Van's Air Force
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Lift Reserve Indicator
- Thread starter tin man
- Start date
hevansrv7a
Well Known Member
Only With
I am only half qualified to respond. I installed one from the beginning. I have flown other aircraft without, of course.
1] I followed the installation instructions and never had to adjust the angle of the probe.
2] I does in fact indicate the same place on the dial for stalls or minimum sink while IAS varies with conditions of atmosphere and load.
3] Once you know where the stall is, it is very nice for making short approaches while getting on the backside of the power curve. It is just a lot more useful information than a stall horn, for example.
4] While I have not flown with other AOA's, I think the precision is greater because of the sweep of the dial and the number of tick marks.
5] My minimum sink reading/speed is such that my Best L/D is just off the scale to the right. My best guess at best angle of climb is that it's at full scale to the right, just shy of the peg. While I'm not certain because of the fixed pitch prop, I can hit that mark very consistently and airspeed alone can't do that.
6] If my fancy glass panel ever failed entirely I'd still have this nice non-electric steam dial with which to make a good landing regardless of load or density altitude.
7] I would do it again.
I am only half qualified to respond. I installed one from the beginning. I have flown other aircraft without, of course.
1] I followed the installation instructions and never had to adjust the angle of the probe.
2] I does in fact indicate the same place on the dial for stalls or minimum sink while IAS varies with conditions of atmosphere and load.
3] Once you know where the stall is, it is very nice for making short approaches while getting on the backside of the power curve. It is just a lot more useful information than a stall horn, for example.
4] While I have not flown with other AOA's, I think the precision is greater because of the sweep of the dial and the number of tick marks.
5] My minimum sink reading/speed is such that my Best L/D is just off the scale to the right. My best guess at best angle of climb is that it's at full scale to the right, just shy of the peg. While I'm not certain because of the fixed pitch prop, I can hit that mark very consistently and airspeed alone can't do that.
6] If my fancy glass panel ever failed entirely I'd still have this nice non-electric steam dial with which to make a good landing regardless of load or density altitude.
7] I would do it again.
gmcjetpilot
Well Known Member
Yea people love AOA indicators
"Lift Reserve Indicator" or LRI is a trademark or brand name of one AOA (angle of attack) on the market. The LRI is indeed a AOA indicator. It is all pneumatic, meaning it does not use electrical power to work. The gauge is a sensitive differential pressure gauge. It uses two air ports at different angles, like a pitot. The difference in pressure between ports is calibrated to indicate AOA on the gauge. I have not personally used the LRI product.
There are many other AOA products on the experimental market, and except for the LRI, all of other ones I know of use electronics to get the job done. Many (including LRI) use differential pressure on two port method. One brand (AFS) uses flush ports installed in wing wing tips surface. Others require some kind of "mast" exposed or sticking out (LRI, Dynon). One brand, Rite-Angle AOA, uses an actual "AOA vane" like the big jets do. This AOA vane (like a weather vane) is attached to a little transducer, that measures actual angle of the relative air flow, no differential pressure at all. Both differential pressure and vane method work. The vane method is a direct reading of AOA and the Diff press is a "derived" method.
Just to mention it there is the "Piper stall tab" mounted in the leading edge. Near stall (critical AOA), it gives you a buzzer warning but no AOA gauge or display. Cessna does a similar thing but their stall warning is totally pneumatic, like a flute player blowing over the mouthpiece, which is closer to the LRI. The Piper tab is like the rite-angel AOA vane in a way. Both Piper and Cessna mount in the leading edge of the wing. You can buy a Piper style stall tab from Spruce for $90, Reddish. This at least will give you a wake up call, "hey dummy you are near stall". The down side it gives no other AOA indication other than when you are near stall. Some AOA indicators like the LRI require you look at it; they have no buzzer or aural warning. That might be the biggest negative to the LRI, there is NO aural warning or flashing light. So it is critical you place it in the panel so its in you normal scan. Some folks mount the AOA on-top of the glare-shield, since on visual approach you will most likely have your eyes outside. Also the LRI does not make that small adjustment for flaps up or down like other units. The Dynon does not adjust for flaps but the AFS and Rite-angle do.
