What are the Required Aircraft Inspections?

Added: 2026-05-28

[00:00:00]Required aircraft inspections. This is from FAR 91.409 which talks about inspections. So no person may operate a civil aircraft unless the following documents are within the aircraft. For this we use the pneummonic aviates. So the only kind of nuance here is that this I is actually a one. And we'll get to what these are, but this is probably the best pneummonic because it says aviates, right? And so it matches what we're doing being an aviator. The A in aviates, the first A stands for annual inspection. The V stands for VR. The one, remember that's a one, stands for 100 hour inspection.

[00:00:38]The second A stands for the altimeter inspection. The T stands for transponder. The E stands for ELT or emergency locator transponder. And the S stands for static and pedo system inspection. Let's go over kind of a little bit more information on each of these. Starting with the first A of Aviates, which is annual. So the annual inspection is required every 12 calendar months. That makes sense. It's an annual. It's required annually. So 12 calendar months. It's required for both visual flight rules and instrument flight rules. So VFR and IFR flight.

[00:01:11]Just real quick, if you don't know, maybe if you're just getting started, let's go over what VFR and IFR flight are. So VFR stands for visual flight rules. It's a set of regulations allowing pilots to operate an aircraft in weather conditions clear enough to navigate and control the aircraft by visual reference to the ground and other obstacles without relying solely on instruments. So basically, think of good weather flying is kind of VFR. And then instrument flight rules or IFR is a set of regulations allowing a pilot to operate an aircraft in weather conditions where navigation and control rely primarily on instruments rather than visual reference. So think of IFR is you can't rely on seeing out, you know, the windshield of your aircraft.

[00:01:50]So you have to focus and trust your instrument. So that's what IFR is. Think of that as kind of bad weather flying.

[00:01:56]Private pilots are only allowed to fly under VFR, but as a private pilot, we still need to know what inspections are required for each because a lot of the aircraft we will fly, we'll have equipment and inspections done for both VFR and IFR. So we're going to say which ones of these are required for both. and AV8 includes ones inspections that are required for both VFR and IFR. All right, so one quick thing is I mentioned a calendar month. So a calendar month means that you get the whole month. So what's an example of that? If your aircraft got an annual inspection on August 7th, 2024, then the next annual is not due until after August 31st, 2025. So it wouldn't be due August 7th, 2025. you get the rest of that month and then a year later, right? So, let's kind of do an example. The way I think of it, I started the date the annual was done.

[00:02:46]So, August 7th, 2024 here, and then you jump a year ahead and then you just go to the end. So, now we're looking at August 7th, 2025 here. And then you just go to the end of the month, which is August 31st. So, that would be the last day that you can get your annual inspection before the aircraft is no longer airworthy. So, that's what calendar month means. We'll talk about that more in more regulations. So it's important to kind of know what that means when they say calendar month. All right, so let's move on. The next one, the V in aviates is for VR. So we got a picture of a VR instrument here. We'll talk about this more in the course later. It's required every 30 days and it's required for IFR flight only. The next one is the one of AV8s. Well, that's kind of acting like an I when we say AV8s is the 100 hour inspection.

[00:03:31]It's required every 100 hours of aircraft operation per the aircraft HOBS meter. The hobs meter just kind of keeps track of the time that the aircraft engine is running. So every 100 hours that the aircraft engine is running, that's when the 100 hours due. It's only required for aircraft that are used for hire, and that includes both VFR and IFR flights. What is for hire? So one example of for hire would be hiring a pilot and his or her airplane to give you a tour on vacation. Another example would be a student pilot paying a flight instructor for instruction and the use of an airplane that is also owned by the flight instructor. So they generally say you're getting an aircraft for hire when you hire both the aircraft like you're renting the aircraft and you're renting you know the pilot in command. So that's generally what they mean by as for hire.

[00:04:20]Private pilots are not allowed to fly for hire. However, an aircraft can still be used for hire even if the pilot operating the aircraft isn't receiving direct compensation. Therefore, aircraft still get 100hour inspections in certain situations. So, the aircraft you're likely to train in at your flight school or flight club or whatever, it's probably going to get that 100 hour done because they could still rent their aircraft for other purposes like for hire. And, you know, also 100 hour means you're getting more inspections on your aircraft, which is a good thing. Okay. A 100 hour inspection can be completed up to 10 hours after the hour it is due if and only if the aircraft is flying to a place to get the inspection completed.

[00:05:02]What does this mean? Let's do an example. Say your last 100 hour inspection was completed with your HOBS meter saying 11:02.2. Your aircraft engine has been running for 11:02.2. You get a 100hour inspection at that time. So your next 100 hour inspection would be due 100 hours from then. So 11:02.2 + 100 is 1202.2. So that's when it's due. But let's say you don't have a certified mechanic to perform this inspection at your airport.

[00:05:32]So you have to fly, let's just make say it's 10 hours away where you have to go.

