# AD 83-11-01 R1: Emergency Flotation System

- Type: Airworthiness directive
- Status: Current
- Products: Airbus Helicopters AS350B, AS350C, AS350D and AS350D1 with STC SH2825SW or SH4032SW
- Effective: December 20, 1984
- Published: December 10, 1984
- Issued: December 10, 1984
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-4959
- Docket: 83-ASW-23
- Registered aircraft: 21 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/43106C1D622FEF9086256A4E004A154E.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/83-11-01-R1

## The airworthiness directive

83-11-01 R1 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS): Amendment 39-4657 as amended by Amendment 39-4959. Applies to all SNIAS Model AS350B, AS350C, AS350D, and AS350D-1 helicopters, certificated in all categories, that have Air Cruiser flotation kits installed in accordance with STC SH4032SW or SH2825SW, and delivered by AHC prior to April 4, 1983.

Compliance is required as indicated unless already accomplished in accordance with Aerospatiale Helicopter Corporation Service Bulletin No. SB 350-18, dated April 4, 1983.

To prevent possible failure of the Air Cruiser emergency flotation system, accomplish the following prior to further overwater flight.

  (a) Reroute harness and add 1/4 inch diameter heat shrink tubing to electrical harness in accordance with Figure 1.

  (b) Add 3/4 inch diameter heat shrink tubing to encase both mechanical cable and electrical harness. Assure that 3/4 inch tube overlaps 1/4 inch shrink tubing as shown in Figure 1.

  (c)Install four supporting clamps, P/N MS21919WDG2, on each float bottle valve assembly side plate (drill and fit per Figure 1).

  (d) Install three clamps, P/N MS21919WDG36, on each cross tube to support squib harness (reference Figure 2). Ground strap is to be clamped at the lowest point on cross tube that will allow float to be pivoted between operating and ground handling position.

  (e) Inspect the harness installation and perform the electrical test described in Air Cruiser's Overhaul Manual, reference 25.60.93, page 706, or FAA approved equivalent.

  (f) Materials necessary to complete the modification are listed below.

DESCRIPTION PART NUMBER SOURCE QUANTITY Rivet MS20470AD3-4 Std. hdw 4 Bracket AN743-13 Std. hdw 2 Clamp MS21919WDG2 Std. hdw 8 Clamp MS21919WDG36 Std. hdw 6 Screw NAS603-9P Std. hdw 4 Washer AN960-10L Std. hdw 4 Nut MS21044N3 Std. hdw 4 Heat Shrink Tubing 3/4 Inch Raychem 10 ft.

(Mouser Alt)

HeatShrink Tubing 1/4 Inch Raychem 3 ft.

(Mouser Alt)

Amendment 39-4657 became effective June 13, 1983. This Amendment 39-4959 becomes effective December 20, 1984.

FIGURE 1, PART 1 AD 83-11-01

Heat Shrink Tubing to Extend Inboard Past Clamp on Cross Tube. (High & Low Skid Gear)

NOTE: Ground strap to be clamped at lowest point on Cross tube that will allow float to be pivoted between operating and ground handling position. Do not clamp or otherwise secure ground strap to mech. control & elect wire bundle except where both can be clamped together on cross tube.

FIGURE 2 AD 83-11-01

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H9EU](https://openairdocs.org/tcds/H9EU): Airbus Helicopters; names 4 of 10 models: AS350C, AS350B, AS350D1, AS350D

## 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: 21 (21 by airframe model, 0 by engine model)
- Makers: Aerospatiale 13, S N I A S 6, Eurocopter 1, Eurocopter France 1

Models with the most aircraft:

- [Aerospatiale AS350B](https://openairdocs.org/model/aerospatiale-as350b): 13 aircraft (airframe model)
- [S N I A S AS-350B ECUREUIL](https://openairdocs.org/model/s-n-i-a-s-as-350b-ecureuil): 5 aircraft (airframe model)
- [S N I A S AS350D ASTAR](https://openairdocs.org/model/s-n-i-a-s-as350d-astar): 1 aircraft (airframe model)
- [Eurocopter AS350B](https://openairdocs.org/model/eurocopter-as350b): 1 aircraft (airframe model)
- [Eurocopter France AS350B](https://openairdocs.org/model/eurocopter-france-as350b): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/83-11-01-R1/models.md
Every aircraft: https://openairdocs.org/ad/83-11-01-R1/aircraft.md

## Related documents

- [STC SH2825SW](https://openairdocs.org/stc/SH2825SW): Installation of AirCruisers Model D24724 emergency flotation gear.. Air Cruisers Company, Named in the applicability
- [STC SH4032SW](https://openairdocs.org/stc/SH4032SW): Installation of Air Cruisers Model D24724 emergency flotation gear.. Air Cruisers Company, Named in the applicability

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