|Doug with the remaining USAF CT-43A
during ground testing at Ramstein AFB April 1996.
Having heard Doug Hughes 2001 DOD E3 Program
Review Paper Aircraft E3 Upsets in Las Vegas, I knew he had been
involved with several interesting and high profile aircraft safety
and accident investigations. I had occasion to hear some details
recently when I stopped in his Alion office in Annapolis since
we were working on the same Department of Defense Ultra Wideband
study. As Doug and I talked about his work, I realized that he
would be a good candidate for the EMC Personality Profile column.
I thought that our readers would be interested in some of his
high profile endeavors. References are provided at the end of
this article for those readers that may be interested in obtaining
Doug didnt choose EMC as a career. It chose him. He obtained
his first amateur radio license while attending a high school
in a small Missouri Ozarks town. He has held K0LGZ, W0JBK, W3EWP,
and is currently W3HO. Ham radio, electronics, and playing the
trumpet were his passions during high school. Jazz trumpet players
normally starve, while electronic engineers dont, so his
educational direction was easy. Doug admits his trumpet skills
are limited, even today.
|Doug Hughes, USAF CT-43A Accident
Investigation, Flight Test Technical Director, over Croatia,
The University of Missouri at Rolla was within budget and commuting
distance for Doug and it had a great ham station W0EEE, so he
obtained his BSEE there in 1963. That university didnt have
the EMC reputation it has today, but at least four of Dougs
classmates ended up doing EMC work professionally. Bill Hord went
on to receive a PhD from Rolla and make his fame in the radar
field, but he was Dougs EM theory teacher while a graduate
assistant. Even Bill couldnt make Doug understand Maxwells
equations. It was Dougs most-hated course and would become
his nemesis. What goes around, etc.
Like many UMR graduates, Doug went to St. Louis to work for McDonnell
Aircraft, eventually McDonnell-Douglas, and now Boeing. Mr. Mac
probably rolled over in his grave after the Boeing takeover/merger
(many say that MacAir took over Boeing, but that is out of scope
for this profile).
Assignment to MacAirs excellent EMC group on the first day
out of the three-week drafting school was a stroke of good (or
bad, depending on outlook) fortune for Doug. He was trained by
the St. Louis EMC experts: Gus Weinstock, Phil McBrayer, Walt
McKerchar, and UMR classmates Dick Shimamoto and Cliff Skouby.
Doug did a lot of interface wiring design, subcontractor monitoring
trips, aircraft testing, proposal writing, and future technology
work while with MacAir. He also met and married a student nurse
One of the most enduring of the MacAir educational experiences
dealt with the RF susceptibility of position-transducer-fed flight
control avionics. The Phantom II (F/RF-4) aircraft was in production
during that era and included an Aileron-Rudder Interconnect (ARI)
circuit. Signals from position transducers on each aileron were
added, amplified, and used to control a hydraulic valve to add
a small amount of rudder when turning. The Wright Brothers had
a mechanical method to do the same to connect their wing warp
and rudder on the original Wright Flyer. The hip cradle controlled
it they literally flew by the seat of their pants.
Emissions from on-board communications transmitters would couple
into the wiring between the aileron position transducers and the
ARI amplifier at the vertical stabilizer base. It even happened
once during an important sales flight when the Shah of Iran came
to St. Louis to purchase some F-4s. He was flying the back seat
of an RF-4 and noted controls for the high-frequency (HF) radio.
The Shah received permission from the pilot to operate aeronautical
mobile on the HF ham bands using his ham radio license. It was
embarrassing when his ham transmission caused the rudder to move.
|CT-43A Crash Position Indicator Signal
Coverage Diagram as predicted by JSC/Alion staff Linda Sparks,
Richard Albus, and David Quasny.