The LRI is passive, no electronics, just pitot lines. The electronic ones add bells and whistles like audio/voice alarms or other display options, as well as flap position compensation. They all work on similar principals regardless, relative air flow to the chord of the wing, ie AOA.
Some of the most popular AOA's are ones integrated with EFIS products like Dynon and Advance Flight Systems Inc., which makes a stand alone and EFIS integrated AOA. The Adv Flt Sys AOA has both stand alone and EFIS displays. Then Dynon comes with the EFIS but requires you buy their special pitot mast.
*Reddish stall tab (buzzer only, no AOA $100)
*The LRI has dedicated two port mast sticking out LINK ($450-$550)
*The Dynon integrates the AOA port with a pitot. ($200-$400 opinion with EFIS)
*Adv Flt Sys, two flush ports in wing upper/lower surfaces LINK ($890 stand alone or EFIS option)
*Rite-Angle AOA Lancair, Wingtip vane, Pitot/Vane combo, RV AOA vane ($800 stand alone)
As you know regardless of "attitude" or indicated airspeed you can stall. Also stall IAS varies with weight and load factor (e.g., pulling g's in a turn). The critical AOA (stall) is the same no matter what. Knowing AOA is a good thing.
Can you fly without AOA? Sure most GA pilots do fly just on indicated air speed. We use the 1.3 or 30% margin to a "known" Vso or Vs1 on approach (w/ some extra for the kids or wind). You have to consciously be aware IAS to stall goes up when ever you "pull g's", sustained steep turn or pulling back on the stick, pitching up in any attitude. Our gross weight from min to max does not vary much, so we can pretty much use one conservative value for 1g stall (Vso/Vs1) at max weight, which is about a 5 mph spread. If you really want to fly at the edge of the envelope for short fields, than yes, AOA and weight counts, a lot. In a large jet, weight difference from min to max is great, so stall speed varies significantly. That's why pilots of larger planes must do detailed weight and speed calculations before every takeoff and landing. When you're on the airline, you hear the obligatory Captain PA, "we're doing some last minute paper work", it really means the FO is calculating W&B and speeds while the Captain talks. It's that or they're adding up their per diem check for the month.
You have lots of choices. LRI is a good one, just not as fancy as others. Another choice, is the DIY, study the principle and make your own? There are plans on the web to make your own LRI style AOA indicator for $60 + sweat equity. I have the Dynon AOA only because I had the EFIS already. It was only a $200 option. My older Dynon does not have an audio warning for critical AOA (stall), but I think the new ones do. Audio is kind of a good idea. Say you lose you engine and are gliding, maneuvering and you are distracted. That buzzer or flashing light might save you back side. On the down side I saw a video of T/G's using the AFS AOA. The AOA warning was going off on takeoff and landing and was distracting and annoying. On the other hand, why do people stall with an airspeed indicator? They're not looking or conscious of their airspeed. The RV gives OK aerodynamic seat-O-pant stall warning, but close to the ground, near stall you have a high sink situation. That is not pretty. If you don't have speed approaching the ground to flare you're in deep kimchi. An AOA can give you that margin in an emergency if you know who it use it. Regardless, know your V-speeds and practice your approach to stall and full stall recoveries (at altitude). An AOA is no substitute for airmanship. Be careful.
PS HUD - Heads Up Display idea for LED AOA indicators: LINK
People who have them (any AOA indicator) love them and swear by them. I've not used one in a RV. I have used them in other planes. This is a must read for you. Sam's builder site has a nice right up of the LRI installation and operation, LINK.Looking for first hand feedback from those that have flown without one and then later installed one in an RV.
Thanks in advance, Tom - looking for a spring project.
