# AD 49-27-01: Fuel Line Rework - Type: Airworthiness directive - Status: Current - Products: Consolidated Vultee Aircraft Corporation, Stinson Division BT-13, BT-13A (Army SNV-1) and BT-13B (Navy SNV-2) - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Registered aircraft: 98 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/88282E7812AAB97586256A380059F0F6.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/49-27-01 ## The airworthiness directive 49-27-01 CONVAIR: Applies to All BT-13 Series Aircraft. Compliance required not later than November 1, 1949. Certain cases of engine failures at takeoff in these aircraft have been traced to fuel starvation as a result of accumulations of water or ice in a short segment of the fuel line, between the fuel selector valve and the emergency pump unit. The segment of fuel line from the valve outlet port to a point approximately 12 inches forward forms a water trap which cannot be drained without disconnecting the line. To preclude the possibility of engine malfunctioning from ice accumulation in this line, either of the following modifications must be accomplished: 1. Provide a new support bracket for the fuel selector valve which will raise the bottom of the valve, and the lowest point of the fuel line from the valve to the emergency fuel pump unit inlet port, to a height slightly above the level of the emergency pump unit inlet when the aircraft is in the 3-pointposition on level terrain, or 2. Provide a new selector valve, having the outlet port not lower than the inlet ports, and installed in such a manner that there will be a continuous up slope in the fuel lines from the fuel tank outlet to the emergency pump unit inlet when the aircraft is in the 3-point attitude. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-2-571](https://openairdocs.org/tcds/A-2-571): Consolidated Vultee Aircraft Corporation Stinson Division; names 3 of 4 models: BT-13B (Navy SNV-2), BT-13, BT-13A (Army SNV-1) ## 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: 98 (98 by airframe model, 0 by engine model) - Makers: Consolidated Vultee 74, Convair 17, Cons Vultee/Basinger 1, Cons Vultee/Lacey 1, Cons Vultee/Pittman 1, Consolidated Vultee/Gunderson 1, Consolidated Vultee/Vanech 1, Consolidated/Nocco C 1, Vultee/Reed Ron 1 Models with the most aircraft: - [Consolidated Vultee BT-13A](https://openairdocs.org/model/consolidated-vultee-bt-13a): 56 aircraft (airframe model) - [Convair BT-13A](https://openairdocs.org/model/convair-bt-13a): 11 aircraft (airframe model) - [Consolidated Vultee BT-13B (SNV-2)](https://openairdocs.org/model/consolidated-vultee-bt-13b-snv-2): 11 aircraft (airframe model) - [Consolidated Vultee BT-13](https://openairdocs.org/model/consolidated-vultee-bt-13): 7 aircraft (airframe model) - [Convair BT-13](https://openairdocs.org/model/convair-bt-13): 3 aircraft (airframe model) - [Convair BT-13B](https://openairdocs.org/model/convair-bt-13b): 3 aircraft (airframe model) - [Consolidated/Nocco C VULTEE BT-13](https://openairdocs.org/model/consolidated-nocco-c-vultee-bt-13): 1 aircraft (airframe model) - [Cons Vultee/Pittman BT13](https://openairdocs.org/model/cons-vultee-pittman-bt13): 1 aircraft (airframe model) - [Consolidated Vultee/Gunderson BT-13A](https://openairdocs.org/model/consolidated-vultee-gunderson-bt-13a): 1 aircraft (airframe model) - [Consolidated Vultee/Vanech BT-13A](https://openairdocs.org/model/consolidated-vultee-vanech-bt-13a): 1 aircraft (airframe model) - [Cons Vultee/Basinger BT-13A](https://openairdocs.org/model/cons-vultee-basinger-bt-13a): 1 aircraft (airframe model) - [Cons Vultee/Lacey BT-13B](https://openairdocs.org/model/cons-vultee-lacey-bt-13b): 1 aircraft (airframe model) - [Vultee/Reed Ron BT-13A](https://openairdocs.org/model/vultee-reed-ron-bt-13a): 1 aircraft (airframe model) All 13 models: https://openairdocs.org/ad/49-27-01/models.md Every aircraft: https://openairdocs.org/ad/49-27-01/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.