# The Great Ongoing Aviation Thread (general and other) (Part 1) **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 23, 2011, 2:17am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499 "2011-10-23T02:17:01Z")\ **Posts on this page:** 20\ **Page:** 100
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [April 27, 2021, 6:02pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1982 "2021-04-27T18:02:48Z")
Maybe this? [Hiller VZ-1 Pawnee - Wikipedia](https://en.wikipedia.org/wiki/Hiller_VZ-1_Pawnee) ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [April 27, 2021, 6:10pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1983 "2021-04-27T18:10:12Z")
No. Imagine an early helicopter with a vertical 6 cyl. Rotor blade above the engine. Propeller below. the prop and engine are shrouded in a bell shaped funnel that is wide at the top and the rotor is above it. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [April 28, 2021, 1:58am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1984 "2021-04-28T01:58:14Z")
I’m constantly amazed at the aircraft I never knew existed. I’m sure there are much better pictures of this but I got a kick out of the source for this one. [Sikorsky CH-37 Mojave in Popular Mechanics.](https://books.google.com/books?id=1t4DAAAAMBAJ&q=1954+Popular+Mechanics+January&pg=PA93#v=snippet&q=1954%20Popular%20Mechanics%20January&f=false) You will have to scroll down to page 93. Can’t link to the exact spot. I love looking at old Popular Mechanics magazines so that’s why I used that link. This helicopter is the grand daddy of the modern twin turbine helicopter. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [April 28, 2021, 2:16am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1985 "2021-04-28T02:16:19Z")
and while you’re there go to page 117 and see the de Havilland Sea Vixen under development. Keep scrolling down and look at vertical lift planes and then you come to an article on wind turbines. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [April 28, 2021, 12:50pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1986 "2021-04-28T12:50:32Z")
Next time you renew your driver license: > **[Americans get another reprieve on a new ID requirement to fly | CNN](https://www.cnn.com/travel/article/real-id-deadline-extended-pandemic/index.html)** > > The US Department of Homeland Security (DHS) again delayed the deadline for enforcement of REAL ID requirements, the latest pandemic-related extension for the program aimed at establishing a consistent security standard for issuing driver's licenses... ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [April 28, 2021, 1:10pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1987 "2021-04-28T13:10:12Z")
Here in Bozeman MT I saw a coaxial (counter-rotating dual rotor) helicopter fly overhead the other day. Any idea what it could be? Wiki says there are very few models, most of them Russian, although there are a couple of Sikorskys. It looked pretty new and modern. ---
**Author:** ![cytop](https://avatars.discourse-cdn.com/v4/letter/c/f17d59/32.png) [@cytop](https://boards.straightdope.com/u/cytop)\ **Post date:** [April 28, 2021, 1:25pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1988 "2021-04-28T13:25:44Z")
I think a KAMAN K-Max (US, with intermeshing contra-rotating rotors) might be more common than the various KAMOV (Russian, contra-rotating coaxial rotors) in that neck of the woods… Just a guess. > **[Kaman K-MAX](https://en.wikipedia.org/wiki/Kaman_K-MAX)** > > Pages for logged out editors learn more > > > The Kaman K-MAX (company designation K-1200) is an helicopter with intermeshing rotors (synchropter) designed and produced by the American manufacturer Kaman Aircraft. > Developed during the 1980s and 1990s, the K-MAX builds on the work of the German aeronautical engineer Anton Flettner. Performing its maiden flight on December 23, 1991, it was specially designed to optimally perform external cargo load operations and is capable to lifting payloa... ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [April 28, 2021, 1:33pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1989 "2021-04-28T13:33:53Z")
An interesting helicopter. it looks like it uses ailerons to change the angle of the rotor blades. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [April 28, 2021, 1:40pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1990 "2021-04-28T13:40:32Z")
That looks like it! Thanks! ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [April 28, 2021, 1:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1991 "2021-04-28T13:45:00Z")
[Found it!](https://fireaviation.com/2015/09/09/k-max-on-the-kootenai/) ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [April 28, 2021, 2:14pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1992 "2021-04-28T14:14:05Z")
