# SAIB 2026-12: GLOBAL POSITIONING SYSTEM

- Type: Special airworthiness information bulletin (advisory, not mandatory)
- Status: Current
- Revision: 0
- Issued: July 10, 2026
- Product type: Appliance, Large Airplane, Small/Large Airplane, Small Airplane
- PDF: https://openairdocs.org/files/sha256/93/b5/93b5bed4c3737bcc563e11387d11eacbdab4b16c040a8684de555a679ef47d55
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID100335831520260710141812.0001
- DRS record last changed: July 10, 2026
- Page: https://openairdocs.org/saib/2026-12

## Text

FAA Aviation Safety

**SPECIAL AIRWORTHINESS**

INFORMATION BULLETIN SUBJ: GLOBAL POSITIONING SYSTEM SAIB: 2026-12 Date: July 10, 2026 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin informs owners and operators of an issue with aircraft equipped with certain Collins Global Navigation Satellite System (GNSS) receivers.

At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

The European Geostationary Navigation Overlay Service (EGNOS) Satellite Based Augmentation System (SBAS) performed a ground system update v242B in November 2023. This exposed an issue that certain affected Collins SBAS receivers GPS-4000S/GLU-2100/GLUS-2100/GLUS-2100A that are not meeting the applicable minimum operational performance standards of TSO C145d/e section

3. f. (1), specifically section 2.1.1.4.9 of DO-229E.

This non-compliance leads to incorrect processing of the integrity information MT6 message sent by SBAS for an alert of Issue of Data Fast correction (IODF) value of 3.

The issue is prevalent to SBAS in EGNOS and potentially other coverage areas, where a more extensive use of the Message Type 6 (MT6) message is used to alert GNSS receivers to improve integrity information.

The availability of Localizer Performance with Vertical (LPV) guidance and other SBAS based approach types may be impacted.

The European Union Aviation Safety Agency (EASA) has issued EASA AD 2025-0088, dated April 16, 2025, requiring the replacement of affected receivers with serviceable receivers.

Recommendations

This issue affects GNSS receivers GPS-4000S/GLU-2100/GLUS-2100/GLUS-2100A with the following specific hardware part number and Operational Program Software (OPS), as applicable:

**GPS-4000S**

- 822-2189-100

- 822-2189-101

**GLU-2100**

- 822-2532-100 with OPS COL4E-0087-0010 or COL4F-0087-0011

- 822-2532-300 with OPS RCU4F0009000002 or RCU4B0009000600

The FAA recommends that owners and operators who have affected GNSS receiver hardware and software configurations, as applicable, upgrade affected receivers to serviceable receivers in accordance with the applicable Collins Aerospace service information listed in Table 1 below.

Table 1: Affected and Serviceable Receivers Affected Receivers Serviceable Receivers

H/W P/N S/W P/N H/W P/N S/W P/N SIL/SB GPS-4000S 822-2189-100 N/A 822-2189-102 N/A 523-0836242 Rev 2 or later 822-2189-101 GLU-2100 (HW) GLUS-2100 (SW) 822-2532-100 COL4E-0087-0010 822-2532-100 COL4B-0087-0712 (See Note 1) 523-0836243 Rev 1 or later COL4F-0087-0011 GLU-2100 (HW) GLUS-2100A (SW) 822-2532-300 RCU4F0009000002 822-2532-300 RCU490009000004 523-0836244 Rev IR or later RCU4B0009000600 RCU4A0009000601 Note 1: Additional field loadable software required, refer to service information letter.

For Further Information Contact

Paul Rau, Aviation Safety Engineer, 1801 Airport Road, Suite 100, Wichita, KS 67209, United States; phone: (316) 946-4149; e-mail: paul.rau@faa.gov.

For Related Service Information Contact

Collins Aerospace, 400 Collins Road NE, Cedar Rapids, IA 52498; phone: (319) 295-5000.

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