Garmin G5 Calibration Pitch Shows Nose High Level Flight

[fly4usa]

FYI I have done my research but want to get feedback from people who have zeroed out pitch attitude in flight. This is a club plane. It is in hanger for annual, which I am teaching Instrument students.

I asked our club maintenance, A&P / AI to adjust it so it reads level in cruise not 3 degrees nose up. He installed the dual G5's in this plane. I am sure there is nothing wrong with the unit itself (AHRS). I am sure our A&P followed the Garmin instructions to his understanding. I have read those instructions and talked to Garmin.

HOWEVER tells installer to reference Manufactures LEVELING instructions. LEVEL in Cessna Manual is LEVEL for rigging plane. It was not intendant to LEVEL Electronic Flight Instruments that did not exist at the time. Most know the common GA Vacuum Attitude Instrument the pitch reference was adjustable. This was to account for different pilots seated height, parallax, preference. The knob was on face, similar to say altimeter Baro setting knob, there to adjust as required.

To get this Cessna AIRCRAFT LEVEL (to ground not flight level) you compress the nose strut, jack the mains and use two screws on side of fuselage and level.

On level ramp, strut inflated normally, the plane sits nose high, close to flying attitude in level flight. The GARMIN Installation instructions does not specify HOW to level plane but refers you to manufactures maintenance manual. Of course the manufacture (Cessna) does not have a FLIGHT ATTITUDE level. I think some planes do have this procedures. You mechanics let me know please.

Garmin says it is OK to level the plane to flight attitude stance to calibrate. I need to convince my A&P of this, point of this thread. Getting all the data to present to Maintenance.

NOTE: The certified G5's are not (easily) PILOT adjustable (the ones sold to experimental or EAB kit plane builders are adjustable by pilot without out going into CAL MODE). This G5 is in a certified mighty Cessna. This does not mean you can't change the certified G5, only it is not intended to be pilot adjustable, requires some special button pushing,.

NOTE: I talked to GARMIN and they said STC does not prohibit calibration to read level in flight, only that it be set and left alone.

NOTE planes can be built a little off, the level reference screws in the case of Cessna off as well.

Question, Keep in mind I am going to coordinate this with a licensed A&P and AI: HOW TO LEVEL IN FLIGHT ATTITUDE OR CAL THE G5 TO READ LEVEL IN FLIGHT:

My guesses
1) Set it level per Cessna and subtract an additional 2.5 degree off set nose down;
2) Level plane 2.5 degree nose up from Cessna level, using digital inclinometer (using Cessna's level datum), set Cal offset to read level.
3) Do it in flight if possible, VFR of course (any one do this?)

PLEASE DO NOT SAY HOW TO GET INTO CAL MODE. If you like to PM me that would be welcomed. I think I know, not a big secret at this point.
I understand WHY GARMIN and REGS have made it so it is not a (easy) pilot adjustment.
Again this will be done with/by A&P and I have coordinated with Garmin.

People with personal G5 experience, observations, success in getting G5 to read level in flight, how you did it, love to hear your input.
Please no opinions, criticism unless I said something wrong, then give me a hard reference please; just facts, observable experience please, much appreciated.

I will discuss with my A&P and tell him what I found. Right now he is OK with it as is, but then he is not a pilot. He is right, it is OK if you accept flying 3 degrees nose up as level flight. I do not accept it and there is no reason to tolerate it. I need to explain it to him.

Kind Regards

George
CFI-I-II, ATP CE500, B737, B757, 767

 

[Clip4]

You are not flying a vacuum attitude indicator. A PFD showing a couple degrees up pitch is normal.

 

[TCABM]

Dual G5s in a 172 for a couple of years. Yes, level flight results in about +3* pitch. Our previous AI had a moveable moveable miniature aircraft that could be set to relative level.

The G5 is using an absolute level that takes a but of adjustment to get used to. Can’t be of help convincing your installer to do what you’re asking though.

 

[Matthew]

My rental 172/G5 combo shows the same 3-ish degree nose up when level. I can’t dial it out and I’m not getting into that on someone else’s plane.

 

[TCABM]

Now that I’m back at home, take the installation manual to your installer and discuss the note at the bottom of page 137. Any method other than what’s described in section 6.3.7 invalidates the STC.

 

[fly4usa]

Now that I’m back at home, take the installation manual to your installer and discuss the note at the bottom of page 137. Any method other than what’s described in section 6.3.7 invalidates the STC.

Thank you. Note
"In flight level cruse attitude is not necessarily the same as the leveling points provided by the manufacture. Adjustments to the pitch and roll offsets can be made to compensate for the aircraft flight characteristics." Garmin told me the same thing, and it does not violate the STC.

As far as the other comments that they also have 3 degree pitch up that is good info. A&P's are great, keep the planes flying but they are not pilots. The instructions to install them work, but with fancy electronics we can dial them in. May be Garmin did not want the liability and used the KISS method. The calibration takes a minute of button pushing, not a difficult thing.