Fascinating idea for a helicopter. ---
**Author:** ![cytop](https://avatars.discourse-cdn.com/v4/letter/c/f17d59/32.png) [@cytop](https://boards.straightdope.com/u/cytop)\ **Post date:** [April 28, 2021, 2:43pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1993 "2021-04-28T14:43:22Z")
The original designer of the concept, [Anton Flettner](https://en.wikipedia.org/wiki/Anton_Flettner), was brought to the US as part of Operation Paperclip - same as another, probably more well known, German engineer/scientist - Wernher von Braun. @Tride - I just love that paint job 🙂 ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [April 28, 2021, 5:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1994 "2021-04-28T17:18:52Z")
Actually, I take it back. That ship crashed a year ago, killing the pilot. They must have a 2nd one. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 28, 2021, 5:37pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1995 "2021-04-28T17:37:52Z")
> [@Tride](#): > > Here in Bozeman MT I saw a coaxial (counter-rotating dual rotor) helicopter … Good job spotting it and figuring out which kind it was! Here’s a note on terminology. A “co-axial” helicopter has the two rotors stacked on a common axis, although with separate concentric drive shafts. Like this: > **[Sikorsky S-97 Raider](https://en.wikipedia.org/wiki/Sikorsky_S-97_Raider)** > > The Sikorsky S-97 Raider is a high-speed scout and attack compound helicopter based on the Advancing Blade Concept (ABC) with a coaxial rotor system under development by Sikorsky Aircraft. Sikorsky planned to offer it for the United States Army's Armed Aerial Scout program, along with other possible uses. The S-97 made its maiden flight on 22 May 2015. > Sikorsky's earliest attempt at a fast compound helicopter with stiff coaxial rotors was the Sikorsky S-69 (XH-59A) flown in the 1970s. Its top s... The Kamov or US license-built K-Max that you saw has “enmeshed rotors” where the shaft axes are not parallel and the two rotors pass through each other’s rotor disk. This **[wikipic](https://en.wikipedia.org/wiki/Kaman_K-MAX#/media/File:Kaman_K-MAX_-_Marine_Corps_Air_Station_Yuma_(cropped).jpg)** pretty well shows the K-Max arrangement. Here’s an much earlier US helo with a similar design, also designed & built by Kaman: > **[Kaman HH-43 Huskie](https://en.wikipedia.org/wiki/Kaman_HH-43_Huskie)** > > The Kaman HH-43 Huskie is a helicopter developed and produced by the American rotorcraft manufacturer Kaman Aircraft. It is perhaps most distinctive for its use of twin intermeshing rotors, having been largely designed by the German aeronautical engineer Anton Flettner. > First flown on 21 April 1953, the HH-43 went into production and was operated by several military air services, including the United States Air Force, the United States Navy and the United States Marine Corps. It was primarily in... Scroll down in the article for better pix of the rotor system; the headline picture hides more than it reveals. Continuing the taxonomy … Two-rotor helos where the two rotor disks don’t interact can be set up as a “tandem rotor” configuration, like (among several others) the famous and still in production: > **[Boeing CH-47 Chinook](https://en.wikipedia.org/wiki/Boeing_CH-47_Chinook)** > > The Boeing CH-47 Chinook is a tandem-rotor helicopter originally developed by American rotorcraft company Vertol and now manufactured by Boeing Defense, Space & Security. The Chinook is a heavy-lift helicopter that is among the heaviest lifting Western helicopters. Its name, Chinook, is from the Native American Chinook people of Oregon and Washington state. > The Chinook was originally designed by Vertol, which had begun work in 1957 on a new tandem-rotor helicopter, designated as the Vertol Mod... or the rarely seen “transverse rotor” configuration like this Soviet beast: > **[Mil V-12](https://en.wikipedia.org/wiki/Mil_V-12)** > > The Mil V-12 (NATO reporting name: Homer), given the project number Izdeliye 65 ("Item 65"), is a prototype helicopter designed in the Soviet Union and the largest helicopter ever built. The designation "Mi-12" would have been the designation for the production helicopter and did not apply to V-12 prototypes. > Design studies for a giant helicopter were started at the Mil OKB in 1959, receiving official sanction in 1961 by the GKAT (Gosudarstvenny Komitet po Aviatsionnoy Tekhnike - State Committee... For any of these wiki articles, scrolling down to the Specifications section gives a nice 3-view drawing that highlights how the various rotor systems fit onto the fuselage and interact or don’t with each other. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [April 28, 2021, 5:56pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1996 "2021-04-28T17:56:27Z")
