Page 36 - Volume 21 Number 11

34 • TWIN & TURBINE November 2017
component, a notice may come to you in the mail.
A Letter from the IRS
Receiving a SB (Service Bulletin) or AD (Airworthiness Directive) in the mail is right up there with a letter from the IRS. An SB is a notice from a manufacturer informing operators of a product improvement or problem. Having realized that there are distinct levels of seriousness, manufacturers
may categorize them as informational, optional, recommended, alert or mandatory. It may be something minor like replacing the original metal chains on the fuel caps with plastic retaining lanyards, or something severe like a crankshaft inspection. The first thing to do is read the section that describes to whom the AD or SB applies. Affected users are normally identified by the component manufacturers name and serial numbers or part numbers for the affected component. Although a service
bulletin may be listed as mandatory, compliance isn’t necessarily required unless accompanied by an AD. I’ll add a caveat here: a recent “mandatory” SB (that is not yet an AD) for a piston-engine component or described failure to comply with the SB as possibly resulting in “a sudden and catastrophic failure of the engine.” Try justifying non-compliance with that one when someone prosecutes you for crashing into their pre-school. An Airworthiness Directive (AD) is issued when the FAA believes that a perilous condition exists in a product (engine, airframe, appliance or propeller) and the potentially unsafe condition needs special inspection, alteration or repair. An AD will often reference a service bulletin as a method of complying with the AD. An example of an AD is the wing attach bolts on many Beechcraft and the pressure decay test on many combustion heaters for the cabin. AD’s are legally enforceable regulations, and if you own or operate the listed item, compliance is mandatory.
Don’t put off until tomorrow, what you can do today.
– Benjamin Franklin (and your AMT)
We can agree that the following are critical components for keeping the airplane in the air: The wings, empennage, fuselage and flight controls. If any of these are missing or severely damaged, we will have an aircraft control, weight and balance or life support issue. Those components are followed very closely by the propulsion system that may include propellers or turbine components and a fuel storage and delivery system. We won’t necessarily die without a propulsion system, but an off-airport landing in a twin-and-turbine style airplane would be interesting. A landing gear system is next on our list of priorities so that we may land on a nice surface of our choosing. Again, this system isn’t needed for survival, but it should increase our odds during the landing. With the above axioms in mind, consider the following list of squawks that owners (myself included) most often ask AMT’s to defer, and my experience with some of them:
AOPA Product Half Page 4/C Ad
Jet Journal Section
www.aopa.org