"Lift Reserve Indicator" or LRI is a trademark or brand name of one AOA (angle of attack) on the market. The LRI is indeed a AOA indicator. It is all pneumatic, meaning it does not use electrical power to work. The gauge is a sensitive differential pressure gauge. It uses two air ports at different angles, like a pitot. The difference in pressure between ports is calibrated to indicate AOA on the gauge. I have not personally used the LRI product.
There are many other AOA products on the experimental market, and except for the LRI, all of other ones I know of use electronics to get the job done. Many (including LRI) use differential pressure on two port method. One brand (AFS) uses flush ports installed in wing wing tips surface. Others require some kind of "mast" exposed or sticking out (LRI, Dynon). One brand, Rite-Angle AOA, uses an actual "AOA vane" like the big jets do. This AOA vane (like a weather vane) is attached to a little transducer, that measures actual angle of the relative air flow, no differential pressure at all. Both differential pressure and vane method work. The vane method is a direct reading of AOA and the Diff press is a "derived" method.
Just to mention it there is the "Piper stall tab" mounted in the leading edge. Near stall (critical AOA), it gives you a buzzer warning but no AOA gauge or display. Cessna does a similar thing but their stall warning is totally pneumatic, like a flute player blowing over the mouthpiece, which is closer to the LRI. The Piper tab is like the rite-angel AOA vane in a way. Both Piper and Cessna mount in the leading edge of the wing. You can buy a Piper style stall tab from Spruce for $90, Reddish. This at least will give you a wake up call, "hey dummy you are near stall". The down side it gives no other AOA indication other than when you are near stall. Some AOA indicators like the LRI require you look at it; they have no buzzer or aural warning. That might be the biggest negative to the LRI, there is NO aural warning or flashing light. So it is critical you place it in the panel so its in you normal scan. Some folks mount the AOA on-top of the glare-shield, since on visual approach you will most likely have your eyes outside. Also the LRI does not make that small adjustment for flaps up or down like other units. The Dynon does not adjust for flaps but the AFS and Rite-angle do.
The LRI is passive, no electronics, just pitot lines. The electronic ones add bells and whistles like audio/voice alarms or other display options, as well as flap position compensation. They all work on similar principals regardless, relative air flow to the chord of the wing, ie AOA.
Some of the most popular AOA's are ones integrated with EFIS products like Dynon and Advance Flight Systems Inc., which makes a stand alone and EFIS integrated AOA. The Adv Flt Sys AOA has both stand alone and EFIS displays. Then Dynon comes with the EFIS but requires you buy their special pitot mast.
*Reddish stall tab (buzzer only, no AOA $100)
*The LRI has dedicated two port mast sticking out LINK ($450-$550)
*The Dynon integrates the AOA port with a pitot. ($200-$400 opinion with EFIS)
*Adv Flt Sys, two flush ports in wing upper/lower surfaces LINK ($890 stand alone or EFIS option)
*Rite-Angle AOA Lancair, Wingtip vane, Pitot/Vane combo, RV AOA vane ($800 stand alone)
As you know regardless of "attitude" or indicated airspeed you can stall. Also stall IAS varies with weight and load factor (e.g., pulling g's in a turn). The critical AOA (stall) is the same no matter what. Knowing AOA is a good thing.
Can you fly without AOA? Sure most GA pilots do fly just on indicated air speed. We use the 1.3 or 30% margin to a "known" Vso or Vs1 on approach (w/ some extra for the kids or wind). You have to consciously be aware IAS to stall goes up when ever you "pull g's", sustained steep turn or pulling back on the stick, pitching up in any attitude. Our gross weight from min to max does not vary much, so we can pretty much use one conservative value for 1g stall (Vso/Vs1) at max weight, which is about a 5 mph spread. If you really want to fly at the edge of the envelope for short fields, than yes, AOA and weight counts, a lot. In a large jet, weight difference from min to max is great, so stall speed varies significantly. That's why pilots of larger planes must do detailed weight and speed calculations before every takeoff and landing. When you're on the airline, you hear the obligatory Captain PA, "we're doing some last minute paper work", it really means the FO is calculating W&B and speeds while the Captain talks. It's that or they're adding up their per diem check for the month.
