F-15B Aeronautics Research Test Bed

NASA's Dryden, now Armstrong, Flight Research Center in Edwards, California, uses a 

modified F-15B aircraft as a test bed for a variety of flight research experiments. Coupled 

with either a flight test fixture or a Propulsion 

Flight Test Fixture mounted underneath the 

aircraft, the F-15B Research Test Bed aircraft 

provides a unique flight research capability.

Aircraft Description

Armstrong's F-15B is a two-seat version of the 

F-15 tactical fighter aircraft built by McDonnell Douglas, now a division of The Boeing 

Company. The aircraft was obtained in 1993 

from the Hawaii Air National Guard. In addition to flying research missions, Dryden's 

F-15B also is used for crew training, pilot 

proficiency and safety chase support for other 

research aircraft.

Bearing NASA tail number 836, the F-15B 

is a 64 feet long and has a wingspan of just 

under 43 feet. It is powered by two Pratt and 

Whitney F100-PW-100 turbofan engines that 

can produce almost 24,000 pounds of thrust 

each in full afterburner. It is capable of dash 

speeds well in excess of Mach 2, more than 

twice the speed of sound, at altitudes of 40,000 

to 60,000 feet, although speeds are limited to 

Mach 2 when a flight test fixture is mounted 

beneath the fuselage. The aircraft has a fullfuel takeoff weight of about 42,000 pounds 

and a landing weight of about 32,000 pounds. 

It has aerial refueling capability for extendedduration research missions.

A data acquisition system gives the F-15B a 

capability that makes it one of the most versatile 

research aircraft NASA flies. The data system 

includes a research airdata system for the aircraft itself, a Global Positioning System (GPS) 

navigation package, a nose boom that contains 

an airdata probe, a digital data recorder and 

telemetry antennas. In addition, an on-board 

video system monitored from the rear seat of 

the cockpit transmits high-speed airborne video 

and photography to researchers on the ground.

Flight Test Fixtures 

The F-15B carries one of several flight test 

fixtures mounted underneath its fuselage to 

help conduct flight research experiments. 

The Eagle Aero probes fly attached to the red device underneath NASA’s F-15B research test bed aircraft 

during a test flight in early 2011. (NASA / Carla Thomas)
F-15B Aeronautics Research Test Bed 2 NASA Facts

The Advanced Flight Test Fixture is built primarily of 

carbon/epoxy materials and is in two sections: an upper 

avionics pylon and a lower test article. The avionics pylon is a permanent structure housing avionics, research 

instrumentation and other support equipment. Individual 

experiments are mounted on the lower section for flight 

testing. When needed, a removable air data probe is installed near the bottom of the test article's nose. Since the 

lower section is removable, it may be replaced by other 

aerodynamic shapes for specific experiments. 

A Propulsion Flight Test Fixture (PFTF) allows the aircraft 

to carry and test advanced prototype engines and propulsion 

technology. It is a "flying engine test stand," allowing actual 

flight data on experimental engines that would otherwise 

be gleaned from traditional ground test stands. The PFTF 

is equipped with three bays containing removable racks 

that can be used for experimental systems, instrumentation 

and other critical equipment for a research mission, including small fuel tanks and instrumentation for experimental 

engines. The PFTF also is equipped with a force balance 

consisting of two instrumented attachment points for small 

test engines. The force balance instrumentation can measure various parameters on an experimental engine, such as 

thrust, inlet drag and aerodynamic movement.

The Centerline Instrumented Pylon (CLIP) is a test 

pylon that was structurally designed to carry larger span 

experiments, such as an airfoil, underneath the centerline 

of the F-15B aircraft. The CLIP has a large splitter plate 

at its bottom to protect the experimental attachments 

below from both aircraft noise and airflow disturbances, 

as well as to promote airflow around the test article.

Recent Research Experiments and Projects

Channeled Center-body Inlet Experiment

The F-15B research aircraft flight-tested an advanced 

propulsion concept, the Channeled Center-body Inlet 

Experiment, or CCIE, in 2011. 

A primary research objective of the CCIE project was to 

define and measure the airflow through an experimental 

jet engine inlet, then compare it to the airflow through 

a standard inlet by use of two interchangeable center 

bodies installed in the engine inlet that directed and compressed airflow through the engine.