Doug was taught that there is no such thing as an uncommanded
flight control surface movement. Increased wire shielding and
ARI amplifier filtering fixed the problem. Doug participated in
the ARI and nine additional air safety investigations during his
five years at MacAir. He didnt know Dick Ford back then,
but both had a part in the Forrestal Fire investigation. Doug
was asked to perform the circuit analysis of the LAU-10 rocket
launcher pod to determine the possibility of CVN-59 on-board radar
emissions to cause inadvertent missile launch from a MacAir product
F-4B parked on deck 29 July 1967. The missile hit a parked A-4
and knocked off the center fuel tank starting a fire with 134
fatalities. John McCain (now Senator McCain) was in the A-4, but
escaped, only to be shot down and captured a few weeks later.
|Doug and Sandy Hughes.
Doug was directly involved with resolving a fatal EMI problem
with the F/RF-4 lower UHF communications antenna coupling to the
nose-gear steering electro-hydraulic system. Again, it was RF
susceptibility of signals from position transducers.
Another interesting safety investigation while at MacAir involved
EMI between F-4 and RF-4 radars that were allocated to the same
frequency band. Doug was assigned to be the liaison engineer for
a study to be done by John Wibbe at the DOD Electromagnetic Compatibility
Analysis Center (ECAC) in Annapolis. This led Doug to join the
ECAC/IITRI staff in late 1968 for just two years.
Doug was planning to spend the time learning everything about
EMC at ECAC and then return to share it at MacAir. Doug is now
with Alion at the DOD Joint Spectrum Center, so only the names
have changed, the job is still about the same 36 years later.
Doug has said he never returned to St. Louis because he never
learned everything about EMC.
Upon moving to the Annapolis area, Doug resumed his graduate studies
at George Washington University and received a MSEE in Communications
Theory in 1971. He and I took the Coherent Communications (phase-locked-loop)
course from Vitirbis book together. We ended up teaching
the professor more than he taught us. Doug had actually built
a phase-locked loop in a ham radio frequency synthesizer.
EMC engineering at ECAC/JSC/ IITRI/Alion is anything but dull.
Doug, like many of his colleagues, has been called upon to do
a large variety of important projects. He has defined and performed
EMC tests; helped to develop the centers major Cosite Analysis
Model; performed many analyses of densely packed radiating/receiving
electronics; spent eight years doing personnel and project management
including hiring, development, training, project production, etc;
platform equipment placement studies; DOD equipment technical
database development and spectrum certification; electronic warfare
EMI fratricide deconfliction; developed EMC analysis methods for
low-observable platforms: frequency management studies of frequency-agile
DOD systems; frequency sharing studies of civil and DOD systems
with common frequency allocations; and involvement with the on-going
ultra wideband decisions.
But Doug is most proud of his work with air safety studies, including
combat search and rescue. Since 1997, Doug has supported the development
of the Combat Survivor Evader Locator (CSEL) system. CSEL will
save many downed airmens lives in the future.
During the mid 1990s, Doug noted the literature mentioning
that the commercial Boeing 737 airliner had problems with erratic
rudder movement. He suspected EMI, and the DOD has small fleets
of B737 derivative aircraft, so he arranged an EMI-Lessons-Learned
brief to be given to the staff of the US National Transportation
Safety Board (NTSB) in early February 1996. That presentation
led to Doug being called upon to participate in many accident
investigations as an EMC subject matter expert. The lessons learned
were many and beyond this profile. A number of URLs are appended
to this profile for readers to study independently. Doug is also
available to answer specific questions via his home e-mail at
|Doug and Sandy with family.
Many readers already know of the JSC involvement with the USAF
IFO 21 (Ron Brown Department of Commerce Mission to Croatia) and
TWA 800 accident investigations. Doug and Rich DeSalvo were called
upon to go to Ramstein AFB Germany and to Croatia as JSCs
on-site representatives to the USAF Accident Investigation Board
for the IFO 21 CT-43A accident of April 3, 1996 in Croatia. Rich
and Doug had both served on the RTCAs SC-177 study of portable
electronics EMI aboard aircraft, and there was a suspected mobile
telephone use during the critical approach flight phase. Doug,
Rich, and a large group of support staff back in Annapolis and
with the FAA in DC and Atlantic City investigated this and 13
additional E3 issues. A major finding was due to JSCs analysis
of why the Crash Position Indicator signal could only be detected
by search and rescue aircraft to the northwest of the accident
site. Both the mountain and aircraft vertical stabilizer shielded
the radiation in other directions. Results of the JSC work were
included in the Boards briefing, which was given to President
Clinton and Vice President Gore on June 6, 1996. Interested readers
are encouraged to down load the excellent summary published by
the Flight Safety Foundation. A link is presented below.
