Airworthiness

Airworthiness is a concept that encompasses two distinct areas: flyability and compliance. “Flyable” is a practical concept that answers “Do we think the aircraft is safe to operate?” Compliance is a legal concept distinct from flyability: “Does your airplane have the right documents, maintenance, and proof thereof?” For example, if you’re half an hour past a scheduled oil change or missing a required placard that says “max baggage weight 50 lbs,” the aircraft is still flyable, but it’s not compliant, and therefore not airworthy.

As far as compliance goes, the aircraft needs to conform to its type certificate (3.5) and be maintained per the OEM’s and the FAA’s requirements as well as keep up on any Airworthiness Directives (ADs) that may come out. Although the owner/operator is required to document the maintenance (91.417), you, the PIC, are responsible for operating an airworthy aircraft (91.7), so it’s important to know what’s required and how to show you’re both flyable and compliant. If an oil change was performed, but not documented, or you can’t find it in the maintenance log, then you can’t show that you’re compliant. The big pillars of maintenance and airworthiness that you operationally need to worry about, and will be tested on during an evaluation, are ADs/SBs, Preventive Maintenance, Documents and Certificates, Required Equipment, and Squawks (what happens when something breaks). Each of them has their own set of mnemonics to help you out.

Airworthiness directives and Service bulletins

Service bulletins are put out by the OEM, and are recommended. Airworthiness Directives, as the name suggests, are required by the regulator. Some problems that the OEM discovers get turned into ADs when the OEM thinks they need more urgent attention, as in the example of the A330neo bleed valves.

Preventive Maintenance

This is pretty straightforward. You, as a pilot, are allowed to make basic repairs like replacing a seatbelt, refilling hydraulic fluid, etc. It’s listed in Part 43 Appendix A section (c). A memory jingle I use is “Forty-three A C, is maintenance allowed for me.” Know some examples if you get asked by an evaluator, but if they ask you something like “Are you allowed do any electrical work” and you’re not sure, tell them where you’d look to be sure, and have that page tabbed out/bookmarked in your reference document.

Documents and Certificates: SPARROW

• S – Supplements (21.5): you need to have any relevant supplements on board the aircraft for any added equipment (e.g. aftermarket GPS, nav, etc.). Some supplements override other information in the POH, so you need to be careful what you reference. I flew a Seminole that started its life with injected IO-360 engines, but was later converted to carbs (presumably for fleet commonality). The POH had all of the original injected references, data, and procedure in it, and a supplement for the carbs in the back that overrode many of the injected engine procedures. Several students got tripped up by this.
• P – Placards 91.9: make sure you have required placards. If one falls off, check the CEL and KOEL to see if it’s optional or required.
• A – Airworthiness Certificate 91.203: the certificate doesn’t have an expiration date, but the aircraft must be maintained per its Type Certificate to remain airworthy
• R – Registration Certificate 91.203: good for 7 years
• R – Radio Station License (international flights only)
• O – Operating Handbook (91.9, 21.5, and 23.2620)
• W – Weight and Balance (23.2620) If your aircraft has any modifications (e.g. replacing halogen with LED bulbs, new panel, etc.), make sure the updates are included in the W&B form.
  

Required Inspections: AAv1ate

• A – AD Compliance in the maintenance log (91.417(a)(2)(v))
  
• A – Annual inspection (91.409) every 12 calendar months
• V – VOR check for IFR ops (91.171)
• 1 – 100 hr (FAR 91.409)
  
• A – Altimeter/Pitot Static System 24 calendar months (91.411)
• T – Transponder 24 calendar months (91.413)
• E – ELT 12 months, ½ battery life, or 1 hr usage (91.207)

faa Required Equipment: a tomato flames flaps grabcard

Note: these items are the minimum required by the FAA, not necessarily the OEM. If you get asked whether you need something that's not on these lists, but seems like an obvious yes, scroll down to ATACK PICS below. It's probably listed in there somewhere.

VFR Day: A TOMATO FLAMES (91.205b)

• A – Airspeed indicator
• T – Tachometer
• O – Oil pressure gauges
• M – Manifold pressure gauge
• A – Altimeter
• T – Temperature gauge (liquid-cooled engines)
• O – Oil temp gauge
• F – Fuel gauges
• L – Landing gear position indicators
• A – Anti-collision lights (if A/c mfr 1996+)
• M – Magnetic compass
• E – Emerg. Equip. (ELT+FFF: fire ext., floaties, flares)
• S – Seatbelts

VFR Night: FLAPS (91.205c)

• F – Fuses/breakers
• L – Landing lights
• A – Anti-collision lights
• P – Position/nav lights
• S – Source of power

IFR: GRABCARD (91.205d)

• G – Generator/alternator
• R – Rate of turn indicator
• A – Altimeter (sensitive)
• B – Ball: coordination indicator
• C – Clock
• A – Attitude indicator
• R – Radios: nav and comm
• D – Directional gyro
  

Squawks/Inoperative equipment: ATACK PICS

You will inevitably get some questions about applied airworthiness. Here’s how I like to address them: If something is broken, you need to figure out if it’s a flyability issue or a compliance issue. If it’s an obvious flyability issue (e.g. missing wing), don’t go. If you’re unsure (e.g. small dent from a bird strike), check to see if it’s already written up and addressed, else write it up, talk to maintenance, and have them ok it. If in doubt, it’s better to play it safe and not go. If you think it’s flyable but you’re not sure if it’s compliant, go through this list:

• 91.213: don’t fly if inop equip required by:
• A – Airworthiness Directive
• T – Type Certificate Data Sheet (you typically don’t have to dig this deep, check the CEL and KOEL first)
• A – A TOMATO FLAMES FLAPS GRABCARD (91.205)
• C – Comprehensive Equipment List: this is typically chapter 6 in Cessna POHs. Go here for things that would always be go/no-go regardless of the weather/day conditions (e.g. passenger seats).
• K – Kinds of Operations Equipment List: go here for things that might be different based on day/night VFR/IFR (lights, gyro instruments, etc.). Sometimes this is more restrictive than 91.205, so you need to focus on the overlap of the categories. For example, in G1000 C172s the PFD and MFD are both required (POH 6-22), even though you could argue that 91.205 data can be represented on a single screen.

Else...

• P – PIC discretion
• I – Inop the equipment
• C – Pull circuit breaker or note W/B
• S – SFP (21.197) from FSDO required if item is in ATACK: get a special flight permit if, say, your required baggage placard is missing, or you have an inop strobe but your airplane is otherwise flyable.

Here’s a little flow chart to help you out:

minimum equipment lists

Some operators have FAA-approved minimum equipment lists (MEL) and OEM-approved configuration deviation lists (CDL) that lay out what to do in the case something's inoperative. An MEL is a bit like ATACK PICS all bundled into one document. On the E175, for example, you're allowed to fly with a broken coffee maker (would you want to?), as long as you comply with the MEL provisions and put inop stickers in the appropriate places. Again, the flyability/compliance piece is important: you're not airworthy if you're missing one of the little inop stickers in the right place, so make sure you've got those all.

Cessna 172 anti-collision lights

There’s a chance you get the question about which lights on a 172 count as “anti-collision lights” (Beacon? Strobe? Both?) and which ones are allowed to be inop. The Letts LOI has your answer.

conclusion

It's important to show your ability to establish whether the aircraft you have is flyable and compliant, and therefore airworthy. Knowing the above mnemonics should have you set for the vast majority of practical situations as well as evaluator questions. The more confidently you present them, the less likely you will be to get follow-up questions.