You have lots of choices. LRI is a good one, just not as fancy as others. Another choice, is the DIY, study the principle and make your own? There are plans on the web to make your own LRI style AOA indicator for $60 + sweat equity. I have the Dynon AOA only because I had the EFIS already. It was only a $200 option. My older Dynon does not have an audio warning for critical AOA (stall), but I think the new ones do. Audio is kind of a good idea. Say you lose you engine and are gliding, maneuvering and you are distracted. That buzzer or flashing light might save you back side. On the down side I saw a video of T/G's using the AFS AOA. The AOA warning was going off on takeoff and landing and was distracting and annoying. On the other hand, why do people stall with an airspeed indicator? They're not looking or conscious of their airspeed. The RV gives OK aerodynamic seat-O-pant stall warning, but close to the ground, near stall you have a high sink situation. That is not pretty. If you don't have speed approaching the ground to flare you're in deep kimchi. An AOA can give you that margin in an emergency if you know who it use it. Regardless, know your V-speeds and practice your approach to stall and full stall recoveries (at altitude). An AOA is no substitute for airmanship. Be careful.
PS HUD - Heads Up Display idea for LED AOA indicators: LINK
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Sam Buchanan
been here awhile
Looking for first hand feedback from those that have flown without one and then later installed one in an RV.
Thanks in advance
Tom
looking for a spring project.
Just in case you missed the link in George's post, here are details of the installation of the LRI in my flying RV-6:
http://thervjournal.com/liftreserve.htm
I highly recommend the LRI based on several hundred hours of use. It is a great backup for an EFIS and will get you safely on the ground if the rest of the panel takes a hike.
hibeam
Active Member
Will never build another plane without one.
I have the LRI installed in an RV-9A and love it. I don't look at the airspeed for TO or Ldng anymore. Another safety feature is trimming for slow flight while waiting over Rush lake at OSH without running up the tail of the spam cans. AOA gives you the correct flying /approach/climbing speed regardless of humidity, heat or degree of bank. Let's you land slowest safe speed with confidence.
I mounted mine where the ASI usually sits in the six pack panel.
Add to the safety features the fact that it is anolog and needs no electricity makes it invaluable.
Gene
I have the LRI installed in an RV-9A and love it. I don't look at the airspeed for TO or Ldng anymore. Another safety feature is trimming for slow flight while waiting over Rush lake at OSH without running up the tail of the spam cans. AOA gives you the correct flying /approach/climbing speed regardless of humidity, heat or degree of bank. Let's you land slowest safe speed with confidence.
I mounted mine where the ASI usually sits in the six pack panel.
Add to the safety features the fact that it is anolog and needs no electricity makes it invaluable.
Gene
Jerry Cochran
Well Known Member
Thanx Geo!
George,
That's a great informative piece you just did on LRI's, most info I've found in one place on them. Keep the good info coming and never mind the t-shirts...
Jerry
George,
That's a great informative piece you just did on LRI's, most info I've found in one place on them. Keep the good info coming and never mind the t-shirts...
Jerry
LRI company still open? LRI needle sticking, need help
This thread has been dormant for awhile, but I thought I'd try. We have a Lift Reserve Indicator installed. For awhile now the needle has been sticking on the right peg making it less useful as we approach lower speeds during landing phase, etc. You can't rely on the reading until you reach up and tap it..
We're reached out to InAir Instruments Via their Phone Number and Email with no response.
http://www.liftreserve.com/
Does anyone have any experience fixing a sticking needle or know the status of the company or another way of getting in contact with them?
Appreciate any help, thanks!
This thread has been dormant for awhile, but I thought I'd try. We have a Lift Reserve Indicator installed. For awhile now the needle has been sticking on the right peg making it less useful as we approach lower speeds during landing phase, etc. You can't rely on the reading until you reach up and tap it..
We're reached out to InAir Instruments Via their Phone Number and Email with no response.
http://www.liftreserve.com/
Does anyone have any experience fixing a sticking needle or know the status of the company or another way of getting in contact with them?
