# AD 54-09-01: Carburetor Hotspot Heater Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Fairchild Engine Division, Fairchild Engine and 6-440-C2 (L-440-1), 6-440-C3, 6-440-C4 and 6-440-C5 (Military L-440-2, 3,5,7)
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Registered aircraft: 308 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/80E220F7CB4D341C8625682B0060DD83.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/54-09-01

## The airworthiness directive

54-09-01 RANGER: Applies to All 6-440-C Series Engine Models. To be accomplished as indicated. To preclude the failure of carburetor hotspot heater assembly P/N 7683, 7697, 7699 or 7708, due to corrosion from accumulations of exhaust products which in some instances have been found to completely close the inner passages, the following inspection should be accomplished by July 31, 1954, and additionally, as indicated below: 1. Remove the manifold pipes and inspect the hotspot casting for cracks on both the outside surfaces and the inside carburetor air passages, particularly at the bottom. 2. If no cracks are evident, the hotspot may be replaced with the hot air supply blocked off, per Ranger Engine Service Bulletin No. 91. Since no appreciable benefit in icing protection is provided by the use of the hotspot, it will be permissible to operate the engine with the hotspot blocked off. If the hotspot is blocked off, it is suggested that hot lubricating oil be applied to coatthoroughly the internal passage walls formerly used for exhaust gas circulation through the hotspot; this will tend to retard further corrosion. 3. If it is desired to continue to use a heated hotspot, it should be checked initially, and at 400-hour intervals to ascertain that the hot air passages are unobstructed with carbon or other exhaust gas products. This can most easily be accomplished by blocking off one hot air boss with a plate and pouring into the other hot air passage, 120 cc's of oil or gasoline. If this will not all be contained in the hotspot casting, a new hotspot casting should be utilized since no satisfactory method is known whereby all of the deposits can be removed. 4. If the hotspot has been used unheated since the last overhaul, only the initial inspection in 1. need be performed before normal overhaul.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E-216](https://openairdocs.org/tcds/E-216): Fairchild Engine Division Fairchild Engine and Airplane Corp.; names 4 of 4 models: 6-440-C3, 6-440-C2 (L-440-1), 6-440-C5 (Military L-440-2; 3;5;7), 6-440-C4

## 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: 308 (0 by airframe model, 308 by engine model)
- Makers: Fairchild 258, Grumman 17, Dehavilland 4, Ryan Aeronautical 3, Great Lakes 2, Ewertz-William 1, Guy-Fox 1, Hammerle Edward A 1, Hooper A V 1, Jeffery J Brooks 1

Models with the most aircraft:

- [Fairchild 6-440 series](https://openairdocs.org/engine/fairchild-6-440-series): 292 aircraft (engine model)
- [Fairchild 6-440-C5](https://openairdocs.org/engine/fairchild-6-440-c5): 11 aircraft (engine model)
- [Fairchild 6-440-C2](https://openairdocs.org/engine/fairchild-6-440-c2): 4 aircraft (engine model)
- [Fairchild 6-440-C4](https://openairdocs.org/engine/fairchild-6-440-c4): 1 aircraft (engine model)

All 4 models: https://openairdocs.org/ad/54-09-01/models.md
Every aircraft: https://openairdocs.org/ad/54-09-01/aircraft.md

Its text cites no advisory circulars or STCs.

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