Talk:Cessna 195/Archive 1
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| Archive 1 |
Untitled
I added two sections to this entry, based on fuzzy, decades-old memories of the great Cessna 195. If anybody has more accurate information, please feel free to amend or amplifyRaymondwinn 09:22, 8 June 2007 (UTC)
- It might need to be "wikified" a bit though. BabyNuke 19:21, 9 June 2007 (UTC)
Performance
I've owned, and still currently operate, a Cessna 195 for forty years. The owner's handbook, and the markings on the airspeed indicator, both clearly indicate the Never Exceed Speed as 200 MPH. So clearly, that is the "maximum speed" of the airplane. There is actually no airspeed designated technically a "maximum speed" for any airplane although there are maximum speeds for lowering the gear (in a retractable aircraft) or flaps, for example. The maximum speed an airplane can safely move through the air is the Vne, or Never Exceed Speed. Similarly, the designated maximum structural cruising speed for the Cessna 195 is indicated to be 178 MPH. For some reason, the article indicates these speeds as 185 MPH and 170 MPH, both clearly wrong numbers. I edited the data and inserted the correct numbers according to the Cessna 195 handbook and the airspeed indicator markings, but somebody deleted my edit and re-inserted the incorrect values. I don't want to get into an edit war. A third disinterested party should look up these data and put the correct numbers in the chart.74.178.174.50 (talk) 20:51, 13 July 2017 (UTC)
- The template a place for Vne and a place for maximum speed, which is Vh (maximum horizontal speed). They aren't the same thing. - Ahunt (talk) 14:04, 14 July 2017 (UTC)
There is no "maximum horizontal speed" designated by Cessna for the 195. The maximum structural cruising speed given is 178 MPH, NOT 170. The figure 185 MPH does not appear anywhere in the pilots operating handbook. The correct maximum speed is designated by Cessna is 200 MPH, attainable in a dive. I don't know where people are getting those other figures, but no reference is given. I have both the type certificate specs and the Cessna 195 Pilots Operating Handbook to back me up.98.162.136.248 (talk) 00:06, 16 July 2017 (UTC)
I should add that there is no "Vh" designated for the 195, rather a Vno. That's the maximum structural cruising speed which I mentioned before. Technically, that's the maximum speed at which a 30 f/min gust will not cause structural damage.98.162.136.248 (talk) 00:36, 16 July 2017 (UTC)
- The maximum speed is from the cited ref, which I have a copy of here, "Christy. Joe: The Complete Guide to Single Engine Cessna, 3rd Edition, pages 18-23. Tab Books, 1979. ISBN 0-8306-2268-3" - Ahunt (talk) 22:54, 16 July 2017 (UTC)
Ok! That's the problem. You are using a tertiary reference, a popular book with one or two page blurbs on a variety of aircraft. That is not a proper reference, it is not authoritative in any manner. The proper references to use for determining various V-speeds for an aircraft are the following: The Type Certificate Data Sheet, the FAA approved Flight Manual, and the Pilot's Operating Handbook. As I have mentioned, I own and operate a Cessna 195. I have all the mentioned references. The Type Certificate Data Sheet, generated from data by the manufacturer and approved by the FAA, is the fundamental document for certifying an aircraft. The Cessna 195 falls under Type Certificate A-790. Feel free to google it and read the performance numbers. The FAA approved Flight manual, which in the Cessna 195, a legacy aircraft, is one printed page, reiterates the figures from the TCDS, including the performance numbers. The Pilots Operating Handbook, developed and printed by Cessna, and included, along with the FAA approved Flight Manual, with every purchased aircraft, also posts OFFICIAL performance numbers which specify a Vne (maximum speed) of 200 MPH, and a maximum structural cruising speed of 178 MPH. My God, what more solid references does Wikipedia need? I can't believe a reputable reference source such as Wikipedia aspires to be would utilize some popular tertiary source like a "used airplane guide" instead of the OFFICIAL, MANUFACTURER GENERATED AND FAA APPROVED documents. I don't know where Joe Christy dreamed up his figures, but it's obvious he never looked at a Cessna 195 reference (maybe never even saw a real Cessna 195). We need to put official figures in this article.74.178.174.50 (talk) 18:22, 18 July 2017 (UTC)