Doug and fellow JSC/Alion staff member Martin Macrae performed
the TWA 800 and subsequent Swiss Air 111 and Egypt Air 990 EMC
analyses for the NTSB and Canadian Transportation Safety Board.
Rich DeSalvo provided the JSC interface. An English professor
at Harvard had written a series of papers calling into question
the need to study the possibility of RF emissions from DOD transmitters
causing EMI to these three aircraft. Her work received wide distribution,
and she was even interviewed by Katie Couric on the NBC Today
The NTSB spent approximately $1M on the TWA 800 EMI investigation,
including full-scale ground testing in New Mexico of a B747-100
and center fuel tank wiring. Applicable links are presented below.
No EMI source was found to be causal, but switching transients
were measured within an order of magnitude of the 0.25 mJ HERF
threshold. An order of magnitude below switching transients as
an EMI source were portable electronics, and yet another order
below portable electronics were sources from the external electronic
environment, the original hypothesis of the Harvard professor,
Dr. Elaine Scarry. The EMC analysis material appears on pp. 159-164
of the NTSB TWA 800 report. Doug wrote the last paragraph on page
The external EM environments were predicted for TWA 800, Swiss
Air 111, and Egypt Air 990. Potential EMI causes of an 18-minute
Swiss Air 111 VHF communications blackout were also postulated
for the Canadian TSB.
|The three Michigan grandsons with
their game faces.
Doug is a full member of the International Society of Air Safety
having performed the mandatory ten investigations by 1967. He
has participated in a total of 29 investigations, two of which
were in support of American Airlines.
Dougs wife Sandy is a Registered Nurse working in a private
OB/GYN practice. They have a daughter and son, both of whom are
married to their college sweethearts. Their daughter Laura is
also a Registered Nurse, works at the University of Michigan Hospital
in Ann Arbor, married to an industrial engineer, and mother to
three active hockey-playing boys. Their son Darren is an English
PhD candidate at the University of Tennessee, a web site developer,
and is married to a famous forensic artist.
Doug and Sandy hope to retire to Michigan in early 2005 to be
closer to the grandsons and to the child who will pick their
assisted-living home in the distant future. Doug plans to
continue building a model railroad in the Michigan basement and
to be on call for interesting air safety investigations involving
those weird radio frequency signals and EMI. A quote of his is
popular with fellow practitioners in the small air safety investigation
community EMI leaves no scratch marks.
Joanna & Darren Hughes
Dougs Model Railroad
CVN 59 Forrestal Fire (7/29/67)
RTCA STUDIES OF PORTABLE ELECTRONICS USE ABOARD (SC-177 1992-96,
IEEE SPECTRUM - September 1996
IFO 21 (4/3/96)
(Flight Safety Digest, July-August 1996: pp 1-25, CPI coverage
page 15, E3 pp 18-19)
TWA 800 (7/17/96)
(Systems Group Reports in .PDF)
Korean Airlines 801 (8/6/97)
AAL 1340 (2/9/98)
Swiss Air 111 (9/2/98)
Thai Airways International Tg261 (12/11/98)
USAF RQ-4A GLOBAL HAWK (3/29/99)
Global Hawk vehicle went out of control over the China Lake, CA
range due to an inadvertent command-destruct signal from the Tonopah,
NV range and was destroyed.
Egypt Air 990 (10/31/99)
AAL 1291 (11/20/00)
Thai Airways International Ltd fatal B737-400 fuel tank explosion
at Bangkok, Thailand (3/3/01)
AAL 587 (11/12/01)
TWA 800, Egypt Air 990, Swiss Air 111, and Electromagnetic Interference
(Dr. Elaine Scarry of Harvard theory)
© 2004 Douglas J. Hughes
Used by permission EMC