerodynamic data.
Most recent uses of the dye and smoke at Dryden have been during high angle of attack research flights with the forward-swept wing X-29 and a highly modified F-18. The tinted fluids are released from tiny orifices installed on the aircraft and the pattern created by the flow of air is studied by engineers to improve their knowledge of aerodynamics.
The Fluid System Lab helped design and install hydraulic and pneumatic
systems used to convert a Convair (CV)-990 jetliner into the Landing Systems
Research Aircraft (LSRA). The project aircraft was used to test and evaluate
space shuttle tires under varying loads and landing conditions. Installed
in the belly of the modified 990 was a landing gear strut and wheel system,
along with a mechanism to lower and raise the gear system and produce
several hundred thousand pounds of pressure during test operations.
 |  | | CV-990 aircraft landing gear | Smoke flow visualization on X-29 aircraft |
Experience
Skills required to work in the Fluid System field can be obtained in
several
ways. Many vocational schools offer training in fluid dynamics, a necessity
in this specialized field. Skills and knowledge can also be gained
through on-the-job
training at some of the larger civilian aviation repair facilities, and also
from aviation and fluid dynamics training in the U.S. Armed Forces. NASA
does
not require formal school training to work in this field; however,
applicants
must have a good working knowledge of fluid dynamics and fluid and
gaseous flow
requirements. They must also possess and demonstrate the ability to read and
comprehend engineering drawings, produce the required fluid systems from
those
drawings, and operate shop equipment competently and safely.
Fluid System Lab personnel must be capable of taking part in the engineering
design process of aircraft modifications or manufacture to assure that
the proper fluid systems are recommended.
Document Number: IS-97/08-DFRC-02
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