Short-Field Ops: Publications?

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Guys,

Aside from a POH, do you have any recommended reading on good short-field technique in piston singles?

Going up Friday afternoon/evening to do some short-field work with my CFI, and I don't have any of my old stuff on SF work. This'll be in a C-172 L with 40-degree flaps. I'd like to read/brush up on this before I go up.

Thanks in advance.
 

rframe

pǝʇɹǝʌuı
http://www.amazon.com/Mountain-Flying-Bible-Sparky-Imeson/dp/1880568179

Contains much more than landings, but a great book.

Short field landings are 98% about precise approach airspeed control. Too fast and it's no longer short, too slow and you die or do a carrier landing so hard you need a chiropractor appointment after flying. With a good precise approach there's minimal energy for the flare, so timing it right is important. If using the "checkride" strategy of a steep obstacle-based short field approach you'll have a rapid sink rate and it's easy to hit hard, save your energy and transition briskly at the right time, just as you hit ground effect. It should be harder to balloon than normal if you're as slow as you should be on approach.
 

Hammertime

Well-Known Member
.... This'll be in a C-172 L with 40-degree flaps...
Throw the barn doors out, and don't miss! No offense, but if you can't do a short field in that, you got problems. The fact that you're studying up means you are miles ahead of 95% of the other students.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Throw the barn doors out, and don't miss! No offense, but if you can't do a short field in that, you got problems. The fact that you're studying up means you are miles ahead of 95% of the other students.
Thanks!

I'm returning to flying after a 3-year hiatus, and, really, I hadn't practiced short-field since I got my certificate (I know, I know - shame on me) and this is part of a fairly extensive flight review. Even if it wasn't, some instruction in SF is a good thing, because there are a LOT of short strips in this part of the country and it'd be nice to be able to explore them.

I've found some videos and stuff, and while the AFH is good, I guess I was looking for an outline on technique or something like that. I know my CFI will likely cover all this, but I'd like to go in as prepared as possible.
 

Capt. Chaos

Well-Known Member
Even if it wasn't, some instruction in SF is a good thing, because there are a LOT of short strips in this part of the country and it'd be nice to be able to explore them.

What is your criteria for a "short field"? <3000, <1000? Pavement, dirt? Patch of gravel on a mountianside?
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
What is your criteria for a "short field"? <3000, <1000? Pavement, dirt? Patch of gravel on a mountianside?
Good question. The field we're going to work at is 2240x50 according to Airnav, but there are some other <2500' strips in the area, too.

I did some short-field work in a PA-18 when I was getting my TW endorsement, and we landed in all kinds of fields, islands in the lake, etc, which were pretty short. But I've not tried anything really short in a 172 before. I know I can do it, but I'd like to have some instruction for confidence and proficiency. Y'know...trying not to die in an airplane. :)
 

z987k

Well-Known Member
You can land a 172 with 40* flaps in less than 500ft. Any kind of headwind and you can request a hover taxi.

Oh, and remember to retract them in the flare. ;)
 

shdw

Well-Known Member
If you're in a Cessna it's real easy, just bring along a sharp stick. After you takeoff pop your main with your stick then hand it to your CFI and ask him/her to pop the other for you. You'll have a nice short landing.

Now for the serious part, Stick and Rudder. Great book for all types of basic flying skills, and a solid chapters worth on short field technique.
 

shdw

Well-Known Member
I've found some videos and stuff, and while the AFH is good, I guess I was looking for an outline on technique
My apologies for not completely reading this before my first post. Have a look at the attached lesson, section IV covers the technique I use.

I realize many pilots prefer a long time stabilized approach. Personally I don't like being slow for very long, just like I don't prefer a long slipping approach for crosswind. I'd rather crab with a transition to a slip at the end.
 

Attachments

z987k

Well-Known Member
One thing I don't think is taught much is that if there isn't a 50 foot obstacle the real world way to land as short as possible is to drag it in low and slow.
 

Cessnaflyer

Wooooooooooooooooooooooooooooooo
Good question. The field we're going to work at is 2240x50 according to Airnav, but there are some other <2500' strips in the area, too.

I did some short-field work in a PA-18 when I was getting my TW endorsement, and we landed in all kinds of fields, islands in the lake, etc, which were pretty short. But I've not tried anything really short in a 172 before. I know I can do it, but I'd like to have some instruction for confidence and proficiency. Y'know...trying not to die in an airplane. :)
We land a full Dash-8 in that distance, you will do fine.
 

Hammertime

Well-Known Member
(Just to stir up sme good clean fun...)

I realize many pilots prefer a long time stabilized approach. Personally I don't like being slow for very long...
I agree, however a lot depends on your definition of slow. In the aircraft I fly our ref speed is computed to be at approximately 1.3 Vso. In a C-172R (the only model I can remember the speeds for), Vso was 33 kts. 1.3 x that is 44 kts. Cessna's published short field approach speed is 60(?*), which is approximately 1.8 Vso. Therefore, IMHO that is not anywhere near slow. In fact, it is much closer to VL/D MAX which actually makes landing more difficult.

