---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Sat 07/28/12: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:12 AM - Re: Re: Nanchang accident. (Warren Hill) 2. 11:47 AM - Re: Re: Nanchang accident. (Brian Lloyd) 3. 12:24 PM - Re: airshow comments (keithmckinley) 4. 02:14 PM - Re: Re: Nanchang accident. (Bill Geipel) 5. 02:37 PM - Re: Re: Nanchang accident. (Brian Lloyd) 6. 05:04 PM - Re: Re: Nanchang accident. (Byron Fox) 7. 06:20 PM - Re: Re: Nanchang accident. (Bill Geipel) 8. 06:21 PM - Re: Re: Nanchang accident. (Bill Geipel) ________________________________ Message 1 _____________________________________ Time: 11:12:37 AM PST US From: Warren Hill Subject: Re: Yak-List: Re: Nanchang accident. Brian, What the Lift Reserve Indicator is telling you is the lift status of the wing. Certainly one of the most critical items on takeoff and approach. It's indication is independent of density altitude, airspeed, loading, etc. Sounds a lot like AOA to me. Pure AOA, combined information, whatever... this is all just chat room semantics. It is an AOA indication direct or indirect and if it adds additional information, all the better. On takeoff and landing, I'll have my eyes in this more than the airspeed indicator. It is a lovely instrument, certainly worthy or consideration by anyone who is looking to move safety up to the next level. All of these indicators (Advanced AOA, Right Angle, Alpha Systems, InAir Instruments) add the same kind of extra, very valuable information which I have come to believe is the right information for these two important aspects of flight. However, to dismiss the LRI variation on this theme is disingenuous. Warren On Jul 26, 2012, at 8:55 PM, Brian Lloyd wrote: > Many people like the the LRI. Unfortunately, the LRI does NOT display AoA, at least not directly. AoA is a factor but I was never able to discern what that instrument was telling me. =46rom what I can tell, it displays AoA times airspeed which probably is just total lift. Regardless, it is DEFINITELY NOT pure AoA and cannot be treated as such. If you want AoA you need to get a different instrument. ________________________________ Message 2 _____________________________________ Time: 11:47:47 AM PST US Subject: Re: Yak-List: Re: Nanchang accident. From: Brian Lloyd On Sat, Jul 28, 2012 at 11:09 AM, Warren Hill wrote: > Brian, > > What the Lift Reserve Indicator is telling you is the lift status of the > wing. Certainly one of the most critical items on takeoff and approach. > It's indication is independent of density altitude, airspeed, loading, etc. > Sounds a lot like AOA to me. Pure AOA, combined information, whatever... > this is all just chat room semantics. It is an AOA indication direct or > indirect and if it adds additional information, all the better. On takeoff > and landing, I'll have my eyes in this more than the airspeed indicator. It > is a lovely instrument, certainly worthy or consideration by anyone who is > looking to move safety up to the next level. All of these indicators > (Advanced AOA, Right Angle, Alpha Systems, InAir Instruments) add the same > kind of extra, very valuable information which I have come to believe is > the right information for these two important aspects of flight. However, > to dismiss the LRI variation on this theme is disingenuous. > Many of the people on this list have flown aircraft that have an instrument that displays alpha, the actual angle-of-attack of the wing. If you are used to flying with such an instrument then an instrument that purports to deliver that information but doesn't can lead to erroneous decisions. So, to me, the key is to know *exactly* what the instrument is telling you. When I first encountered the LRI I considered buying one because I really like knowing just where the airfoil is operating. I studied the instrument and became confused because I couldn't see that it could work as a true AoA instrument. Then then went and read the patent. Again I couldn't see how it would function as a true AoA instrument. I then borrowed an aircraft with an LRI installed an did my own flight testing. I confirmed for myself that it does not behave as a true AoA indicator. Now that is not to say that it is not useful, far from it. A properly installed LRI will always properly indicate critical AoA, i.e. stall. From that point of view it is quite useful. Also, in unaccelerated flight, e.g. on a stabilized approach, it does a very good job of telling you just how far you are from stall so that is also very useful. But as you load up the airframe in maneuvering flight, the indications become less useful. A needle indication that indicates substantial margin from stall in unaccelerated flight may actually be quite close to critical AoA in accelerated flight. So, while I am not denigrating the LRI, I am trying to make sure that others here understand that it is NOT displaying alpha. That's all. At