---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Tue 07/28/09: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:43 AM - Re: Maximum structural cruise (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 2. 03:53 PM - Re: Maximum structural cruise (Sarah Tobin) 3. 05:30 PM - THIS WILL WORK (Frank) 4. 05:42 PM - Re: THIS WILL WORK (Byron Fox) 5. 07:26 PM - Re: Maximum structural cruise (Roger Kemp M.D.) 6. 08:14 PM - Re: Maximum structural cruise (Keith Pickford) 7. 08:44 PM - Re: Maximum structural cruise (Roger Kemp M.D.) 8. 09:27 PM - mounting fuel flow transducer in a CJ (keithmckinley) 9. 09:59 PM - Re: Maximum structural cruise (ACTIVE NZ - Andrew) 10. 11:55 PM - Re: Maximum structural cruise (Jan Mevis) ________________________________ Message 1 _____________________________________ Time: 06:43:38 AM PST US Subject: RE: Yak-List: Maximum structural cruise From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Comments: In the Marine Corps, there really is no such thing as a Max Mach Operating Limitation on most tactical aircraft .... I am sure there is probably one for the prop driven aircraft, but on the jets, the mach limit is that speed you reach while going straight down in burner... If you happen to have burner. Of note is the fact that we too are seeing major structural fatigue problems in a lot of our older aircraft. That was the single MAJOR REASON that the A-6E Intruder was retired early. On my personal YAK-50, I was originally told that the aircraft was rated at plus 9, negative 6 G. Then I did a ton of research and found that you were supposed to RECORD certain parameters of each flight and this added points to a number that when it was met, the wings on the aircraft were basically retired. In the case of the YAK-50, in many cases the whole aircraft was "retired" sometimes after just 50 hours of flight time. Of note is the fact that most everyone pulls that recording equipment out of the 50's AND 52's, and doesn't "bother with it anymore". Lot's of other pilots have done this kind of thing before our YAK's came on to the scene. Examples: T-34's. AT-6's. Both of those aircraft types have experienced the "WING OFF" warning light illuminating during flight. With fatal results in every case... And most of those were wearing chutes by the way. I have personally limited my 50 to plus 5 G's and negative 2. Even that is questionable, but I am willing to take the risk, but do acknowledge that it IS a risk. I also do not compete the aircraft anymore, and I don't participate in any ACM stuff. Eddy current and magnafluxing tests are pretty much out of my budget range. So... It's a risk. Mark -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of netmaster15@juno.com Sent: Tuesday, July 28, 2009 2:15 Subject: RE: Yak-List: Maximum structural cruise Doc, Thankyou for your response on the subject of " max structural cruise" . If I understand you correctly we are both saying the same thing; the water gets a bit muddy when we try to reconcile simantic differences. eg, reference your first paragraph: " .....while operating in STRUCTURAL CRUISE LIMITATION...." Please define "structural cruise". Also, what discipline categorizes structural cruise as a LIMITATION as opposed to a NORMAL OPERATING condition? All Operations Manuals I have been exposed to in the last 63 years cite Limitations as Vne, VA, Vlo, Vle, Vfe,max allow. TO Gr WT, max fuel, max tire speed, max pressure differential, max operating altitude, plus several other operating limitations. All these limitations are derived from one source; the TYPE CERTIFICATE AND DATA SHEETS and amendments thereto, eg, supplemental type certificates if applicable. Also in your first paragraph you use the phrase "....while operating within their envelope...." But you do not specify what envelope you're referring to. I agree, there is no yellow arc on the airspeed indicator in an F-5 but there is certainly a Mach meter and a Max Mach operating LIMITATION. Plainly, it is very difficult to translate terminology between two different disciplines. I'll have to finish this treatise at a later time; I'm already beyond my curfew limitation. I look forward to your continuing thoughts on this subject. BTW, I currently own and fly both a YAK -50 and a Harmon Rocket and you're correct, I don't want any major dissassemblies at altitude so I'm always alert for new ways to assure the aircraft remains in reuseable condition. Cheers! Cliff ---------- Original Message ---------- From: "ACTIVE NZ - Andrew" Subject: RE: Yak-List: Maximum structural cruise DOC Please excuse me for intruding on your list. I fly a Harmon Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a partnership that is rebuilding a Yak-3 in New Zealand. Anyway... I have been concerned about this issue for some time, in my Harmon Rocket. It goes kinda fast, and sometimes I hit pretty harsh bumps when I'm flying in the yellow arc. (yeah, I know, I should anticipate better.) I've often wondered if there's a way to check for metal fatigue or overstressing - is this magnaflux thing something that can be done to wing and horizontal stablizer spars? Is it a reasonably common procedure (ie, likely to be available in NZ)...or a real specialist kinda thing? Andrew ________________________________ From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Roger Kemp M.D. Sent: Tuesday, July 28, 2009 3:30 PM Subject: RE: Yak-List: Maximum structural cruise Cliff, AnswerYes I know of 2 aircraft that went down while operating in structural cruise Limitation as you say. Both were Class A accidents with 2 fatalities in each. One an F-5F and the other a T-38. I served as the flight surgeon representative to the SIB (safety investigation board) on the F-5 and I was the interim representative on the T-38 SIB. Four men died while operating their aircraft within NORMAL OPERATION PROCEDURE as you say. We call it differently since we dont have a yellow arcs on our airspeed indicators. Incidentally, one of the IPs in the F-5 was a good friend of mine. So yes, I know firsthand of two aircraft that failed while operating within their envelope. Now the question I have for you is: Are you prepared to totally bet your rosy pink on whatever Red Star Aircraft it is you are flying? Have you NDId/ magnafluxed your aircraft to determine if you have metal fatigue or not. Its a military aircraft not a spam can. It was and is operated like or as a military aircraft. Cruise limits dont exist. Vne and G limits do. An you do not know for dead nuts sure what the real structural (read metal fatigue state) integrity of your spare or spine is. You can only hope that the entries in that Eastern bloc aircrafts log book really were done and not just pencil whipped. Granted, these aircraft are tough as nails but so are/ were the F-5, T-38, F-15, A-10, and the F-16. Their wing are cracking. In some cases the wings are falling off as well as their dorsal spines are breaking. You just never know. Ohmake it 3 aircraft that I know of that broke up while operating within their NORMAL OPERATING LIMITS. I believe the St Louis Guard lost a twin tail sissy to structural failure while operating in normal ops limits approximately a year and a half ago. That Eagle driver was lucky, he got out with a shattered elbow and some contusions. Rumor has it they are still extracting fragments of seat cushion from his rosy pink after he sucked it up while tumbling/ somersaulting in the pit while trying to figure out why his jet was not responding any longer. By the way my comment initially was made in jest in response to Sabers last line of his post. I was not aware we had a MAX GUST LOAD on the YAK. Maybe the CJ does. G limits yesVne yes max crosswind limits yes.Max Gust Load ??? We do not have cocktail hours in any of the squadrons I have served with either. Either the beer light was lit or it was not. The beer