It is harder on students to make small pitch changes and maintain precise altitude. If I can get the A&P to adjust it, based on note and calling Garmin, adjusting for "aircraft flight characteristics", it will indicate ZERO pitch (+/-) in level cruise. Why "get use to it". I was using a G1000 the other day. They seem to have adjusted that properly to real zero pitch in level flight.

 

[TCABM]

… I have to say it makes it harder on students to make small pitch changes…

I disagree, but this comes down to technique and I believe a solid scan provides better awareness of performance than worrying about just attitude, not that I’m accusing you of that.

It’s super easy to forget the G5 AI is only primary for AI and drop the remaining analog stuff out of the scan which I believe is detrimental to not just partial panel operations, but is also fundamental to instrument flying.

 

[fly4usa]

I disagree, but this comes down to technique and I believe a solid scan provides better awareness of performance than worrying about just attitude, not that I’m accusing you of that.

It’s super easy to forget the G5 AI is only primary for AI and drop the remaining analog stuff out of the scan which I believe is detrimental to not just partial panel operations, but is also fundamental to instrument flying.

The thing I dislike, is drift. Sir I did not ask for a lecture about SCAN- CROSS CHECK - INTERPRET - CONTROL. I want LEVEL FLIGHT to READ LEVEL.... not 3 degee nose up. I don't care what you think about my preference based on my experience, 14k hours, 10% of that dual given in all GA ratings and Part 121. My position is reasonable. It is FAR easer to LEVEL the primary controlling instrument (AI/PDF) when you can put the airplane Index on the big ZERO degree horizon line, than floating half way between 2.5 and 5 degrees. We are flying with precision in IMC. VFR who cares, don't need an AI or PDF.

Yes I can fly it as is. Yes my students could "get use to it". Not the point.

I teach "Aircraft Attitude Instrument Flying" and use FAA-H-8083-15, ACS, AIM and FAR's and many other references. So you are not going to tell me something new. A good HORIZON level index is more than helpful in level offs, holding altitude, vs some space between 2.5 and 5 degrees pitch for level. Yes VSI is in scan.

You know the difference between CONTROLLING and MONITORING instruments? The AI/PDF is controlling and very important. Why do you want it to lie to you? Why do you want it to be inaccurate and less useful and get use to it, when you can correct it when that is possible? Why make it harder to fly IMC?

If you have no index (space between indexes) at level, it is not as precise. Nothing you say will change my mind. Either you are a sloppy flyer and accept it or you are just a better pilot. I am sure it is the latter. Kidding you are not better. Joke. I am sure you never make errors in your scan (fixation, omission and emphasis).

Please answer my question...WHAT REASON do you have to not adjust Pitch Indication to match the flight characteristics of the aircraft and not some calibration to maintenance rigging level and accept what ever random pitch you get? OK. Stick to topic.

I have established it is OK to calibrate the G5 to read level in flight. Now what is the best way to calibrate zero pitch. Close +/- 0.5 degree is fine.
3 Deg nose up in nominal level flight is not good for me. Do as you like. What do you fly and what flight and Nav instruments? Does your AI read 3 degrees nose up in level flight. Do you fly IMC or VFR only?

Maintenance level is not flight instrument level or level. The G5 is a FLIGHT INSTRUMENT. Garmin does not prohibit nor does STC prohibit calibrating to read zero in flight. ANYONE DISAGREE? Even Garmin says OK.

PS The argument pitch in level flight changes with speed (power) and gross weight is a red herring fallacy, to redirect the conversation. It also changes with density altitude. Cessna's, especially a C152/C172, have narrow weight, CG, speed ranges. Typically the small SEL Cessna's fly 655 to 75% power, below 8000' MSL, 3/4th to 1/2 fuel, one or two people, clean. Nominal for training, 65% power, 3000', two souls, 3/4 fuel. Even if solo, 45 min of fuel slightly lower pitch than nominal as I describe. Slow flight, pattern more nose up, but you don't fly there all day. The change in AOA is small. Biggest pitch change is with power (speed). Instrument flying you are at cruise or 90 kts until landing in a SkyHawk.

I don't care if level on G5 is +/- 0.5 degree off zero in nominal cruise. 3 Degrees nose up indicated on AI/PFD is not acceptable in a little plane that has a pitch range, especially in IMC. You want to be close to your BASE LINE, Horizon. Especially for instrument training. Most other GA EFI systems (Aspen, Dynon, G1000 read level or at most 1 degree nose up in level flight). The G5's in this plane need to be calibrated, and it is a common problem. Garmin left the calibration kind of vague and references the airframe manufactures LEVEL. You get the results we have. The A&P's just need to be educated and pilots need to insist they get better calibration. IMHO.

This is LEVEL not half way up between 2.5 and 5 degree.

https://www.gulfcoastavionics.com/cdn/shop/products/G5-Attitude-HSI_580x_crop_center.jpg?v=1631302218

George, ATP, CFI-I-ME

 

[chemgeek]

According to the installation manual, you can set the G5 to level when the plane is leveled as per the manufacturer's instructions (recommended) or you may adjust it permanently on the ground to another value to approximate level flight at cruise if desired. For certificated installs, it cannot be adjusted in flight.