Appreciate any help, thanks!
Ed_Wischmeyer
Well Known Member
I think that the LRI product now is different from the older LRIs, but I'm not sure. The older LRIs were a combination of AOA and airspeed, not just AOA, to give lift reserve, that is, how much extra lift you could get out of the wing before you ran out of airspeed or ran out of AOA. If you're at high AOA already, the wing can't give much more lift before you run out of AOA. And if you're at low airspeed, the wing can't give much more lift, even if you're not close to critical AOA. The 1982 patent (US4559822A) somehow does not cite the 1967 patent (US3470740A) and although I skimmed them, I did not study them.
So far I've got 170 hours on a visual AOA (heads down on the primary flight display), and occasionally it comes off scale and that's interesting. Personally, however, I think that a lot of this AOA stuff is poorly thought through hype. Aural AOA, i.e., progressive stall warning, sure, I'll buy that. But I have as yet to read anywhere as to how one adjusts AOA on final for reported winds and gusts, whereas that's easy to do with airspeed. And I've got maybe 700 hours in airplanes and gliders with no stall warning systems at all. I don't have any AOA / stall warning in the RV-8 and don't miss it.
And as for visual AOA displays, if you're too busy to look at the airspeed, why would you not also be too busy to look at AOA? And as for glareshield mounted displays, they can be okay if you actually look at them, but "cognitive capture" (related terms are inattentional blindness, tunnel vision and target fixation) means that you can look right past them if you're stressed and focused intently on the runway. Also, on an overly steep base to final turn, the AOA indicator could be so offset from where runway is in the canopy as to be ignorable in your peripheral vision.
When push comes to shove, and the pilot is so stressed / focused on the runway that cognitive capture means that he doesn't see a visual AOA indicator, and similarly doesn't hear a stall warning, what good are they? Evaluating AOA on a calm day, straight in approach is nigh unto worthless at best, deliberate falsification at worst.
So far I've got 170 hours on a visual AOA (heads down on the primary flight display), and occasionally it comes off scale and that's interesting. Personally, however, I think that a lot of this AOA stuff is poorly thought through hype. Aural AOA, i.e., progressive stall warning, sure, I'll buy that. But I have as yet to read anywhere as to how one adjusts AOA on final for reported winds and gusts, whereas that's easy to do with airspeed. And I've got maybe 700 hours in airplanes and gliders with no stall warning systems at all. I don't have any AOA / stall warning in the RV-8 and don't miss it.
And as for visual AOA displays, if you're too busy to look at the airspeed, why would you not also be too busy to look at AOA? And as for glareshield mounted displays, they can be okay if you actually look at them, but "cognitive capture" (related terms are inattentional blindness, tunnel vision and target fixation) means that you can look right past them if you're stressed and focused intently on the runway. Also, on an overly steep base to final turn, the AOA indicator could be so offset from where runway is in the canopy as to be ignorable in your peripheral vision.
When push comes to shove, and the pilot is so stressed / focused on the runway that cognitive capture means that he doesn't see a visual AOA indicator, and similarly doesn't hear a stall warning, what good are they? Evaluating AOA on a calm day, straight in approach is nigh unto worthless at best, deliberate falsification at worst.
rv7boy
Forum Peruser
It's a Dwyer gauge
Sticky needle? The gauge itself is just a Dwyer differential pressure gauge. I don't have the Dwyer catalog in front of me now, but I did buy one one time with the plans to build my own. There's nothing really fancy or exotic about the gauge except the Dwyer faceplate has been replaced with one with red and green background indicating "lift reserve."
Sorry I don't have the Dwyer part number but with a little research you could find one that has the correct range for this application.
P.S. A "little research" (2 minutes and three mouse clicks) and I found this. It's a Dwyer Series 2-5000 Minihelic II differential pressure gauge.
