# AD 68-17-04: Stall Warning System - Type: Airworthiness directive - Status: Current - Products: Cessna 150, 150A, 150B, 150C, 150D, 150E, 150F, 150G, 150H, 150J, 150K, 150L and 54 more - Effective: September 7, 1968 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-650 - Registered aircraft: 32,815 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1B432556F74D37E786256A3400626E7A.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/68-17-04 ## The airworthiness directive 68-17-04 CESSNA: Part 39, Amendment 39-650. Applies to Models 150 (Serial Numbers 15061533 through 15069308), 172 (Serial Numbers 17254893 through 17257161), 177 (Serial Numbers 17700001 through 17701164), 180 (Serial Numbers 18051824 through 18051977), 185 (Serial Numbers 185-1198 through 185-1429), F150 (Serial Numbers F150-0001 and up), F172H (Serial Numbers F172-0320 and up), and Reims Rocket (Serial Numbers FR172-0001 and up), airplanes equipped with pneumatic stall warning system, Cessna Part Number 0413029-200, and those Model 150, 172, 177, and 185 airplanes other than the serial numbers listed above in which the pneumatic stall warning system has been installed as a replacement for the originally installed system. Compliance required as indicated. To assure proper operation of the stall warning system in flight accomplish the following: (a) Prior to flight, test the pneumatic stall warning system and determine if it is functioning properly, as provided in Paragraph 16-53A of Cessna 100 Series Service Manual, 1963 through 1967, which tells operators to test the horn operation by covering the opening in the left wing with a clean cloth, such as a handkerchief, and applying a slight suction by mouth to draw air through the horn. A properly functioning horn will provide a sound that is clearly audible. The check required by this part of the Airworthiness Directive maybe performed by the pilot. (b) Within 10 hours time in service after the effective date of this Airworthiness Directive, install a placard on the instrument panel in full view of the pilot with the following wording: "Preflight test the pneumatic stall warning system as directed by AD 68-17-04." (c) If, as a result of the preflight test required in paragraph (a) of this Airworthiness Directive, it is determined that the pneumatic stall warning system is not functioning properly, repair it by removal of Cessna reed assembly Part Number 04130281 and the installation of Cessna reed assembly Part Number 0413483-2 and by the affixing of 18 x 14 or 18 x 16 mesh screen over the exposed horn bell inside the cabin and over the left wing opening or by any other modification approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Central Region. Thereafter, flight test the aircraft to assure that the stall warning horn sounds at 5 to 10 mph above the stall warning speed and if not, recalibrate in accordance with the provisions of the afore cited paragraph of the Cessna 100 Series Service Manual or paragraph 15-41 of the Model 177 Service Manual. NOTE: The mesh screen need not be installed in the cabin of Cessna Model 177 aircraft. (d) If, as a result of the preflight test required in paragraph (a) of this Airworthiness Directive, it is determined that the pneumatic stall warning system is not functioning properly, and parts for the repair of the pneumatic stall warning system as call for in paragraph (c) ofthis Airworthiness Directive are not available, repair the system by installing a properly functioning pneumatic stall warning system, Cessna Part number 0413029-200 and continue the required preflight test until the repair called for in paragraph (c) of this Airworthiness Directive has been accomplished. (e) After completion of the repair referred to in paragraph (c) above, the preflight test