---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Sat 08/30/08: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:13 AM - Re: Yak-52 heavy spar (Richard Goode) 2. 07:28 AM - Re: Yak-52 heavy spar (tjyak50) 3. 10:14 AM - Re: Re: Yak-52 heavy spar (Richard Goode) 4. 05:58 PM - Re: Re: Yak-52 heavy spar (vectorwarbirds@aol.com) 5. 06:35 PM - Re: Yak-52 heavy spar (Royden Heays) 6. 09:38 PM - Re: Yak-52 heavy spar (Herb Coussons) ________________________________ Message 1 _____________________________________ Time: 01:13:26 AM PST US From: "Richard Goode" Subject: Re: Yak-List: Yak-52 heavy spar The "simplistic notion" is that there is something called a "heavy spar" that makes a 52 safe to fly hard.I'm simply making it clear that there is a range of mandatory SB's that you must have to fly a 52 to its design limits. Yes ,I have discussed the whole issue of 52[and50/55] structural integrity for many hours over a number of meetings with Dimitry Dratch [Yak chief designer for light aircraft] and his designers in Moscow. They had no vested interest to imagine or create problems that did not exist,and each structural SB was brought about by a specific problem across a huge fleet [1200] of aircraft. 107SB is a complex issue but the point that it was issued to make money is absurd!It came out in 1990 when Yak was well funded,and importantly they would get NO money from it since they did not make the 107 kits! You are correct,and there have been no total failures in 52s,BUT there have been a wide variety of serious problems begining-and I have seen the reports and photos.The reason that the 52 remained safe was the introduction of the SBs.Also because few pilots fly them at their design limits-AND because most 52s have been modified. If you have any doubts about the seriosness of the approach of Yak,you should consider the history of the 50,with 4 fatal crashes due to structural problems,and many more prevented by very diligent inspections and,of course a raft of SBs. Richard Richard Goode Aerobatics Rhodds Farm Lyonshall Hereford HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com ----- Original Message ----- From: Roger Baker To: yak-list@matronics.com Sent: Saturday, August 30, 2008 1:04 AM Subject: Re: Yak-List: Yak-52 heavy spar Richard, Nice of you to chime in on this matter, but you did not answer the mans question. I don't think I quite follow you when you say "It is a great pity that this simplistic notion still continues". To what "simplistic notion" were your referring? I would be interested in knowing what the "number of structural problems" that emerged actually were. Does anyone (such as yourself) have a verified list of the actual structual problems that are supposed to have been occuring on Yak 52's? If so, is there any independant verification that these problems were truly occuring in the real world. I do know the trail that led to Bulletin #107 and from that, I believe that bulletin 107 is nonsense....written in an attempt to raise some money at the bureau in those dark days of the early to mid 90's when they had no funding from anybody. If you know different, I would appreciate hearing about it. So far as I know, NO Yak 52, with or without the wing attach and spar carry through modifications mandated by 59 and 60, has crashed due to structural failure. Roger Baker On Aug 29, 2008, at 9:41 AM, Richard Goode wrote: I see there is another enquiry about how to identify the heavy spar on the Yak-52. It is a great pity that this simplistic notion still continues. To confirm: Yak-52 is a very tough aeroplane but when it began being flown hard, a number of structural problems emerged. As they emerged, Yakovlev instituted a series of mandatory Service Bulletins to allow the aeroplane to continue to fly at the same G limits. Unfortunately, many aeroplanes have not been modified; some logbooks have been falsified etc. There are actually 114 Service Bulletins, of which many are trivial. Our view is that there are 31 serious structural Bulletins, which really should be installed on any 52s doing aerobatics at more than (say) 4G. The list of these important Bulletins is as follows: 9 48 71 18 53 72 28 54 75 34 59 80 36 60 82 37 62 92 38 66 93 41 67 99 45 69 100 47 70 106 107 The critical wing Bulletins are: 59 for stronger wing mountings 60 for stronger centre section 107 ' external (underneath) spar-strap 59 and 60 came out together in 1987 and 107 in 1991 So the practicality is that an aeroplane built after the middle of 1991 SHOULD have all SBs incorporated. Also, any aeroplanes incorporating 107 are almost certainly incorporating all earlier Bulletins. 107 can be identified by being a metal plate, about 4=92 long, bolted under the wing to the main spar, but proud of the under-wing surface. Richard Goode Aerobatics Rhodds Farm Lyonshall Hereford HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics .com/Navigator?Yak-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ontribution ------------------------------------------------------------------------- ---- This message has been scanned for viruses and dangerous content by http://www.invictawiz.com and is believed to be clean. ------------------------------------------------------------------------- ---- ________________________________ Message 2 _____________________________________ Time: 07:28:12 AM PST US Subject: Yak-List: Re: Yak-52 heavy spar From: "tjyak50" Richard: The tone of your email implies that we, U.S. Americans..., are unfamiliar with the modifications of the Yak 52. When a person uses the term "Heavy Spar" what