Sticky needle? The gauge itself is just a Dwyer differential pressure gauge. I don't have the Dwyer catalog in front of me now, but I did buy one one time with the plans to build my own. There's nothing really fancy or exotic about the gauge except the Dwyer faceplate has been replaced with one with red and green background indicating "lift reserve."
Sorry I don't have the Dwyer part number but with a little research you could find one that has the correct range for this application.
P.S. A "little research" (2 minutes and three mouse clicks) and I found this. It's a Dwyer Series 2-5000 Minihelic II differential pressure gauge.
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Sam Buchanan
been here awhile
Naw...I don't buy any of that. I've been flying an analog LRI in the RV-6 for over 15 years and 1200 hrs and there is absolutely no issue with including the LRI in the normal visual landing scan. And my LRI isn't even on the glareshield:
(This photo is a few years old, the old GPS has been replaced by an iFly, and the transponder by the cool Stratus ESG ADS-B device. By the way, the LRI probe also runs the AOA indicator in the Dynon which provides an aural indicator)
If the pilot is so stressed out over landing that it is impossible to see any of the panel then some retraining is overdue. I have flown the LRI into a wide variety of landing scenarios and it has never failed to be my primary instrument in conjunction with a good visual scan. I have never been so busy landing the RV-6 that I didn't have time for the occasional glance at the LRI.
AOA is easier to fly in gusting conditions because it doesn't bounce around like airspeed indicators. Where it really shines is landing on short, tight strips where max landing performance is desired. If the pilot was to get stressed, this would be the time--but a scan trained with the LRI reduces stress, not increases stress.
I'm sure Ed is happy with his RV-8 as it is, but I find his objections to a good AOA to be invalid.
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Sam Buchanan
been here awhile
There ya go. With a little patience, the Dwyer gauge bezel can be unscrewed, the needle gently pulled from the shaft, and the LRI dial face inserted in place of the generic Dwyer face. Instant LRI gauge!
Boy Sam, seeing your panel brings back memories of following your build. My 6A followed close behind, started in ?97 and finished in ?06.
I have an LRI as well (panel pic on the recent GRT/Hudly HUD thread) and I too have no issues with including it in a normal scan on landing. For example, I sneak a glance at it turning base to final.
I have an LRI as well (panel pic on the recent GRT/Hudly HUD thread) and I too have no issues with including it in a normal scan on landing. For example, I sneak a glance at it turning base to final.
Ed_Wischmeyer
Well Known Member
Naw...I don't buy any of that. I've been flying an analog LRI in the RV-6 for over 15 years and 1200 hrs and there is absolutely no issue with including the LRI in the normal visual landing scan...
If the pilot is so stressed out over landing that it is impossible to see any of the panel then some retraining is overdue. I have flown the LRI into a wide variety of landing scenarios and it has never failed to be my primary instrument in conjunction with a good visual scan. I have never been so busy landing the RV-6 that I didn't have time for the occasional glance at the LRI.
AOA is easier to fly in gusting conditions because it doesn't bounce around like airspeed indicators. Where it really shines is landing on short, tight strips where max landing performance is desired. If the pilot was to get stressed, this would be the time--but a scan trained with the LRI reduces stress, not increases stress.
We disagree, of course -- but agreeably.
I did not write, hint nor imply that looking at AOA was a problem as part of a normal visual scan. What I wrote was that instruments can and do get dropped when the scan breaks down due to a stressful situation, like those immediately preceding an inadvertent low altitude stall or spin.
When pilots have a stall/spin accident base to final, it's a pretty safe bet that they're focused on something other than the instruments.
Both and I another regular poster here have had wind shear encounters in which the aural AOA warning was not heard till after the event. And the literature is full of events in which aural sensing was first to be dropped in stressful situations.
And as for AOA not bouncing around like airspeed, that's easy to do -- just dampen the sucker within an inch of its life. From what I've read, AOA sensors are so inherently noisy that they have to be heavily damped. The trouble with heavy damping is that a damped signal tells you what was happening a little while ago, not what's happening right now. (Those of you who have studied first order lag filters will understand. Same for finite impulse response filters.) When I asked Garmin what their AOA algorithm was on the G3X so that I could understand exactly what it was telling me, their answer was, "proprietary."
