# AD 2006-16-18 R1: Installing a warning placard on the TAWS/RMI

- Type: Airworthiness directive
- Status: Current
- Products: Airbus A300 B2-1A, A300 B2-1C, A300 B2-203, A300 B2K-3C, A300 B4-103, A300 B4-203, A300 B4-2C, A300 B4-601, A300 B4-603, A300 B4-605R, A300 B4-620, A300 B4-622 and 91 more
- Effective: July 18, 2008
- Published: June 13, 2008, 73 FR 33663–33665
- Issued: June 3, 2008
- Issued as: Final rule
- Supersedes: [AD 2006-16-18](https://openairdocs.org/ad/2006-16-18)
- Superseded by: Nothing supersedes this AD
- Product type: Appliance
- Amendment: 39-15557
- Docket: FAA-2007-0290 (https://www.regulations.gov/docket/FAA-2007-0290)
- Project: 2007-NM-250-AD
- Registered aircraft: 11,796 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/17/6c/176c41dc2ff512821d3ad850895d71f343bcf1814aea1f5543b9b6ac1c9a135a (from https://www.govinfo.gov/content/pkg/FR-2008-06-13/pdf/E8-13165.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/06/13/E8-13165/airworthiness-directives-sandel-avionics-incorporated-model-st3400-terrain-awareness-warning
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/54C800C12880B88986257467004B455F.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/2006-16-18-R1

## Summary

The FAA is revising an existing airworthiness directive (AD) that applies to Sandel Avionics Incorporated Model ST3400 TAWS/RMI units as described above. The existing AD currently requires installing a warning placard on the TAWS/RMI and revising the Limitations section of the airplane flight manual (AFM). The existing AD also requires installing upgraded software in the TAWS/RMI. This new AD allows installing later revisions of the software described in the existing AD. This AD results from a report that an in-flight bearing error occurred in a Model ST3400 TAWS/RMI configured to receive bearing information from a very high frequency omnidirectional range (VOR) receiver interface via a composite video signal, due to a combination of input signal fault and software error. We are issuing this AD to prevent a bearing error, which could lead to an airplane departing from its scheduled flight path, which could result in a reduction in separation from, and a possible collision with, other aircraft or terrain.

## The airworthiness directive

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-14718 (71 FR 48461, August 21, 2006) and adding the following new airworthiness directive (AD):

2006-16-18 R1 Sandel Avionics Incorporated: Amendment 39-15557. Docket No. FAA-2007-0290; Directorate Identifier 2007-NM-250-AD.

### (a) Effective Date

  (a) This airworthiness directive (AD) is effective July 18, 2008.

### (b) Affected ADs

  (b) This AD revises AD 2006-16-18.

### (c) Applicability

  (c) This AD applies to Sandel Avionics Incorporated (Sandel) Model ST3400 terrain awareness warning system/radio magnetic indicator (TAWS/RMI) units approved under Technical Standard Order(s) C113, C151a, or C151b; as identified in Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004; as installed on various small and transport category airplanes, certificated in any category, including, but not limited, to the airplane models listed in Table 1 of this AD.

*Table 1.—Manufacturers/Airplane Models*

| Manufacturer | Airplane model(s) |
| --- | --- |
| Airbus | A300. |
| Avions Marcel Dassault-Breguet Aviation (AMD/BA) | Falcon 10. |
| Boeing | 727, 737, 747. |
| Bombardier (LearJet) | 24, 35, 36, 55. |
| British Aerospace (Operations) Limited | Jetstream Series 3101. |
| Cessna | 208, 208B, 421C; 501, 525, 550, 560, 650, S550. |
| Embraer | EMB-120. |
| Dassault-Aviation | Mystere-Falcon 50, Mystere-Falcon 200. |
| Gulfstream | G-I, G-1159A (G-III) |
| Israel Aircraft Industries (IAI) | 1124, 1125 Westwind Astra. |
| McDonnell Douglas | DC-10. |
| Piper | PA-31T2. |
| Raytheon | 58; 1900D, 400; A36; BAe.125 Series 800A; HS.125 Series 600A/700A; Hawker 800-XP; 200, 300, 350; A200, B100, B200, B300, C90, C90A, C90B, E90, F90; MU-300-10. |
| Sabreliner | 60 (NA-265-60). |
| Twin Commander | 500-A, 695A. |
| Viking Air Limited | DHC-6. |

### (d) Unsafe Condition

  (d) This AD results from a report that an in-flight bearing error occurred in a Model ST3400 TAWS/RMI unit configured to receive bearing information from a very high frequency omnidirectional range (VOR) receiver interface via a composite video signal, due to a combination of input signal fault and software error. We are issuing this AD to prevent a bearing error, which could lead to an airplane departing from its scheduled flight path, which could result in a reduction in separation from, and a possible collision with, other aircraft or terrain.