- Yeah none of those refs list the maximum level speed and the cited ref does. It is a reliable source. The other official numbers from the TCDS etc are already in the specs. If you can show that the max level speed is wrong, by citing another source that lists it, then we can fix it. - Ahunt (talk) 01:25, 19 July 2017 (UTC)
Yikes! Are you not listening!? THERE IS NO "MAX LEVEL SPEED" determined for the 195. Cessna never called for one, one was never flown by test pilots, it appears NOWHERE in official documents, just in your silly used airplane guide. The closest thing is Maximum Structural Crusing Speed, determined and noted by the manufacturer and the FAA as 178 MPH. Can I be any clearer than that? THERE IS NO MAX LEVEL SPEED FOR THE 195 except in Joe Christy's head!98.162.136.248 (talk) 02:33, 19 July 2017 (UTC)
- It obviously came from some source, like a flight test, because it is in the book. - Ahunt (talk) 03:29, 19 July 2017 (UTC)
Yes, that is my point. The reference you have is not an official document. It's a book written by a private individual for popular consumption. It's what's called a tertiary source, because the data in it does not come from the author's own research, nor does he quote and reference original research or testing (that would make it a secondary source). The author simply states "data" without reference. You admit you don't know where his quoted numbers come from: "they must have come from somewhere." It's hardly better than numbers quoted by a friend at a bar over a couple of beers. If you are writing an encyclopedia article, and you want to record aircraft performance numbers, you should use primary sources. For an aircraft, that should be the Type Certficate Data Sheet. If it's not there, then the manufacturer did not test, and did not specify officially, that parameter, and it should not be included.98.162.136.248 (talk) 13:55, 19 July 2017 (UTC)
- It is still a reliable source, published by an independent publisher with editorial oversight. Janes doesn't give lists of where all their data comes from either, but we accept it, as they are a reliable source. The max level speed given is reasonable and in line with the other speeds, like cruise and Vne. The rest of the data in the book obviously comes from a variety of sources, including TCDS, aviation media flight reviews, etc. It obviously wasn't made up. Unless you have a ref that refutes it I think we can end this discussion. - Ahunt (talk) 00:12, 21 July 2017 (UTC)
With all due respect, I don't think we can end this discussion, much as it distresses you.There is a principle of encyclopedia referencing at stake here. Your source is reputable, but it is not authoritative, and presents unsourced data. The performance numbers quoted appear nowhere in the manufacturer's or FAA source documents. The only numbers which should appear in an encyclopedia reference article about an aircraft are those provided by the manufacturer or in official FAA documents. It is not proper to quote numbers that "obviously come from a variety of sources." And you are incorrect in stating that one of those sources may be the TCDS. Look up the TCDS for the 195; it's available as a PDF in the FAA website. Your numbers do not appear anywhere in the TCDS. Flight reviews by popular publications are useless in this context, since many examples of the identical aircraft type will fly at different speeds, depending on rigging, condition of the engine, piloting technique, and so many other factors it is difficult to list them all. All a popular trade magazine can tell you from a flight review is"this particular aircraft on this day with this pilot went at this speed." For the official performance you need to quote official numbers.98.162.136.248 (talk) 14:24, 21 July 2017 (UTC)
- Your statement "The only numbers which should appear in an encyclopedia reference article about an aircraft are those provided by the manufacturer or in official FAA document" is just not correct. As per WP:RS any reliable source may be used to reference articles and furthermore we have no requirement to just quote "official performance" or "official numbers". This is an encyclopedia article, not a legal certification document. You haven't shown any source that refutes or contradicts the cited ref, so there is no reason not to use this source. - Ahunt (talk) 17:05, 21 July 2017 (UTC)
