Boeing Aircraft Paint Spec

Boeing Aircraft Paint Spec

Boeing provides some infos on the paint spec for the external antennas.
Basically, the antennas should not be painted over i.e. Marker Beacon Antenna and ADF Loop Antenna.
Radio Altimeter Antenna is straightly NOT recommended to be painted.
Most antennas installed on airplanes are already been painted by the antenna manufacturers.
Boeing has not developed any procedures to carry out cosmetic repairs or rework on the antenna.

Discussion:
As a general rule, the antennas should not be painted over. Most antennas installed on airplanes are already painted by the antenna manufacturers and Boeing does not paint over these antennas nor does Boeing recommend painting over them.
While Boeing does not develop procedures for the maintenance of vendor build parts, if an antenna is not damaged structurally and only requires cosmetic repairs, we have found that the following generally does not effect system performance: Apply BMS 10-60 Type II polyurethane enamel or an equivalent paint which is non-metallic, skydrol resistant epoxy enamel or polyurethane enamel. This paint should be applied in accordance with BAC5845. If a primer is required, Boeing suggests the use of BMS 10-79, Type II or III.
Note: Antennas must be re-tested after being re-painted.
The following more specific guidelines are offered for your consideration:

VHF Communication Antenna:
This antenna is BFE, was supplied by Sensor and is supplied by Dorne and Margolin. The suppliers prefer to have operators return the antennas to them for repair. Also, painting the antenna voids the manufacturer warranty. Therefore we don't recommend painting it. However, if the operator must paint the antenna, Boeing recommends using non-metallic, BMS10-60, Type II polyurethane enamel, color white, applied per BAC5845.

VHF (VOR/ILS) Navigation Antenna:
This antenna is an integral part of the vertical fin. Boeing has no objection to painting the VHF Nav Antenna with non-metallic, BMS10-60, Type II polyurethane enamel, applied per BAC5845.

Marker Beacon Antenna:
Boeing recommends that the Marker Beacon Antenna should not be repainted by the operator. This is a high Q antenna and is sensitive to the finish that is applied. It is recommended that the antenna be returned to the vendor for refurbishing.

ADF Sense Antenna:
Boeing has no objection to painting this antenna.

ADF Loop Antenna:
Repainting the ADF Loop Antenna is generally not recommended by vendors and no repainting instructions are provided.

Radio Altimeter Antenna:
Repainting the RA Antenna is not recommended.

Note: The metal rim around the RA Antenna may be painted for corrosion protection, but it is critical to system performance that the fastener holes and countersunk areas around the holes be free of paint and making surface to surface contact with the airplane.

ATC / DME Antenna:
Painting the antenna voids the manufacturer warranty. Therefore we don't recommend painting it. If the operator must paint this antenna, use paint using BMS10-11, Type II epoxy enamel, color BAC201 orange, applied per BAC5736.

TCAS Antenna:
Do not paint. The TCAS Antennas installed by Boeing arrive from the TCAS suppliers fully finished. Since this antenna uses very low signals to determine the direction of incoming signals, the TCAS suppliers have advised BOEING in the past that they do not recommend operators paint the TCAS Antenna. Boeing suggests that the appropriate TCAS Vendor be directly contacted for advice on Antenna painting.



Question and Answer

1) What are the paint specs for external antenna?
The paint specifications for external antennas are controlled by the individual vendors supplying each antenna. Boeing does not specify nor have detailed knowledge of these individual paint specifications.

2) Can Boeing recommend the type of paint those normally use to paint external antenna (i.e. type & P/N)?
Boeing does not recommend painting over external antennas. However, if an antenna must be painted, we suggest using BMS 10-60 Type II polyurethane enamel or an equivalent paint which is non-metallic, skydrol resistant epoxy enamel or polyurethane enamel. If a primer is required, Boeing suggests the use of BMS 10-79, Type II or III.

3) Please advices if paint below can be used to paint the external antenna?
High Solids Polyurethane Enamel Topcoat (Eclipse Series) White Topcoat Gloss P/N: BAC70846 Spec BMS 10-72 and primer High Solid electrostatic Epox Primer P/N: 10P20-44 Spec BMS 10-72.
Subject to restrictions listed in the preceding "Discussion" section, Boeing has No Technical Objection (NTO) to the use of the decorative paint system defined below for use in painting external antennas:
- High Solids Polyurethane Enamel Topcoat (Eclipse Series) White Topcoat Gloss P/N: BAC70846 Spec BMS 10-72 and primer High Solid electrostatic Epox Primer P/N: 10P20-44 Spec BMS 10-72.
Note: While Boeing has reviewed the available technical information on this paint as proposed for this use and it appears to satisfy form, fit and function requirements, Boeing has not tested nor certified it for this particular use. Therefore, after painting, it is recommended that you perform airplane tests to verify satisfactory system operation of each antenna.

4) Is there any Boeing Services Letter with regards to the External Antenna Painting or Antenna Rework / Repair?
Boeing has not prepared or released any Services Letter on rework / repair of vendor supplied antennas.

5) We understood that Marker Beacon Antenna should not be painted and ADF Loop Antenna and Radio Altimeter Antenna are straightly NOT recommended to be painted. Please advice if Boeing has come out with any Service Letter with regards to this?
Boeing has not prepared or released any Services Letter recommending that the Marker Beacon Antenna, the ADF Loop Antenna or the Radio Altimeter Antenna NOT be painted.

6) Kindly advice the proper procedure to carry out cosmetic repairs or rework on the external antenna?
For vendor supplied antennas, Boeing has not developed any procedures to carry out cosmetic repairs or rework.
Note: For vendor supplied antennas when the damage has been only cosmetic such as non-penetrating minor paint scratches, there are antennas which Boeing has painted using BMS 10-60 Type II polyurethane enamel or an equivalent paint which is non-metallic, skydrol resistant epoxy enamel or polyurethane enamel. In these cases, Boeing has found that system performance has not been degraded. This work has included limited sanding, use of some primer and application of less than 3 mils of the paint.


Source of References
1) Boeing MESSAGE NUMBER:1-1JLT7F dated 12 May 2005
2) Boeing MESSAGE NUMBER:1-1K31I4 dated 13 May 2005