It uses the same aileron style rotors that the HH-43B Huskie used. I’ve seen that in the AF Museum and didn’t realize kaman built it. They even use the same wood spar design as the Huskie which they say is more durable. I’m guessing they steer with exhaust thrust and rotor wash over the rudder. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 28, 2021, 6:01pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1997 "2021-04-28T18:01:17Z")
> [@Magiver](#): > > An interesting helicopter. it looks like it uses ailerons to change the angle of the rotor blades. Not quite ailerons, but yes, the tabs on the trailing edge of each rotor “fly” them up and down to achieve both collective and cyclic control. Pretty wild to think about how the pilot’s control inputs of collective & cyclic stick position get translated into moving each of those four flaps differentially between each other and as they whirl around the circle ~5x/second. Correctly accounting for the delay & angular rotation between when the tab deflects and the blade itself responds by moving. Pure mechanical engineering magic. A Russian specialty even nowadays. Servo tabs like this were / are common means of control boosting on late WWII and early jet age aircraft. And some not so early. The elevators and ailerons on the 707 and the DC-9 / MD-80 / MD-90 / B-717 are controlled that way. The backup control system for the 727 & 737 ailerons & elevators are similar although they’re normally hydraulically powered. In the case of the DC9 / MD80 / etc. elevator it’s even crazier: The pilot’s yoke is connected to small tab which in turn is connected to a larger tab which is in turn connected to the elevator. So for say aircraft nose up motion the pilot moves the yoke aft which moves the baby tab up via mechanical cables which pushes the medium tab down via airloads which pushes the elevator up via airloads which pushes the whole tail down via airloads which pushes the nose up because the fuselage is rigid. It’s a 2-stage mechanical power amplifier using the passing airflow as a power source. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 28, 2021, 6:06pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1998 "2021-04-28T18:06:52Z")
> [@Magiver](#): > > I’m guessing they steer with exhaust thrust and rotor wash over the rudder. Assuming you’re talking about yaw-axis control … I don’t know for sure about the Kamov / K-Max or the Huskie but any dual-rotor helo can generate yaw forces by what amounts to differential thrust on the two main rotors. In response to yaw pedal input by the pilot the various blades tilt to produce no net pitch force, no net roll force, but some unbalanced yaw or torque force on the fuselage. Heading change AKA yaw is the resulting output. So that’s another layer of mechanical magic in the control mixers that make the 4 (or sometimes 6) rotor blades do all the work of all the control surfaces of a conventional airplane plus all the lifting of the wings plus all the stabilization effects of the fixed stab & vertical fin. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [April 28, 2021, 6:17pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/1999 "2021-04-28T18:17:30Z")
> [@LSLGuy](#): > > The Kamov or US license-built K-Max > [@LSLGuy](#): > > I don’t know for sure about the Kamov / K-Max Are you indicating that the K-Max is licensed from Kamov? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 28, 2021, 6:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/2000 "2021-04-28T18:45:09Z")
That’s totally what I wrote. But upon further research, it’s totally wrong. Thanks for calling that out. I’m not sure exactly what wiring in my memory got crossed there. Kamov’s are usually co-axial rotor, not enmeshed rotors. See > **[List of Kamov aircraft](https://en.wikipedia.org/wiki/List_of_Kamov_aircraft)** > > Pages for logged out editors learn more > > > This is a list of aircraft produced by Kamov, a Russian aircraft manufacturer. But the Russians (/ Soviets?) did make a couple enmeshed models and I’m somehow recalling something about some design collaboration or licensing between them and the West. Clearly I’m full of stuff on that one. Thanks. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [April 28, 2021, 6:54pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/2001 "2021-04-28T18:54:42Z")
> [@LSLGuy](#): > > That’s totally what I wrote. But upon further research, it’s totally wrong. I thought it sounded wrong. I checked, and couldn’t find anything so I thought I’d ask. I’d thought the Soviets had a helicopter with intermeshing rotors, that looked like the Kaman Huskie. I thought it was the Kamov Ka-31, but it does indeed have coaxial rotors. [Previous page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=99) [Next page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=101)