Having said all this, you should realize that there is no ONE setting that will indicate zero degrees attitude at ALL flight speeds and CG values. My G5 AI is set to level with the plane on the ground leveled as per manufacturer's instructions. In level flight at typical cruise settings, it will indicate about 2 degrees nose up with 1 aboard. At 90 kt (approach speed) it will indicate about 3-4 degrees nose up in level flight with 1 aboard. Put two aboard in the front and it will need another 1 degree or so nose up to achieve the same numbers.

These are very precise electronic instruments that can accurately display +/- 1 degree attitude easily for reproducible numbers. This is a boon for IFR flight. I know when flying solo that 3-4 degrees nose up and 2200 rpm I will get 90 kt in level flight. Back off to 1900-2000 rpm and I get 500 fpm descent at the same 90 kt, etc. These "numbers" are absolutely reproducible from flight to flight.

Your mechanical AI is a RELATIVE attitude indicator, based on wherever you leveled it last. "Level" depends on what airspeed and CG you have. (I won't consider for now parallax issues which make the mechanical AI even less precise to monitor.) Your G5 is an ABOSOLUTE attitude indicator, referenced to a fixed attitude. Flying a G5 means learning new "numbers" for your aircraft, which will be absolutely repeatable for any given airspeed and CG loading. And no parallax issues.

 

[TCABM]

…

Welcome to POA, where thread drift is a requirement.

… Please answer my question...WHAT REASON do you have to not adjust Pitch Indication to match the flight characteristics of the aircraft and not some calibration to maintenance rigging level and accept what ever random pitch you get? OK. Stick to topic….

I’ve done that, you don’t like it, and that’s okay. I also know that ‘level flight’ may be reproduced in various attitudes give different pitch and power settings, even in “cruise” configurations. Max range is a different pitch/power combo than max available power.

You’ve been provided with the documentary reference to have the conversation with your installer. Hopefully you get what you want out of it. If not maybe you can find an installer that will do what you want.

Good luck in your endeavor.

 

[Gary Ward]

Here's mine, been flying it since 2018.

Another...earned my instrument rating with this panel.

How do know when the plane is in level flight? Vertical speed indicator?

 

[Bell206]

I asked our club maintenance, A&P / AI to adjust it so it reads level in cruise not 3 degrees nose up

HOWEVER tells installer to reference Manufactures LEVELING instructions. LEVEL in Cessna Manual is LEVEL for rigging plane.

So if I understand your dilemma, you have a G5 installed per the approved STC instructions that gives an indication which you do not accept in flight, and you want the mechanic who installed it to modify that installation, based on data not included with the STC, to give you the indications you believe to be acceptable in flight, all on an aircraft you do not own. Is this correct?

 

[fly4usa]

Here's mine, been flying it since 2018.

Another...earned my instrument rating with this panel.
How do know when the plane is in level flight? Vertical speed indicator?

Ha ha. I know what Attitude Inst Flying is, OK, but why not have it read level in (nominal normal level flight at cruise speed)? Second if the G5's in the plane I was teaching was as close as yours NO PROBLEM... It is 3 degrees nose up. That is ridiculous. There is NO REASON to "get use to it", "look at the VSI (no kidding)".... When your PRIMARY and CONTROLLING INST that is KEY to precise flying if adjusted properly will tell you if VSI is ZERO without even looking. Cheers.

 

[bradg33]

Asking people for help, then arguing with them, then simply declaring that your position is "reasonable" is not a way to make friends and influence people. Maybe dial it back a notch or two with the lengthy, ranty posts, ALL CAPS and aggression. Do that, and you might actually get some assistance.

 

[TCABM]

… Do that, and you might actually get some assistance.

He’s gotten all the assistance he can get with the reference to installation manual and specific note re: level calibration.

The underlying challenge appears to be the understanding of relative level in a mechanical AI versus absolute level as implemented in the G5.

 

[fly4usa]

According to the installation manual, you can set the G5 to level when the plane is leveled as per the manufacturer's instructions (recommended) or you may adjust it permanently on the ground to another value to approximate level flight at cruise if desired. For certificated installs, it cannot be adjusted in flight.

Having said all this, you should realize that there is no ONE setting that will indicate zero degrees attitude at ALL flight speeds and CG values. My G5 AI is set to level with the plane on the ground leveled as per manufacturer's instructions. In level flight at typical cruise settings, it will indicate about 2 degrees nose up with 1 aboard. At 90 kt (approach speed) it will indicate about 3-4 degrees nose up in level flight with 1 aboard. Put two aboard in the front and it will need another 1 degree or so nose up to achieve the same numbers.

These are very precise electronic instruments that can accurately display +/- 1 degree attitude easily for reproducible numbers. This is a boon for IFR flight. I know when flying solo that 3-4 degrees nose up and 2200 rpm I will get 90 kt in level flight. Back off to 1900-2000 rpm and I get 500 fpm descent at the same 90 kt, etc. These "numbers" are absolutely reproducible from flight to flight.

