Cessna 172S model Flap settings

Tommay85

Tommay85

Well-Known Member
Ok, so my room mate and I are debating as to what the full flap setting is on the C172S. I maintain that they switched it with the P model to 30 degrees flaps(which they did) and never switched back. Reason being to increase gross weight, but it's also my understanding that a lot of people were crashing them because of the 40 degree flap setting as well.

The POH doesn't say anything about it and everything I find that says it's 30 degrees isn't "official". Cessna's website doesn't say anything either.

The debate came about when I made the comment that landing with 40 degrees of flaps in the C172F that I fly was nuts unless you absolutely had to. For now I've been teaching my students to only go to 30 degrees until they get more comfortable/consistent.

I will say that with the F model about 2000-2100RPMs is required to stay on glide path and speed. The S model only requires about 17-1800, so something must be different with the flaps.

Someone have any information on this? I would really love to be proven wrong or right. No, a schools standardization manual doesn't count! ;) I'm convinced UND's is wrong and the ones I find that say 30 degrees are right! UND's is the only one on the planet so far that says full flaps is 40.
 
Codyjp said:
The M's were the last of the 40 degree models. I sure miss that setting. The M's practically hovered!
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See, that's what I'm saying to the guy, but he won't buy it until something "official" says it! He's a pretty hair brained instructor(scary), but sometimes just won't believe what you tell him. Thanks though!

I like the 40 degree flap setting too. Just not while sitting right seat as the instructor! :D

UND's standardization manual for landings says it's 40, but I don't buy it. You can even see the difference with full flaps between the two models I fly! I think they're just lazy and brought back the standardization manual from back when we used to fly cessnas in the 70s. It's probably why I should leave there and focus on free-lance!
 
On second thought, the N models were the end... They switched to 3o with the P models. However, most of the N models have been upgraded to the engines that don't have the single drive mag and one of the requirements for that STC is to disable the last 10 degrees of the flaps. It seems that Cessna regretted having them after they built them.
 
UAL747400 said:
Someone have any information on this? I would really love to be proven wrong or right. No, a schools standardization manual doesn't count! ;) I'm convinced UND's is wrong and the ones I find that say 30 degrees are right! UND's is the only one on the planet so far that says full flaps is 40.
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I did not find anything in that standardization manual that says that full flaps are 40 degrees.
 
coa787 said:
I did not find anything in that standardization manual that says that full flaps are 40 degrees.
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You got me, I didn't actually double check to see if it said anything. ;)

I did check the PIM and it says nothing specific, just 10, 20, and full.

There's more than a few instructors that think this and I'm positive they're wrong. I know, it's trivial mumbo-jumbo, but misinformation either on my part(saying it's 30) or everyone else(saying it's 40) bugs the hell out of me.
 
Codyjp said:
Are UND guys required to have usernames that are a combination of an airline or manufacturer and a number?
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Haha, no! I was only 16 and a HUGE monumental aviation dork when I opened this account! Then I realized that there are girls in this world! :D
 
UAL747400 said:
You got me, I didn't actually double check to see if it said anything. ;)

I did check the PIM and it says nothing specific, just 10, 20, and full.

There's more than a few instructors that think this and I'm positive they're wrong. I know, it's trivial mumbo-jumbo, but misinformation either on my part(saying it's 30) or everyone else(saying it's 40) bugs the hell out of me.
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Maybe they were thinking about the Warrior? You know that the CFIs teach out of several aircraft per day, and it's easy to mix numbers up. I've had to correct my CFIs a number of times.
 
coa787 said:
Maybe they were thinking about the Warrior? You know that the CFIs teach out of several aircraft per day, and it's easy to mix numbers up. I've had to correct my CFIs a number of times.
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Nah, my room mate, and a few others definitely think it's 40 on the Cessna.

Alright, the FAA type certificate data sheet says it's 30 for the S model and the 40 degrees indeed went away with the P model. Now that that's put to rest, time for a beer I think! Yeah, I know, it's 2 in the morning! :rawk:
 
I like the 40* flap setting. It makes short field landings really easy. I just hate the models that have the flap switch with three places: Down, Neutral, and Up. Students tend to put it in the up position instead of neutral and it makes for some interesting go arounds.
 
Just to set the record straight, people don't crash because fo 40 degrees of flaps. The crash because of poor fundamentals or bad decision making. I love the 40 degree settings.
 
I'm a huge fan of the 40 setting. Normally fly a couple of N and P models. One N model (1977) has 40 flaps and I use it for nearly every landing. One N model (1978) has the engine with the STC and is limited to 30 flaps - piece of metal bolted on to the flap switch and labeled as 30 max. One N model (1979) only shows that it ever had 30 flaps.
 
Had this debate today with my standardization pilot...he insists it's 40 and wants me to show him concrete proof of it being 30 (already checked...every POH reference is 10, 20, FULL). I'm considering going out to the ramp with a protractor :P Having flown a 172M quite a bit back home, I can say there's a big difference between the SP's flaps 30 and the flaps 40 barndoors hanging off of the M. Also, UND ignores Cessna's POH note saying to add 9 knots to final approach for flaps 0, we still drag it in at 61. Older UND guys--any explanation? The rest of our stan man seems to be in line with the POH.
 
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