The question of how do you adjust target AOA for reported winds and gusts remains unanswered. Sure, you can keep lowering the nose to keep the AOA down for the gusts you've already encountered, but that's reactive, not proactive.
And I never wrote, hinted nor implied that an LRI would increase stress, so I feel no obligation to reply to that statement.
Calm, benign wind conditions, go for it. I will agree that training is the solution to stressful situations, but more than the kind of training that's fashionable now. If the EAA Founder's Innovation Prize judges ever get over their fascination with gadgets, I'll explain all this at Oshkosh.
But it's nice that we both have safety as a primary objective.
Sam Buchanan
been here awhile
We disagree, of course -- but agreeably.
I did not write, hint nor imply that looking at AOA was a problem as part of a normal visual scan. What I wrote was that instruments can and do get dropped when the scan breaks down due to a stressful situation, like those immediately preceding an inadvertent low altitude stall or spin.
The whole point of AOA is avoid getting into an inadvertent low altitude stall or spin........
Oh well, I just know the thing is very useful and it is my primary instrument for pattern operations (benign and especially otherwise) and I consider it a huge enhancement to safety. If someone chooses not to use AOA...that be ok with me.
Ed_Wischmeyer
Well Known Member
Naw...I don't buy any of that. I've been flying an analog LRI in the RV-6 for over 15 years and 1200 hrs and there is absolutely no issue with including the LRI in the normal visual landing scan. And my LRI isn't even on the glareshield:
If the pilot is so stressed out over landing that it is impossible to see any of the panel then some retraining is overdue. I have flown the LRI into a wide variety of landing scenarios and it has never failed to be my primary instrument in conjunction with a good visual scan. I have never been so busy landing the RV-6 that I didn't have time for the occasional glance at the LRI.
AOA is easier to fly in gusting conditions because it doesn't bounce around like airspeed indicators. Where it really shines is landing on short, tight strips where max landing performance is desired. If the pilot was to get stressed, this would be the time--but a scan trained with the LRI reduces stress, not increases stress.
Good answers, but none of them address the points I was trying to raise:
* The point is not whether AOA works when you have time to look at it, the point is whether AOA visual indicators work when a pilot is in a stressful situation when the whole visual scan breaks down, such as those situations that lead to low level loss of control. The case of a pilot being stressed in nominal conditions was not what I (intended to) address. By the way, visual stall warning indicators are no longer certifiable in FAR 23;
* For what I've read of AOA sensors, the raw data they provide is so noisy that that they have to be heavily damped. The flip side of damping is that a damped signal inherently has lag, meaning, it tells what was going on a short while ago rather than what's going on right now. I asked Garmin what their AOA algorithm was on the G3X so that I could understand what it was telling me, and their response was that the algorithm was proprietary;
* The question of how to adjust AOA for forecast winds and gusts, before you encounter those gusts, remains unaddressed;
* I never wrote, hinted nor implied that an LRI would increase stress, so I will not address that canard;
The good news is that we agree on making safety a priority.
Sam Buchanan
been here awhile
Well, Ed....it appears you definitely believe in redundancy.....
Ed_Wischmeyer
Well Known Member
Stupid internet... I typed in the first response and it didn?t show up in the forum. So I retyped it. Now they?re both there. Grrr.
I need a Typing Reserve Indicator or something.
Grrrr.
I need a Typing Reserve Indicator or something.
Grrrr.
Maniago,
The LRI guy still has a website up. http://www.liftreserve.com/ but doesn't answer the phone are emails.
Best,
Chris
The LRI guy still has a website up. http://www.liftreserve.com/ but doesn't answer the phone are emails.
Best,
Chris
maniago
Well Known Member
uhhhhh thanks Chris. I know all that. I was just wondering if anyone had successfully contacted him since your May posting......
-----
Ok nevermind....I see it was only a few days ago. I read May 2017 for some reason.....
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