Figure 4-45 - Gtp 59 Oat Probe Dimensions - Garmin G5 Installation Manual

For tube and fabric aircraft it may be necessary to use a bonding strap from the doubler plate shown in
Figure 4-46 to the tubular structure to electrically bond the probe. See AC43.13-1B or later for electrical
bonding to tubular structure. The bonding strap must:
1. Have the cross-sectional area greater than 0.016 square inches (approx. 20,800 circular mils).
QQB575R30T437 7/16" tubular braid (24,120 circular mils) or QQB575F36T781 3/4" flat braid
(20,800 circular mils) meet this requirement.
2. Be as short as possible, not to exceed 6 inches. When installed, the strap must not loop back on
itself.
3. Use MS20659-130 lug and #10 stud (or larger) attached to local aircraft metallic structure with
minimum thickness of 0.032 inches.
4. Use a 5/16 stud size terminal lug connected directly to GTP 59 probe.
For metal, and tube-and-fabric aircraft, if the GTP 59 is installed in an access panel in Lightning Zone
2A, the access panel must be at least 0.032-inch thick aluminum or, if the access panel is less than 0.032-
inch thick aluminum, a doubler that is at least 0.032-inch thick aluminum (per Figure 4-46) must be
installed.
GTP 59 Probe Installation in Metallic Airframes
For aircraft with metallic airframes, a doubler is required when the GTP 59 probe is installed in the skin.
The doubler must be a minimum of 2 inches in diameter, with a minimum thickness of 0.032 inches and
at least one gauge thicker than the skin. The doubler material and installation must be provisioned by the
aircraft structural repair manual or standard practices manual, or alternatively:
1. Use the same material as the aircraft skin. If the material used in the construction of the aircraft
skin is not known, 2024-T3 aluminum per AMS-QQ-A-250/5 can be used.
2. If corrosion protection methods are not specified by the model-specific aircraft standard practices
manual, the doubler material must be chemical conversion coated per MIL-DTL-5541 Type II or
MIL-DTL-81706 Type II and primed with a high-solids chemical and solvent resistant epoxy
primer per MIL-PRF-23377, Class N.
CAUTION
The GTP 59 probe must not be mounted in a fuel tank area (wet or dry). An air scoop or ducted
inlet is an adequate location for the GTP 59 probe. The probe must be located no closer to the
inlet edge than the width of its narrowest opening.
Garmin G5 Electronic Flight Instrument Part 23 AML STC Installation Manual
Figure 4-45 – GTP 59 OAT Probe Dimensions
Page 77
190-01112-10
Rev. 21