November 2012

NASA/TM–2012-217782

Procedure for Automated Eddy Current Crack

Detection in Thin Titanium Plates

Russell A. Wincheski

Langley Research Center, Hampton, Virginia
NASA STI Program . . . in Profile

Since its founding, NASA has been dedicated to the 

advancement of aeronautics and space science. The 

NASA scientific and technical information (STI) 

program plays a key part in helping NASA maintain 

this important role.

The NASA STI program operates under the 

auspices of the Agency Chief Information Officer. 

It collects, organizes, provides for archiving, and 

disseminates NASA’s STI. The NASA STI 

program provides access to the NASA Aeronautics 

and Space Database and its public interface, the 

NASA Technical Report Server, thus providing one 

of the largest collections of aeronautical and space 

science STI in the world. Results are published in 

both non-NASA channels and by NASA in the 

NASA STI Report Series, which includes the 

following report types:

 TECHNICAL PUBLICATION. Reports of 

completed research or a major significant phase 

of research that present the results of NASA 

Programs and include extensive data or 

theoretical analysis. Includes compilations of 

significant scientific and technical data and 

information deemed to be of continuing 

reference value. NASA counterpart of peerreviewed formal professional papers, but 

having less stringent limitations on manuscript 

length and extent of graphic presentations.

 TECHNICAL MEMORANDUM. Scientific 

and technical findings that are preliminary or of 

specialized interest, e.g., quick release reports, 

working papers, and bibliographies that contain 

minimal annotation. Does not contain extensive 

analysis.

 CONTRACTOR REPORT. Scientific and 

technical findings by NASA-sponsored 

contractors and grantees.

 

ONFERENCE PUBLICATION. 

Collected papers from scientific and 

technical conferences, symposia, seminars, 

or other meetings sponsored or cosponsored by NASA.

 SPECIAL PUBLICATION. Scientific, 

technical, or historical information from 

NASA programs, projects, and missions, 

often concerned with subjects having 

substantial public interest.

 TECHNICAL TRANSLATION. 

English-language translations of foreign 

scientific and technical material pertinent to 

NASA’s mission.

Specialized services also include organizing 

and publishing research results, distributing 

specialized research announcements and feeds, 

providing information desk and personal search 

support, and enabling data exchange services.

For more information about the NASA STI 

program, see the following:

 Access the NASA STI program home page 

at http://www.sti.nasa.gov

 E-mail your question to help@sti.nasa.gov

 Fax your question to the NASA STI 

Information Desk at 443-757-5803

 Phone the NASA STI Information Desk at 

443-757-5802

 Write to:

 STI Information Desk

 NASA Center for AeroSpace Information

 7115 Standard Drive

 Hanover, MD 21076-1320
National Aeronautics and 

Space Administration

Langley Research Center 

Hampton, Virginia 23681-2199

November 2012

NASA/TM–2012-217782

Procedure for Automated Eddy Current Crack

Detection in Thin Titanium Plates

Russell A. Wincheski

Langley Research Center, Hampton, Virginia
Available from:

NASA Center for AeroSpace Information

7115 Standard Drive

Hanover, MD 21076-1320

443-757-5802
Procedure	for	Automated	Eddy	Current	Crack	Detection	in	Thin	Titanium	Plates

Russell Wincheski

NASA	LaRC,	Hampton	VA	23681

1.0 Purpose

1.1	This	procedure	provides	the	detailed	instructions	for	conducting	Eddy	Current	

(EC)	inspections	of	thin	(5-30	mils)	titanium	membranes	with	thickness	and	

material	properties	typical	of	the	development	of	Ultra-Lightweight	Diaphragm	

Tanks	Technology	(ULTT).				The	inspection	focuses	on	the	detection	of	partthrough,	surface	breaking	fatigue	cracks	with	depths	between	approximately	0.002”	

and	0.007”	and	aspect	ratios	(a/c)	of	0.2-1.0	using	an	automated	eddy	current	

scanning	and	image	processing	technique.

2.0 Scope

2.1 This	procedure	is	applicable	to	the	inspection	of	thin	titanium	membranes	at	

NASA	Langley	Research	Center.		The	procedure	may	be	implemented	at	other	

locations	as	per	discretion	of	the	ULTT	Development	Team.