Your mechanical AI is a RELATIVE attitude indicator, based on wherever you leveled it last. "Level" depends on what airspeed and CG you have. (I won't consider for now parallax issues which make the mechanical AI even less precise to monitor.) Your G5 is an ABOSOLUTE attitude indicator, referenced to a fixed attitude. Flying a G5 means learning new "numbers" for your aircraft, which will be absolutely repeatable for any given airspeed and CG loading. And no parallax issues.

NOPE it does not say FOR CERTIFIED INSTALLS, IT CANNOT BE ADJUSTED... NO WHERE DOES IT SAY THAT... You are wrong. You were off to a good start. What you may be confused with is per REGS the PILOT can not adjust it from the menu. You have to go into CONFIG mode, which was not intended to be easily user accessed or adjusted. No where does it say it can not be calibrated with OFFSET to read level in level flight (and Garmin told me it does not violate STC which is an AML-STC by the way). Second the note above clearly gives you wiggle room to adjust for flight characteristics. I can imagine some FAA bureaucrat thinking maintenance level is level in flight. You almost ALWAYS need some positive AOA in level flight in GA planes.

I called Garmin. They said it does not violate the STC which is NOT a full STC. Do your research before spewing. I worked in certification at Boeing and consultant in my early career. It is an "An AML-STC is a multi-model approval method that allows a set of compliance data i.e. type design data and substantiating data, to be designated as 'baseline data' that is applicable to various aircraft models". So the install is generic and NOT specific for a reason.

So the instructions are VERY GENERIC. It says just go see the manufactures maintenance manual for "LEVEL". Some manufactures have "LEVEL" just for jigging/rigging the aircraft/controls for maintenance/repair. Other manufactures also give reference to attitude for flight. Cessna does not have this flight level attitude. So please, show me. Again I called Garmin and they said NOTHING violates the STC by making the G5 PDF read properly, i.e., zero pitch level flight. Even if just my preference there is nothing WRONG with wanting it to show zero pitch in level flight.

They made it easy to get an blanket STC and did not get into calibration. FAA also is not always wise or practical. WHAT? FAA not always competent? No. So your appeal to authority is not impressive. If I were "The Administrator" I would specify do a base line level (like they are now in Cessna) and calibrate pitch OFFSET to read within 1 Degree of LEVEL in nominal cruise. The PROBELM is the nominal part. Then the FAA heads explode and say NOMINAL. That becomes a STC issue and why Garmin avoided it and lust has you calibrate (in the case of Cessna's) 2.5 to 3 degrees nose up. . So they went the EASY way. So use common sense not be pedantic and petulant. If you are a pilot you know FAR's are interpreted differently. In this case SAFETY rules. There is nothing unsafe about OFFSET to zero in level flight. Do as you like.

IT IS SAFER IMHO FOR AI / PDF TO READ LEVEL (ZERO or near zero pitch) IN LEVEL FLIGHT IN SMALL GA PLANES. I specify small Part 23 GA planes. LARGE aircraft have huge range of operating speeds, CG, weight, high lift device configs, power, operational altitudes. You do get use to flying X-degrees nose up for level (or even descent) in large aircraft. You memorize pitch for many phases of flight. C172 level varies very little unless doing slow flight. I do not want to get "use to it". My students HAND FLYING down to MINS and not bust MDA. OK. I see no reason or logic or safety reason not to adjust to read zero pitch level. In fact the SIM we fly with G1000 is LEVEL in LEVEL FLIGHT... Then you get into the C172 with G5's and it is 3 degrees nose up level. (IF some one says VSI I will give you a metaphorical dope slap, we all know).

Adjusting to RIGGING or MAINTENANCE LEVEL without offset to level flight is easy and why Garmin vaguely references it to make getting STC easy. Again it was done so GARMIN did not have to do individual STC's which would be a MASSIVE pain and take forever. The FAA in all their wisdom did not realize that this would result in planes flying around with LEVEL pitch attitude being all over the place. This is a flaw which we do not have to live with. As they kept it VAUGE to get the AML-STC through, the vagueness works in our advantage. We can adjust it as the manual says to compensate for the AERODYNAMIC specifics of that aircraft, to paraphrase the note on page 137.