the same time I looked at the Advanced Flight Systems AoA, and the RiteAngle AoA. I opted to purchase the AFS AoA Pro (I liked its installation simplicity relative to the RiteAngle) and installed it in my CJ6A. I tested it over flight loads from 0.5G to 5G and verified that it properly displays alpha under all accelerations. Over the entire flight regime it shows zero lift/zero alpha regardless of airspeed (really useful when you know you have blown a maneuver and want to exit gracefully without having the airframe depart) and it shows me exactly how much more I can pull before I will reach critical AoA. For these reasons I feel that the AFS AoA met my needs far better than the LRI. So, I know that many of you think I am an asshole and that I am unfairly denigrating Bill Geipel's invention just because I AM an asshole. But I would like you to reconsider and do your own analysis of the various instruments knowing what they tell you. If after doing that you decide you like the LRI better then I encourage you to install one. I found that it did not tell me what I wanted to know and instead opted for a different instrument. And I wanted the pilots here who have flown using an AoA indicator to be aware that the LRI might not be telling them what they think it is telling them. But the LRI is indeed a useful instrument. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 brian@lloyd.com +1.767.617.1365 (Dominica) +1.916.877.5067 (USA) ________________________________ Message 3 _____________________________________ Time: 12:24:27 PM PST US Subject: Yak-List: Re: airshow comments From: "keithmckinley" MY favorite is Wall Mart Warbird! Btw, when you hear those comments and feel a need to respond, ask them what airplane they own. Otherwise enjoy the show and the free gas. -------- Keith McKinley 700HS KFIT Read this topic online here: http://forums.matronics.com/viewtopic.php?p=379424#379424 ________________________________ Message 4 _____________________________________ Time: 02:14:12 PM PST US Subject: Re: Yak-List: Re: Nanchang accident. From: Bill Geipel When you think about it, who cares what the angle of attack is or if it is r eal AOA or what the critical AOA is i.e. 15 units. Cessna never told me at w hat angle the wing will stall so I don't really care. What I do know from al l these units is where the wing will stall. Not much more needed. I know for a fact when the LRI is loaded up in an accelerated maneuver it is still acc urate. As soon as the needle hits the critical AOA, you stall. Whether its 6 0 or 160 kts. The only unit that displays true AOA is Rite Angle. It actuall y has a little wing flying in undisturbed air staying parallel to the relati ve wind. The rest use pressure differential. They all have 2 ports, they mea sure the difference. They all tell how much lift is still available in the wing. They tell you no t when the wing will buffet, but when it actually departs. Pick your price, y our display choice, many lites, few lites, chevrons, or analog gauge, and ha ve fun. When I'm out mixing it up with the boys, I can pull until I feel the rumble, the needle or lights are approaching L/D max, that all means I'm getting ma x performance from my wing. Pull anymore, I lose,(stall), pull any less I l ose. ( The fight). Bill On Jul 28, 2012, at 12:45 PM, Brian Lloyd wrote: > On Sat, Jul 28, 2012 at 11:09 AM, Warren Hill wrote: > Brian, > > What the Lift Reserve Indicator is telling you is the lift status of the w ing. Certainly one of the most critical items on takeoff and approach. It's i ndication is independent of density altitude, airspeed, loading, etc. Sounds a lot like AOA to me. Pure AOA, combined information, whatever... this is a ll just chat room semantics. It is an AOA indication direct or indirect and i f it adds additional information, all the better. On takeoff and landing, I' ll have my eyes in this more than the airspeed indicator. It is a lovely ins trument, certainly worthy or consideration by anyone who is looking to move s afety up to the next level. All of these indicators (Advanced AOA, Right Ang le, Alpha Systems, InAir Instruments) add the same kind of extra, very valua ble information which I have come to believe is the right information for th ese two important aspects of flight. However, to dismiss the LRI variation o n this theme is disingenuous. > > Many of the people on this list have flown aircraft that have an instrumen t that displays alpha, the actual angle-of-attack of the wing. If you are us ed to flying with such an instrument then an instrument that purports to del iver that information but doesn't can lead to erroneous decisions. So, to me , the key is to know *exactly* what the instrument is telling you. > > When I first encountered the LRI I considered buying one because I really l ike knowing just where the airfoil is operating. I studied the instrument an d became confused because I couldn't