they mean (generally) is Service Bulletin 59 and 60. Service Bulletin 59 and 60 clearly are more massive (slightly greater weight) and also increase overall strength and hence we assign the adjective "Heavy". It is a colloquialism of sorts. In my opinion, a Yak 52 with the "Heavy Spar" is indeed safe to fly "hard". Many others, possibly including yourself, agree with me (us). Perhaps your misunderstanding is due to the language barrier between this American Yak-list and your native language in the U.K. Have a nice weekend. Tom Johnson (signed). Read this topic online here: http://forums.matronics.com/viewtopic.php?p 1603#201603 ________________________________ Message 3 _____________________________________ Time: 10:14:30 AM PST US From: "Richard Goode" Subject: Re: Yak-List: Re: Yak-52 heavy spar Again,this is too simplistic!The SBs subsequent to 59 & 60 are there because there have been real problems with the structure when flown at the design limits.You can be sure that EVERY 52 that was flown in the East was flown at or very near these limits. Also,I have seen various Logs saying that the 52 concerned had the various SBs embodied whe they had not,and unless you really know what to look for,it is very hard to know if they have or not. If a 52 has not had ALL the SBs embodied my firm conviction is that it should not be flown hard.I do not consider a 52 with only 59 & 60 to be fully modified. It is possible that I am over-cautious but I did spend 4 months in one hospital bed after airframe failure [not a Yak],and I would not wish that on anyone.I have also spent a lot of time with the Yakovlev designers,and I am sure that every SB is there because it is needed IF the plane is flown as was intended!! Richard Richard Goode Aerobatics Rhodds Farm Lyonshall Hereford HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com ----- Original Message ----- From: tjyak50 To: yak-list@matronics.com Sent: Saturday, August 30, 2008 3:27 PM Subject: Yak-List: Re: Yak-52 heavy spar Richard: The tone of your email implies that we, U.S. Americans..., are unfamiliar with the modifications of the Yak 52. When a person uses the term "Heavy Spar" what they mean (generally) is Service Bulletin 59 and 60. Service Bulletin 59 and 60 clearly are more massive (slightly greater weight) and also increase overall strength and hence we assign the adjective "Heavy". It is a colloquialism of sorts. In my opinion, a Yak 52 with the "Heavy Spar" is indeed safe to fly "hard". Many others, possibly including yourself, agree with me (us). Perhaps your misunderstanding is due to the language barrier between this American Yak-list and your native language in the U.K. Have a nice weekend. Tom Johnson (signed). Read this topic online here: http://forums.matronics.com/viewtopic.php?p 1603#201603 ------------------------------------------------------------------------- ---- This message has been scanned for viruses and dangerous content by the http://www.invictawiz.com MailScanner, and is believed to be clean. ------------------------------------------------------------------------- ---- ________________________________ Message 4 _____________________________________ Time: 05:58:20 PM PST US Subject: Re: Yak-List: Re: Yak-52 heavy spar From: vectorwarbirds@aol.com Richard, I for one appreciate your knowledge and advice on this matter, I feel as you do that you cannot be too safe.? As we are looking for a 52 to add to our Nanchang stable your, as well as others, experience and real world problems have helped us greatly, and I just want you to know that there are many of us out here that listen carefully to what you and others have to say.? And I for one take those things to heart.? Fly Safe Comrade and thank you!! Gary Bunn Vector Warbirds USA -----Original Message----- From: Richard Goode Sent: Sat, 30 Aug 2008 10:12 am Subject: Re: Yak-List: Re: Yak-52 heavy spar Again,this is too simplistic!The SBs subsequent to 59?& 60 are there because there have been real problems with the structure when flown at the design limits.You can be sure that EVERY 52 that was flown in the East was flown at or very near these limits. Also,I have seen various Logs saying that the 52 concerned had the various SBs embodied whe they had not,and unless you really know what to look for,it is very hard to know if they have or not. If a 52 has not had ALL the SBs embodied my firm conviction is that it should not be flown hard.I do not consider a 52 with only 59 & 60 to be fully modified. It is possible that I am over-cautious but I did spend 4 months in one hospital bed after airframe failure [not a Yak],and I would not wish that on anyone.I have also spent a lot of time with the Yakovlev designers,and I am sure that every SB is there because it is needed IF the plane is flown as was intended!! Richard ? Richard Goode Aerobatics Rhodds Farm Lyonshall Hereford HR5 3LW United Kingdom ? Tel:?? +44 (0) 1544 340120 Fax:? +44 (0) 1544 340129 www.russianaeros.com ----- Original Message ----- From: tjyak50 Sent: Saturday, August 30, 2008 3:27 PM Subject: Yak-List: Re: Yak-52 heavy spar Richard: The tone of your email implies that we, U.S. Americans..., are unfamiliar with the modifications of the Yak 52.?? When a person uses the term "Heavy Spar" what they mean (generally) is Service Bulletin 59 and 60.? Service Bulletin 59 and 60 clearly are more massive (slightly greater weight) and also increase overall strength and hence we assign the adjective "Heavy".? It is a colloquialism of sorts. In my opinion, a Yak 52 with the "Heavy Spar" is indeed safe to fly "hard". Many