Then you say "These are very precise electronic instruments that can accurately display +/- 1 degree attitude easily for reproducible numbers. This is a boon for IFR"

My friend what does this have to do with all the tea in China? I have flown glass since 1990 in large aircraft. This has nothing to do with the topic. Electric and Vacuum AI's and DG/HSI's were accurate. Sure DG's drifted. I just flew in a C177 with uAvionix versions of G5's. They opted not to get the remote Magnetometer. Heading drifted like crazy. Also AHRS is not 100% accurate and a compromise in small planes. Your worship of SMALL cheap GA AHRS driving Flight instruments is misplaced. Many report commercial maneuvers can tumble G5's. I never had a Vacuum / Electro-mechanical Gyro tumble doing Commercial maneuvers. Large jets have two or three IRS units and a FMS, far more accurate than these little electronic "gyros". Also the G5 is a small instrument made to go into a 3.125" instrument space. The blank spot BETWEEN 2.5 and 5 degree pitch is NOT a precise way to hold pitch. Level with HORZ g ing right through the tips of the Flying-V is precise. Last the G5 has built in battery back up, but all these little GA planes have very basic 1960's automotive level electrical systems. A transport aircraft has way more electrical redundancy. Newer GA planes have emergency or backup DC bus architecture. However retro fit with hybrid steam/glass does not. The good thing is tablets with GPS and EFB and hand held radios are very accessible. Highly recommend that flying IMC in a small plane.

 

[fly4usa]

He’s gotten all the assistance he can get with the reference to installation manual and specific note re: level calibration.

The underlying challenge appears to be the understanding of relative level in a mechanical AI versus absolute level as implemented in the G5.

Well the AI (vacuum or electro mechanical) had ability to adjust, at least with GA. The Reg for EFI is the aircraft pitch reference is not PILOT adjustable, or at least not easily adjustable. Garmin realized this is not really a benefit or what pilots want, so in their non Cert G5's for the Kit/Experimental market they have pilot adjustable pitch.

However this REG does not say it should not read zerop pitch (or close) in level flight. Read post above. This is a REG / FAA thing, not necessarily a logical or safety thing. We all know REGS are interpreted (written by lawyers for lawyers). The REG however is understandable, set roll/pitch calibration offset and leave it alone. This inherently requires pilots ACCEPT level being slightly Nose High or Nose Low in level flight, not adjustable to preference. I'M GOOD with that. 1 degree +/- OK... 3 degrees nose up in a C152 or C172 is ludicrous (yes I know about the VSI and scan / cross-check / interpret / control).

I do not believe the INTENT of the REG that prohibits (easy) pilot adjustment of pitch reference, prohibits base installation calibration accounting for AERODYNAMIC characteristics of the plane, to read closer to ZERO pitch in level flight.

I would be happy with zero to +1 max, +/- 0.5 degree. Close is good enough. Having LEVEL reference closer to ZERO than +5 for level helps in critical phase of flight (leveling off at MDA in IMC and turbulence) that is at NO INDEX (halfway between 2.5 and 3). Your brain has to do the math.

For avoiding spatial disorientation the ARTIFICIAL HORIZON is key. +3 in level flight is JUST NOT RIGHT. Help the pilot relate instrument flying to VFR. What if I moved your glare shield down 6 inches. Would that HELP you maintaining level flight in VFR. Oh sure you could get use to it. Use your VSI in your Cub? Oh VFR does not require VSI. You all see my point.

We all know just because the REGS say it is OK does not mean it is safe. NOT SAYING to violate REGS, just that per the MANUAL and GARMIN it is OK to FINE TUNE the pitch calibration offset to read something reasonable. You set and forget.

ALSO NOT ALL PLANES ARE RIGGED or BUILT the same from factory. Some are off. The REF rig level screws may be off. The instrument panel may be tilted slightly. The tail, wing, empennage may not be straight. Some common sense was included in the STC and installers need to understand that. I think we are good. We shall see how my discussion with MX goes.

If it were my plane it would be fine. I am dealing with an A&P. I think he is amenable to making at least some additional adjustment to get closer. He is not entrenched, just did BASE-LINE generic installation, did nothing wrong. However MX and PILOTS and ENGINEERS and EVERYONE have to work together.

 

[Bell206]

Again I called Garmin and they said NOTHING violates the STC by making the G5 PDF read properly, i.e., zero pitch level flight.

Since Garmin states there's no issue, with your background, why didn't you request an Engineering Order (EO) from Garmin specific to the aircraft S/N to change the STC instructions? Have done this a few times myself with STCs. This would give the mechanic alternate approved data to change the configuration vs putting the responsibility of the change all on his certificate. Any number of options can be available to tweak an approved installation provided you choose to educate yourself on how to pursue them.

 

[bradg33]

PLEASE DO NOT SAY HOW TO GET INTO CAL MODE. If you like to PM me that would be welcomed. I think I know, not a big secret at this point.
I understand WHY GARMIN and REGS have made it so it is not a (easy) pilot adjustment.
Again this will be done with/by A&P and I have coordinated with Garmin.

To get into config mode on the G5, you hold down the knob while powering it on.

 

[xander75]

@fly4usa I would 100% agree with you that a straight and level flight needs to be represented like that in the instrument.
In fact I had the same nuisance, I thought I could get used to it, but it bothered the F out of me. We put the plane on jacks, leveled it and make some config adjustments. coming to find out that the unit (Aspen PFD1000) was not mounted securely and could slightly tilt top outward at times making it represent a nose up attitude.
so yes calibration (and nothing to do with certification) is critical as when in the soup you need to be able to trust it 1000% and not mentally adjust to its representation.
xander

 

[fly4usa]

To get into config mode on the G5, you hold down the knob while powering it on.