see that it could work as a true AoA in strument. Then then went and read the patent. Again I couldn't see how it wo uld function as a true AoA instrument. I then borrowed an aircraft with an L RI installed an did my own flight testing. I confirmed for myself that it do es not behave as a true AoA indicator. > > Now that is not to say that it is not useful, far from it. A properly inst alled LRI will always properly indicate critical AoA, i.e. stall. =46rom tha t point of view it is quite useful. Also, in unaccelerated flight, e.g. on a stabilized approach, it does a very good job of telling you just how far yo u are from stall so that is also very useful. But as you load up the airfram e in maneuvering flight, the indications become less useful. A needle indica tion that indicates substantial margin from stall in unaccelerated flight ma y actually be quite close to critical AoA in accelerated flight. So, while I am not denigrating the LRI, I am trying to make sure that others here under stand that it is NOT displaying alpha. That's all. > > At the same time I looked at the Advanced Flight Systems AoA, and the Rite Angle AoA. I opted to purchase the AFS AoA Pro (I liked its installation sim plicity relative to the RiteAngle) and installed it in my CJ6A. I tested it o ver flight loads from 0.5G to 5G and verified that it properly displays alph a under all accelerations. Over the entire flight regime it shows zero lift/ zero alpha regardless of airspeed (really useful when you know you have blow n a maneuver and want to exit gracefully without having the airframe depart) and it shows me exactly how much more I can pull before I will reach critic al AoA. For these reasons I feel that the AFS AoA met my needs far better th an the LRI. > > So, I know that many of you think I am an asshole and that I am unfairly d enigrating Bill Geipel's invention just because I AM an asshole. But I would like you to reconsider and do your own analysis of the various instruments k nowing what they tell you. If after doing that you decide you like the LRI b etter then I encourage you to install one. I found that it did not tell me w hat I wanted to know and instead opted for a different instrument. And I wan ted the pilots here who have flown using an AoA indicator to be aware that t he LRI might not be telling them what they think it is telling them. > > But the LRI is indeed a useful instrument. > > -- > Brian Lloyd, WB6RQN/J79BPL > 3191 Western Dr. > Cameron Park, CA 95682 > brian@lloyd.com > +1.767.617.1365 (Dominica) > +1.916.877.5067 (USA) > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 5 _____________________________________ Time: 02:37:08 PM PST US Subject: Re: Yak-List: Re: Nanchang accident. From: Brian Lloyd On Sat, Jul 28, 2012 at 2:11 PM, Bill Geipel wrote: > When you think about it, who cares what the angle of attack is or if it is > real AOA or what the critical AOA is i.e. 15 units. > Well, actually, I do. And I understand that you do not and that is just fine. > Cessna never told me at what angle the wing will stall so I don't really > care. > Well, I don't care about the actual angle either, just where I am between an alpha of zero and critical AoA. > What I do know from all these units is where the wing will stall. Not much > more needed. I know for a fact when the LRI is loaded up in an accelerated > maneuver it is still accurate. > But only WRT critical AoA. The LRI specifically is not helpful to find an alpha of zero or the alpha that produces best L/D, other points I really like to know, especially if I am vertical. > As soon as the needle hits the critical AOA, you stall. Whether its 60 or > 160 kts. The only unit that displays true AOA is Rite Angle. It actually > has a little wing flying in undisturbed air staying parallel to the > relative wind. The rest use pressure differential. They all have 2 ports, > they measure the difference. > Well, the Advanced Flight Systems AoA is a four-port device. It actually samples pitot and static pressures as well. That way it can correct for IAS leaving just AoA on the display. > > They all tell how much lift is still available in the wing. > I guess that is where you and I differ. I am not really interested in the lift available in the wing but what AoA the wing is operating at and the percentage of increase in AoA remains to me. It tells me how much harder I *can* pull, where best L/D is, and it tells me where to put the stick to achieve an alpha of zero if I want the aircraft ballistic or if I've botched a maneuver and want to fall through without stalling and/or spinning. Doing loops and blow your entry speed or initial pull? You can see at a glance you aren't going to make so so you just pop the stick to zero alpha and let the nose fall through. No "falling out the top" of a loop ever again. That is where you want to know alpha at something other than critical AoA (stall). They tell