Aviation Window Services
7114 Rustic Trail, Suite 100 Boulder, CO 80301
303-444-2171

Why use an FAA certified repair station which specializes in windows?

Certification is the foundation of customer confidence: Aircraft window maintenance is equally important to that of avionics, airframe and power plant repairs. Training, experience & reputation are of key importance.

• FAA is aviation’s governing body: To become an FAA Certified Repair Station a Company must prove to the FAA that they are experts in their relevant field. Annually, the FAA must audit and approve the processes the company uses to repair items and return them to service (re-certification). Extensive record keeping of each repair is a requirement. Aviation Window Services has met these stringent criteria set forth by the FAA.

• Insurance: At AWS we carry a comprehensive liability insurance package. o Technicians: Certified Repair Station means a qualified repair technician is doing the work: We conduct a proprietary two year technician training program & the majority of our techs have 15+ years experience.

• “Repair of Plexiglas surfaces showing the following defects: superficial scratches, cracks, crazing. This job is to be performed with great care and successful results will depend on the skill of the maintenance man”. (MM Falcon 20: 56-00, page 801)

How does repair prolong window life?

• Arrest Damage: Scratches are stress risers. As such, not being static deformities, they propagate. Maintenance Manuals (MMs) allowable damage limits are specified to address and arrest this damage growth factor at a safe threshold. It is addressed through repair or replace requirements. Likewise for pits, chips, and crazing.

• Avoid Replacement: Rather than replacing a window when allowable damage limits have been reached or surpassed, repair will enable safe, continued use of the window at much lower cost than the alternative and required replacement option.

• Repair Early: In addition to allowable damage limits, MM’s specify a minimum material thickness for windows. Removal of damage at the earliest sign will help retain maximum material thickness, allowing for more rounds of future scratch removal, providing an outcome of maximum window lifespan.

  “The repairs are intended to maintain in good condition, and increase the life of, the cabin windows.” (SRM Hawker 600/700: 56-20-11, page 201)

  “This repair is intended to increase the window panel life by blending out edge damage due to surface shaling or erosion.” (SRM hawker 800:56-10-31, page 208)

How does repair improve optical clarity?

• Damage Removal: By clearing up damage such as pits, chips, scratches, hazing and crazing, impediments to outward vision are removed, resulting in an unobstructed view, allowing for safer piloting.

How does repair actually save money?

• Repair is a less expensive option:

  • Citation II windshield repair cost: $1,900, per side**.
  • Citation II windshield replacement cost: $22,000, per side.

• In this case repair cost is one tenth the cost of replacement and repair can be repeated many times before the required window replacement threshold is reached. This threshold is defined as the window’s minimum thickness. Each time a window is repaired, some of the material is removed: essentially equivalent to the depth of the damage. The sooner the damage is arrested, the less material removed, the greater the retained acrylic material thickness, thus economically extending window life. Remember: each repair results in like new window clarity. o

• Repair economically extends window life: because the cost of window repair is proportionally so much less than the cost of replacement, many rounds of repair can be applied to a window before the replacement cost is matched, with a correspondingly much greater service life per dollar.

  “To avoid further deterioration which could lead to panel replacement, it is recommended that all scoring, crazing, etc. should be rectified in accordance with the SRM as soon as possible” (MM Hawker 800: 56-20-11, page 801)

  “Leaving damage in the outer ply of the window may reduce the window’s ultimate service life. Therefore, it is recommended, but not required, that any damage to the window be repaired as soon as practical.” (MM Citation 560: 56-10-00, page 805)

• Repair reduces downtime compared to time required for window replacement:

• Two things to remember: Window repair is much faster than window replacement and window repair most often does not interfere with typical and routine maintenance activities.

• Lear 35 windshield replacement time per side: 100-120 hrs per side. Adds considerably to maintenance downtime as the function of replacement is time consuming to begin with, and is additionally time consuming as virtually no avionics repair or installation can be performed simultaneous to window replacement.

• Lear 35 windshield repair time: 5 hrs. per side. Often done during normal maintenance, adding no extra time to the schedule.

• Our mobile technicians come to you, fitting in with your maintenance schedule. We minimize their travel expense keeping overall cost down.

• ** Repair cost can be as low as $1,100 for light damage.

What about replacement with used windows?