light was lit when the last jet landed. Cocktail hour... Doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of netmaster15@juno.com Sent: Monday, July 27, 2009 3:35 PM Subject: RE: Yak-List: Maximum structural cruise Doc, How many people do you know who have "busted their asses" due to exceeding max structural cruise without exceeding Vne? This should raise the questions: What is max structural cruise meant to protect? and, Is max structural cruise a "LIMITATION" , or a NORMAL OPERATION PROCEDURE? If the latter, then, I submit it is no different than any other number within the yellow arc and does not deserve to be over dignified beyond those numbers within such parameter. In other words, it is nothing more than cocktail information. If one insists upon operating within the yellow arc, do not encounter turbulent air lest you exceed MAX GUST LOAD; now there IS a number you should know and understand beyond the cocktail hour. Cliff Umscheid ---------- Original Message ---------- From: "Roger Kemp M.D." Subject: RE: Yak-List: Maximum structural cruise Just rememberthe ass you bust maybe your own. doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of jblake207@comcast.net Sent: Monday, July 27, 2009 10:47 AM Subject: Re: Yak-List: Maximum structural cruise Find attached a "Vee" Speeds chart that I use for my CJ. Developed from the manuals and from lots of questions asked of people like Pappy, Sapp, Savarese and others. If I were a lawyer, I'd make a comment about using at your own risk and that this office cannot be held liable for any incorrect data... blah, blah, blah. I'm not a lawyer, so let me simply say use or lose. JB ----- Original Message ----- From: "Warren Hill" Sent: Sunday, July 26, 2009 10:12:26 PM GMT -06:00 US/Canada Central Subject: Yak-List: Maximum structural cruise Fellow CJ-ers, I wonder if there is a consensus on a figure in knots for maximum structural cruise for the CJ-6A? Warren Hill Mesa, AZ On Jul 26, 2009, at 6:19 PM, Chris Wise wrote: > G'Day, > > Thanks to Walt, Pappy and Dennis for replying. > The M14P has a rubber lip seal as well as a slinger, like Walt says. > The slinger by itself is inadequate, especially during aeros. > Any other advice would be appreciated re removing prop reduction box > and the prop shaft. > > Thanks and Cheers, > Chris. > > -Matt Dralle, List ========= =================================== ttp://www.matronics.com/Navigator?Yak-List =================================== tronics.com =================================== www.matronics.com/contribution =================================== http://www.matronics.com/Navigator?Yak-List http://forums.matronics.com http://www.matronics.com/contribution =================================== ttp://www.matronics.com/Navigator?Yak-List =================================== tronics.com =================================== www.matronics.com/contribution =================================== ky"Z+M4Gq(wrIQhaxr^jzZ("X,ZIJr*'!y:0ZwE,jwfffi0fr(Z(jBm &j',r5h.+- ________________________________ Message 2 _____________________________________ Time: 03:53:02 PM PST US From: Sarah Tobin Subject: RE: Yak-List: Maximum structural cruise 5 Gs? That's it? I haven't flown the 50, but in my 55, I routinely fly 6G positive and 3G negative. Heard anything regarding the 55? Smash --- On Tue, 7/28/09, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote: > From: Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E > Subject: RE: Yak-List: Maximum structural cruise > To: yak-list@matronics.com > Date: Tuesday, July 28, 2009, 8:31 AM > "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" > > > > > Comments: > > > In the Marine Corps, there really is no such thing as a Max > Mach Operating Limitation on most tactical aircraft .... I > am sure there is probably one for the prop driven aircraft, > but on the jets, the mach limit is that speed you reach > while going straight down in burner... If you happen to have > burner. > > Of note is the fact that we too are seeing major structural > fatigue problems in a lot of our older aircraft. That > was the single MAJOR REASON that the A-6E Intruder was > retired early. > > On my personal YAK-50, I was originally told that the > aircraft was rated at plus 9, negative 6 G. Then I did > a ton of research and found that you were supposed to RECORD > certain parameters of each flight and this added points to a > number that when it was met, the wings on the aircraft were > basically retired. In the case of the YAK-50, in many > cases the whole aircraft was "retired" sometimes after just > 50 hours of flight time. Of note is the fact that most > everyone pulls that recording equipment out of the 50's AND > 52's, and doesn't "bother with it anymore". Lot's of > other pilots have done this kind of thing before our YAK's > came on to the scene. Examples: T-34's. > AT-6's. Both of those aircraft types have experienced > the "WING OFF" warning light illuminating during > flight. With fatal results in every case... And most > of those were wearing chutes by the way. I have > personally limited my 50 to plus 5 G's and negative 2. > Even that is questionable, but I am willing to ! > take the risk, but do acknowledge that it IS a risk. > I also do not compete the aircraft anymore, and I don't > participate in any ACM stuff. > > Eddy current and magnafluxing tests are pretty much out of > my budget range. So... It's a risk. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of netmaster15@juno.com > Sent: Tuesday, July 28, 2009 2:15 > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > Doc, Thankyou for your response on the subject of " > max structural cruise" . If I understand you correctly > we are both saying the same thing; the water gets a bit > muddy when we try to reconcile simantic differences. eg, > reference your first paragraph:" > .....while operating in STRUCTURAL CRUISE > LIMITATION...."Please define "structural > cruise". Also, what discipline categorizes structural cruise > as a LIMITATION as opposed to a NORMAL OPERATING condition? > All Operations Manuals I have been exposed to in the > last 63 years cite Limitations as Vne, VA, Vlo, Vle, Vfe,max > allow. TO Gr WT, max fuel, max tire speed, max pressure > differential, max operating altitude, plus several other > operating limitations. All these limitations are derived > from one source; the TYPE CERTIFICATE AND DATA SHEETS and > amendments thereto, eg, supplemental type certificates if > applicable. Also in your first paragraph you use the > phrase "....while operating within their envelope...." > But you do no! > t specify what envelope you're referring to. I agree, > there is no yellow arc on the airspeed indicator in an F-5 > but there is certainly a Mach meter and a Max Mach > operating LIMITATION. Plainly, it is very difficult to > translate terminology between two different > disciplines. > > I'll have to finish this treatise at a later time; > I'm already beyond my curfew limitation. I look forward to > your continuing thoughts on this subject. BTW, I > currently own and fly both a YAK -50 and a Harmon > Rocket and you're correct, I don't want any major > dissassemblies at altitude so I'm always alert for new ways > to assure the aircraft remains in reuseable condition. > Cheers! > > Cliff > > ---------- Original Message ---------- > From: "ACTIVE NZ - Andrew" > To: > Subject: RE: Yak-List: Maximum structural cruise > Date: Tue, 28 Jul 2009 16:29:33 +1200 > > > > DOC > > Please excuse me for intruding on your list. I fly a Harmon > Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a > partnership that is rebuilding a Yak-3 in New Zealand. > > Anyway... > > I have been concerned about this issue for some time, in my > Harmon Rocket. It goes kinda fast, and sometimes I hit > pretty harsh bumps when I'm flying in the yellow arc. (yeah, > I know, I should anticipate better.) I've often