C172 tailstrikes

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woxof

Pre-takeoff checklist
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woxof
Got an email recently from a flight school stating that they have had a lot of tailstrikes on the S model and that it is more vulnerable to tailstrikes than the earlier version. One school I fly at has painted the bottom of the tail tie down ring yellow to make a scrape more visible.

I have flown both and did feel like I came close to one a few months back in a bounced landing. But is there really something about the new version that makes it more likely to have a tailstrike than the old version.
 
It is a little heavier so it favors slightly more speed than the older models. Not a big difference though.

The panel is a little lower than in an M model so it's a little different sight picture. It's about the same as an N/P though.

There's the 30 vs 40 degree flap difference but I would expect it to make students come in with the nose lower.

:dunno:
 
woxof said:
they have had a lot of tailstrikes on the S model and that it is more vulnerable to tailstrikes than the earlier version.
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I don’t believe that. It’s no different. If you’re landing with full flaps, which most of the time you are, than you’ll end up running out of elevator authority before the tail hits the ground. Now, you CAN tailstrike any 172, but it does require some talent to do so.
 
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One thing I've heard, but have no time in a G1000 172, is that the G1000 computers are installed in the aft baggage compartment and can make the aircraft more tail heavy than older 172s. I've heard that is part of the reason the newer 172s are placarded against spins.
 
I owned a Nav III 172S and struck the tail..once...before I soloed. CFI framed it for me..as he'd never seen this happen.


It was because I was ham fisted and couldn't land the plane worth a flip.
 
Eh? The 172S G1000 has the same spin limitations as the others: utility category only, slow deceleration.

Now you may find it harder to get into the utility category envelope, but the book doesn't outright prohibit it.
 
My instructor used to call that the "Texas Softfield" takeoff when you started the run with full aft stick and held it there until the tail dragged.
 
midwestpa24 said:
One thing I've heard, but have no time in a G1000 172, is that the G1000 computers are installed in the aft baggage compartment and can make the aircraft more tail heavy than older 172s. I've heard that is part of the reason the newer 172s are placarded against spins.
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Are they?

Screen Shot 2018-09-13 at 12.16.27 PM.png
 
When I was training in a 172 I became quite proficient and digging holes in the tarmac with the nose gear.. my cfi kept telling me to pull back, you’ll never hit the tail in your flare.
 
flyingron said:
Eh? The 172S G1000 has the same spin limitations as the others: utility category only, slow deceleration.

Now you may find it harder to get into the utility category envelope, but the book doesn't outright prohibit it.
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Ok, as I said it was just what I'd heard but I have no experience in them. Latest model 172 I've been in was a 99-2000 model SP.
 
Kelvin said:
I owned a Nav III 172S and struck the tail..once...before I soloed. CFI framed it for me..as he'd never seen this happen.
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It ain't that hard. Happens a lot when students are practicing short/soft field takeoffs and landings.

As to why the S models would be more vulnerable is a mystery, especially since the factory put skids below the tail ring and older models often don't have skids.
 
benyflyguy said:
When I was training in a 172 I became quite proficient and digging holes in the tarmac with the nose gear.. my cfi kept telling me to pull back, you’ll never hit the tail in your flare.
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"Never" is false. In training you're flying it with the CG near the forward limit. What is not possible under one scenario may be more than possible or even likely with another.
 
The R and S models ARE more tail-heavy. It shows up when you want to get it into the Utility category for spins, and find that the rear seat has to come out.
And soft-field technique, using a bit of power, gives more than enough elevator authority to bang the tail even with only two on board. With someone in the back it's much easier to make a taildragger of it. Those later models also had a lot of "improvements" added: heavier doorpost/gear bulkhead parts. Heavier stab forward spar. Leather seats. REALLY heavy seats to meet the rewritten FAR23 requirements: 26G front, 19G rear. They're built like bridges and weight at least three times what the old ones did. The autopilot servos. And of course, the G1000 adds a whack of boxes in the back. All of this stuff (except maybe the front seats) is aft of the CG. And it's part of the reason why the airplane weighs 300 pounds more than an old M model.