One center body was channeled; the other had a conventional, smooth shape. Slots cut along the length of the 

channeled center body simulated a simple device that in 

an actual inlet would allow optimization of the amount 

of air flowing into the engine, resulting in improved airflow efficiency at a wide variety of speeds and improved 

fuel efficiency.

Eagle Aero Probes

Armstrong's F-15B was also used to flight test two new 

supersonic shockwave probes to determine their viability as 

research tools in 2011. Sonic boom researchers expect the 

probes developed by Eagle Aeronautics of Hampton, Virginia, to aid their understanding of supersonic shockwaves. 

The ultimate goal of NASA's sonic boom research is to find 

ways to control and lessen the noise from shockwaves, so 

that supersonic flight could become more routine. 

Supersonic Boundary Layer Transition Laminar 

Flow Studies

In 2010, NASA Armstrong partnered with the Aerion 

Corp. in the first phase of a flight experiment called the 

The channeled center-body inlet design, shown here in a subscale test version mounted underneath NASA's F-15B flight 

text fixture, could improve airflow and fuel efficiency of jet 

engines at a wide variety of speeds. (NASA / Tony Landis)

Aerion Corporation's test article used in the initial Supersonic 

Boundary Layer Transition flight test project in 2010 is shown 

attached to the Centerline Instrumented Pylon slung beneath 

NASA's F-15B research aircraft. (NASA / Tony Landis)
FS-2015-05-055 AFRC

National Aeronautics and Space Administration

Armstrong Flight Research Center

P.O. Box 273

Edwards, California 93523

NASA Facts

Supersonic Boundary Layer Transition, or SBLT, project, 

an effort accomplished through a Space Act Agreement 

between the two partners. NASA Armstrong provided 

the F-15B test bed along with the required ground and 

flight support for the effort. NASA and Aerion shared 

in the resulting data from the flights, which took the 

experiment to speeds up to Mach 2.0, or twice the speed 

of sound.

The flights gathered baseline data on a composite flat 

plate to aid calibration of instrumentation designed to 

investigate the extent and stability of natural laminar 

or smooth airflow at supersonic speeds over a special 

test airfoil section during second-phase flights in 2012. 

Engineers used the data to determine the effect of airfoil 

manufacturing tolerances on laminar airflow. Aerion 

engineers expect the research to aid in development of a 

highly efficient laminar-flow airfoil design for the firm's 

planned supersonic business aircraft. 

Quiet Spike

From 2006 to 2009, Gulfstream Aerospace and NASA 

Armstrong teamed in a project called Quiet SpikeTM to 

investigate the suppression of sonic booms. 

The project centered around a retractable, 24-foot-long 

lance-like spike mounted on the nose of NASA's F-15B. 

When the aircraft flew at supersonic speeds, the spike 

created three small shock waves that travelled parallel 

to each other all the way to the ground, producing less 

noise than typical shock waves that build up at the front 

of supersonic jets.

Space Shuttle Return-to-Flight LIFT project

As part of NASA’s space shuttle return-to-flight effort following the loss of the shuttle Columbia and its 

crew during the STS-107 re-entry from space on Feb. 1, 

2003, engineers at NASA's Johnson Space Center asked 

Armstrong to help model insulating foam loss from the 

shuttle's external fuel tanks.

The flight test effort, called the Lifting Insulating Foam 

Trajectory project, used a Dryden-designed foam ejection system installed in the F-15B's flight test fixture to 

acquire data on how insulating foam debris or "divots" 

behaved when the small pieces were shed from shuttle 

external fuel tanks during launch. The F-15B tested the 

flight characteristics of the divots in a real flight environment at speeds up to Mach 2.

The 24-foot-long "Quiet Spike" sonic boom mitigator mounted 

on the nose of NASA's F-15B test bed was developed by 

Gulfstream Aerospace as a means of controlling and reducing 

the sonic boom caused by an aircraft flying faster than sound. 

(NASA / Tom Tschida)

Two panels of Space Shuttle TPS insulation were mounted 

on the flight test fixture underneath NASA's F-15B during the 

Lifting Foam Trajectory flight test series in 2005. (NASA / Jim 

Ross)