wondered if > there's a way to check for metal fatigue or overstressing - > is this magnaflux thing something that can be done to wing > and horizontal stablizer spars? Is it a reasonably common > procedure (ie, likely to be available in NZ)...or a real > specialist kinda thing? > > Andrew > > > > ________________________________ > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of Roger Kemp M.D. > Sent: Tuesday, July 28, 2009 3:30 PM > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > > > Cliff, > > AnswerYes I know of 2 aircraft that went down while > operating in structural cruise Limitation as you > say. Both were Class A accidents with 2 fatalities in each. > One an F-5F and the other a T-38. I served as the flight > surgeon representative to the SIB (safety investigation > board) on the F-5 and I was the interim representative on > the T-38 SIB. Four men died while operating their > aircraft within NORMAL OPERATION > PROCEDURE as you say. We call it differently since > we dont have a yellow arcs on our airspeed > indicators. Incidentally, one of the IPs in the F-5 > was a good friend of mine. So yes, I know > firsthand of two aircraft that failed while > operating within their envelope. > > Now the question I have for you is: Are you prepared to > totally bet your rosy pink on whatever Red Star Aircraft it > is you are flying? Have you NDId/ magnafluxed your > aircraft to determine if you have metal fatigue or not. > Its a military aircraft not a spam can. It was and > is operated like or as a military aircraft. Cruise limits > dont exist. Vne and G limits do. An you do not know > for dead nuts sure what the real structural (read > metal fatigue state) integrity of your spare or spine is. > You can only hope that the entries in that Eastern bloc > aircrafts log book really were done and not just > pencil whipped. Granted, these aircraft are tough as > nails but so are/ were the F-5, T-38, F-15, A-10, and the > F-16. Their wing are cracking. In some cases the wings are > falling off as well as their dorsal spines are breaking. You > just never know. > > Ohmake it 3 aircraft that I know of that > broke up while operating within their NORMAL > OPERATING LIMITS. I believe the St Louis Guard > lost a twin tail sissy to structural failure while > operating in normal ops limits approximately a > year and a half ago. That Eagle driver was lucky, he got out > with a shattered elbow and some contusions. Rumor has it > they are still extracting fragments of seat cushion from his > rosy pink after he sucked it up while tumbling/ > somersaulting in the pit while trying to figure out why his > jet was not responding any longer. > > By the way my comment initially was made in jest in > response to Sabers last line of his post. I was not > aware we had a MAX GUST LOAD on the YAK. > Maybe the CJ does. G limits yesVne yes > max crosswind limits yes.Max Gust Load ??? > > We do not have cocktail hours in any of the squadrons > I have served with either. Either the beer light was lit or > it was not. The beer light was lit when the last jet > landed. Cocktail hour... > > Doc > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of netmaster15@juno.com > Sent: Monday, July 27, 2009 3:35 PM > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > > > Doc,How many people do you know who have > "busted their asses" due to exceeding max structural > cruise without exceeding Vne? This should raise the > questions: What is max structural cruise meant to protect? > and, Is max structural cruise a "LIMITATION" , or a NORMAL > OPERATION PROCEDURE? If the latter, then, I submit it is no > different than any other number within the yellow arc and > does not deserve to be over dignified beyond those numbers > within such parameter. In other words, it is nothing more > than cocktail information. If one insists upon operating > within the yellow arc, do not encounter turbulent air lest > you exceed MAX GUST LOAD; now there IS a number you > should know and understand beyond the cocktail hour. > > Cliff Umscheid > > ---------- Original Message ---------- > From: "Roger Kemp M.D." > To: > Subject: RE: Yak-List: Maximum structural cruise > Date: Mon, 27 Jul 2009 13:29:36 -0500 > > Just rememberthe ass you bust maybe your > own. > > doc > > > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of jblake207@comcast.net > Sent: Monday, July 27, 2009 10:47 AM > To: yak-list@matronics.com > Subject: Re: Yak-List: Maximum structural cruise > > > > Find attached a "Vee" Speeds chart that I use for my > CJ. Developed from the manuals and from lots of > questions asked of people like Pappy, Sapp, Savarese and > others. > > > > If I were a lawyer, I'd make a comment about using at your > own risk and that this office cannot be held liable for any > incorrect data... blah, blah, blah. I'm not a lawyer, > so let me simply say use or lose. > > > > JB > > > > > ----- Original Message ----- > From: "Warren Hill" > To: yak-list@matronics.com > Sent: Sunday, July 26, 2009 10:12:26 PM GMT -06:00 > US/Canada Central > Subject: Yak-List: Maximum structural cruise > > > Fellow CJ-ers, > > I wonder if there is a consensus on a figure in knots for > maximum structural cruise for the CJ-6A? > > Warren Hill > Mesa, AZ > > On Jul 26, 2009, at 6:19 PM, Chris Wise wrote: > > > G'Day, > > > > Thanks to Walt, Pappy and Dennis for replying. > > The M14P has a rubber lip seal as well as a slinger, > like Walt says. > > The slinger by itself is inadequate, especially during > aeros. > > Any other advice would be appreciated re removing prop > reduction box > > and the prop shaft. > > > > Thanks and Cheers, > > Chris. > > > > > > > > > > > > -Matt Dralle, List ========= > > > > > > =================================== > ttp://www.matronics.com/Navigator?Yak-List > =================================== > tronics.com > =================================== > www.matronics.com/contribution > =================================== > > > > http://www.matronics.com/Navigator?Yak-List > http://forums.matronics.com > http://www.matronics.com/contribution > > > > =================================== > ttp://www.matronics.com/Navigator?Yak-List > =================================== > tronics.com > =================================== > www.matronics.com/contribution > =================================== > > > ky"Z+M4Gq(wrIQhaxr^jzZ("X,ZIJr*'!y:0ZwE,jwfffi0fr(Z(jBm > &j',r5h.+- > > > Forum - > FAQ, > - MATRONICS WEB FORUMS - > List Contribution Web Site - > -Matt > Dralle, List Admin. > > > > ________________________________ Message 3 _____________________________________ Time: 05:30:09 PM PST US From: "Frank" Subject: Yak-List: THIS WILL WORK THE PERFECT SOLUTION TO NATIONAL HEALTH CARE Here is one way to ensure a perfect national health care system...................... DEMAND POLITICIANS BELONG TO THE SAME HEALTH CARE PLAN THEY WOULD IMPOSE ON THE REST OF US! ! ! Guaranteed to work......don't you think? Pass it on and let's see what happens ! ________________________________ Message 4 _____________________________________ Time: 05:42:48 PM PST US From: Byron Fox Subject: Re: Yak-List: THIS WILL WORK Please save this sort of e-mail for other venues. Thanks, Blitz Sent from my iPhone On Jul 28, 2009, at 5:28 PM, "Frank" wrote: > THE PERFECT SOLUTION TO NATIONAL HEALTH CARE > > Here is one way to ensure a perfect national health care > system...................... > > DEMAND POLITICIANS BELONG TO THE SAME HEALTH CARE PLAN THEY WOULD > IMPOSE ON THE REST OF US! ! ! > > Guaranteed to work......don't you think? > > Pass it on and let's see what happens ! > > ________________________________ Message 5 _____________________________________ Time: 07:26:08 PM PST US From: "Roger Kemp M.D." Subject: RE: Yak-List: Maximum structural cruise Andrew, So you are one of the guys involved in restoring that YAK 3 in NZ. I think I talked to someone