2.2 Where	the	procedure	allows	for	equivalent	processes	or	equipment	to	be	used,	

the	ULTT	Development	Team	must	review	those	processes	and/or	equipment.		

Any	equivalency	determination	and	rationale	for	allowance	of	use	shall	be	

documented.

3.0 Personnel

3.1 Only	personnel qualified	and	certified	as	Level	II or	higher in	Eddy	Current	

Method	of	inspection	per	the	requirements	of	NAS-410	or	ASNT-SNT-TC-1A	

shall	perform	this	inspection.	Personnel	qualified	and	certified	to	Level	II	or	

Level	III,	per	the	requirements	of	NAS-410	or	ASNT-SNT-TC-1A shall	make	

accept/reject	decisions per	the	requirements	of	this	procedure.	Additional	

training	specific	to	the	automated	eddy	current	scanning	and	data	analysis	shall	

be	documented	as	part	of	the	qualifications	for	Level	II	and	Level	III	personnel	

conducting	these	exams.			Any	deviation	from	these	personnel	requirements	

must	be	reviewed	and	accepted	by	the	ULTT	Development	Team.

3.2 All	personnel	performing	this	inspection	shall	demonstrate	a	working	

knowledge	of	crack	detection	using	an	MIZ-27	SI	or	equivalent	impedance	plane	

eddy	current	instrument.
2

4.0 Equipment

4.1 The	following	equipment	or	equivalent	is	required	to	perform	this	procedure.		

4.2 Any	substitutions	to	the	equipment	list	shall	require	review	and	approval	by	the	

ULTT	Development	Team.

4.2.1 MIZ-27-SI	Eddy	Current	Impedance	Plane	Instrument

4.2.2 Uniwest	ETC-2446	3-6	MHz	Swivel	Probe

4.2.3 Spring	loaded	probe	carrier	ensuring	constant	force	contact	between	

probe	face	and	sample	under	test

4.2.4 National	Instruments	USB-6259	Multifunction	Data	Acquisition	

Device

4.2.5 Compumotor	model	4000	Stepper	Motor	Controller

4.2.6 Minimum	two-axis	stepper	motor	controlled	scanning	table	with	

minimum	0.010”	position	accuracy

4.2.7 Desktop	computer	with	motion	control	and	data	acquisition	software

4.2.8 Data	analysis	computer	with	data	analysis	software

4.2.9 Calibration	sample	with	known	defect

5.0 System	Configuration

5.1 Position	the	sample	under	test	on	the	scanning	table,	ensuring	no	potential	

obstructions	exist	between	the	sample	surface	and	the	probe	scan	path.

5.2 Place	a thin	nonconductive	protective	tape,	not	to	exceed	.0025 inch	thickness,	

on	the	probe	face.		Inspect	the	tape	between	all	scans	and	replace at	the	first	sign	

of	wear.

5.3 Mount	the	ETC-2446	probe	in	the	probe	carrier	and	position	the	probe on the	

sample	under	test.		Ensure	the	probe	face	sits	with	the	eddy	current	coils	normal	

to	the	sample	surface.		The	probe	should	be	rotated	such	that	split	between	the	

two	coils	is	parallel	(perpendicular)	to	the	anticipated	crack	growth	direction	

(high	stress	direction).		Figure	1	displays	an	image	of	the	probe	face	showing	the	

coil	dimensions	and	the	split	between	the	differential	pickup	coils.

5.4 Connect	the	probe	to	the	MIZ-27-SI	eddy	current	instrument.		Use	probe	and	

cable	adapters	as	required.

5.5 Connect	analog	outputs	1-8	of	MIZ-27-SI	to	NI	6259	DAQ	device.

5.6 Configure	the	MIZ-27-SI	in	Differential	Driver	Pickup	(DD-a)	mode;	500	

samples/sec;	Average	on	16;	20dB	Driver	Pickup	Gain.		Configure	each	channel	

as	per	the	following	table:
3

0.5 mm

0.75 mm

.35 

mm

Coil Split

Figure	1.		Image	of	probe	face	of	the	ETC-2446	probe	showing	split between	the	

differential	pick-up	coils.