you not when the wing will buffet, but when it actually departs. > Pick your price, your display choice, many lites, few lites, chevrons, or > analog gauge, and have fun. > Well, you do have to know what they are telling you so that you don't ask the display for information it can't give you. > When I'm out mixing it up with the boys, I can pull until I feel the > rumble, the needle or lights are approaching L/D max, that all means I'm > getting max performance from my wing. Pull anymore, I lose,(stall), pull > any less I lose. ( The fight). > And if you are happy with your instrument then that is the instrument you should use. In my case I want information your instrument doesn't give me so it didn't serve my purposes. So, I am not trying to denigrate your LRI. I am just trying to make sure that the people on the list are aware that these instruments are NOT all equal, especially the pilots who have expectations from flying heavier iron that had true AoA instruments in them. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 brian@lloyd.com +1.767.617.1365 (Dominica) +1.916.877.5067 (USA) ________________________________ Message 6 _____________________________________ Time: 05:04:45 PM PST US Subject: Re: Yak-List: Re: Nanchang accident. From: Byron Fox Installed a LRI in our CJ about 9 years ago. It has performed reliably, and was particularly helpful at Truckee Airport i n the Sierras on warm 9,000' density altitude days a few weeks ago. Provides comfort for a day-to-day sea level pilot. ...Blitz Sent from my iPhone On Jul 28, 2012, at 11:09 AM, Warren Hill wrote: > Brian, > > What the Lift Reserve Indicator is telling you is the lift status of the w ing. Certainly one of the most critical items on takeoff and approach. It's i ndication is independent of density altitude, airspeed, loading, etc. Sounds a lot like AOA to me. Pure AOA, combined information, whatever... this is a ll just chat room semantics. It is an AOA indication direct or indirect and i f it adds additional information, all the better. On takeoff and landing, I' ll have my eyes in this more than the airspeed indicator. It is a lovely ins trument, certainly worthy or consideration by anyone who is looking to move s afety up to the next level. All of these indicators (Advanced AOA, Right Ang le, Alpha Systems, InAir Instruments) add the same kind of extra, very valua ble information which I have come to believe is the right information for th ese two important aspects of flight. However, to dismiss the LRI variation o n this theme is disingenuous. > > Warren > > > > On Jul 26, 2012, at 8:55 PM, Brian Lloyd wrote: > >> Many people like the the LRI. Unfortunately, the LRI does NOT display AoA , at least not directly. AoA is a factor but I was never able to discern wha t that instrument was telling me. =46rom what I can tell, it displays AoA ti mes airspeed which probably is just total lift. Regardless, it is DEFINITELY NOT pure AoA and cannot be treated as such. If you want AoA you need to get a different instrument. > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 7 _____________________________________ Time: 06:20:33 PM PST US From: Bill Geipel Subject: Re: Yak-List: Re: Nanchang accident. You care what AOA is. Doesn't help you fly better. LRI is helpful maintaining L/D max. Vx. Cessna spent the money to determine i t. LRI will maintain it as that speed changes with altitude. Advanced system has has four ports, two came with the airplane. It still is m easuring pressure differential. We don't differ. They all tell you that. I've used them all, studied them al l and you can gain what you Ned from them all. The harder you pull, the furt her toward the red they all move. When You get there stop pulling. There is n o hidden or difficult science to any of the AOA systems. If there were, I co uldn't have figured it out. As long as you know where it will stall, you know everything. Most normal av iators will have what they need. I have zero interest and am not promoting any one system. They were all desi gned to do the same thing. Different ways to skin a cat. Bill On Jul 28, 2012, at 3:34 PM, Brian Lloyd wrote: > > > On Sat, Jul 28, 2012 at 2:11 PM, Bill Geipel wro te: > When you think about it, who cares what the angle of attack is or if it is real AOA or what the critical AOA is i.e. 15 units. > > Well, actually, I do. And I understand that you do not and that is just fi ne. > > Cessna never told me at what angle the wing will stall so I don't really c are. > > Well, I don't care about the actual angle either, just where I am between a n alpha of zero and critical AoA. > > What I do know from all these units is where the wing will stall. Not much more needed. I know for a fact when the LRI is loaded up in an accelerated m aneuver it is still accurate. > > But only WRT critical AoA. The LRI specifically is not helpful to find an a lpha of zero or the alpha that produces