Title: Laser Coating Removal Technologies
1Laser Coating Removal Technologies Technology
Summary (Airframe Applications)
830 Jury Court, Suite 5 San Jose, CA 95112 (408)
947-1181 Fax (408) 947-1666 Email
info_at_lasertronics.com www.lasertronics.com
2Federal Aviation Administration Transport
Airplane Directorate Aircraft Certification
Services Approves the GLC Laser Process Initial
Approval, July 21, 2006, Global Approval, August
26 2009
Description Use of Laser Energy for the removal
of paints, sealants and other coatings from
aircraft structure. - In accordance with GLC
Process Specification . . . Approval specifies
The removal of paint, sealant, corrosion and
rust on metal substrates listed in SAE MA4872
Annex D, regardless of aircraft manufacturer.
(Use of the process is) approved for Boeing,
McDonnell-Douglas, and Airbus aircraft Annex D
includes the following materials (and/or
materials families) 2024 T3 clad Aluminum
AZ31B Magnesium 2024 T3 bare Aluminum
T1 6AI-4V Titanium 7150 T351 and T7351
(Incl. 7075 T6) 4340 Steel The FAA-issued
operations specification defines the GLC process
as an Alternate Method of Compliance (AMOC) to
the sealant stripping procedures specified in
Boeing Alert SB 737-53A1262, Appendix A required
by para. (f) of AD (Airworthiness Directive)
2006-0712." This approval is transferable with
airplanes transferred to other operators. -
Approval of this type of AMOC for a
foreign-registered aircraft is the responsibility
of the appropriate civil aviation authority of
the state of registry.
3A-10 Aircraft Wing Tank Cleaning
Requirement Remove sealant from restricted fuel
tank cells to facilitate inspections Current
methods Hand scraping, chemical stripping or
water jet Motivation Current processes are
slow, poor quality, FOD/corrosion
hazard Experience Pacific Northwest Ntnl
Lab/LMCO/USAF feasibility study shows 3 day
turnaround vs.10 days for current processes,
payback after 5 aircraft Enabling Technology
Fiber-optic-delivered laser energy (GLC
patent) Form, Fit and Function(s) of small
rotary workhead (GLC patent)
Metal detection to prevent overstripping if
required (GLC patent) Certification USAF
Suitability for Flight Line Operation, focus on
fire and personnel safety
Typical Fuel Tank
(One of) Lasertronics Confined-spaces workhead
tools
Laser-cleaned fasteners
4Boeing 737 Lap/Butt Joint Scribe Line Detection
Requirement Remove sealant from lap/butt joints
without fuselage damage Ensure no
obscuration/distortion of scribe line/incipient
fractures Current method Solvent softening and
scrubbing or scraping of the sealant Motivation
Current process too slow (24-48 hours), scrubbing
can fill or obscure scribe marks
FAA AD requires complete initial inspection,
periodic re-inspection Experience Successful
5-cycle strip tests qualify GLC laser process for
FAA certification Enabling Technology
Fiber-delivered laser ablation energy (GLC
patent) Metal (Aluminum) detection and
protection (GLC patent apld) Certification
FAA-approved GLC laser process is an Alternate
Means of Compliance (AMOC) satisfying AD
requirements for all metal aircraft regardless of
manufacturer
Boeing 737
The Culprit joint scratches become cracks
Solvent/scrub obscures scribe (UAL 737 micrograph)
Fatigued structure of Aloha Airlines Flight 243
Lasertronics FAA-approved workhead in action
5Low Observable Coating Maintenance
Requirement Selectively strip multiple coating
layers Current method Hand sanding (jitterbug
sander) Motivation Current process too slow,
control is poor, causes damage or overstripping
of low observable coatings and/or underlying
substrate Experience Lasertronics has
demonstrated color-selective capabilities on
most stealth platforms, including UAVs Enabling
Technology Fiber-delivered laser ablation
energy (GLC patent) Color selectivity (GLC
patent applied for) Certification USAF approved
Lasertronics color-selective process 2007
USAF approved laser ablation for aircraft in
general 2007
Northrop B2
A Lasertronics hand-held color- selective workhead
Boeing UAV stripped result
LO stripping setbacks of 0.25 are typical
NGC RD LO sample result
6Automated Rotor Blade Stripping System
Requirement Remove top coat to primer without
blade damage Alternative method Hand sanding
w/high probability of damage Motivation Current
process slow, toxic waste hazard, 10
damage/scrap rate Experience Completed
prototype laser installation in 2009 under
NCMS/DOD program grant Enabling Technology
Fiber-delivered laser energy (GLC patent)
Color selectivity (GLC patent applied
for) Certification Sikorsky Aircraft approval
on blades/composites US Navy acceptance, 2009
by NADEP FRC-East, MCAS Cherry Point, North
Carolina
Manual blade stripping at Fleet Readiness Center-
East Cherry Point
Robot design
GLC Triple laser robot-mounted workhead
Damage from hand sanding
7Composite Surface Prep for Bonding
Requirement Automatically clean, texturize
(scuff coat) and activate carbon fiber
reinforced plastic for next-generation Boeing
aircraft Alternative method Hand
sanding Motivation Current process too slow,
ineffective, damage prone Experience 2 years of
post-stripping adhesion testing with Boeing,
prior testing with NGC LMCO Enabling
Technology Fiber-delivered laser ablation
energy (GLC patent) Composite
surface/improved scanning (GLC patent applied
for) Certification Informal OEM advisory that
Lasertronics treated coupons outperform all
others in terms of pre-bond, pre-paint adhesion
and consistency
Boeing 787
Treated Boeing 787 composite showing undamaged
fiber
F-35 scarf joint surface - CO2 process results
F-35 scarf joint surface - machined results
Lasertronics process results - one pass