Table	1:		Eddy	Current	Configuration	for	Crack	Detection	in	Thin	Titanium	Plates

5.7 Configure	the	MIZ-27-SI	analog	outputs	as	per	the	following	table:

Table	2:		Analog	Output	Configuration	for	MIZ-27-SI	Eddy	Current	Instrument

5.8 Under	motion	control,	move	the	probe	to	a	central	area	of	sample	and	null	all	

channels.

Channel	

Number

Drive	Frequency	

(MHz)

Drive	

Voltage	(V)

Gain	(db) Rotation	

Angle	(deg)

Ch1 1 12 40 23

Ch2 2 5 40 322

Ch3 4 2 40 213

Ch4 5 1 40 116

Analog	

Outputs

Channel Multiplier Screen	

Equivalent

1-2	H-V 1 1 +/- 10	volts

3-4	H-V 2 1 +/- 10	volts

5-6	H-V 4 1 +/- 10	volts

7-8	H-V 5 1 +/- 10	volts
4

6.0 System	Calibration	

6.1 Rotation	Angle	Calibration

6.1.1 Under	motion	control,	scan	the	probe	over	the	calibration	defect	and	

note	probe	response.		If	probe	response	is	not	vertical	adjust	rotation	

angle	such	that	all	channels	produce	a	vertical	response	similar	to	that	

shown	in	Figure	2.	

6.2 Calibration	Scan

6.2.1 Under	motion	control,	perform	a	pre-scan	of	the	sample	edges	to	

check	for	obstructions	and	to	ensure	consistent	contact	between	the	

probe	and	the	sample	under	test.

6.2.2 Position	the	probe	at	the	start	position	of	the	scan.

6.2.3 Adjust	the	scan	control	software	to	acquire	data	at	a	scan	speed	no	

greater	than	1.5”/second	and	a	sampling	distance	no	greater	than	

0.010”/sample.		Configure	the	scan	control	software	for	unidirectional	

scanning	during	data	acquisition	in	order	to	minimize	hysteresis	in	

data	due	to	scan	direction	effects.	

6.3 Perform	a	two-dimensional	scan	over	the	calibration	defect	and	save	the	probe	

response	on	all	channels.

6.4 Calibration	Data	Analysis

6.4.1 Perform	data	analysis	on	C-Scan	images	developed	from	the	eddy	

current	vertical	channel	amplitude	versus	(x,y)	position.		Figure	3	

displays	a	plot	of	the	raw	C-Scan	data	for	the	calibration	flaw	in	

calibration	sample	number	19.

Figure	2.		Probe	response	for	scan	over	calibration	flaw	in	calibration	sample	19	at	4	

MHz	drive	frequency.

-1 -0.5 0 0.5 1

-1

-0.5

0

0.5

1

Eddy Current Horizontal Channel Respone (V)

Eddy Current Vertical Channel Response (V)
5

Figure	3.		Eddy	current	vertical	channel	C-Scan	data	for	calibration	flaw	in	

calibration	sample	19	at	4	MHz	drive	frequency.		Color	axis	unit	is	volts.

6.4.2 Signal	processing	of	the	C-Scan	image	may	be	applied	to	enhance	

contrast	in	the	flaw	response.		In	particular,	the	flaw	response	can	be	

significantly	enhanced	by	the	application	of	a	differential	filter	in	the	

direction	perpendicular	to	the	coil	split	of	the	eddy	current	probe.		

Additional	processing	such	as	interpolation	of	data	between	acquired	

data	points	and	background	subtraction	may	also	be	applied	as	

required.		

6.4.2.1 Standard	data	processing	includes	application	of	a	differential	

filter	perpendicular	to	the	coil	split	direction	and	one	point	

interpolation	of	data	between	acquired	data	points.

6.4.2.1.1 Differential	filtering	is	performed	by	shifting	data	

array	a	distance	of	0.020”	(approximate	coil	spacing	

of	ETC-2446	probe)	and	then	subtracting	shifted	

array	from	original	data.

6.4.2.1.2 Data	interpolation	is	performed	using	a	linear	

interpolation	between	every	two	nearest	neighbor	

data	points	to	define	the	amplitude	of	a	new	data	

point	equidistant	from	the	two	neighbors.

