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View Full Version : Aircraft Certification - CAR 3 effective May 15 1956


AC103
25th Nov 2018, 23:57
Hi folks, I am doing a bit if a dive into how the likes of Vd Vne Vc Vno Va Vfe etc. are derived.

Here is an example from the TCDS for the PA-28-181
(PA-28-181: CAR 3 effective May 15, 1956, including Amendments 3-2 and 3-4; paragraphs 3.304 and 3.705 of Amendment 3-7 effective May 3, 1962; FAR 23.207, 23.221, 23.955 and 23.959 as amended by Amendment 23-7 effective September 14, 1969; FAR 23.1557(c)(1) as amended by Amendment 23-18 effective May 2, 1977; and FAR 23.1327 and 23.1547 as amended by Amendment 23-20 effective September 1, 1977. FAR 36, Appendix G, Amendment 36-16 for the PA-28-181 (Archer III), S/N 2890206 through 2890231, 2843001 and up, and 2881001 and up.)

I have found the latest CFRs on the https://www.gpo.gov/ website and an old copy of CAR 3 from 1949 but can see from the low Vno numbers in the POH that Vc must have been claimed using the newer weaker standard of 33 √(W/S) rather than 38 √(W/S) from the 1949 version.

Anyone know where to get copies of the specific versions of the documents quoted above so I can see exactly under what regs the numbers were derived?
Even better do we know if it is possible to discover the test pilot notes submitted for the original type certificate?

selfin
26th Nov 2018, 00:50
HeinOnline has archived the CFRs from 1938 to present. See https://home.heinonline.org/titles/Code-of-Federal-Regulations--Federal-Register/

See also Richard McKinney's (Assistant Law Librarian, Federal Reserve Board) Research Guide to the Federal Register and the Code of Federal Regulations, https://www.llsdc.org/fr-cfr-research-guide -- "Originally published by the Law Librarians Society of Washington, D.C., Inc. as an article in the Fall, 2002 issue of Law Library Lights (https://www.llsdc.org/assets/sourcebook/fall02.pdf), Vol. 46, No. 1, p. 10-15."

selfin
26th Nov 2018, 01:06
The US DOT National Transportation Library also used to make various databases, including one for the historic CARs, available online. The present site (https://dotlibrary.specialcollection.net) requires a login but according to a Mar 2016 snapshot (https://web.archive.org/web/20160306004934/http://dotlibrary.specialcollection.net/Home) in Wayback Machine there were over two thousand records in the Civil Aeronautics Regulations (sic) database.

AC103
26th Nov 2018, 02:22
Wow, an hour from Q to A. Go pprune! https://dotlibrary.specialcollection.net/Contents with a free login looks to be the best free option. https://home.heinonline.org/titles/Code-of-Federal-Regulations--Federal-Register/ looks to be the best paid option back to 1938 and https://www.gpo.gov/fdsys/ now https://www.govinfo.gov for post 1997 free. Still haven't been able to find were 33 √(W/S) changed from 38 √(W/S) though... digging..

selfin
26th Nov 2018, 11:59
The FAA Regulatory Guidance Library (RGL (https://rgl.faa.gov/)) archives historic CARs and FARs, including the edition of CAR 3 reissued on 15 May 1956 and subsequent amendments 3-1 through to 3-8. A handy map (pdf (https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgccab.nsf/0/82ba3fcc6fbe750886256fab00762434/$FILE/1926%20Act.pdf)) of CAR 3 from its inception in late 1945 up until recodification in 1965 as 14 CFRs 21 and 23 is listed as "1926 Act.pdf" (ie Air Commerce Act of 1926) under CAR 0.

AC103
27th Nov 2018, 07:23
The RGL is awesome! Funny seeing how Vd has changed from today's 23.335 "The speed increase resulting when, from the initial condition of stabilized flight at VC/MC, the airplane is assumed to be upset, flown for 20 seconds along a flight path 7.5° below the initial path, and then pulled up with a load factor of 1.5" to 1931's AB "For airplanes which are to be dived to high speeds the manufacturer is responsible for the choice of a suitable design speed. The use of the actual terminal velocity is recommended for such cases" :D

And yes spot on selfin, the 38 to 33 factor change was for the move from MPH to Knots. Some very smart folks here!

:ok: