Conference : Aircraft : Share your feedback and opinions on Vertipedia's aircraft! http://vertipedia.vtol.org/forum/ Post discussions with the Vertipedia team it has been agreed to restructure this entry to reflect only the XV-15 TRRA and remove the XV-3 as the parent Type. The rationale is that that the XV-15 TRRA was not a part of the XV-3 Type, which only represented part of the lineage of the development of tilt rotors. This The entry is now in accord with the the definition of Parent Types in the Glossary. [i]* Last updated by: comodo15 on 12/21/2016 @ 3:53 AM *[/i] http://vertipedia.vtol.org/forum/messages.cfm?threadid=52C6BAAB-F3FC-BD38-6685C591AFF67A3A&r=1 2016-12-21T03:53:42-05:00 XV-15 There are a number of different forms of anti-torque device. These include, - Fenestrons, or ducted/shrouded tail rotors - these usually include many more blades than tail rotors. They produce anti-torque control through a combination of directed loads from the blades and induced loads over the duct - Reaction jet devices (simple force generation through directed air flow providing a reacting force on the structure - NOTAR type devices (which use the Coanda effect to provide torque control through flow induced loads over the tail boom) http://vertipedia.vtol.org/forum/messages.cfm?threadid=DD10CD18-0A85-1AE2-037D2EF0417B634F&r=2 2016-09-01T20:06:13-05:00 Tip-jet propulsion systems and anti-torque devices Thanks comodo15, that makes sense. Are there anti-torque devices other than tail rotors? http://vertipedia.vtol.org/forum/messages.cfm?threadid=DD10CD18-0A85-1AE2-037D2EF0417B634F&r=3 2016-08-31T22:47:32-05:00 Tip-jet propulsion systems and anti-torque devices A great question! To make the rotor rotate something has to overcome the drag forces on each blade, which require a compensating torque to applied to the rotor. If this torque is applied within the rotor itself the net torque at the axis of rotation of the rotor is zero, so there is no need for any other compensating torque. This is the situation with rotors like the Hiller Hornet, where the applied torque comes from tip jets at the end of each rotor blade. For most rotorcraft the forces on the blades cause a net moment to be applied through the rotor shaft and through the fuselage. Hence the aircraft would rotate in the direction of the applied torque at the blades without some compensating effect. This is normally applied by a tail rotor (or similar device), which stops the fuselage rotating. http://vertipedia.vtol.org/forum/messages.cfm?threadid=DD10CD18-0A85-1AE2-037D2EF0417B634F&r=4 2016-08-25T21:34:30-05:00 Tip-jet propulsion systems and anti-torque devices I see you have some aircraft with main rotors driven by tip jets, such as the [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=294]Hiller Hornet[/url], the [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=381]Fairey Ultra-Light[/url], and the [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=384]Sud-Ouest Djinn[/url]. These aircraft either have no tail rotors, or very small ones. I thought helicopters needed tail rotors to keep them from spinning around. Why don't these aircraft need them? Is there something inherent with tip jets that causes this? Thanks very much! http://vertipedia.vtol.org/forum/messages.cfm?threadid=DD10CD18-0A85-1AE2-037D2EF0417B634F&r=5 2016-08-16T21:28:14-05:00 Tip-jet propulsion systems and anti-torque devices I was unable to find any examples of an in-service aircraft called H-92 either, but I did find a number of references showing that the H-92 has (or is to have) a more powerful engine than the S-92. Likewise with the CH-148. I have changed the aircraft designation to CH-148 Cyclone and made a note that it is the RCAF version of the H-92, which itself is a militarized S-92. Thanks for the feedback! http://vertipedia.vtol.org/forum/messages.cfm?threadid=2D95E3DE-9149-7D56-0B19FCD9482C2F23&r=6 2016-07-09T17:17:01-05:00 H-92 Superhawk We now have an entry for the [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=369]H-92 Superhawk[/url] in the database but I am not sure if this is correct. Sikorsky have flown an 'H-92', the military version of the S-92 but I believe this was actually an S-92 with internal modifications to reflect a military fit.I believe that the only true military variant of the S-92 to have flown is the CH-148 Cyclone for the RCAF. Assuming I am correct, H-92 could be used as a variant to cover all military versions of the S-92 (S-92 would then be used for commercial aircraft)with a Type of S-92/H-92. The current aircraft entry for the H-92 would then become CH-148 Cyclone. There are actually 2 engines associated with the CH-148, CT7-8A1 for the initial 6 aircraft (as an interim) and CT7-8A7 as the final engine standard. From my understanding the CT-8C has never been produced (it does not show in the FAA TCDS for the CT7-8 series of engines). http://vertipedia.vtol.org/forum/messages.cfm?threadid=2D95E3DE-9149-7D56-0B19FCD9482C2F23&r=7 2016-07-09T16:34:03-05:00 H-92 Superhawk I see that both Ship 1 and Ship 2 have been added as separate aircraft and that they have been given the parent Type of XV-3. This does not seem correct for 2 reasons. 1. Both aircraft should only be added as separate aircraft if there are differences between them that can be recognized in any of the data fields in Vertipedia, excepting the Aircraft Notes 2. If both Ships are added then why would the parent type not be XV-15? The XV-3, currently allocated to the parent type, was a completely different aircraft Also, TRRA, was the formal name of the XV-15 and that has now been lost in the overall designation. The Aircraft of the Month has also been altered to show N702NA as Ship 2 but Ship 2 was N703NA - See [url=http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A20030180000]Smithsonian entr[/url]y for the type [i]* Last updated by: comodo15 on 12/21/2016 @ 3:54 AM *[/i] http://vertipedia.vtol.org/forum/messages.cfm?threadid=52C6BAAB-F3FC-BD38-6685C591AFF67A3A&r=8 2016-05-06T18:55:56-05:00 XV-15 Mike Verier in "Bell AH-1 Cobra" (Osprey, 1990, pp 30-31) notes that due to various short timeframes, proposal and marketing needs, and so on, Bell referred to what would become the 209 as a "modified UH-1H" in order to calm US Army doubts about how quickly they could produce it. In the language of the proposals, it was called the UH-1 Cobra. General Howze is the one who gave it the nickname of HueyCobra. The Army wished to stay with the UH-1 procurement system, though, and the order for the first two production aircraft designated UH-1H. But just a few days later, it was changed to AH-1G (with G being the next available "open" letter in the UH-1 family). The Army at that time was having legal issues with Piper Aircraft, who also named aircraft after Indian tribes, so the Army went with "Cobra" rather than the tradition of helicopters also being named after Indian tribes. And it's been that way ever since! So 209 by itself, or used in conjunction with AH-1, seems perfectly accurate. http://vertipedia.vtol.org/forum/messages.cfm?threadid=AF46F7A5-E30C-4198-4137D9468AF27DCD&r=9 2016-04-12T15:05:48-05:00 Bell Model 209 I agree. While the 209 may have been referred to at some point with the UH designation, I don't think it was ever official. As an interesting side note (also from Wikipedia): "By June 1967, the first AH-1G HueyCobras had been delivered. Originally designated as UH-1H, the "A" for attack designation was soon adopted and when the improved UH-1D became the UH-1H, the HueyCobra became the AH-1G. The AH-1 was initially considered a variant of the H-1 line, resulting in the G series letter." Which explains why the first production version started with "G" instead of "A" -- but don't ask why the LAST production version was the F! Maybe it's like when Dad saw Junior's report card: "What