Tailstrikes can damage more than the tiedown ring. It can crack the aft bulkead. It can damage the aft stabilizer spar because of the mass balance weights in the elevator tips. It can crack rudder hinge brackets because of the big mass balance at the top of the rudder, and that weight can also wrinkle the rudder skins at the horn.
 
Dan Thomas said:
The R and S models ARE more tail-heavy. It shows up when you want to get it into the Utility category for spins, and find that the rear seat has to come out.
And soft-field technique, using a bit of power, gives more than enough elevator authority to bang the tail even with only two on board. With someone in the back it's much easier to make a taildragger of it. Those later models also had a lot of "improvements" added: heavier doorpost/gear bulkhead parts. Heavier stab forward spar. Leather seats. REALLY heavy seats to meet the rewritten FAR23 requirements: 26G front, 19G rear. They're built like bridges and weight at least three times what the old ones did. The autopilot servos. And of course, the G1000 adds a whack of boxes in the back. All of this stuff (except maybe the front seats) is aft of the CG. And it's part of the reason why the airplane weighs 300 pounds more than an old M model.
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That was along the lines of what I had been told. The new G1000 172S are much more tail-heavy than their predecessors, with a lot of emphasis on the location of the G1000 boxes.
 
Ryanb said:
I don’t believe that. It’s no different. If you’re landing with full flaps, which most of the time you are, than you’ll end up running out of elevator authority before the tail hits the ground. Now, you CAN tailstrike any 172, but it does require some talent to do so.
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It doesn't require that much talent. I did it once after landing in a full stall and then pulling back a little more for the aerodynamic braking. The landing and the pull back were smooth. Heard a strange noise and realized it was the sound of the tie down ring scraping the runway. This was a 172P with just me (about 230 lbs then) and about 10 gallons of gas. That puts the CG about 1/3 of the way back.
 
 
asicer said:
Google says no, they ARE NOT.
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That's about what I would have guessed. My suspicion was that any avionics weight added in the tail of the newer 172s would be offset by additional weight of an IO-360 on the nose. The more correct statement may be "The R and S models are heavy."
 
asicer said:
Google says no, they ARE NOT.
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Interesting. Incidentally, Cessna provides a fleet W&B with the airplane, which is not an actual W&B for that serial number, and which is sometimes off. I found our 2006 S model to be heavier than stated. Nothing had been added since manufacture.

At any rate, if one does the W&B calculations for one of those airplanes when he's going up with an instructor, he'll find he's close to or beyond the utility aft limit. I calculated for the R model that you posted, and without the rear passenger and baggage the CG is a 40.03. Aft utility limit is 40.5. That will be a steam gauge airplane. The G1000 airplane weighs around 100 pounds more and its empty CG is farther aft. Got a chart for one of those?
 
I've had one tailstrike in the RV-9A, when I and my pax tried to get into the plane at the same time. Put enough weight on the steps aft of the wing and it'll do a nice wheelie. :)
 
I love to flair and hold her off as much as the next guy, but tail striking a 172, damn!
 
asicer said:
A little farther back at 41.6. Not enough to induce a tailstrike, I don't think.
http://www.falconaviation.com/Rental Fleet/N1107G.php#
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More than an inch past the 40.5 Utility limit, which is what we found with ours. No, it makes no excuse for a tailstrike; that usually comes from either too much nose-up elevator on a soft-field takeoff, or holding the nose off too long with too much power on a soft-field landing. You can do that solo, with no baggage.
 
This is spot on.

The marketing numbers left off the avionics IIRC...the UL of my '05 172SP was lower than the fleet number...

Dan Thomas said:
Interesting. Incidentally, Cessna provides a fleet W&B with the airplane, which is not an actual W&B for that serial number, and which is sometimes off. I found our 2006 S model to be heavier than stated. Nothing had been added since manufacture.

At any rate, if one does the W&B calculations for one of those airplanes when he's going up with an instructor, he'll find he's close to or beyond the utility aft limit. I calculated for the R model that you posted, and without the rear passenger and baggage the CG is a 40.03. Aft utility limit is 40.5. That will be a steam gauge airplane. The G1000 airplane weighs around 100 pounds more and its empty CG is farther aft. Got a chart for one of those?
Click to expand...
 
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