In the first place, I have shown official sources that refute the cited reference: both the TCDS and the Cessna Flight Manual show different performance numbers! In the second place, Wikipedia correctly allows "any reliable source" as a reference, but you have to use your judgement when different sources give discrepant data. Which is "more reliable?" It should be obvious that official documents from the FAA and the manufacturer trump a popular unreferenced buyers guide.98.162.136.248 (talk) 03:42, 22 July 2017 (UTC)
- Specs are always going to vary based on when the data was gathered and for what purposes, (ie the very brief CAR3 flight test dne back then for cert vs later pilot media reviews, etc). You haven't shown any other source that contradicts this one number we are discussing. Until you do there really isn't any case to remove this one number. - Ahunt (talk) 15:59, 22 July 2017 (UTC)
You keep saying I haven't "shown any source that contradicts your numbers." In the name of God! What more sources do you need than the manufacturer's flight manual and the official type certificate data sheet!? A comic book, perhaps? This is bizarre!!!98.162.136.248 (talk) 02:17, 23 July 2017 (UTC)
- And which ref there exactly gives the max horizontal speed? - Ahunt (talk) 11:22, 23 July 2017 (UTC)
Once again, Cessna did not specify a Vh for the 195. Most small general aviation aircraft do not have Vh determined by the manufacturer, probably because even at max continuous power, these aircraft can't approach Vne. The closest thing is the maximum structural cruising speed, which in the 195 is 178 MPH. If manufacturer's flight test data did not specify a certain V speed, then independent flight reviews, like trade publications, consumer reports, and the like can only tell you how the particular aircraft they tested, under the particular maintenance state of the aircraft, with that particular pilot, with that particular loading, under those particular meteorological conditions, and in that particular flight profile, performed. (Sorry! Tried to get too much info in that last sentence!). But you get my drift. If Cessna did not specify Vh, and you do want to include that value in the article, then you should say something like "Cessna did not specify a Vh speed for the 195, but pilot Tyrone Binkleburger, flying a flight review for The Clown Pilots Association Magazine in February 1955, was able to sustain 170 MPH at full throttle in level flight. " (The Jacobs R755-A2 and-B2 engines can be run at full throttle continuously) 98.162.136.248 (talk) 16:56, 23 July 2017 (UTC)
- That is why we specify the cited refs for the specs, so people now where the numbers come from. We don't just regurgitate official sources, but use all reliable refs. So as you can see the article already does exactly that. There is no need to say who flew the specific flight test, as even the TCDS doesn't specify that. - Ahunt
(talk) 12:25, 24 July 2017 (UTC)
As someone who has written both scientific research papers and technical papers, I can tell you that there is a difference between primary references and secondary or tertiary references. The manufacturer's data and the TCDS do not need to specify which pilot did the flight testing because those references are primary, the data was generated following strict testing protocols and designated official data by both the manufacturer and the FAA. The references you quote are secondary or tertiary references, which give you numbers without specifying how they came upon those numbers. If you use a buyer's guide or one of those "Golden Book of Cessna Airplanes" books, you have no idea where or how they got their numbers. Those references are appropriate if you want to quote their impressions of the airplane, but they are not appropriate to quote for performance numbers. As an airframe and powerplant mechanic with inspection authorization, and a commercial pilot-owner of a Cessna 195 for over 40 years, I can tell you those numbers are wrong, period.74.178.174.50 (talk) 13:20, 24 July 2017 (UTC)
I see the performance numbers were rearranged somewhat. Not the way I would have expressed it, but I think the compromise is good enough. Thank you for your civil and courteous discussion on this issue. And if you haven't done so already, find a pilot friend and take a ride in a 195!98.162.136.248 (talk) 23:03, 25 July 2017 (UTC)