[00:05:36]Likely there would be something closer hopefully. But let's say you have to fly 10 hours away to an airport where the inspection gets done. Here you have taken advantage of the rule of getting up to 10 extra hours to fly if you need to fly somewhere to get it done. So you actually get your inspection done at 1212.2 on your HOBS meter. So instead of getting it done when it was due, we take off let's say at 12:02.1, we fly 10 hours and then we get it done at 1212.2. Okay. So according to the FARS that is okay because we flew only if and only if right we flew to somewhere where that 100 hour was going to get done. The tricky part that students kind of get tripped up on is when would the next 100 hour be due? Would it be due 100 hours from this time the 12.2 or would it be done 100 hours from this time the 1202.2 and the answer is it's 100 hours from the 1202.2. The FAA says that you must include the extra hours you overflew the last inspection date in your calculation. That wording is confusing to me. It means that you don't start your 100 hour timer when you actually got it done here at 1212.2. You don't restart here and get it done at 1312.2. You start it when it was due again. You start it, it was due here. So the new 100 hour clock starts here and you get have to get it done again 1302.2. So technically, it's only 90 hours between the times when your 100 hours were done. But the FA doesn't care about that. An easy way to remember this is just to remember that no matter if you go over extra any hours or not, it's due every 100 hours of HOBS time. So it's due at 11:02.2, 120.2, 1302.2, 1402.2, and so on. All right, the next A in Aviates is alimeter. Got a picture of an altimeter here. Again, we'll talk about this more in detail later in the course. Again, that's calendar month, so you get that the whole month. This is required for IFR flight only, which is kind of surprising, but again, the aircraft we fly are likely to maybe be getting this anyways, even if the aircraft isn't being used for IFR flight, or maybe it is. It's always good to get extra inspections, right? And you'll be able to see these inspections in your aircraft maintenance log books. The next one, the T in aviates, is for transponder. It's required every 24 calendar months as well. And it's not required whether it's IFR flight or VFR flight, but instead it's required in specific areas that you fly. And we have another video in a lesson where we go over this in detail, but it's required when you fly in a mode veil, when you fly in class alpha bravo or Charlie airspace, or you fly above class Bravo or Charlie airspace, or you fly above 10,000 ft MSL. There's a couple more times when it's required, and again, we go over that in a different video, but that's when it's required to have a transponder. So, if you're required to have a transponder these flights, then you would be required to get the inspection every 24 calendar months. And finally, the E. So, I guess not the last one because we got the S at the end of Aviates, is for emergency locator transmitter, which is ELT, and it requires a functional check every 12 calendar months. And then it requires the battery to be replaced at it half its used life or after an hour of cumulative use. So if it turns on and it's been used for half an hour one day and then another day gets turned on and used for a half hour, that would be an hour of cumulative use and you'd have to get the battery replaced. Or let's say it's never really used but it reaches its halflife, then it would have to be replaced. The halflife will either be found in like the user guide for the the ELT or sometimes like right here on the side it'll be printed on the side of the actual ELT itself or maybe it's marked in like the maintenance log books for the aircraft. And this is required for both VFR and IFR flight. All right.

[00:09:22]Finally, the S and AV8s is the last one.

[00:09:25]It stands for static and pedo system.

[00:09:28]This is kind of a diagram of static and pedo system. Again, we go in detail in videos and lessons on the static and pedo system and the aircraft instruments that are a part of that in different lessons and videos, but just for the sake of inspections, this is required to be inspected every 24 calendar months.

[00:09:43]And it's only for IFR flight, which again is a bit surprising. I personally, even if I wasn't flying IFR, would want my static and pedo system to be inspected every 24 calendar months, if not more. So, how do we check if inspections have been done on our aircraft? Because again, you know, keeping an aircraft airworthy is up to the owner and operator of the aircraft, but we as private pilots, we have to make sure that the aircraft we're flying is airworthy. So, we have to know and when you're on your check ride, you'll have to know and prove that your aircraft is airworthy. How do we check if inspections have been done in the correct amount of time that it's required? Well, certified mechanics will notate and sign the aircraft maintenance logs when the inspections are performed.

[00:10:25]So, it's just like a flight pilot log book. You'll have an aircraft log book.

[00:10:29]Some aircraft will have one maintenance log book like called like an aircraft log like this. And some will have two.

[00:10:34]It'll be like a power plant log book and then so that would be like for the engine. So, one for the power plant or aka the engine and then one for the airframe. But then some just have one.

[00:10:44]So, you'll look through there. You'll see the date, maybe a note or two on what inspection was completed, if everything looked good, and then the signature and number of the certified mechanic who did that inspection. and you'll be able to say, okay, yeah, the, you know, the static imped system was inspected, you know, 20 months ago.

[00:11:01]That's within the 24 calendar months, so we're good there. And so on. You can check the annual, the 100 hour, and all those things will be noted, signed off in these logs. If you come across an aircraft engine or power plant log book with no operating history, it is likely due to the aircraft having just received a new engine. Either that or you have the wrong log book. But I put this in here because this is a question that we have been hearing could be possible question that you'll get from your examiner or maybe on the FAA written. So you know if it has no operating history what kind of situation might that be?

[00:11:34]Well an aircraft can get a new engine.

[00:11:36]So it would have you know airframe log book with a bunch of history but the engine power plant log book would have no history. And that's sometimes why they have two different maintenance log books for airframe and