53-09-03: Outboard Tension Bar Pins
FAA order 53-09-03 is an airworthiness directive. The FAA's subject line: Outboard Tension Bar Pins. It names Hiller UH-12: about 217 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: other and general.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Hiller Aviation
- Models
- UH-12, UH-12A, UH-12B
- On this site
- Hiller UH-12 217 registered
Dates and paperwork
- 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 (950 characters)
53-09-03 HILLER: Applies to All UH-12, UH-12A, UH-12B, HTE-1, HTE-2, H-23A and H-23B Model Helicopters.
Compliance required as soon as possible but no later than the next 25-hour inspection and as indicated in part C below.
The following has been found necessary to prevent fatigue failure of the clevis head on the outboard tension torsion bar pins, P/N 51414-1:
A. Inspect P/N 51414-1 pins to determine the fillet radius under the clevis head. If radius is less than 0.030 inch the pin must be scrapped and replaced with a pin having at least 0.030-inch radius before further flight.
B. If radius is 0.030 or greater and the pin has less than 500 hours total time it may be reinstalled. If a featheredge is found at the base of the clevis it should be carefully removed.
C. All 51414-1 pins must be replaced when they have accumulated a total of 500 hours of flight time.
(Hiller Service Bulletin No. 36 covers this procedure.)
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 November 6, 2026. Connections as data: /graph/directive/53-09-03.json · aircraft systems.