others, possibly including yourself, agree with me (us). Perhaps your misunderstanding is due to the language barrier between this American Yak-list and your native language in the U.K. Have a nice weekend. Tom Johnson (signed). Read this topic online here: http://forums.matronics.com/viewtopic.php?p 1603#201603 http://www.matronicsnbsp;?????????????; via the Web href="http://forums.matronics.com">http://forums.matronics.com generous bsp;??????????????????? href="http://www.matronics.com/contribution">http://www.matronics.com/c================ ----------------------------------------------------------------------------- This message has been scanned for viruses and dangerous content by the http://www.invictawiz.com MailScanner, and is believed to be clean. ----------------------------------------------------------------------------- ________________________________ Message 5 _____________________________________ Time: 06:35:38 PM PST US From: "Royden Heays" Subject: RE: Yak-List: Yak-52 heavy spar Hello Richard, Do you have a similar list of SB's for the Yak 55M that you could post, and if yes, do you have each one of them available in English Royden Heays Vancouver BC Canada -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Richard Goode Sent: 29 Aug 2008 9:41 AM Subject: Yak-List: Yak-52 heavy spar I see there is another enquiry about how to identify the heavy spar on the Yak-52. It is a great pity that this simplistic notion still continues. To confirm: Yak-52 is a very tough aeroplane but when it began being flown hard, a number of structural problems emerged. As they emerged, Yakovlev instituted a series of mandatory Service Bulletins to allow the aeroplane to continue to fly at the same G limits. Unfortunately, many aeroplanes have not been modified; some logbooks have been falsified etc. There are actually 114 Service Bulletins, of which many are trivial. Our view is that there are 31 serious structural Bulletins, which really should be installed on any 52s doing aerobatics at more than (say) 4G. The list of these important Bulletins is as follows: 9 48 71 18 53 72 28 54 75 34 59 80 36 60 82 37 62 92 38 66 93 41 67 99 45 69 100 47 70 106 107 The critical wing Bulletins are: 59 for stronger wing mountings 60 for stronger centre section 107 - external (underneath) spar-strap 59 and 60 came out together in 1987 and 107 in 1991 So the practicality is that an aeroplane built after the middle of 1991 SHOULD have all SBs incorporated. Also, any aeroplanes incorporating 107 are almost certainly incorporating all earlier Bulletins. 107 can be identified by being a metal plate, about 4' long, bolted under the wing to the main spar, but proud of the under-wing surface. Richard Goode Aerobatics Rhodds Farm Lyonshall Hereford HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com ________________________________ Message 6 _____________________________________ Time: 09:38:16 PM PST US From: Herb Coussons Subject: Re: Yak-List: Yak-52 heavy spar Yes you mentioned the 50 and the 55 in a previous email - i would ask for the same info for the 55 and others on the list may want to see a list for the 50. Thanks, herb On Aug 30, 2008, at 8:34 PM, Royden Heays wrote: > Hello Richard, > > Do you have a similar list of SB=92s for the Yak 55M that you could > post, and if yes, do you have each one of them available in English > > Royden Heays > Vancouver BC > Canada > > -----Original Message----- > From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com > ] On Behalf Of Richard Goode > Sent: 29 Aug 2008 9:41 AM > To: yak-list@matronics.com > Subject: Yak-List: Yak-52 heavy spar > > > I see there is another enquiry about how to identify the heavy spar > on the Yak-52. > It is a great pity that this simplistic notion still continues. > > To confirm: > > Yak-52 is a very tough aeroplane but when it began being flown hard, > a number of structural problems emerged. As they emerged, Yakovlev > instituted a series of mandatory Service Bulletins to allow the > aeroplane to continue to fly at the same G limits. > > Unfortunately, many aeroplanes have not been modified; some logbooks > have been falsified etc. > There are actually 114 Service Bulletins, of which many are trivial. > Our view is that there are 31 serious structural Bulletins, which > really should be installed on any 52s doing aerobatics at more than > (say) 4G. > > The list of these important Bulletins is as follows: > > > 9 48 71 > 18 53 72 > 28 54 75 > 34 59 80 > 36 60 82 > 37 62 92 > 38 66 93 > 41 67 99 > 45 69 100 > 47 70 106 > 107 > > The critical wing Bulletins are: > > 59 for stronger wing mountings > 60 for stronger centre section > 107 ' external (underneath) spar-strap > > 59 and 60 came out together in 1987 and 107 in 1991 > So the practicality is that an aeroplane built after the middle of > 1991 SHOULD have all SBs incorporated. > > Also, any aeroplanes incorporating 107 are almost certainly > incorporating all earlier Bulletins. > > 107 can be identified by being a metal plate, about 4=92 long, bolted > under the wing to the main spar, but proud of the under-wing surface. > > > Richard Goode Aerobatics > Rhodds Farm > Lyonshall > Hereford > HR5 3LW > United Kingdom > > Tel: +44 (0) 1544 340120 > Fax: +44 (0) 1544 340129 > www.russianaeros.com > > > http://www.matronics.com/Navigator?Yak-List > http://forums.matronics.com > http://www.matronics.com/contribution > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/yak-list Browse Digests http://www.matronics.com/digest/yak-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.