(*Several numbers are sticking in my head. 57, 60, and 62, and I can't remember which...)
 

shdw

Well-Known Member
In the aircraft I fly our ref speed is computed to be at approximately 1.3 Vso.
What you missed is it's 1.3 Vso of calibrated airspeed (CAS). You'll note on most a/c that near stall speed indicated vs calibrated is significantly different. However, 1.3 Vso of calibrated will put you in an airspeed range where indicated and calibrated are much closer. I'll get you the 172R models speeds tomorrow, my PoH is in the car and I'm in bed. But for now here are the 172 RG speeds:

Stall w/30 flaps: Indicated 40 -- Calibrated 47

1.3 * 47 (calibrated speed remember) is 61 which computes to approximately 60 indicated. Short field approach speed book value is 63 and normal approach speed is 60-70 with 30 flaps. Book values are based on indicated.

In other words, you're calculation of 1.8 is inaccurate because you cannot calculate 1.3 Vso from your indicated stall speed. :)

PS To the students here, think of CAS as Calculation airspeed. It will help you to remember that it is imperative that you use CAS when doing any performance calculations. Especially when near stall speed, as 1.3 Vso of an indicated speed will put you dangerously slow when compared with the CAS that you should be using for this calculation.
 

TwoTwoLeft

o- - - - - - -l
All that CAS stuff is fine and correct for building a foundation of the short field approach in ground school. However, if you leave it at that and say "Ok now who wants to go flyin" you're going to end up with a student who flies with their eyes glued to the airspeed indicator with out being conscious of the big picture that makes up the short field operation. What really should be emphasized is what it takes to fly the airplane to obtain and maintain those speeds. With and with out power. Referencing an ASI needle position rather than a number. Concepts like how to identify and control sink rate, feeling and interpreting what the airplane is telling you through control feel and sound and using induced drag and how to control it are all too often forgotten. Learn how the airplane flies and feels at different weights and change your numbers accordingly. You're flying small airplanes here, not jets. In a few airplanes I can subtract 5 mph off my approach speed if I'm solo. That 5 mph can make or brake a short field.

If you're going to nitpick over +- a knot or two indicated on an ANALOG ASI you've got your priorities mixed up.
 

killbilly

Vocals, Lyrics, Triangle, Washboard, Kittens
Wow. This is great discussion and information. Thanks very much! Since y'all have been kind enough to share your thoughts I'll do a write-up after the lesson and post it here.

I got in the habit, actually, of privately writing-up my lessons when I was training for the PPL - it helped me organize my thoughts about the learning and connect some dots mentally. I don't know if other people do this, but I find it helpful. In trying to convey the ideas on paper, it would often force me to ask my CFI for clarification in areas that I didn't even realize weren't 'sticking' well at the time. Made for a better overall experience.
 

Hammertime

Well-Known Member
What you missed is it's 1.3 Vso of calibrated airspeed (CAS)...
Actually, In a discussion about being slow (i.e airspeed in relation to stall speed), CAS is irrelevant. The PTS does not refer to either, it just states (the manufacturers recommended approach speed or) 1.3 Vso. All the speeds I quoted were from the 172R Information Manual, and listed KIAS. Vso is 33 KIAS, short field approach speed is 62 KIAS.

Definition of IAS quoted from the PHAK (my emphasis):
"Indicated airspeed (IAS)—the direct instrument reading obtained from the ASI, uncorrected for variations in atmospheric density, installation error, or instrument error. Manufacturers use this airspeed as the basis for determining aircraft performance. Takeoff, landing, and stall speeds listed in the AFM/ POH are IAS and do not normally vary with altitude or temperature."

I am glad that you brought up the 172RG, despite the fact that it is an entirely different airplane with different V speeds altogther. Many pilots will say that certain models of Cessna are easier to land than others. This highlights my point. If you do the math based on the published KIAS numbers in for each aircraft, you'll find that the older Skyhawks, 172RGs, and 150/152s published approach speeds are closer to 1.3 Vso, and further behind the power curve than late model C-172s.

For the students on here, CAS (Calibrated Airspeed) is a correction to KIAS published by the manufacturer to allow for a more accurate calculation of True Airspeed (TAS). When operating the aircraft, the only speed you should be using is Indicated. Indicated airspeed is important, as it tells you how fast the wing is moving through the airmass regardless of altitude or temperature. This is why the manufacturer publishes all limitation and operating airspeeds in KIAS. To reiterate, when performing a stall, a 172R at max gross weight, in unaccelerated flight will stall at approximately 33 KIAS.

(Edit: Screwy font...)
 

shdw

Well-Known Member
The PTS does not refer to either, it just states (the manufacturers recommended approach speed or) 1.3 Vso.
Also from the PHAK:

VS0—the calibrated power-off stalling speed or the minimum steady flight speed at which the aircraft is controllable in the landing configuration. (Emphasis added)

Admittedly the PHAK is quite vague regarding CAS, making mention but a couple times in the entire book that I'm aware of. And no where is the importance of CAS emphasized. It should be, it's important.


When operating the aircraft, the only speed you should be using is Indicated.
Nobody here has stated otherwise. What was stated is to fly safely, especially when referencing stall speeds, you should convert to calibrated, calculate, and then convert back to indicated.
 
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