Probe Position Along X Axis (inches)

Probe Position Along Y Axis (inches)

4.6 4.8 5 5.2 5.4

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

-1

-0.5

0

0.5

1
6

6.4.2.2 Figure	4	displays	an	image	of	the	processed	vertical	channel	CScan	at	4	MHZ	for	sample	number	19	(raw	C-Scan	data	

displayed	in	Figure	3)	following	the	procedure	of	section	

6.4.2.1.

7.0 Analysis	and	Sizing	of	Calibration	Flaw

7.1 Following	the	data	processing	of	section	6.4.2.1	crack	analysis	and	sizing	may	be	

performed.		Automated	crack	detection	and	sizing	is	based	upon	the	amplitude	

of	the processed	vertical	channel	C-Scan	as	shown	in	Figure	4.

7.2 A	threshold	indication	is	set	in	the	automated	crack	detection	routine.		

7.2.1 The	noise	floor	in	the	data	is	defined	as	3x	the	standard	deviation	of	

the	processed	signal	level	(from	section	6.4.2.1)	on	an	unflawed	

sample	(or	away	from	a	defect	in	a	flawed	sample).		Using	this	

definition	calibration	studies	at	NASA	LaRC	found	the	noise	floor	at	4	

MHz	to	be	0.225	Volts.

7.2.2 The	indication	threshold	is	then	defined	as	3x	the	noise	floor	for	the	

system.		Using	this	definition	calibration	studies	at	NASA	LaRC	defined	

the	indication	threshold	to	be	0.675	Volts	for	4	MHz	drive	frequency.

Probe Position Along X Axis (inches)

Probe Position Along Y Axis (inches)

4.6 4.8 5 5.2 5.4

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

-1

-0.5

0

0.5

1

1.5

2

Figure	4.		Processed	C-Scan	data	for	calibration	flaw	in	calibration	sample	19	at	4	

MHz	drive	frequency.		Color	axis	unit	is	volts.
7

7.3 The	processed	C-Scan	data	(as	per	section	6.4.2.1)	is compared	to	the	indication	

threshold	to	perform	automated	crack	detection	and	sizing.		All	pixels	above	the	

threshold	are	set	to	unity	while	all	pixels	below	the	threshold	are	set	to	zero.		

7.3.1 The	crack	length	is	calculated	as	the	positional	difference	between	the	

nonzero	pixels	with	the	largest	and	smallest	positions.

7.3.2 The	crack	depth	is	calculated	based	upon	the	peak	indication	strength.		

Figure	5	displays	a	plot	of	the	4	MHz	peak	indication	for	the	C-Scan	

data	processed	as	per	section	6.4.2.1	for	a	series	of	fatigue	crack	

panels.		The	crack	depths	of	these	panels	have	been	estimated	by	the	

vendor	based	upon	measured	surface	crack	lengths	during	processing	

(Engineering	Materials	Laboratory	(EML)	Report	Nos.	1008-10,	1103-

9,	and	1107-4).	The	slope	of	the	best fit	to	the	data	is	inverted	to	

calculate	the	predicted	crack	depth	from	the	eddy	current	response.

7.4 A	C-Scan	plot	of	the	threshold	data	can	be	generated	for	automated	flaw	

detection.		The	plot	can	also	be	annotated	with	measured	crack	length	and	depth	

as	per	section	7.3.		Figure	6	displays	a	C-Scan	plot	of	the	automated	crack	

detection	and	sizing	for	sample	number	19.

Figure	5.		Eddy	Current	respose	versus	estimated	crack	depth	for	4.0	MHz	

inspection	frequency.	
8

Figure	6.		Automated	crack	detection	and	sizing	for	calibration	flaw	in	sample	19	at	

4	MHz	drive	frequency.	

7.5 Upon	successful	calibration	and	sizing	of	the	calibration	flaw	the	system	

configuration	shall	be	noted	and	held	constant	during	inspection	of	samples	

under	test.

8.0 Inspection	of	Samples	Under	Test

8.1 Following	successful	calibration,	inspection	of	the	sample	under	test	may	be	

performed.	