about that bird at onetime then decided the expense would exceed the benefit. Looks like that may well be the case with the current economy here in the US. To answer your question, yes the capability to eddy current and magnaflux along with, NDT (xray) exist. The expense of xraying the airframe for me is prohibitive. I probably could get the guys in the airframe shop to NDT my bird when they are doing one of our jets but that would be highly illegal for me to ask for that. So, I just have to pull panels and stick a digital camera in the wings and fuselage to snap pictures of those places that I cannot see by looking in. Another thing to invest in I would guess (I have not yet) is a bore scope. Still though, if you can see the cracks with your eyes it is already a big problem. http://www.directindustry.com/scripts/IDPHeader.php?s=9257 &URL=http%3A%2F%2Fwww.geinspectiontechnologies.com%2Fen%2Fproducts%2Fed dy_current%2Findex.html&IDVisite=&MotCle=&RefCat=&IDProduit=57817 &IDProdSource=&SourceType=Produit The above url will show you a portable eddy current system (Pulstec) made by GE for the aerospace industry. I have not had the guts to ask the cost of the devise and the practicality of having a portable eddy current sytem begs practicality for me. Magnaflux is a spray kit that can be found in most auto parts stores. It is a combination of penetrentt and developer that you spray on the surface to detect a crack. It works well for accessible areas of the airframe. I used it to find a crack in my fuel tank on my 50. Here is the URL for Magnaflux for more info. http://www.magnaflux.com/ProductOverview/Penetrant/tabid/96/Default.aspx The two above systems are affordable not practical for doing a complete spar. Someone else can comment of that. I Doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of ACTIVE NZ - Andrew Sent: Monday, July 27, 2009 11:30 PM Subject: RE: Yak-List: Maximum structural cruise DOC Please excuse me for intruding on your list. I fly a Harmon Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a partnership that is rebuilding a Yak-3 in New Zealand. Anyway... I have been concerned about this issue for some time, in my Harmon Rocket. It goes kinda fast, and sometimes I hit pretty harsh bumps when I'm flying in the yellow arc. (yeah, I know, I should anticipate better.) I've often wondered if there's a way to check for metal fatigue or overstressing - is this magnaflux thing something that can be done to wing and horizontal stablizer spars? Is it a reasonably common procedure (ie, likely to be available in NZ)...or a real specialist kinda thing? Andrew _____ From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Roger Kemp M.D. Sent: Tuesday, July 28, 2009 3:30 PM Subject: RE: Yak-List: Maximum structural cruise Cliff, AnswerYes I know of 2 aircraft that went down while operating in structural cruise =9CLimitation=9D as you say. Both were Class A accidents with 2 fatalities in each. One an F-5F and the other a T-38. I served as the flight surgeon representative to the SIB (safety investigation board) on the F-5 and I was the interim representative on the T-38 SIB. Four men died while operating their aircraft within =9C NORMAL OPERATION PROCEDURE=99 as you say. We call it differently since we don=99t have a yellow arcs on our airspeed indicators. Incidentally, one of the IP=99s in the F-5 was a good friend of mine. So yes, I know firsthand of two aircraft that failed while operating within their envelope. Now the question I have for you is: Are you prepared to totally bet your rosy pink on whatever Red Star Aircraft it is you are flying? Have you NDI=99d/ magnafluxed your aircraft to determine if you have metal fatigue or not. Its=99 a military aircraft not a spam can. It was and is operated like or as a military aircraft. Cruise limits don=99t exist. Vne and G limits do. An you do not know for dead nuts sure what the real structural (read metal fatigue state) integrity of your spare or spine is. You can only hope that the entries in that Eastern bloc aircraft=99s log book really were done and not just pencil whipped. Granted, these aircraft are tough as nails but so are/ were the F-5, T-38, F-15, A-10, and the F-16. Their wing are cracking. In some cases the wings are falling off as well as their dorsal spines are breaking. You just never know. Ohmake it 3 aircraft that I know of that =9C broke up=9D while operating within their =9C NORMAL OPERATING LIMITS=9D. I believe the St Louis Guard lost a twin tail sissy to structural failure while operating =9C in normal ops limits=9D approximately a year and a half ago. That Eagle driver was lucky, he got out with a shattered elbow and some contusions. Rumor has it they are still extracting fragments of seat cushion from his rosy pink after he sucked it up while tumbling/ somersaulting in the pit while trying to figure out why his jet was not responding any longer. By the way my comment initially was made in jest in response to Saber=99s last line of his post. I was not aware we had a =9CMAX GUST LOAD=9D on the YAK. Maybe the CJ does. G limits yesVne yes max crosswind limits yes.Max Gust Load ??? We do not have cocktail hours in any of the squadrons I have served with either. Either the beer light was lit or it was not. The beer light was lit when the last jet landed. Cocktail hour... Doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of netmaster15@juno.com Sent: Monday, July 27, 2009 3:35 PM Subject: RE: Yak-List: Maximum structural cruise Doc, How many people do you know who have "busted their asses" due to exceeding max structural cruise without exceeding Vne? This should raise the questions: What is max structural cruise meant to protect? and, Is max structural cruise a "LIMITATION" , or a NORMAL OPERATION PROCEDURE? If the latter, then, I submit it is no different than any other number within the yellow arc and does not deserve to be over dignified beyond those numbers within such parameter. In other words, it is nothing more than cocktail information. If one insists upon operating within the yellow arc, do not encounter turbulent air lest you exceed MAX GUST LOAD; now there IS a number you should know and understand beyond the cocktail hour. Cliff Umscheid ---------- Original Message ---------- From: "Roger Kemp M.D." Subject: RE: Yak-List: Maximum structural cruise Just remember=C3=A2=82=AC=C2the ass you bust maybe your own. doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of jblake207@comcast.net Sent: Monday, July 27, 2009 10:47 AM Subject: Re: Yak-List: Maximum structural cruise Find attached a "Vee" Speeds chart that I use for my CJ. Developed from the manuals and from lots of questions asked of people like Pappy, Sapp, Savarese and others. If I were a lawyer, I'd make a comment about using at your own risk and that this office cannot be held liable for any incorrect data... blah, blah, blah. I'm not a lawyer, so let me simply say use or lose. JB ----- Original Message ----- From: "Warren Hill" Sent: Sunday, July 26, 2009 10:12:26 PM GMT -06:00 US/Canada Central Subject: Yak-List: Maximum structural cruise Fellow CJ-ers, I wonder if there is a consensus on a figure in knots for maximum structural cruise for the CJ-6A? Warren Hill Mesa, AZ On Jul 26, 2009, at 6:19 PM, Chris Wise wrote: > G'Day, > > Thanks to Walt, Pappy and Dennis for replying. > The M14P has a rubber lip seal as well as a slinger, like Walt says. > The slinger by itself is inadequate, especially during aeros. > Any other advice would be appreciated re removing prop reduction box > and the prop shaft. > > Thanks and Cheers, > Chris. > > -Matt Dralle, List ========= ttp://www.matronics.com/Navigator?Yak-List tronics.com www.matronics.com/contribution http://www.matronics.com/Navigator?Yak-List http://forums.matronics.com http://www.matronics.com/contribution ~ _____ ________________________________ Message 6 _____________________________________ Time: 08:14:15 PM PST US From: Keith Pickford Subject: RE: Yak-List: Maximum structural cruise Andrew - I believe Air New Zealand do have xray equipment at Chrischurch - Regards - Keith - Yak 52 Ashburton NZ --- On Wed, 29/7/09, Roger Kemp M.D. wrote: From: Roger Kemp M.D. Subject: RE: Yak-List: Maximum structural cruise Received: Wednesday, 29 July, 2009, 2:24 PM Andrew, So you are one of the guys involved in restoring that YAK 3 in NZ. I think I talked to someone about that bird at onetime then decided the expense wou ld exceed the benefit. Looks like that may well be the case with the curren t economy here in the US. To answer your question, yes the capability to eddy current and magnaflux a long with, NDT (xray) exist. The expense of xraying the airframe for me is prohibitive. I probably could get the guys in the airframe shop to NDT my b ird when they are doing one of our jets but that would be highly illegal fo r me to ask for that. So, I just have to pull panels and stick a digital ca mera- in the wings and fuselage to snap pictures of those places that I c annot see by looking in. -Another thing to invest in I would guess (I hav e not yet) is a bore scope. Still though, if you can see the cracks with yo ur eyes it is already a big problem. http://www.directindustry.com/scripts/IDPHeader.php?s=9257&URL=http%3A% 2F%2Fwww.geinspectiontechnologies.com%2Fen%2Fproducts%2Feddy_current%2Finde x.html&IDVisite=&MotCle=&RefCat=&IDProduit=57817&IDProdSource=&So urceType=Produit The above url will show you a portable eddy current system (Pulstec) made b y GE for the aerospace industry. I have not had the guts to ask the cost of the devise and the practicality of having a portable eddy current sytem be gs practicality for me. - Magnaflux is a spray kit that can be found in most auto parts stores. It is a combination of penetrentt and developer that you spray on the surface to detect a crack. It works well for accessible areas of the airframe. I used it to find a crack in my fuel tank on my 50. -Here is the URL for Magnaf lux for more info. http://www.magnaflux.com/ProductOverview/Penetrant/tabid /96/Default.aspx The two above systems are affordable not practical for doing a complete spa r. Someone else can comment of that. I Doc - From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@mat ronics.com] On Behalf Of ACTIVE NZ - Andrew Sent: Monday, July 27, 2009 11:30 PM Subject: RE: Yak-List: Maximum structural cruise - DOC - Please excuse me for intruding on your list. I fly a Harmon Rocket, (mainly ) but eavesdrop on the Yak list cos I'm in a partnership that is rebuilding a Yak-3 in New Zealand. - Anyway... - I have been concerned about this issue for some time, in my Harmon Rocket. It goes kinda fast, and sometimes I hit pretty harsh bumps when I'm flying in the yellow arc. (yeah, I know, I should anticipate better.) I've often w ondered if there's a way to check for metal fatigue or overstressing - is t his magnaflux thing something that can be done to wing and horizontal stabl izer spars? Is it a reasonably common procedure (ie, likely to be available in NZ)...or a real specialist kinda thing? - Andrew - - - ________________________________ Message 7 _____________________________________ Time: 08:44:05 PM PST US From: "Roger Kemp M.D." Subject: RE: Yak-List: Maximum structural cruise Cliff, I was using your own terminology from your post to reply with. Personally, the Ops Limits published in the POH and the DASH 1 are the numbers I am familiar with when flying my spam can or YAK. With the my guys in the squadron it is the DASH 1. Like Jon (Saber), I too have had to scrounge to find the Regulator V speeds. Part 23 of the FAA Reg addresses all of the catagories that you refer to for civilian normal, utility, aerobatic, and commuter category aircraft. The following URL will take you to the electronic version of the FAA Regs. http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr;sid=6da4e564d2b1 01b3527c1d742e918420;rgn=div5;view=text;node=14%3A1.0.1.3.10;idno= 14;cc=ecfr#14:1.0.1.3.10.3.70.8 FAA reg 23.33 refers to the Gust Limitations you refered to. The AF has its=99 own set of regs that address the ops limits as does the published DASH 1 for each of the operational aircraft. I am not aware of a Max Mach for the F16. I am aware of max G limitations for various stores configurations. Were you referring to Critical Mach? Mcr? The number where the aircraft is flying at the lowest Mach number at which the airflow over a small region of the wing reaches the speed of sound? Are you trying to take me down the path of a discussion on Mach tuck. If so, why and what does it have to do with flying YAK 50=99s? We are never going to get there so compressibility is not an issue. It was an issue for the Bf 109, P-51, P-38, P-47, Spitfire, Me-262 and the P-80 along with the Gloster Meteor. I have not heard the Russians discuss it with the YAK 3=99s but they probably experienced Mach tuck too. It was an issue with the Mig 15 early own as I understand too. Then again the intake was subject to Mcr with shock wave development in the intake causing compressor stalls too. A lot has been learned about flying transonic and supersonic since we were kids. I believe your question was =9C How many people do you know who have "busted their asses" due to exceeding max structural cruise without exceeding Vne=9D The answer is 3 that I am aware of personally that broke up operating within the published ops limits for the particular aircraft. You=99ll have to tell me what the max structural cruise is though. Are we back to operating in the yellow arc? Check 6, Doc PS. By the way, tonight at 2200, the Military Channel is having show on called Operation Red October. It is about German owned MIG 29 vs the F-18. Enjoy. From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of netmaster15@juno.com Sent: Tuesday, July 28, 2009 1:15 AM Subject: RE: Yak-List: Maximum structural cruise Doc, Thankyou for your response on the subject of " max structural cruise" . If I understand you correctly we are both saying the same thing; the water gets a bit muddy when we try to reconcile simantic differences. eg, reference your first paragraph: " .....while operating in STRUCTURAL CRUISE LIMITATION...." Please define "structural cruise". Also, what discipline categorizes structural cruise as a LIMITATION as opposed to a NORMAL OPERATING condition? All Operations Manuals I have been exposed to in the last 63 years cite Limitations as Vne, VA, Vlo, Vle, Vfe,max allow. TO Gr WT, max fuel, max tire speed, max pressure differential, max operating altitude, plus several other operating limitations. All these limitations are derived from one source; the TYPE CERTIFICATE AND DATA SHEETS and amendments thereto, eg, supplemental type certificates if applicable. Also in your first paragraph you use the phrase "....while operating within their envelope...." But you do not specify what envelope you're referring to. I agree, there is no yellow arc on the airspeed indicator in an F-5 but there is certainly a Mach meter and a Max Mach operating LIMITATION. Plainly, it is very difficult to translate terminology between two different disciplines. I'll have to finish this treatise at a later time; I'm already beyond my curfew limitation. I look forward to your continuing thoughts on this subject. BTW, I currently own and fly both a YAK -50 and a Harmon Rocket and you're correct, I don't want any major dissassemblies at altitude so I'm always alert for new ways to assure the aircraft remains in reuseable condition. Cheers! Cliff ---------- Original Message ---------- From: "ACTIVE NZ - Andrew" Subject: RE: Yak-List: Maximum structural cruise =C3=AF=C2=BB=C2 DOC Please excuse me for intruding on your list. I fly a Harmon Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a