• Total Price: While this option is a consideration, repair of your windows will consistently provide a lower cost alternative when compared to three cost factors of used window installation: used window cost + removal/installation labor + downtime.

• New vs. Used: If your windows cannot be repaired and must be replaced, then a re-certified, used window may provide a smart value option compared to a new window.

Why not just put in new windows?

• Structural Damage: There are situations that dictate new windows as the only call: lack of minimum thickness in the window, cracks, compromised fastener integrity. These are structural damage. In the case of fastener integrity, we do prism inspections to inspect for this problem.

• Surface Damage: It is surface damage that can typically be repaired, saving the window from being prematurely replaced with a new window.

• Repair Option: While new windows are expensive to begin with, the labor fee is also high, as the removal and installation procedure is very time consuming. A primary benefit of many aircraft windows is that acrylic can be repaired, so it inherently provides for numerous rounds of maintenance before reaching the inevitable and expensive endpoint of required replacement.

What is the safety risk of flying with window damage?

• Structural Damage is Not Allowed: The manuals are clear: for good reason, as catastrophic failure is a potential. We do not repair structural damage.

• Reduced Clarity: In terms of surface damage, the primary risk is that of reduced clarity, which must not be underestimated. Repair equals Clarity!

• Stress Riser: As for damage compromising the window as a stress riser, surface damage is safe as long as it is no deeper than the allowable limit specified in the manual.

• Repair Early: The key aspect to remember about surface damage is that it grows deeper over time. Our process removes surface damage and revives the windows with like new clarity

What is the difference between allowable limits and minimum thickness?

• Damage Depth vs. Window Thickness: Limits and minimums are dictated by the manuals. The maximum allowable damage depth is a gauge for mandatory window repair or replacement. When damage is removed, the amount of material removed by grinding and polishing is a bit more than the damage depth. When that amount of acrylic is removed, a measurement is taken to insure the minimum window thickness is still present. Minimum thickness of the window has to be preserved or the window must be replaced. Likewise, for the repair option to be approved, the damage cannot penetrate below the window’s minimum thickness.

• We will assess the damage status before recommending the work.

Why remove damages which do not exceed criteria for damage limits?

• Keep good outward vision: for example, if the flight crew’s outward vision is compromised by surface damage, it may be that the damage is not particularly deep, but proves a hindrance to vision and can be economically cleared.

  “Defect acceptance criteria for cockpit windshields NOTE: If the pilot considers that his visibility is affected by a windshield with defects which do not exceed the tolerances, he can request the replacement of the windshield.” (MM Falcon 10: 56-00-01, page 305)

  Optimize Window Thickness: If damage is revealed during a scheduled inspection or noted at any time by the pilot, but it is not quite at the depth limit, it is known that it will grow. In this case, we often recommend removal of the damage at the earliest sign. This saves money by doing it while the plane is already down and it will clear the defects before they grow deeper, saving valuable window thickness. WHY REPAIR?

  “Caution: Scoring and crazing of window plies may result in cracks that spread rapidly resulting in the need to replace the window or plies, repair damage as soon as possible. (SRM Hawker 800: 56-20-11, page 206)

  “Leaving damage in the outer ply of the window may reduce the window’s ultimate service life. Therefore, it is recommended, but not required, that any damage to the window be repaired as soon as practical.” (MM Citation 560: 56-10-00, page 805)

What is Crazing?

• Appearance: Crazing appears as a fine web like pattern of small scratches, often only detectable in the hangar by shining a flashlight into the window at an angle. When the plane is in flight, the sun angle will do the same thing to the crazing, presenting a hindrance to vision.

• Cause: Crazing isn’t exactly a bunch of little scratches, because it is caused by the porous structure of the acrylic allowing some passage of moisture, sulphides and atmospheric contaminants, accelerated by pressurization and temperature variance. This action stresses the acrylic, producing crazing. Poor cleaning processes, using inappropriate solvents, also can induce crazing.

