Looping a 172?

[404 Titan]

Peter Fanelli

I will grant you that the earlier models of C172 (up to the “P” model) were certified under CAR Part 3 but all light aircraft designed and produced after the 1st February 1965 are certified under FAR Part 23. The grandfathering of aircraft originally designed prior to this date was allowed.

Later aircraft such as the C177 and Cirrus SR20 are certified under FAR Part 23. To say most current light aircraft were designed under CAR Part 3 is a slight stretch. Let’s just say a very large proportion of them were.

Have you got a copy of the design standards under CAR Part 3? I have tried searching without any luck. It would be interesting to see what the differences are regarding “Limiting Loads” and “Ultimate Loads”. I don’t think there will be much though?

[VH-XXX]

Fair go, the BAK is pretty comprehensive these days!

[djpil]

Have you got a copy of the design standards under CAR Part 3? I have tried searching without any luck. It would be interesting to see what the differences are regarding “Limiting Loads” and “Ultimate Loads”. I don’t think there will be much though?

CAR 3 is still available at http://rgl.faa.gov/Regulatory_and_Gu...e?OpenFrameSet
Quite a bit of difference in the flight loadings.
Worth repeating:

I can't believe that there aren't more people who are appalled by this sort of cowboy nonsense .... Don't encourage this sort of behaviour and dob the idiots in if you hear of it.

.... but the idiots never listen.

Would this be the same school where instructor classes talk of looping warriors?

.. one instructor was dobbed in by some-one who witnessed it and I've heard that's not the only flying school he's been kicked out of.

[404 Titan]

djpil

Thanks for that.

CIVIL AIR REGULATIONS

PART 3—AIRPLANE AIRWORTHINESS—NORMAL, UTILITY, ACROBATIC, AND
RESTRICTED PURPOSE CATEGORIES

SUBPART C—STRENGTH REQUIREMENTS
GENERAL

§ 3.186 Maneuvering load factors.

(a) The positive limit maneuvering load factors shall not be less than the following values (see Fig. 3-2):

N = 2.1 + (24000÷(W + 10000)) ---------Category N

except that n need not be greater than 3.8 and shall not be less than 2.5. For airplanes certificated as characteristically incapable of spinning, n need not exceed 3.5.

n = 4.4--------------------------------Category U
n = 6.0--------------------------------Category A

(b) The negative limit maneuvering load factors shall not be less than -0.4 times the positive load factor for the N and U categories, and shall not be less than -0.5 times the positive load factor for the A category.

(c) Lower values of maneuvering load factor may be employed only if it be proven that the airplane embodies features of design which make it impossible to exceed such values in flight. (See also § 3.106.)

So what I have gathered from this is that aircraft manoeuvring load limits under CAR Part 3 are:

Normal category:

+3.8g but not less than +2.5g. If A/C is incapable of spinning then it doesn’t need to be greater than +3.5g.
&
-1.52g

Utility category:

+4.4g
&
-1.76g

Aerobatic category:

+6.0g
&
-3.0g

FAR PART 23—AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES

23.337 Limit maneuvering load factors.

(a) The positive limit maneuvering load factor n may not be less than—

(1) 2.1+(24,000÷(W+10,000)) for normal and commuter category airplanes, where W=design maximum takeoff weight, except that n need not be more than 3.8;

(2) 4.4 for utility category airplanes; or

(3) 6.0 for acrobatic category airplanes.

(b) The negative limit maneuvering load factor may not be less than—

(1) 0.4 times the positive load factor for the normal utility and commuter categories; or

(2) 0.5 times the positive load factor for the acrobatic category.

(c) Maneuvering load factors lower than those specified in this section may be used if the airplane has design features that make it impossible to exceed these values in flight.

So what I have gathered from this is that aircraft manoeuvring load limits under FAR Part 23 are:

Commuter category:

+3.8g
&
-1.52g

Normal category:

+3.8g
&
-1.52g

Utility category:

+4.4g
&
-1.76g

Aerobatic category:

+6.0g
&
-3.0g

So in conclusion apart from having a new category in Commuter class, I really can’t see any difference in the manoeuvre load limits between CAR Part 3 and FAR Part 23.