specified in paragraph (a) of this Airworthiness Directive may be discontinued and the placard required in paragraph (b) of this Airworthiness Directive removed from the aircraft. This amendment becomes effective September 7, 1968. ## Affected data sheets (10) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 3A12](https://openairdocs.org/tcds/3A12): Textron Aviation Inc.; names 17 of 18 models: 172F (USAF T-41A), 172M, 172Q, 172R, 172K, 172G, 172A, 172… - [TCDS 3A19](https://openairdocs.org/tcds/3A19): Textron Aviation Inc.; names 13 of 18 models: 150L, 150B, 150D, 150E, 150M, 150K, 150C, 150G… - [TCDS 5A6](https://openairdocs.org/tcds/5A6): Textron Aviation Inc.; names 11 of 11 models: 180E, 180J, 180F, 180H, 180A, 180, 180B, 180D… - [TCDS A13EU](https://openairdocs.org/tcds/A13EU): Textron Aviation Inc.; names 7 of 14 models: F150G, F150H, F150L, F150K, F150M, F150J, F150F - [TCDS 3A24](https://openairdocs.org/tcds/3A24): Textron Aviation Inc.; names 6 of 8 models: 185B, 185E, 185C, 185A, 185D, 185 - [TCDS A18EU](https://openairdocs.org/tcds/A18EU): Textron Aviation Inc.; names 6 of 6 models: FR172G, FR172J, FR172K, FR172E, FR172H, FR172F - [TCDS A13CE](https://openairdocs.org/tcds/A13CE): Textron Aviation Inc.; names 3 of 3 models: 177, 177A, 177B - [TCDS 3A17](https://openairdocs.org/tcds/3A17): Textron Aviation Inc.; names 1 of 12 models: 172RG - [TCDS A20CE](https://openairdocs.org/tcds/A20CE): Textron Aviation Inc.; names 1 of 1 models: 177RG - [TCDS A4EU](https://openairdocs.org/tcds/A4EU): Textron Aviation Inc.; names 1 of 11 models: F172H ## 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: 32,815 (32,815 by airframe model, 0 by engine model) - Makers: Cessna 31,566, Textron 1,239, Reims Aviation S A 5, P Z L Koliber 4, Reims 1 Models with the most aircraft: - [Cessna 172M](https://openairdocs.org/model/cessna-172m): 3,573 aircraft (airframe model) - [Cessna 172N](https://openairdocs.org/model/cessna-172n): 3,138 aircraft (airframe model) - [Cessna 172S](https://openairdocs.org/model/cessna-172s): 1,915 aircraft (airframe model) - [Cessna 172](https://openairdocs.org/model/cessna-172): 1,805 aircraft (airframe model) - [Cessna 150L](https://openairdocs.org/model/cessna-150l): 1,447 aircraft (airframe model) - [Cessna 150M](https://openairdocs.org/model/cessna-150m): 1,439 aircraft (airframe model) - [Textron 172S](https://openairdocs.org/model/textron-172s): 1,239 aircraft (airframe model) - [Cessna 180](https://openairdocs.org/model/cessna-180): 1,177 aircraft (airframe model) - [Cessna 172P](https://openairdocs.org/model/cessna-172p): 1,111 aircraft (airframe model) - [Cessna 150F](https://openairdocs.org/model/cessna-150f): 1,063 aircraft (airframe model) - [Cessna 172K](https://openairdocs.org/model/cessna-172k): 1,026 aircraft (airframe model) - [Cessna 150G](https://openairdocs.org/model/cessna-150g): 977 aircraft (airframe model) - [Cessna 177B](https://openairdocs.org/model/cessna-177b): 843 aircraft (airframe model) - [Cessna 177RG](https://openairdocs.org/model/cessna-177rg): 788 aircraft (airframe model) - [Cessna 172H](https://openairdocs.org/model/cessna-172h): 780 aircraft (airframe model) - [Cessna 150H](https://openairdocs.org/model/cessna-150h): 756 aircraft (airframe model) - [Cessna 172G](https://openairdocs.org/model/cessna-172g): 722 aircraft (airframe model) - [Cessna 172F](https://openairdocs.org/model/cessna-172f): 717 aircraft (airframe model) - [Cessna 172R](https://openairdocs.org/model/cessna-172r): 683 aircraft (airframe model) - [Cessna 150J](https://openairdocs.org/model/cessna-150j): 659 aircraft (airframe model) All 63 models: https://openairdocs.org/ad/68-17-04/models.md Every aircraft: https://openairdocs.org/ad/68-17-04/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.