partnership that is rebuilding a Yak-3 in New Zealand. Anyway... I have been concerned about this issue for some time, in my Harmon Rocket. It goes kinda fast, and sometimes I hit pretty harsh bumps when I'm flying in the yellow arc. (yeah, I know, I should anticipate better.) I've often wondered if there's a way to check for metal fatigue or overstressing - is this magnaflux thing something that can be done to wing and horizontal stablizer spars? Is it a reasonably common procedure (ie, likely to be available in NZ)...or a real specialist kinda thing? Andrew _____ From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Roger Kemp M.D. Sent: Tuesday, July 28, 2009 3:30 PM Subject: RE: Yak-List: Maximum structural cruise Cliff, Answer=C3=A2=82=AC=C2Yes I know of 2 aircraft that went down while operating in structural cruise =C3=A2=82=AC=C5=93Limitation=C3=A2=82=AC=C2=9D as you say. Both were Class A accidents with 2 fatalities in each. One an F-5F and the other a T-38. I served as the flight surgeon representative to the SIB (safety investigation board) on the F-5 and I was the interim representative on the T-38 SIB. Four men died while operating their aircraft within =C3=A2=82=AC=C5=93 NORMAL OPERATION PROCEDURE=C3=A2=82=AC=84=A2 as you say. We call it differently since we don=C3=A2=82=AC=84=A2t have a yellow arcs on our airspeed indicators. Incidentally, one of the IP=C3=A2=82=AC=84=A2s in the F-5 was a good friend of mine. So yes, I know firsthand of two aircraft that failed while operating within their envelope. Now the question I have for you is: Are you prepared to totally bet your rosy pink on whatever Red Star Aircraft it is you are flying? Have you NDI=C3=A2=82=AC=84=A2d/ magnafluxed your aircraft to determine if you have metal fatigue or not. Its=C3=A2=82=AC=84=A2 a military aircraft not a spam can. It was and is operated like or as a military aircraft. Cruise limits don=C3=A2=82=AC=84=A2t exist. Vne and G limits do. An you do not know for dead nuts sure what the real structural (read metal fatigue state) integrity of your spare or spine is. You can only hope that the entries in that Eastern bloc aircraft=C3=A2=82=AC=84=A2s log book really were done and not just pencil whipped. Granted, these aircraft are tough as nails but so are/ were the F-5, T-38, F-15, A-10, and the F-16. Their wing are cracking. In some cases the wings are falling off as well as their dorsal spines are breaking. You just never know. Oh=C3=A2=82=AC=C2make it 3 aircraft that I know of that =C3=A2=82=AC=C5=93 broke up=C3=A2=82=AC=C2=9D while operating within their =C3=A2=82=AC=C5=93 NORMAL OPERATING LIMITS=C3=A2=82=AC=C2=9D. I believe the St Louis Guard lost a twin tail sissy to structural failure while operating =C3=A2=82=AC=C5=93 in normal ops limits=C3=A2=82=AC=C2=9D approximately a year and a half ago. That Eagle driver was lucky, he got out with a shattered elbow and some contusions. Rumor has it they are still extracting fragments of seat cushion from his rosy pink after he sucked it up while tumbling/ somersaulting in the pit while trying to figure out why his jet was not responding any longer. By the way my comment initially was made in jest in response to Saber=C3=A2=82=AC=84=A2s last line of his post. I was not aware we had a =C3=A2=82=AC=C5=93MAX GUST LOAD=C3=A2=82=AC=C2=9D on the YAK. Maybe the CJ does. G limits yes=C3=A2=82=AC=C2Vne yes=C3=A2=82=AC=C2 max crosswind limits yes=C3=A2=82=AC=C2.Max Gust Load ??? We do not have cocktail hours in any of the squadrons I have served with either. Either the beer light was lit or it was not. The beer light was lit when the last jet landed. Cocktail hour=C3=A2=82=AC=C2... Doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of netmaster15@juno.com Sent: Monday, July 27, 2009 3:35 PM Subject: RE: Yak-List: Maximum structural cruise Doc, How many people do you know who have "busted their asses" due to exceeding max structural cruise without exceeding Vne? This should raise the questions: What is max structural cruise meant to protect? and, Is max structural cruise a "LIMITATION" , or a NORMAL OPERATION PROCEDURE? If the latter, then, I submit it is no different than any other number within the yellow arc and does not deserve to be over dignified beyond those numbers within such parameter. In other words, it is nothing more than cocktail information. If one insists upon operating within the yellow arc, do not encounter turbulent air lest you exceed MAX GUST LOAD; now there IS a number you should know and understand beyond the cocktail hour. Cliff Umscheid ---------- Original Message ---------- From: "Roger Kemp M.D." Subject: RE: Yak-List: Maximum structural cruise Just remember=C3=83=C2=A2=C3=A2=9A=C2=AC=C3=82=C2the ass you bust maybe your own. doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of jblake207@comcast.net Sent: Monday, July 27, 2009 10:47 AM Subject: Re: Yak-List: Maximum structural cruise Find attached a "Vee" Speeds chart that I use for my CJ. Developed from the manuals and from lots of questions asked of people like Pappy, Sapp, Savarese and others. If I were a lawyer, I'd make a comment about using at your own risk and that this office cannot be held liable for any incorrect data... blah, blah, blah. I'm not a lawyer, so let me simply say use or lose. JB ----- Original Message ----- From: "Warren Hill" Sent: Sunday, July 26, 2009 10:12:26 PM GMT -06:00 US/Canada Central Subject: Yak-List: Maximum structural cruise Fellow CJ-ers, I wonder if there is a consensus on a figure in knots for maximum structural cruise for the CJ-6A? Warren Hill Mesa, AZ On Jul 26, 2009, at 6:19 PM, Chris Wise wrote: > G'Day, > > Thanks to Walt, Pappy and Dennis for replying. > The M14P has a rubber lip seal as well as a slinger, like Walt says. > The slinger by itself is inadequate, especially during aeros. > Any other advice would be appreciated re removing prop reduction box > and the prop shaft. > > Thanks and Cheers, > Chris. > > -Matt Dralle, List ========= ttp://www.matronics.com/Navigator?Yak-List tronics.com www.matronics.com/contribution http://www.matronics.com/Navigator?Yak-List http://forums.matronics.com http://www.matronics.com/contribution ttp://www.matronics.com/Navigator?Yak-List tronics.com www.matronics.com/contribution ky=C2=B7=C3=A8=C5=BE=C3=9B"=C3=8D=C3=AD=C5=93=C2=A2Z+=C3=93M4=C3=93G=C3=9A q=C3=A7(=C2=BA=C2=B8=C5=BE=C2=AEw=C2=B0r=B9=C2=AB=B0=C3=AA=C3 =93=C3=C2=90=C2=B8=C2=AC=C2=B4I=C5=A1=C5-Qh=C2=AE=C3=A9 =9D=C2=B1=C3=ABax=C3=86=C2=AD=C2=AE=B0=C3=A2r=C3=82=C3=A2=C2=B2=C3=91 ^j=C3=9B=C2=ABz=C3=83Z=C2=BE(=C2=B6=C5-=C3=AD=C2=A1=C2=BA=C3=A8=C3=82=C3 =87=C2=AD=C3=A9=C5=A1=C5=B8"=C3=A2=C2=B2=C3=9B=C2=AD=C5-X=C2=AD =B0=C3=AB,=C2=B9=C3=88Z=C2=B0=C2=B8=C2=AC=C2=B5I=C3J=C3=C3=AC r=C2=B8=C2=A9=C2=B6*'[1]=C2=B7!=C5-=C3=B7=99y=C2=AA=C3=9C=9E :0=C5=BEZw=C2=B0=C3=9A=C3=88=C3=A8=C3=82=C3=87=9A=C2=ABE _____ =C3=A1=C2=A2=C3=9A,=C2=AA=C3=9Ejwf=C2=B9=C3=88f=C2=B9=C3=88f=C2=A2 =C2=B7=C5=A1-=C2=B7=C5=B8-=C3=9Bi=C3=C3=BC0=C3=82f=C2=AD =C2=AE=B0=C3=A2r=C3=87(=BA=C3=B3Z=C2=BE(=C2=B6=C5-=C3=98jB=C3 =A2=C2=B2=C3=98m=C2=B6=C5=B8=C3=C3=83 &j=C3=9A=C3=A8=C5=BE',r=B0=C25=C2=AB=C3=A2=C2=81=C2=ABh=C2=AD -=C2=A4.