Wow way to go. Kind of troll-ish bradg13, and disrespectful. You don't know how to send a PM?

Really unless you know what you are doing and IT IS YOUR AIRCRAFT, don't mess with it. This could mask serious installation or hardware (AHRS) issues. You do what you want on your personal airplane with a G5 that you fly low IFR in, but you adjust a G5 in a rental or club aircraft without A&P coordination/signoff, violation of FAR's Part 43, FAA-P-8740-15, AFS-8. Regs and STC the G5 was approved are clear, NOT PILOT adjustable. Guessing that does not matter to you. I'm working with my Maintenance, even though I could adjust it. It is called respect, risk management, resource management with professionals. Try it.

 

[robin ardoin]

Hmmm….3 degrees, more like a half bubble off center…

 

[dmspilot]

The thing I dislike, is drift. Sir I did not ask for a lecture about SCAN- CROSS CHECK - INTERPRET - CONTROL. I want LEVEL FLIGHT to READ LEVEL.... not 3 degee nose up. I don't care what you think about my preference based on my experience, 14k hours, 10% of that dual given in all GA ratings and Part 121. My position is reasonable. It is FAR easer to LEVEL the primary controlling instrument (AI/PDF) when you can put the airplane Index on the big ZERO degree horizon line, than floating half way between 2.5 and 5 degrees.

You are missing the bigger picture which is that pitch attitude for level cruise can be different on every flight, and even can change during the same flight. Weight, center of gravity, density altitude, and airspeed all will change the pitch required. I imagine a 14,000 hour pilot would understand this.

 

[chemgeek]

So much ranting. Set your offset however you think best but don't expect it to read zero degrees in level flight at every airspeed and CG configuration. For certified installs, it is not in-flight adjustable. What are your expectations?

 

[bradg33]

Wow way to go. Kind of troll-ish bradg13, and disrespectful. You don't know how to send a PM?

Really unless you know what you are doing and IT IS YOUR AIRCRAFT, don't mess with it. This could mask serious installation or hardware (AHRS) issues. You do what you want on your personal airplane with a G5 that you fly low IFR in, but you adjust a G5 in a rental or club aircraft without A&P coordination/signoff, violation of FAR's Part 43, FAA-P-8740-15, AFS-8. Regs and STC the G5 was approved are clear, NOT PILOT adjustable. Guessing that does not matter to you. I'm working with my Maintenance, even though I could adjust it. It is called respect, risk management, resource management with professionals. Try it.

Someone forgot to take their pills...

 

[Martin Pauly]

I want LEVEL FLIGHT to READ LEVEL.... not 3 degee nose up.

George,

There is a name for what you want. It's called a flight path vector. When the flight path vector is on the horizon line, the aircraft is in level flight. That's what's shown in the image below; the little circle on the horizon line is the flight path vector. It shows where the aircraft is going.

The exact pitch angle required to be in level flight is variable and changes with airspeed and aircraft weight.

Many electronic attitude indicators these days have a built-in flight path vector. The example below shows level flight as confirmed by the VSI, and by the flight path vector symbol being on the horizon line, while flying with a slight nose-high attitude pitched up about 4 degrees. If this airplane increases airspeed, the pitch angle to maintain level flight would be lower. There is some airspeed where the pitch for level flight would be zero.

It's a simple matter of physics. For lift to exactly offset weight, the angle of attack has to be adjusted when airspeed changes (because lift is proportional to the square of airspeed), and obviously also when the weight changes. And we change angle of attack in level flight by changing pitch. So there cannot be one pitch angle which always results in level flight.

Regards,
Martin

 

[Mikey52]

Ha ha. I know what Attitude Inst Flying is, OK, but why not have it read level in (nominal normal level flight at cruise speed)? Second if the G5's in the plane I was teaching was as close as yours NO PROBLEM... It is 3 degrees nose up. That is ridiculous. There is NO REASON to "get use to it", "look at the VSI (no kidding)".... When your PRIMARY and CONTROLLING INST that is KEY to precise flying if adjusted properly will tell you if VSI is ZERO without even looking. Cheers.

When in level flight, the aircraft is not level to the horizon. There is on most if not all airplanes a positive angle that the axis is above the horizon. Usually 2-5 degrees. At zero, you will be in a descent.

It's an attitude indicator. And in level flight you have a positive angle to the relative wind. To understand level flight you need to look back at your lift vectors.

Do you think it should read 0 at any airspeed. Think of slow flight, you have a higher attitude than at vne, or va.

 

[fly4usa]

When in level flight, the aircraft is not level to the horizon. There is on most if not all airplanes a positive angle that the axis is above the horizon. Usually 2-5 degrees. At zero, you will be in a descent.

It's an attitude indicator. And in level flight you have a positive angle to the relative wind. To understand level flight you need to look back at your lift vectors.

Do you think it should read 0 at any airspeed. Think of slow flight, you have a higher attitude than at vne, or va.