does F stand for? Finished?" http://vertipedia.vtol.org/forum/messages.cfm?threadid=AF46F7A5-E30C-4198-4137D9468AF27DCD&r=10 2016-04-12T01:04:26-05:00 Bell Model 209 This is more a statement of the design origin or heritage rather than a direct justification for the use of the UH-1 designation. I think we should stick to the AH-1 designation as this is what the aircraft is called on the [url=http://www.bellhelicopter.com/company/history/1960-1969]Bell history site (1965)[/url] http://vertipedia.vtol.org/forum/messages.cfm?threadid=AF46F7A5-E30C-4198-4137D9468AF27DCD&r=11 2016-03-29T20:32:11-05:00 Bell Model 209 "[url=https://en.wikipedia.org/wiki/Bell_AH-1_Cobra]Mating the proven transmission, the "540" rotor system of the UH-1C augmented by a Stability Control Augmentation System (SCAS), and the T53 turboshaft engine of the UH-1 with the design philosophy of the Sioux Scout, Bell produced the Model 209[/url]". Could this be the reason for the use of UH-1? http://vertipedia.vtol.org/forum/messages.cfm?threadid=AF46F7A5-E30C-4198-4137D9468AF27DCD&r=12 2016-03-23T21:15:33-05:00 Bell Model 209 What is the basis for the changes to the Aircraft Overview Notes that make reference to the model designation UH-1 rather than AH-1? http://vertipedia.vtol.org/forum/messages.cfm?threadid=AF46F7A5-E30C-4198-4137D9468AF27DCD&r=13 2016-03-14T21:40:14-05:00 Bell Model 209 Agreed. It was put in by mistake as it came from a photo stream marked CH-53K roll-out. The image has now been removed. http://vertipedia.vtol.org/forum/messages.cfm?threadid=A8B749B3-ABE7-9855-6702469AC421B9DC&r=14 2016-02-27T11:01:44-05:00 CH-53K images Nice entry on the [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=15]CH-53K[/url]. However the top image is a CH-53E, not a K. Besides being assigned to an operational squadron (USMC HMH-461), the top image has a significantly different main rotor and hub than the bottom image. FYI! http://vertipedia.vtol.org/forum/messages.cfm?threadid=A8B749B3-ABE7-9855-6702469AC421B9DC&r=15 2016-02-08T22:28:54-05:00 CH-53K images Updated this [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=15]aircraft[/url] to reflect the first flight. Congratulations to the Sikorsky team on a significant milestone! [i]* Last updated by: comodo15 on 10/27/2015 @ 7:44 PM *[/i] http://vertipedia.vtol.org/forum/messages.cfm?threadid=B3CC4830-E447-0F80-3DAEF2EC7DAD27ED&r=16 2015-10-27T19:14:36-05:00 CH-53K first flight Mil-1 has been added. Need to determine whether a separate entry is required to cover early protoypes. http://vertipedia.vtol.org/forum/messages.cfm?threadid=14FAA88A-B018-D9F9-E08D040B3B6F827B&r=17 2015-10-14T18:36:35-05:00 Mil-1 Some data now added for this aircraft, which is interesting as it was the first VTOL aircraft to fly. Would like some better images if possible. http://vertipedia.vtol.org/forum/messages.cfm?threadid=AD66B4CF-027B-9B42-C272A460A67F2494&r=18 2015-09-27T20:29:10-05:00 Breguet-Richet Gyroplane No. 1 The [url=http://vertipedia.vtol.org/aircraft.cfm?aircraftID=297]Hughes XH-17[/url] has now been added to Vertipedia. It is not complete (layout, tail rotor and performance data are still needed) but it is a start! It was good to find that Vertipedia highlighted the primary reference for information on this aircraft (See tab ‘Related Resources’) simply by creating this aircraft. [i]* Last updated by: comodo15 on 9/8/2015 @ 8:05 PM *[/i] http://vertipedia.vtol.org/forum/messages.cfm?threadid=CCD610DE-A80F-389E-5298B50F7E408518&r=19 2015-09-08T19:57:12-05:00 Hughes Helicopters Hot and Mixed Cycle Cranes The [url=https://en.wikipedia.org/wiki/Hughes_XH-17]XH-17[/url] and [url=https://en.wikipedia.org/wiki/Hughes_XV-9]XV-9/9A[/url]? [i]* Last updated by: comodo15 on 9/8/2015 @ 2:16 PM *[/i] http://vertipedia.vtol.org/forum/messages.cfm?threadid=CCD610DE-A80F-389E-5298B50F7E408518&r=20 2015-09-08T14:04:26-05:00 Hughes Helicopters Hot and Mixed Cycle Cranes