+-=C3=BD=C2=A3 ________________________________ Message 8 _____________________________________ Time: 09:27:02 PM PST US Subject: Yak-List: mounting fuel flow transducer in a CJ From: "keithmckinley" Just wondering how you guys with fuel flow instruments in your CJ are mounting the transducer. There is a very short fuel line between pump and carb and I believe there needs to be 6" inches of straight fuel line in and out of the transducer. The angles that the fittings enter the fuel pump and carb make it look a little awkward to get those straight runs. Thanks -------- Keith McKinley 700HS KFIT Read this topic online here: http://forums.matronics.com/viewtopic.php?p=255070#255070 ________________________________ Message 9 _____________________________________ Time: 09:59:07 PM PST US Subject: RE: Yak-List: Maximum structural cruise From: "ACTIVE NZ - Andrew" Sweet. Thx for info, doc & keith...will follow up. And, uh, I never HEARD of an aircraft where the expense exceeds the benefit. Do they make them? :) Andrew ________________________________ From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Keith Pickford Sent: Wednesday, July 29, 2009 3:31 PM Subject: RE: Yak-List: Maximum structural cruise Andrew I believe Air New Zealand do have xray equipment at Chrischurch Regards Keith Yak 52 Ashburton NZ --- On Wed, 29/7/09, Roger Kemp M.D. wrote: From: Roger Kemp M.D. Subject: RE: Yak-List: Maximum structural cruise To: yak-list@matronics.com Received: Wednesday, 29 July, 2009, 2:24 PM Andrew, So you are one of the guys involved in restoring that YAK 3 in NZ. I think I talked to someone about that bird at onetime then decided the expense would exceed the benefit. Looks like that may well be the case with the current economy here in the US. To answer your question, yes the capability to eddy current and magnaflux along with, NDT (xray) exist. The expense of xraying the airframe for me is prohibitive. I probably could get the guys in the airframe shop to NDT my bird when they are doing one of our jets but that would be highly illegal for me to ask for that. So, I just have to pull panels and stick a digital camera in the wings and fuselage to snap pictures of those places that I cannot see by looking in. Another thing to invest in I would guess (I have not yet) is a bore scope. Still though, if you can see the cracks with your eyes it is already a big problem. http://www.directindustry.com/scripts/IDPHeader.php?s=9257&URL=http%3 A%2 F%2Fwww.geinspectiontechnologies.com%2Fen%2Fproducts%2Feddy_current%2Fin dex.html&IDVisite=&MotCle=&RefCat=&IDProduit=57817&IDProdSource= &SourceT ype=Produit The above url will show you a portable eddy current system (Pulstec) made by GE for the aerospace industry. I have not had the guts to ask the cost of the devise and the practicality of having a portable eddy current sytem begs practicality for me. Magnaflux is a spray kit that can be found in most auto parts stores. It is a combination of penetrentt and developer that you spray on the surface to detect a crack. It works well for accessible areas of the airframe. I used it to find a crack in my fuel tank on my 50. Here is the URL for Magnaflux for more info. http://www.magnaflux.com/ProductOverview/Penetrant/tabid/96/Default.aspx The two above systems are affordable not practical for doing a complete spar. Someone else can comment of that. I Doc From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of ACTIVE NZ - Andrew Sent: Monday, July 27, 2009 11:30 PM To: yak-list@matronics.com Subject: RE: Yak-List: Maximum structural cruise DOC Please excuse me for intruding on your list. I fly a Harmon Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a partnership that is rebuilding a Yak-3 in New Zealand. Anyway... I have been concerned about this issue for some time, in my Harmon Rocket. It goes kinda fast, and sometimes I hit pretty harsh bumps when I'm flying in the yellow arc. (yeah, I know, I should anticipate better.) I've often wondered if there's a way to check for metal fatigue or overstressing - is this magnaflux thing something that can be done to wing and horizontal stablizer spars? Is it a reasonably common procedure (ie, likely to be available in NZ)...or a real specialist kinda thing? Andrew ________________________________ Message 10 ____________________________________ Time: 11:55:49 PM PST US From: "Jan Mevis" Subject: RE: Yak-List: Maximum structural cruise I once did +9G and -5G on my Yak 50. No damage, theoretically allowed, but a very unwise thing to do. And I'll do it NEVER again, not with a Yak 50. Yak 50's are destined to be treated as oldtimers. Nice and smooth aerobatics, formation flying. That's it. The 55 is a much stronger built. But even then, why would you pull more than +6G or push more then -3G, unless you try to win Advanced competition ? And for Unlimited you could barely even participate with a 55. Jan YK50 RA2005K -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Sarah Tobin Sent: woensdag 29 juli 2009 0:52 Subject: RE: Yak-List: Maximum structural cruise 5 Gs? That's it? I haven't flown the 50, but in my 55, I routinely fly 6G positive and 3G negative. Heard anything regarding the 55? Smash --- On Tue, 7/28/09, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote: > From: Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E > Subject: RE: Yak-List: Maximum structural cruise > To: yak-list@matronics.com > Date: Tuesday, July 28, 2009, 8:31 AM > "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" > > > > > Comments: > > > In the Marine Corps, there really is no such thing as a Max > Mach Operating Limitation on most tactical aircraft .... I > am sure there is probably one for the prop driven aircraft, > but on the jets, the mach limit is that speed you reach > while going straight down in burner... If you happen to have > burner. > > Of note is the fact that we too are seeing major structural > fatigue problems in a lot of our older aircraft. That > was the single MAJOR REASON that the A-6E Intruder was > retired early. > > On my personal YAK-50, I was originally told that the > aircraft was rated at plus 9, negative 6 G. Then I did > a ton of research and found that you were supposed to RECORD > certain parameters of each flight and this added points to a > number that when it was met, the wings on the aircraft were > basically retired. In the case of the YAK-50, in many > cases the whole aircraft was "retired" sometimes after just > 50 hours of flight time. Of note is the fact that most > everyone pulls that recording equipment out of the 50's AND > 52's, and doesn't "bother with it anymore". Lot's of > other pilots have done this kind of thing before our YAK's > came on to the scene. Examples: T-34's. > AT-6's. Both of those aircraft types have experienced > the "WING OFF" warning light illuminating during > flight. With fatal results in every case... And most > of those were wearing chutes by the way. I have > personally limited my 50 to plus 5 G's and negative 2. > Even that is questionable, but I am willing to ! > take the risk, but do acknowledge that it IS a risk. > I also do not compete the aircraft anymore, and I don't > participate in any ACM stuff. > > Eddy current and magnafluxing tests are pretty much out of > my budget range. So... It's a risk. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of netmaster15@juno.com > Sent: Tuesday, July 28, 2009 2:15 > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > Doc, Thankyou for your response on the subject of " > max structural cruise" . If I understand you correctly > we are both saying the same thing; the water gets a bit > muddy when we try to reconcile simantic differences. eg, > reference your first paragraph: " > .....while operating in STRUCTURAL CRUISE > LIMITATION...." Please define "structural > cruise". Also, what discipline categorizes structural cruise > as a LIMITATION as opposed to a NORMAL OPERATING condition? > All Operations Manuals I have been exposed to in the > last 63 years cite Limitations as Vne, VA, Vlo, Vle, Vfe,max > allow. TO Gr WT, max fuel, max tire speed, max pressure > differential, max operating altitude, plus several other > operating limitations. All these limitations are derived > from one source; the TYPE CERTIFICATE AND DATA SHEETS and > amendments thereto, eg, supplemental type certificates if > applicable. Also in your first paragraph you use the > phrase "....while operating within their envelope...." > But you do no! > t specify what envelope you're referring to. I agree, > there is no yellow arc on the airspeed indicator in an F-5 > but there