### (e) Compliance

  (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

### (f) Installing Placard

  (f) Within 14 days after September 25, 2006 (the effective date of AD 2006-16-18): Install a placard on the TAWS/RMI which states, “NOT FOR PRIMARY VOR NAVIGATION,” in accordance with Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004.

### (g) Revising Airplane Flight Manual (AFM)

  (g) Within 14 days after September 25, 2006: Revise the Limitations section of the applicable AFM to include the following statement: “Use of ST3400 TAWS/RMI for primary VOR navigation is prohibited unless the indicator has 3.07 or A3.06 software or later.” This may be done by inserting a copy of this AD into the AFM.

### (h) Updating Software

  (h) Within 90 days after September 25, 2006, in accordance with Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004: Field-load the TAWS/RMI with updated software having revision 3.07 (for units having serial numbers (S/Ns) under 2000) or revision A3.06 (for units having S/Ns 2000 and subsequent). Revisions of software later than revision 3.07 or A3.06, as applicable, are considered acceptable for compliance with the requirements of this paragraph. The placard and AFM limitations revision installed as required by paragraphs (f) and (g) of this AD may be removed after the software upgrade required by paragraph (h) of this AD has been accomplished.

### (i) Parts Installation

    (i) As of 90 days after September 25, 2006, no person may install, on any airplane, a Model ST3400 TAWS/RMI unit, unless it has been modified in accordance with Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004.

### (j) Alternative Methods of Compliance (AMOCs)

  (j)(1) The Manager, Los Angeles Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

  (2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

### (k) Material Incorporated by Reference

  (k) You must use Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004, to do the actions required by this AD, unless the AD specifies otherwise.

  (1) The Director of the Federal Register previously approved the incorporation by reference of Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004 on September 25, 2006 (71 FR 48461, August 21, 2006).

  (2) For service information identified in this AD, contact Sandel Avionics Incorporated (Sandel), 2401 Dogwood Way, Vista, California, 92081.

  (3) You may review copies of the service information that is incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

## Rule preamble

### Dates

This AD is effective July 18, 2008.

On September 25, 2006 (71 FR 48461, August 21, 2006), the Director of the Federal Register approved the incorporation by reference of Sandel ST3400 Service Bulletin SB3400-01, Revision B, dated September 15, 2004.

### Addresses

For service information identified in this AD, contact Sandel Avionics Incorporated (Sandel), 2401 Dogwood Way, Vista, California 92081.

### For further information contact

Ha A. Nguyen, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5335; fax (562) 627-5210.

### Discussion

The FAA proposed to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) with an airworthiness directive (AD) to revise AD 2006-16-18, amendment 39-14718 (71 FR 48461, August 21, 2006). The existing AD applies to Sandel Avionics Incorporated (Sandel) Model ST3400 terrain awareness warning system/radio magnetic indicator (TAWS/RMI) units approved under Technical Standard Order(s) C113, C151a, or C151b; as installed on various small and transport category airplanes. The proposed AD was published in the Federal Register on March 13, 2008 (73 FR 13498) to require installing a warning placard on the TAWS/RMI, revising the Limitations section of the airplane flight manual (AFM), and installing upgraded software in the TAWS/RMI.

### Comments

We provided the public the opportunity to participate in the development of this AD. We received no comments on the NPRM or on the determination of the cost to the public.

### Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

### Costs of Compliance

This AD describes the installation of later revisions of software than those specified in AD 2006-16-18; however, this change imposes no new costs on operators. Costs are repeated here for operator convenience only.

This AD affects about 300 airplanes of U.S. registry. The actions take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $24,000, or $80 per airplane.

### Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

### Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

  (1) Is not a “significant regulatory action” under Executive Order 12866;

  (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

  (3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

## Affected data sheets (33) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 12 of 17 models: 737-500 Series, 737-900 Series, 737-100 Series, 737-200C Series, 737-700C Series, 737-800 Series, 737-900ER Series, 737-300 Series…
- [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 12 of 14 models: 747-100B Series, 747SP Series, 747-400D Series, 747-400F Series, 747-200B Series, 747-200F Series, 747-300 Series, 747-200C Series…
- [TCDS A35EU](https://openairdocs.org/tcds/A35EU): Airbus SAS; names 9 of 17 models: A300 B4-622R, A300 F4-605R, A300 B4-601, A300 B4-603, A300 B4-622, A300 F4-622R, A300 B4-620, A300 C4-605R Variant F…
- [TCDS A22WE](https://openairdocs.org/tcds/A22WE): The Boeing Company; names 7 of 11 models: DC-10-40, DC-10-10F, DC-10-30, DC-10-30F (KC-10A KDC-10), DC-10-10, DC-10-40F, DC-10-15
- [TCDS A3WE](https://openairdocs.org/tcds/A3WE): The Boeing Company; names 6 of 6 models: 727-100 Series, 727 Series, 727-200 Series, 727-100C Series, 727-200F Series, 727C Series
- [TCDS A24CE](https://openairdocs.org/tcds/A24CE): Textron Aviation Inc.; names 4 of 37 models: A200 (C-12A), 300, 1900D, B300
- [TCDS A3EU](https://openairdocs.org/tcds/A3EU): Textron Aviation Inc.; names 4 of 50 models: HS.125 Series 600A, HS.125 Series 700A, BAe.125 Series 800A (U-125), Hawker 800XP
- [TCDS 3A20](https://openairdocs.org/tcds/3A20): Textron Aviation Inc.; names 3 of 22 models: E90, C90A, C90
- [TCDS A9EA](https://openairdocs.org/tcds/A9EA): De Havilland Aircraft of Canada Limited; names 3 of 5 models: DHC-6-100, DHC-6-200, DHC-6-300
- [TCDS A10CE](https://openairdocs.org/tcds/A10CE): Learjet Inc.; names 2 of 29 models: 24, 55
- [TCDS A12EA](https://openairdocs.org/tcds/A12EA): Gulfstream Aerospace Corporation; names 2 of 7 models: G-1159A, G-1159
- [TCDS A27CE](https://openairdocs.org/tcds/A27CE): Textron Aviation Inc.; names 2 of 2 models: 551, 501
- [TCDS A37CE](https://openairdocs.org/tcds/A37CE): Textron Aviation Inc.; names 2 of 2 models: 208B, 208
- [TCDS 2A4](https://openairdocs.org/tcds/2A4): Twin Commander Aircraft LLC; names 1 of 21 models: 695A
- [TCDS 3A15](https://openairdocs.org/tcds/3A15): Textron Aviation Inc.; names 1 of 27 models: A36
- [TCDS 3A16](https://openairdocs.org/tcds/3A16): Textron Aviation Inc.; names 1 of 21 models: 58
- [TCDS 6A1](https://openairdocs.org/tcds/6A1): Twin Commander Aircraft LLC; names 1 of 9 models: 500A
- [TCDS A14CE](https://openairdocs.org/tcds/A14CE): Textron Aviation Inc.; names 1 of 12 models: B100
- [TCDS A16NM](https://openairdocs.org/tcds/A16NM): Gulfstream Aerospace LP; names 1 of 4 models: 1125 Westwind Astra
- [TCDS A16SW](https://openairdocs.org/tcds/A16SW): Textron Aviation Inc.; names 1 of 4 models: MU-300-10
- [TCDS A1WI](https://openairdocs.org/tcds/A1WI): Textron Aviation Inc.; names 1 of 4 models: 525
- [TCDS A21EU](https://openairdocs.org/tcds/A21EU): British Aerospace Regional Aircraft; names 1 of 3 models: Jetstream Series 3101
- [TCDS A22CE](https://openairdocs.org/tcds/A22CE): Textron Aviation Inc.; names 1 of 6 models: S550
- [TCDS A2SW](https://openairdocs.org/tcds/A2SW): Israel Aircraft Industries Ltd.; names 1 of 6 models: 1124
- [TCDS A2WE](https://openairdocs.org/tcds/A2WE): Sabreliner Aviation LLC; names 1 of 8 models: NA-265-60
- [TCDS A31CE](https://openairdocs.org/tcds/A31CE): Textron Aviation Inc.; names 1 of 1 models: F90
- [TCDS A31SO](https://openairdocs.org/tcds/A31SO): Embraer S.A.; names 1 of 5 models: EMB-120
- [TCDS A33EU](https://openairdocs.org/tcds/A33EU): Dassault Aviation; names 1 of 1 models: Falcon 10
- [TCDS A46EU](https://openairdocs.org/tcds/A46EU): Dassault Aviation; names 1 of 3 models: Mystere-Falcon 50
- [TCDS A7CE](https://openairdocs.org/tcds/A7CE): Textron Aviation Inc.; names 1 of 16 models: 421C
- [TCDS A7EU](https://openairdocs.org/tcds/A7EU): Dassault Aviation; names 1 of 11 models: Mystere-Falcon 200
- [TCDS A8EA](https://openairdocs.org/tcds/A8EA): Piper Aircraft Inc.; names 1 of 6 models: PA-31T2
- [TCDS A9NM](https://openairdocs.org/tcds/A9NM): Textron Aviation Inc.; names 1 of 1 models: 650