8.2 Any	deviations	from	the	system	configuration	shown	in	Table	1	shall	be	

documented	in	a	notes	file	attached	to	inspection	data.

8.3 Position	the	sample	under	test	on	the	scanning	table,	ensuring	no	potential	

obstruction	exists	between	the	sample	surface	and	the	probe	scan	path.

8.4 Inspect	the	protective	tape	on	the	probe	face	and	replace	if	any	signs	of	wear	are	

present.	

8.5 Position	the	ETC-2446	probe	on	the	sample	under	test.		Ensure	the	probe	face	

sits	with	the	eddy	current	coils	normal	to	the	sample	surface.		The	probe	should	

be	rotated	such	that	split	between	the	two	coils	is	parallel	(perpendicular)	to	the	

anticipated	crack	growth	direction	(high	stress	direction).		

peak = 2.253, length=0.0900, depth = 0.0031

Probe Position Along X Axis (inches)

Probe Position Along Y Axis (inches)

4.6 4.8 5 5.2 5.4

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7
9

8.6 Under	motion	control,	perform	a	pre-scan	of	the	sample	edges	to	check	for	

obstructions	and	to	ensure	consistent	contact	between	the	probe	and	the	sample	

under	test.

8.7 Under	motion	control,	move	the	probe	to	an	area	of	sample	away	from	any	edges	

and	null	all	channels.

8.8 Position	the	probe	at	the	start	position	of	scan.

8.9 Configure	the	scan	control	software	to	cover	the	entire	inspection	area.		Maintain	

scanning	speed	and	sampling	distance	equal	to	the	calibration	scan	as	set	in	

section	6.2.3.	

8.10 Perform	a	two-dimensional	scan	over	the	sample	under	test	and	save	probe	

response	on	all	channels.

9.0 Data	Analysis

9.1 Data	analysis	is	performed	using	the	data	acquired	and	stored	in	section	8.

9.2 A	data	analysis	computer	is	used	to	read	in	the	stored	data	file.		Data	analysis	

software	shall	be	able	read	the	horizontal	and	vertical	eddy	current	response	

from	each	eddy	current	channel		(see	tables	1	and	2)	and	display	the	recorded	

voltages	as	a	function	of	probe	position	to	generate	C-Scan	images.		Figure	3	

displays	a	plot	of the	unprocessed	vertical	channel	C-Scan	at	4	MHz	for	Sample	

number	19.

9.3 The	unprocessed	data	may	be	filtered	to	improve	the	signal	to	noise	ratio.		Any	

applied	filtering	technique	must	be	demonstrated	on	a	calibration	sample	before	

being	used	for	accept/reject	decisions	on	an	unknown	sample	under	test.

9.3.1 Standard	data	processing	includes	differential	filter	perpendicular	to	

the	coil	split	direction	and	one	point	interpolation	of	data	between	

acquired	data	points.

9.3.1.1 Differential	filtering	is	performed	by	shifting	data	array	a	

distance	of	0.020”	(approximate	coil	spacing	of	ETC-2446	

probe)	and	then	subtracting	shifted	array	from	original	

data.

9.3.1.2 Data	interpolation	is	performed	using	a	linear	interpolation	

between	every	two	nearest	neighbor	data	points	to	define	

the amplitude	of	a	new	data	point	equidistant	from	the	two	

neighbors.

9.3.2 Figure	4	displays	an	image	of	the	processed	vertical	channel	C-Scan	at	

4	MHZ	for	Sample	number	19	following	the	procedure	of	section	9.3.1

9.4 Indication	analysis	and	sizing	is	performed	based	upon	the	amplitude	of	the	

vertical	channel	C-Scan	data	processed	as	per	section	9.3.1.

9.5 Image	thresholding	may	be	applied	using	the	indication	threshold	defined	in	

section	7.2.

9.6 The	processed	data	can	be	compared	to	the	indication	threshold	to	perform	

automated	indication	detection.		All	pixels	above	the	threshold	are	set	to	unity	

while	all	pixels	below	the	threshold	are	set	to	zero.		
10

9.6.1 The	preliminary	indication	length	is	calculated	as	the	positional	

difference	between	the	nonzero	pixels	with	the	largest	and	smallest	

positions.

