C172N checklist

[Pull what]

We should be teaching what is applicable for the aircraft in question. Any differences on other types should be covered in a type check out.

Wow really? Wish you had been around pre Kegworth.

I hope you will also arrange for all the appropriate PPL technical exams to be made type specific too.

Heard about the instructor who recently sent a solo student to Andrewsfield and she had a radio failure on Box 1 but didnt know that the a/c had two com boxes, I bet he is red hot on type check outs too!

Oh and by the way the OP is referring to a type check out on a C172 and the fact that his instructor couldnt explain why the check was being made(although i think he has edited this out now). Now there is a surprise, a type check instructor who sounds like he needs a type check himself so he can cover those differences you are talking about!

If you have been in training for any length of time you will know that what should be taught and what is actually taught can be poles apart.

[Big Pistons Forever]

Originally Posted by Pull what

This is true for the C172 but the C152 is only required to have a vent cap on the right side

Actually no. The C 152 must have a vented cap on both sides.

[27/09]

Wow really? Wish you had been around pre Kegworth.

I fail to see what Kegworth has to do with this discussion.

I hope you will also arrange for all the appropriate PPL technical exams to be made type specific too.

I don't see why. I'm not familiar with UK exams but those I'm familiar with cover the stuff any PPL should have a grasp of irrsepective of the type being flown.

Heard about the instructor who recently sent a solo student to Andrewsfield and she had a radio failure on Box 1 but didnt know that the a/c had two com boxes,

Kind of proves my point. There's no sense in telling a pilot about how two comms and an audio panel work if there's only one radio fitted, on the other hand however if there's two radios the student should be trained on how they work.

Oh and by the way the OP is referring to a type check out on a C172 and the fact that his instructor couldnt explain why the check was being made

I've only ever operated a C172 with the selector set to "Both". As has been pointed out the process explained in the OP was a futile exercise. Some well meaning instructor came up with "Good idea".

If you have been in training for any length of time you will know that what should be taught and what is actually taught can be poles apart.

True, part of the reason for this thread.

[Pilot DAR]

I have done extensive type training on amphibian aircraft, in particular recently, a Garmin glass cockpit 182 amphib, with just about every piece of avionics it can hold, including auto pilot. As a part of my training, I instructed my charge that he was to consider EVERY control and indicator, and what it does, and what he would do with it when. If he did not know, he was to ask me. This process occurred over several hours of actual cross country (less intense flying). I found this to be effective in leaving "no stone unturned", and reminding me of some things I need to sharpen up on - a few layers of menu pages into the GTN750 and G600...

Though thread drift, I was a participant 35 years ago, in an effort to assist a lost pilot in a 172 (on a perfectly clear winter day). I was one of several people during that event who completely failed to inquire if the plane was equipped with a transponder. It was, and had the pilot known what it was, and to turn it on, we would have saved an hour, and a lot of risky frustration.

It is a part of the student/candidate/new pilot's duty to themselves, to ask "what does this do?" during training and familiarization. They are paying to receive instruction while flying, get what you're paying for! If the instructor/mentor does not know, they better find out themselves!

[normgf1]

Yes. I edited out the reference to the instructor, because it seemed to draw unfair criticism of an otherwise excellent instructor. He was quite able to discuss C172 fuel system in detail. However, he is new to the flight school and to this (still unexplained) edition to the school supplied pre-flight check list. He also asked the all other flight instructors and interestingly none of them knew the reason for the addition either.

I have found all the posts quite interesting, but I've concluded that cycling the fuel selector valve may simply be to prevent it from seizing up as a result of being left on "Both" all the time.

I do know that the senior mechanic has had many years experience maintaining a fleet of c150's, C152's and C172's for this particular flight school.

[Mach Jump]

Not a great deal to add to the comments already made on this thread, except to say that I am generally in favour of checking that the engine will run on each selector position before takeoff if possible.

BPF, in his inimitable way, though, makes a couple of very valid points:

1. It's not in the POH, so Cessna either didn't think of it, or didn't think it was necessary.

2. By making the checklist more complex, we increase the possibility of a mistake, and in doing so, we may inadvertently introduce a risk that is greater than the one we are trying to avoid.