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 11,796 (11,796 by airframe model, 0 by engine model)
- Makers: Beech 4,457, Cessna 2,821, Raytheon 1,507, Boeing 1,268, Textron 673, Hawker Beechcraft 157, Dassault 88, Dehavilland 84, Israel Aircraft Industries 81, British Aerospace 80

Models with the most aircraft:

- [Beech A36](https://openairdocs.org/model/beech-a36): 1,907 aircraft (airframe model)
- [Beech 58](https://openairdocs.org/model/beech-58): 726 aircraft (airframe model)
- [Cessna 208B](https://openairdocs.org/model/cessna-208b): 639 aircraft (airframe model)
- [Cessna 560](https://openairdocs.org/model/cessna-560): 596 aircraft (airframe model)
- [Cessna 421C](https://openairdocs.org/model/cessna-421c): 496 aircraft (airframe model)
- [Raytheon A36](https://openairdocs.org/model/raytheon-a36): 445 aircraft (airframe model)
- [Cessna 525](https://openairdocs.org/model/cessna-525): 442 aircraft (airframe model)
- [Beech B200](https://openairdocs.org/model/beech-b200): 281 aircraft (airframe model)
- [Boeing 737-823](https://openairdocs.org/model/boeing-737-823): 278 aircraft (airframe model)
- [Beech 35](https://openairdocs.org/model/beech-35): 266 aircraft (airframe model)
- [Raytheon HAWKER 800XP](https://openairdocs.org/model/raytheon-hawker-800xp): 251 aircraft (airframe model)
- [Beech 200](https://openairdocs.org/model/beech-200): 234 aircraft (airframe model)
- [Raytheon B300](https://openairdocs.org/model/raytheon-b300): 233 aircraft (airframe model)
- [Textron 525](https://openairdocs.org/model/textron-525): 222 aircraft (airframe model)
- [Beech C90](https://openairdocs.org/model/beech-c90): 216 aircraft (airframe model)
- [Textron 208B](https://openairdocs.org/model/textron-208b): 210 aircraft (airframe model)
- [Raytheon B200](https://openairdocs.org/model/raytheon-b200): 206 aircraft (airframe model)
- [Cessna 650](https://openairdocs.org/model/cessna-650): 201 aircraft (airframe model)
- [Textron B300](https://openairdocs.org/model/textron-b300): 195 aircraft (airframe model)
- [Cessna 501](https://openairdocs.org/model/cessna-501): 189 aircraft (airframe model)

All 191 models: https://openairdocs.org/ad/2006-16-18-R1/models.md
Every aircraft: https://openairdocs.org/ad/2006-16-18-R1/aircraft.md

## Related documents

- [AD 2006-16-18](https://openairdocs.org/ad/2006-16-18) (historical): Installing a warning placard on the TAWS/RMI and 
revising the Limitations section of the airplane flight manual (AFM) · Sandel Avionics ST3400 Terrain Awareness Warning System/Radio Magnetic Indicator (TAWS/RMI) Units. Effective Sep 25, 2006. Replaced by this AD
- [Proposed rule FAA-2007-0290](https://openairdocs.org/proposed/FAA-2007-0290): Notice of proposed rulemaking (NPRM), published Mar 13, 2008

Its text cites no advisory circulars or STCs.

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