9.6.2 The	preliminary	indication	depth	is	calculated	based	upon	the	peak	

indication	strength	as	discussed	in	section	7.3.2.		

9.6.3 As	more	information	becomes	available	on	the	eddy	current	

amplitude	versus	actual	crack	depth	the	plot	in	Figure	5	should	be	

updated	to	incorporate	actual	crack	depth	data.		The	inversion	

function	for	crack	depth	from	measured	eddy	current	response	

should	likewise	be	updated	at	that	time.

9.7 A	C-Scan	plot	of	the	data	after	application	of	the	indication	threshold	can	be	

displayed	for	rapid	visualization	of	any	indications	above	threshold.		Figure	6	

displays	such	a	plot	for	calibration	sample	number	19.

9.8 Further	data	analysis	such	as	analyses	of	the	eddy	current	lissajous	signatures	of	

the	data	should	be	performed	to	validate automatically	detected	indications.		

Such	lissajous	plots	can	be	constructed	by	combining	the	horizontal	and	vertical	

eddy	current	amplitudes	along	a	line	crossing	an	indication.

9.9 The	location,	length,	indication	strength,	and	predicted	depth	of	all	indications	

shall	be	reported	for	the	sample	under	test.	

9.9.1 The	location	of	the	scan	start	position	as	well	as	the	orientation	of	the	

scan	axes	shall	be	noted	on	the	part	under	test	and	recorded	in	an	

inspection	report.

9.9.2 The	location	of	all	indications	shall	be	noted	on	the	part	under	test.

9.9.3 The	distance	of	all	indications	in	(x,y)	coordinates	from	the	start	

position	shall	be	reported	along	with	indication	strength	and	length.

10.0 If	it	is	necessary	to	screen	for	fatigue	cracks	in	directions	away	from	the	primary	

crack	growth	direction,	or	if	no	primary	direction	exists,	bi-directional	scanning	shall	be	

required.

10.1 Rotate	probe	90	degrees	such	that	split	between	the	differential	pickup	coils	

is	perpendicular	to	the	direction	defined	in	Section	8.5.

10.2 Inspect	the	protective	tape	on	the	probe	face	and	replace	if	any	signs	of	wear	

are	present.	

10.3 Position	the	ETC-2446	probe	on	the	sample	under	test.		Ensure	the	probe	

face	sits	with	the	eddy	current	coils	normal	to	the	sample	surface.		

10.4 Acquired	data	as	per	sections	8.8	– 8.10.

10.5 Analyze	acquired	data	as	per	section	9.		Report	all	indications	as	per	section	

9.9.
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Technical Memorandum

 4. TITLE AND SUBTITLE

Procedure for Automated Eddy Current Crack Detection in Thin Titanium 

Plates 

5a. CONTRACT NUMBER

 6. AUTHOR(S)

Wincheski, Russell A.

 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center

Hampton, VA 23681-2199

 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

 8. PERFORMING ORGANIZATION

 REPORT NUMBER

L-20187

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Category 26

Availability: NASA CASI (443) 757-5802

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: help@sti.nasa.gov)

14. ABSTRACT

This procedure provides the detailed instructions for conducting Eddy Current (EC) inspections of thin (5-30 mils) titanium 

membranes with thickness and material properties typical of the development of Ultra-Lightweiight Diaphragm Tanks 

Technology (ULTT). The inspection focuses on the detection of part-through, surface breaking fatigue cracks with depths 

between approximately 0.002" and 0.007" and aspect ratios (a/c) of 0.2-1.0 using an automated eddy current scanning and 

image processing technique. 

15. SUBJECT TERMS

Crack detection; Data acquisition; Eddy current; Inspection; Titanium

18. NUMBER

 OF 

 PAGES

15

19b. TELEPHONE NUMBER (Include area code)

(443) 757-5802

a. REPORT

U

c. THIS PAGE

U

b. ABSTRACT

U

17. LIMITATION OF 

 ABSTRACT

UU

Prescribed by ANSI Std. Z39.18

Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

432938.11.01.07.43.13.01 

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/TM-2012-217782

16. SECURITY CLASSIFICATION OF:

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and 

Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person 

shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

01- 11 - 2012