Clearly you did not read the thread or understand the point of the thread. Everyone knows. However we fly little planes by pitch not Angle of Attack (AOA).

I and 99% of pilots adjust AI's to zero pitch REF in level cruise flight (AI's that can be adjusted). Do you not know this? Now we have non adjustable Electronic AI or PFD's. I'm fine being 3 degrees pitch in slow flight, level flight near stall. However in IFR flying you don't do slow flight IMC. 95% of the time is level at cruise or approach speeds.

As far as "do you think"? No. That is a ludicrous question. The C152 I teach students in and the B767 I fly at work, are worlds apart in Weight, Speed, Altitude envelopes and aerodynamics (swept wing, high lift slats and flaps). Cessna nominal cruise (75% power) level, pitch changes with weight, alitude, but not much. Your point is a strawman.

I want a solid level pitch reference. The horizon (zero pitch) is an easy to read base line Ref. Why? For ease of level off hand flying in IMC. For easy reading reference line (horizon line), not half way somewhere between 2.5 and 5 degrees. Where do you spend most of your time? Level.

PS you can descend in level or nose up indicated pitch ( and AOA). Try it.

OP (me) has resolved the G5 issue 1000%. This thread is closed. Thank you.

George
ATP, CFI, MSME

 

[RussR]

This thread is closed. Thank you.

That's not exactly how discussion forums work!

I get everything you're saying, I used to adjust the airplane on mechanical AI's to be on the horizon in level flight too. And the first glass panels I started flying bugged me too. But it was always kind of a guess anyway, wasn't it? I mean on a typical AI for a 172 or something, 20 degrees up is what, like just 1/2" above the horizon? The reason 3 degrees or whatever seems so egregious now is that with glass displays, that range is expanded to allow more accurate pitch control, so each degree is far larger than it was before.

But that doesn't really matter. None of the turbine equipment I fly (for work, contract, etc) has any adjustability, and we fly a wide range of airspeeds and configurations, meaning a wide range of pitch attitudes for level flight, and do just fine. I imagine the same is true for most new airplanes of all sizes.

When I'm teaching instrument flight, literally the first lesson is to develop a power-attitude-configuration chart. And it's actually WAY easier with a non-adjustable AI, since it means climb out is always going to be, say, 7 degrees nose up, not 3 or 5 or 10 because you bumped that knob when cleaning the plane. If we determine "approach level" is at 2 deg nose up, then it isn't reliant on who set the AI last, it's always about 2 deg.

 

[Groundpounder]

OP (me) has resolved the G5 issue 1000%. This thread is closed. Thank you.

George
ATP, CFI, MSME

That is a lot of percent.

 

[Groundpounder]

George,

There is a name for what you want. It's called a flight path vector. When the flight path vector is on the horizon line, the aircraft is in level flight. That's what's shown in the image below; the little circle on the horizon line is the flight path vector. It shows where the aircraft is going.

The exact pitch angle required to be in level flight is variable and changes with airspeed and aircraft weight.

Many electronic attitude indicators these days have a built-in flight path vector. The example below shows level flight as confirmed by the VSI, and by the flight path vector symbol being on the horizon line, while flying with a slight nose-high attitude pitched up about 4 degrees. If this airplane increases airspeed, the pitch angle to maintain level flight would be lower. There is some airspeed where the pitch for level flight would be zero.

It's a simple matter of physics. For lift to exactly offset weight, the angle of attack has to be adjusted when airspeed changes (because lift is proportional to the square of airspeed), and obviously also when the weight changes. And we change angle of attack in level flight by changing pitch. So there cannot be one pitch angle which always results in level flight.

Regards,
Martin

View attachment 121840

Thank you for posting that Martin. Amazing how many people don’t grasp that concept.

 

[asicer]

George,

There is a name for what you want. It's called a flight path vector. When the flight path vector is on the horizon line, the aircraft is in level flight. That's what's shown in the image below; the little circle on the horizon line is the flight path vector. It shows where the aircraft is going.

The exact pitch angle required to be in level flight is variable and changes with airspeed and aircraft weight.

Many electronic attitude indicators these days have a built-in flight path vector. The example below shows level flight as confirmed by the VSI, and by the flight path vector symbol being on the horizon line, while flying with a slight nose-high attitude pitched up about 4 degrees. If this airplane increases airspeed, the pitch angle to maintain level flight would be lower. There is some airspeed where the pitch for level flight would be zero.

It's a simple matter of physics. For lift to exactly offset weight, the angle of attack has to be adjusted when airspeed changes (because lift is proportional to the square of airspeed), and obviously also when the weight changes. And we change angle of attack in level flight by changing pitch. So there cannot be one pitch angle which always results in level flight.

Regards,
Martin

View attachment 121840

Garmin calls it the "Flight Path Marker" or "FPM" (aka "The Meatball"). Here you can see it as the green circle on the GI275 showing a 2.5 degree climb despite the pitch angle somewhat close to the horizon line.

