172 Approach Speed

dmspilot said:
So book knowledge is not important?
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Actually, not as much as you think. The "book" gives you various V speeds you should adhere to stay safe. They give you boundaries to operate within not hard and fast rules to apply.

This is particularly true when it comes to landing: You need to KNOW HOW TO LAND and adapt to different speeds. Your cite picture is a big part of that process.

A correct cite picture allows you to adjust to different wind conditions which will result in a good to great landing.
 
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Trogdor said:
Actually, not as much as you think. The "book" gives you various V speeds you should adhere to stay safe. They give you boundaries to operate within not hard and fast rules to apply.
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That's not the kind of book knowledge I'm talking about.
 
Gray Ghost said:
I am a student pilot, so please excuse my ignorance.

The Airplane Flying Handbook repeatedly says that you should fly final approach at 1.3 x Vs0. Vs0 in the 172R I am mostly flying is 33 kts. 1.3 times that is 43 kts. Nobody flies the approach that slowly in the 172, and I have been instructed to fly it at 65 kts, which works well.

Can someone explain the discrepancy to me? Does the 1.3 x Vs0 formula just not apply to a 172?

Thanks in advance.
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Our old F-model had an approach speed of 60-65 mph! If you came in at 60, you'd better be riding the throttle, because you could develop an amazing sink rate, and it was quite a yank to keep that front wheel off the deck. Even 65 mph made a huge difference. And 120 mph over the numbers would let you float for a few thousand feet.
 
Gray Ghost said:
I am not allowed to post links here, but reference this manual:

https://www.se.edu/aviation/wp-content/uploads/sites/4/2020/10/172R-POH.pdf

Pages 2-5 and 5-12 both lists Vs0 for the 172R as 33 kts. If I am reading it wrong, someone please tell me.

Also, as I indicated in the OP, I am flying stable approaches at 65 kts just fine. The point of this thread is to understand the theory and why the 1.3 formula doesn't seem to apply.
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Yes I know this is an old thread -

Notice the "FOR TRAINING PURPOSES ONLY" watermark. Anything marked with this is only to be used for training concepts. It is NOT to be used as a source of information for the plane you are flying, nor is it to be used for any sort of flight planning.
 
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Jon Wilder said:
Yes I know this is an old threat -

Notice the "FOR TRAINING PURPOSES ONLY" watermark. Anything marked with this is only to be used for training concepts. It is NOT to be used as a source of information for the plane you are flying, nor is it to be used for any sort of flight planning.
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It's not about the watermark.

Watermarked or not, unless it is the original serial-numbered POH for that specific airplane, including all of the applicable supplements (or an exact duplicate), it's not official and technically informational only.
 
midlifeflyer said:
It's not about the watermark.

Watermarked or not, unless it is the original serial-numbered POH for that specific airplane, including all of the applicable supplements (or an exact duplicate), it's not official and technically informational only.
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But I would also note that if it is for the same model and/or serial number range, it’s information that is valid for flight planning or aircraft-specific information, provided there aren’t mods that supercede the basic POH.
 
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Clip4 said:
VSO is the calibrated power-off stall speed or minimum steady flight speed in the landing configuration (flaps extended, gear down). 1.3 x VSO in a 172 is 62 KIAS. The difference between IAS and CAS with 30° flaps at 62 knots is +/- 1 knot.
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I don't think @Gray Ghost is till with us but, if they are, here's the stall speed table from a 172R showing a 47 KCAS Vs0. 1.3 Vs0 is 61.1 KCAS. As you point out the Calibration Chart shows a 1 KT difference - 62 as you said.

1774288782404.png
 
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