best L/D, other points I really like to know, especially if I am vertical. > > As soon as the needle hits the critical AOA, you stall. Whether its 60 or 1 60 kts. The only unit that displays true AOA is Rite Angle. It actually has a little wing flying in undisturbed air staying parallel to the relative wind . The rest use pressure differential. They all have 2 ports, they measure th e difference. > > Well, the Advanced Flight Systems AoA is a four-port device. It actually s amples pitot and static pressures as well. That way it can correct for IAS l eaving just AoA on the display. > > > They all tell how much lift is still available in the wing. > > I guess that is where you and I differ. I am not really interested in the l ift available in the wing but what AoA the wing is operating at and the perc entage of increase in AoA remains to me. It tells me how much harder I *can* pull, where best L/D is, and it tells me where to put the stick to achieve a n alpha of zero if I want the aircraft ballistic or if I've botched a maneuv er and want to fall through without stalling and/or spinning. Doing loops an d blow your entry speed or initial pull? You can see at a glance you aren't g oing to make so so you just pop the stick to zero alpha and let the nose fal l through. No "falling out the top" of a loop ever again. That is where you w ant to know alpha at something other than critical AoA (stall). > > They tell you not when the wing will buffet, but when it actually departs. Pick your price, your display choice, many lites, few lites, chevrons, or a nalog gauge, and have fun. > > Well, you do have to know what they are telling you so that you don't ask t he display for information it can't give you. > > When I'm out mixing it up with the boys, I can pull until I feel the rumbl e, the needle or lights are approaching L/D max, that all means I'm getting m ax performance from my wing. Pull anymore, I lose,(stall), pull any less I l ose. ( The fight). > > And if you are happy with your instrument then that is the instrument you s hould use. In my case I want information your instrument doesn't give me so i t didn't serve my purposes. > > So, I am not trying to denigrate your LRI. I am just trying to make sure t hat the people on the list are aware that these instruments are NOT all equa l, especially the pilots who have expectations from flying heavier iron that had true AoA instruments in them. > > -- > Brian Lloyd, WB6RQN/J79BPL > 3191 Western Dr. > Cameron Park, CA 95682 > brian@lloyd.com > +1.767.617.1365 (Dominica) > +1.916.877.5067 (USA) > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 8 _____________________________________ Time: 06:21:15 PM PST US Subject: Re: Yak-List: Re: Nanchang accident. From: Bill Geipel Smart aviator. Just need to convince the FAA to get rid of the airspeed indi cator. Bill On Jul 28, 2012, at 6:02 PM, Byron Fox wrote: > Installed a LRI in our CJ about 9 years ago. > It has performed reliably, and was particularly helpful at Truckee Airport in the Sierras on warm 9,000' density altitude days a few weeks ago. Provid es comfort for a day-to-day sea level pilot. > > ...Blitz > > Sent from my iPhone > > On Jul 28, 2012, at 11:09 AM, Warren Hill wrote: > >> Brian, >> >> What the Lift Reserve Indicator is telling you is the lift status of the w ing. Certainly one of the most critical items on takeoff and approach. It's i ndication is independent of density altitude, airspeed, loading, etc. Sounds a lot like AOA to me. Pure AOA, combined information, whatever... this is a ll just chat room semantics. It is an AOA indication direct or indirect and i f it adds additional information, all the better. On takeoff and landing, I' ll have my eyes in this more than the airspeed indicator. It is a lovely ins trument, certainly worthy or consideration by anyone who is looking to move s afety up to the next level. All of these indicators (Advanced AOA, Right Ang le, Alpha Systems, InAir Instruments) add the same kind of extra, very valua ble information which I have come to believe is the right information for th ese two important aspects of flight. However, to dismiss the LRI variation o n this theme is disingenuous. >> >> Warren >> >> >> >> On Jul 26, 2012, at 8:55 PM, Brian Lloyd wrote: >> >>> Many people like the the LRI. Unfortunately, the LRI does NOT display Ao A, at least not directly. AoA is a factor but I was never able to discern wh at that instrument was telling me. =46rom what I can tell, it displays AoA t imes airspeed which probably is just total lift. Regardless, it is DEFINITEL Y NOT pure AoA and cannot be treated as such. If you want AoA you need to ge t a different instrument. >> >> >> >> ========================= ========= >> //www.matronics.com/Navigator?Yak-List >> ========================= ========= >> cs.com >> ========================= ========= >> 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.