So, before adding stuff to the POH checks, consider carefully if the perceived benefits outweigh the potential risks.


MJ

[Meldrew]

Is there any guidance, official Cessna or otherwise, that states how long at a specific RPM, it is expected that the fuel feeding from one tank,will be exhausted before the newly selected tanks fuel takes over?

[Mach Jump]

Is there any guidance, official Cessna or otherwise, that states how long at a specific RPM, it is expected that the fuel feeding from one tank,will be exhausted before the newly selected tanks fuel takes over?

I've never seen anything official on this, but to convince pilots of the danger of changing tanks just before takeoff, I often perform the following demonstration (on the ground) which you can try on your own aircraft.

Set the RPM used for engine checks (usually around 1600-1800). Then switch the fuel off, and start a stopwatch. Most people are surprised how long the engine will run with the fuel off.

The last aircraft I demonstrated this with was a Cherokee 180 which ran normally for 60 secs, before the fuel pressure started dropping, then a further 30 secs before it stopped.

I have done this same demonstration in a C172, and the result was about the same, although I don't remember the actual times.

The point I try to make with this demonstration, is that if you change the fuel tank just before takeoff, and the new tank isn't feeding, the engine will run for just long enough to get you airborne,

So, If you change tanks just before takeoff, you need to run the engine, at the test RPM, for at least as long as you would normally take to test the mags etc. to be sure that it is running on the new tank. (This could be even longer on other types)


MJ

[Meldrew]

Thanks for that observation MJ. At least its a ball park figure to work on. Where I fly from, the approved technique is to always feed from both tanks at all times!

[9 lives]

the approved technique

Following the approved technique is excellent - but make sure that what you are told is "approved", actually is. For certified aircraft, an approval is provided by the authority under whose regulation the aircraft flies. In the case of "G" registered, the UK CAA, "N", the FAA etc. For anything operational, the flight manual, and any applicable supplements will be the "approved technique" for that aircraft. So look there for how to fly the plane, and checklists. That'll be all you need, because it is approved!

In the certified aircraft sense, "approved" means that a competent authority has found that the aircraft meets the design requirements.

Other entities (like flying clubs) do not have the authority to approve aircraft, nor their operation. They may impose standard operating procedures/guidelines, which are their preference, as they own the plane (things like do not land at uncertified runways, or no solo practice forced approaches, for example). But those SOP's should not conflict with what the manufacturer prescribes, and the authority approved for the plane, otherwise, what is the authority doing, and why do we want certified planes?

[flyinkiwi]

My 2c on the subject.

1. I have never flown a 172 in any fuel configuration other than tanks on both. Thankfully I've not needed to cut the fuel off (yet).
2. My opinion is that the OPs flight school introduced tank switching into the 172N checklist to get their students into the habit of fuel management for when they fly other types which may not have a Both setting in their fuel systems. Whether or not this is a good idea I'll leave up to you.

[tecman]

I'm glad MJ mentioned the silliness of doing the run-up, then changing to the other tank just before take-off. It's something I've seen and shaken my head over. A similar no-thought routine is to turn off the electric fuel pump (if you have one) with the 300' (or so) P&T scan, assuming you're flying a typical SEP with no fancy recommended procedures. It's about the worst place to discover your engine-driven fuel pump is in trouble and I've often thought that these guys would be better with no auxiliary pump running at all: at least that way they might discover the problem earlier.

For normal operation I've always operated C172s with the fuel selector in the 'both' position but I quite liked the approach of one operator I encountered who required the selector to be set to the 'off' position on shutdown, just so his students learned not to be afraid of the selector and routinely got the feel of the forces involved. He commented that it was one step in the learning process for students trained on C150s, where the selector was wired on and required a determined action to turn off the fuel.

I wouldn't mind having a 'both' position on my P2002JF but the certification process somehow managed to lose that feature of the LSA P2002S. It's no big deal but, with a VLA and decent in–trim flying standards, 15 min tank changes are in order.