  “Craze Definition: movement and alignment of polymer fibrils perpendicular to an applied stress or strain” (Polycast Technical Corporation)

  “Clearly Identified Reasons for Crazing: accidents, abuse, mishandling, aircraft service environment, exposure to various cleaning agents, environmental factors still under investigation, poor material, poor repairing techniques” (Nordam Transparency Division)

  “Do not use chlorinated hydrocarbon cleaners such as Trichloroethane on or near windshield/window panels. These cleaners and their vapors can cause crazing damage on acrylic panel surfaces” (SRM Challenger PSP 607:56-15-01, page 3)

What is the AWS “Do Not Clean Windows” window placard all about?

• Customer Courtesy: You will receive 2 placards upon completion of your repairs.

• The placard puts you in control of your cleaning process: Appropriate placement of our placard will discourage well intentioned but untrained line personnel from inadvertently damaging your acrylic windows.

• Poor Cleaning Techniques: While many types of damage happen to windows while in flight, a great many expensive repairs are made to windows which have been subject to improper cleaning techniques using stiff brushes, soiled or abrasive cloths, and improper cleaning agents.

“Minor scratches and chips on the outer surface of the panel are usually due to poor maintenance practices or impact” (SRM Hawker 1000: 56-10-11, page 204)

“Do not use chlorinated hydrocarbon cleaners such as trichloroethane on or near windshield/window panels. These cleaners and their vapors can cause crazing damage on acrylic panel surfaces. (SRM Challenger PSP 607: 56-15-01, page 3)

“Maintenance practice precautions- Care must be exercised to avoid scratches or gouges which may be caused by dirty or rough cleaning cloths or grit carried in the water.” (MM Lear 28/29: 56-00-00, page 201)

Why contact AWS prior to a phase inspection?

• Repair prior to Phase Input: Our prices are competitive and our inspections are fair and accurate. If you call AWS prior to the inspection, we can first identify any required repairs, make the repairs and sign off on them prior to the plane’s input to the service center inspection. This helps you to accomplish repairs at the best price and smoothes out the process.

Why not let a local A&P mechanic repair my windows?

You can But, first ask yourself these questions:

• How can I determine the specific window repair experience and capability of the A&P?
• The standard curriculum at most A & P schools does not include window repair.
• Our technicians undergo a 2 year window repair training program & the majority have 15+ years experience.
• Our technician’s employment with AWS is exclusive to window repair.

• What is the risk to my windows if an unqualified technician performs the work?
  • Acrylic repair is a highly nuanced trade and the windows are at stake.
  • Repair has to be done right and with utmost attention to detail and uniformity. An inexperienced mechanic can introduce defects to the windows, such as distortion. Valuable thickness can be unnecessarily removed, decreasing the window’s service life. If a mechanic inadvertently thins the window below allowable thickness, you will lose the window.

• Why would I gamble with my windows?
  • Approved Repairs- Eliminating Scratches on Side Panels:

  “This is very exacting work and much depends on the skill of the operator.” (MM Falcon 10: 56-00-01, page 801)

  “Repair of Plexiglas surfaces showing the following defects: superficial scratches, cracks, crazing. This job is to be performed with great care and successful results will depend on the skill of the maintenance man”. (MM Falcon 20: 56-00, page 801)

If I am selling my aircraft, why contact AWS before the pre buy?

• Damage Report: To know how the windows will fare in a pre purchase inspection. .

• Appraisal: To provide a competitive quote for repair of any existing damage.

• Benchmark: All our inspections are performed in accordance with manufacturer’s criteria; we provide fair and relevant evaluations.

• Restoration: Have us go ahead and prepare the windows for a pre buy: Even without any considerable damage, in need of repair, a polish can be an affordable benefit. Crystal clear windows are an inexpensive way to make a good impression on the buyer.

If I am buying an aircraft, how can an AWS evaluation help me?

• Appraisal: As with any purchase, a qualified third party opinion is invaluable in sizing up the buy. AWS can provide an un-biased and detailed inspection report and quote accordingly for any repair required.

What is the benefit of doing the work at my facility?

• Time & Money: It is more cost effective for the customer to bring AWS to the aircraft, especially while already down for maintenance, avoiding extra scheduling or transit to accomplish the work.

How long has AWS been in business?

• AWS has been in business since January 1997: Furthermore, most of our repairmen have been repairing aircraft windows in excess of 15 years. This experience and skill is evident in all AWS employees and their workmanship.

• All employees are FAA CERTIFIED REPAIRMEN or FAA CERTIFIED A&P MECHANICS. Click here to learn more about us.