is certainly a Mach meter and a Max Mach > operating LIMITATION. Plainly, it is very difficult to > translate terminology between two different > disciplines. > > I'll have to finish this treatise at a later time; > I'm already beyond my curfew limitation. I look forward to > your continuing thoughts on this subject. BTW, I > currently own and fly both a YAK -50 and a Harmon > Rocket and you're correct, I don't want any major > dissassemblies at altitude so I'm always alert for new ways > to assure the aircraft remains in reuseable condition. > Cheers! > > Cliff > > ---------- Original Message ---------- > From: "ACTIVE NZ - Andrew" > To: > Subject: RE: Yak-List: Maximum structural cruise > Date: Tue, 28 Jul 2009 16:29:33 +1200 > > > > DOC > > Please excuse me for intruding on your list. I fly a Harmon > Rocket, (mainly) but eavesdrop on the Yak list cos I'm in a > partnership that is rebuilding a Yak-3 in New Zealand. > > Anyway... > > I have been concerned about this issue for some time, in my > Harmon Rocket. It goes kinda fast, and sometimes I hit > pretty harsh bumps when I'm flying in the yellow arc. (yeah, > I know, I should anticipate better.) I've often wondered if > there's a way to check for metal fatigue or overstressing - > is this magnaflux thing something that can be done to wing > and horizontal stablizer spars? Is it a reasonably common > procedure (ie, likely to be available in NZ)...or a real > specialist kinda thing? > > Andrew > > > > ________________________________ > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of Roger Kemp M.D. > Sent: Tuesday, July 28, 2009 3:30 PM > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > > > Cliff, > > AnswerYes I know of 2 aircraft that went down while > operating in structural cruise Limitation as you > say. Both were Class A accidents with 2 fatalities in each. > One an F-5F and the other a T-38. I served as the flight > surgeon representative to the SIB (safety investigation > board) on the F-5 and I was the interim representative on > the T-38 SIB. Four men died while operating their > aircraft within NORMAL OPERATION > PROCEDURE as you say. We call it differently since > we dont have a yellow arcs on our airspeed > indicators. Incidentally, one of the IPs in the F-5 > was a good friend of mine. So yes, I know > firsthand of two aircraft that failed while > operating within their envelope. > > Now the question I have for you is: Are you prepared to > totally bet your rosy pink on whatever Red Star Aircraft it > is you are flying? Have you NDId/ magnafluxed your > aircraft to determine if you have metal fatigue or not. > Its a military aircraft not a spam can. It was and > is operated like or as a military aircraft. Cruise limits > dont exist. Vne and G limits do. An you do not know > for dead nuts sure what the real structural (read > metal fatigue state) integrity of your spare or spine is. > You can only hope that the entries in that Eastern bloc > aircrafts log book really were done and not just > pencil whipped. Granted, these aircraft are tough as > nails but so are/ were the F-5, T-38, F-15, A-10, and the > F-16. Their wing are cracking. In some cases the wings are > falling off as well as their dorsal spines are breaking. You > just never know. > > Ohmake it 3 aircraft that I know of that > broke up while operating within their NORMAL > OPERATING LIMITS. I believe the St Louis Guard > lost a twin tail sissy to structural failure while > operating in normal ops limits approximately a > year and a half ago. That Eagle driver was lucky, he got out > with a shattered elbow and some contusions. Rumor has it > they are still extracting fragments of seat cushion from his > rosy pink after he sucked it up while tumbling/ > somersaulting in the pit while trying to figure out why his > jet was not responding any longer. > > By the way my comment initially was made in jest in > response to Sabers last line of his post. I was not > aware we had a MAX GUST LOAD on the YAK. > Maybe the CJ does. G limits yesVne yes > max crosswind limits yes.Max Gust Load ??? > > We do not have cocktail hours in any of the squadrons > I have served with either. Either the beer light was lit or > it was not. The beer light was lit when the last jet > landed. Cocktail hour... > > Doc > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of netmaster15@juno.com > Sent: Monday, July 27, 2009 3:35 PM > To: yak-list@matronics.com > Subject: RE: Yak-List: Maximum structural cruise > > > > Doc, How many people do you know who have > "busted their asses" due to exceeding max structural > cruise without exceeding Vne? This should raise the > questions: What is max structural cruise meant to protect? > and, Is max structural cruise a "LIMITATION" , or a NORMAL > OPERATION PROCEDURE? If the latter, then, I submit it is no > different than any other number within the yellow arc and > does not deserve to be over dignified beyond those numbers > within such parameter. In other words, it is nothing more > than cocktail information. If one insists upon operating > within the yellow arc, do not encounter turbulent air lest > you exceed MAX GUST LOAD; now there IS a number you > should know and understand beyond the cocktail hour. > > Cliff Umscheid > > ---------- Original Message ---------- > From: "Roger Kemp M.D." > To: > Subject: RE: Yak-List: Maximum structural cruise > Date: Mon, 27 Jul 2009 13:29:36 -0500 > > Just rememberthe ass you bust maybe your > own. > > doc > > > > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] > On Behalf Of jblake207@comcast.net > Sent: Monday, July 27, 2009 10:47 AM > To: yak-list@matronics.com > Subject: Re: Yak-List: Maximum structural cruise > > > > Find attached a "Vee" Speeds chart that I use for my > CJ. Developed from the manuals and from lots of > questions asked of people like Pappy, Sapp, Savarese and > others. > > > > If I were a lawyer, I'd make a comment about using at your > own risk and that this office cannot be held liable for any > incorrect data... blah, blah, blah. I'm not a lawyer, > so let me simply say use or lose. > > > > JB > > > > > ----- Original Message ----- > From: "Warren Hill" > To: yak-list@matronics.com > Sent: Sunday, July 26, 2009 10:12:26 PM GMT -06:00 > US/Canada Central > Subject: Yak-List: Maximum structural cruise > > > Fellow CJ-ers, > > I wonder if there is a consensus on a figure in knots for > maximum structural cruise for the CJ-6A? > > Warren Hill > Mesa, AZ > > On Jul 26, 2009, at 6:19 PM, Chris Wise wrote: > > > G'Day, > > > > Thanks to Walt, Pappy and Dennis for replying. > > The M14P has a rubber lip seal as well as a slinger, > like Walt says. > > The slinger by itself is inadequate, especially during > aeros. > > Any other advice would be appreciated re removing prop > reduction box > > and the prop shaft. > > > > Thanks and Cheers, > > Chris. > > > > > > > > > > > > -Matt Dralle, List ========= > > > > > > =================================== > ttp://www.matronics.com/Navigator?Yak-List > =================================== > tronics.com > =================================== > www.matronics.com/contribution > =================================== > > > > http://www.matronics.com/Navigator?Yak-List > http://forums.matronics.com > http://www.matronics.com/contribution > > > > =================================== > ttp://www.matronics.com/Navigator?Yak-List > =================================== > tronics.com > =================================== > www.matronics.com/contribution > =================================== > > > ky"Z+M4Gq(wrIQhaxr^jzZ("X,ZIJr*'!y:0ZwE,jwfffi0fr(Z(jBm > &j',r5h.+- > > > Forum - > FAQ, > - MATRONICS WEB FORUMS - > List Contribution Web Site - > -Matt > Dralle, List Admin. > > > > ------------------------------------------------------------------------------------- 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.