75-16-04: Carburetor Air Box Valve
FAA order 75-16-04 is an airworthiness directive in force since July 30, 1975. The FAA's subject line: Carburetor Air Box Valve. It names Piper PA-28 Cherokee, Warrior, Archer and Arrow: about 18,633 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Piper Aircraft Inc.
- Models
- PA-28-151
- On this site
- Piper PA-28 Cherokee, Warrior, Archer and Arrow 18,633 registered
Dates and paperwork
- In force since
- July 30, 1975
- Published
- July 28, 1975 (signed July 16, 1975)
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (2,260 characters)
75-16-04 PIPER AIRCRAFT CORPORATION: Amendment 39-2272. Applies to PA-28-151 airplanes serial numbers 28-7415001 through 28-7515425; certificated in all categories.
Compliance required within the next 50 hours' time in service or at the next scheduled inspection, whichever occurs first, after the effective date of this AD, unless already accomplished.
To prevent over-travel of the carburetor air box valve, accomplish the following or accomplish an alternate modification method approved by the Chief, Engineering and Manufacturing Branch, Southern Region.
(1) Remove lower nose cowl and metal bottom panel for access to the carburetor air box.
(2) Loosen clamps attaching carburetor heat and induction air hoses to air box. Remove hoses from air box.
(3) Remove control cable from bracket and lever on air box. Retain all hardware except cotter pin for reinstallation.
(4) Remove air box bottom and valve by removing (12) #6 screws, nuts, and washers around the bottom of the air box. Retain the air box bottom and valve and attaching hardware for reinstallation.
(5) Remove safety wire securing (4) MS20074-04-04 bolts which mount air box to carburetor. Remove the bolts and AN936A416 washers. Remove air box from carburetor. Remove and discard old 73451-07 gasket, but retain mounting hardware for reinstallation.
(6) Install (2) plates, Piper Part Number 35646002, to top stiffener, secured with 8 (4 each plate) MS28470AL3-4 (Piper P/N 420-201) rivets. Installation must prevent valve over- travel.
(7) Install new gasket Piper P/N 73451-07, and reworked air box on carburetor using (4) MS20874-04-04 bolts and AN936A416 washers. Safety wire bolts.
(8) Reinstall bottom and valve assembly to air box using (12) #6 screws, nuts, and washers previously removed. Insure lever on valve is on the same side of box as control cable bracket.
(9) Reinstall control cable. Tighten the swivel fitting nut to draw the core wire into the recess 1/2 its diameter.
(10) Reinstall carburetor heat and induction air hoses on air box and secure with clamps.
(11) Replace cowling and metal bottom panel.
Piper Service Bulletin 474 also pertains to this same subject.
This amendment becomes effective July 30, 1975.
Related safety bulletins advice on the same designs, not orders
2022-10-192022-20 · Wing Spar
2021-06-29AIR-21-10 · Wing, Attach Fittings (JASC 5740)
2021-03-30AIR-21-07 · WING SPAR, Verification of Correct Washers used with Wing Spar Attach Bolts
2018-11-21SW-18-31 · NAVIGATION, ATTITUDE, AND DIRECTION DATA SYSTEM
2018-08-30CE-18-25 · Powerplant; Air Intake
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 7, 2026. Connections as data: /graph/directive/75-16-04.json · aircraft systems.