The people and equipment of the NAWCWD Weapons Survivability
2/25/2009 - The Naval Air Warfare Center Weapons Division Weapons
Survivability Lab (WSL) at China Lake recently developed and
verified the capability to accurately and realistically test,
evaluate, and document the effects of a Man Portable Air Defense
System (MANPADS) impact on aircraft in an effort to make them
more survivable. This capability is unique to China Lake, and
is known as the Missile Engagement Threat Simulator (METS).
“Our ultimate goal is to make sure the pilot completes
the mission and returns home safely,” said Ronnie Schiller,
METS project manager.
MANPADS are shoulder-launched missile systems which are produced
by more than 25 countries. MANPADS are relatively inexpensive
and widely available to the world, making them a serious threat
to U.S. and allied aircraft. METS will play an important role
in developing a strategy to severely lessen MANPADS effectiveness
by accurately simulating an impact and collecting the necessary
data to help predict the vulnerability of aircraft.
For the last 20 years, Congress has mandated that new aircraft
acquisition programs undergo realistic vulnerability testing
before entering low rate initial production. METS was developed
at China Lake to help aircraft acquisition programs comply with
the Live Fire Test Law by providing a method of effectively
evaluating an aircraft’s ability to tolerate MANPADS.
“There has been a long chain of challenges throughout
this project over the last 15 years,” said Robert Gerber,
lead mechanical engineer, “with over 70 individuals contributing
with very unique solutions. We have come a long way since the
early days of black smoke and mangled missile debris exiting
There are three components of METS. First is the portable,
6-inch, high-pressure gas gun.
The gas gun provides for a mix of interchangeable barrel lengths
and chamber volumes to achieve the desired acceleration profile.
For example, a hovering helicopter requires a higher acceleration
profile than a tail-chase fighter engagement due to the relative
velocity between the MANPADS and the aircraft.
Second is the MANPADS itself. METS uses an actual MANPADS with
two minor modifications to the fuze and fins. The foreign fuze
is replaced with an exploding bridge wire (EBW) fuze. The fins
are replaced with retractable versions that expand once the
MANPADS exits the barrel.
Third are the screens placed near the target. When the fins
contact the charge screens, the current is transferred to the
EBW fuze which in turn detonates the warhead. Different MANPADS
provide for different fuze timings. By varying the charge screen
location, METS has the flexibility to simulate a proximity,
contact, or delayed impact detonation.
“There’s no other facility to conduct MANPADS testing
in a realistic engagement scenario to the fidelity that we can
achieve here at China Lake,” Schiller said.
The WSL conducted three fully configured METS tests in 2008.
An F-14 Tomcat, an AH-1J Sea Cobra, and an F/A-18 Hornet have
been tested. The Hornet test was the first test with a live
MANPADS detonation on an operating aircraft, using realistic
airflow and intercept velocities.
METS has several live fire test and evaluation (LFT&E)
tests scheduled at China Lake in the coming years with the Joint
Cargo Aircraft Program, Joint Aircraft Survivability Program/Joint
Live Fire, and the Joint Strike Fighter (JSF) Program.
Prior to METS, previous test methods included static warhead
testing and free flight testing, which were limited in producing
and analyzing realistic conditions, and provided for inadequate
data collection. Static warhead testing does not account for
the kinetic energy component of damage which can be significant.
Free-flight testing limitations include the lack of external
airflow, exaggerated impact velocities, and difficulties in
targeting. METS addresses all these limitations to create a
significantly more realistic test scenario.
“To have the capability to repeatedly and reliably throw
these weapons at our aircraft, target a certain area, and capture
the data is a big deal,” said Chuck Frankenberger, JSF
vulnerability LFT&E lead. “We use the data to validate
our aircraft vulnerability assessments. MANPADS are one of the
threats we assess against. If there is a significant difference
between our models and the tests, there could be a design change
in the aircraft.”
One challenge for the METS team is that it has to deal with
constantly evolving threats.
“What we hope to build here is an arsenal of all the
different types of weapons that could be used against U.S. or
allied aircraft,” said Jay Kovar, head of the Vulnerability
Branch. “METS is going to be a key tool that provides
us the capability to evaluate aircraft against the emerging
Source: USN Press Release