 

[dmspilot]

I'm fine being 3 degrees pitch in slow flight, level flight near stall.

What kind of plane is near stall at 3° pitch in straight and level flight?

 

[fly4usa]

That's not exactly how discussion forums work!

I get everything you're saying, I used to adjust the airplane on mechanical AI's to be on the horizon in level flight too. And the first glass panels I started flying bugged me too. But it was always kind of a guess anyway, wasn't it? I mean on a typical AI for a 172 or something, 20 degrees up is what, like just 1/2" above the horizon? The reason 3 degrees or whatever seems so egregious now is that with glass displays, that range is expanded to allow more accurate pitch control, so each degree is far larger than it was before.

But that doesn't really matter. None of the turbine equipment I fly (for work, contract, etc) has any adjustability, and we fly a wide range of airspeeds and configurations, meaning a wide range of pitch attitudes for level flight, and do just fine. I imagine the same is true for most new airplanes of all sizes.

When I'm teaching instrument flight, literally the first lesson is to develop a power-attitude-configuration chart. And it's actually WAY easier with a non-adjustable AI, since it means climb out is always going to be, say, 7 degrees nose up, not 3 or 5 or 10 because you bumped that knob when cleaning the plane. If we determine "approach level" is at 2 deg nose up, then it isn't reliant on who set the AI last, it's always about 2 deg.You guy

Yes it is OK to close a thread, especially when you all are SO FAR OFF TOPIC. This is the AVIONICS area of forum not how to fly Instruments. In fact some forums allow the OP to close a thread. I would do it with this thread. READ my first post. NO ONE IS ASKING CAN YOU FLY WITH AI READING 3 DEGREE NOSE UP IN LEVEL FLIGHT. NO ONE... GOT IT? WE (me and my students) have been doing it for awhile. NOT THE POINT. What does it have to do with Calibrating the G5.
You are saying get use to +3 because you can fly it that way? Great. We can and have, but I don't care. We are not going to get use to it. We are doing precision IFR flying, not +/-100 feet but +10 / -0 feet in simulated or actual IMC. I want to calibrate the G5 to be close or closer to ZERO than 5 degrees in level flight. WHY IS THAT WRONG. Is this not OK with you? Do I care? Ha ha.

Russ, I have been flying turbine equipment for 30 years, but still fly GA SEL and MEL planes. A C152 is not turbine, and has NO AUTPILOT or flight director. I fly the B767. We (my students) are shooting approaches in actual IMC, and they are doing check rides in a C152. My students have 100% success rate. I know what I am doing, thank you very much. I am calibrating the G5. That is what is going to happen. Nothing you say has any relevance on the topic.

Then you lecture me on Aircraft Instrument Flying and develop a power-attitude-config chart? OH MY GOSH... Please make it stop. What does that have to do with anything about calibrating a G5? Dude. I am typed o 4 planes, and know the PITCH+POWER=Performance for those planes, and my personal plane and trainers I teach in... It is NOT a matter can you fly with a 3 degree nose up as level flight attitude indication in a C152 but why would you NOT want it to be zero.

We are talking about not flying +/-100 feet. I am taking about +10 feet +0 feet. OK. It is like the difference of an IRON SIGHT vs a RED DOT or SCOPE on a firearm. What one do you think is more accurate? You bust a check ride if you go below MDA right. I want a GO TO LINE for my students to stop descent and assure they are level. I know, been to the rodeo before. Why do you want inaccurate imprecise instruments to get the job done. Don't explain how Scan, Cross Check, Interpret and Control. I know what it takes to fly IMC by sole reference to instruments.

Look Russ I teach my students to fly Partial Panel with NO... AI/DG/HSI, i.e., Partial panel, TB, AS, ALT, VSI, Mag Compass, Tach/Map. You are so far off the topic and you have told me nothing I don't know. I am getting the G5 to read to my preference. I don't need to justify it. Sue me. Ha ha

Since Garmin states there's no issue, with your background, why didn't you request an Engineering Order (EO) from Garmin specific to the aircraft S/N to change the STC instructions? Have done this a few times myself with STCs. This would give the mechanic alternate approved data to change the configuration vs putting the responsibility of the change all on his certificate. Any number of options can be available to tweak an approved installation provided you choose to educate yourself on how to pursue them.

Why would I ask for and Engineering Order or (EO). This is an AML-STC, it is not against a specific make, model of aircraft. They already said it is OK to calibrate, 2 times, on the ground, by maintenance. Done. Even if "EO" was possible engineering time would be $10,000 to $100,000. More likely they would laugh. The amount of paper work to make a change to blanket STC for a specific installation is expensive. NO NEED... We are done and this thread, it is over. Asked and answered many post ago. Did you read or understand this thread?

You are missing the bigger picture which is that pitch attitude for level cruise can be different on every flight, and even can change during the same flight. Weight, center of gravity, density altitude, and airspeed all will change the pitch required. I imagine a 14,000 hour pilot would understand this.

Dude YOU ARE MAKING UP AN ARGUMENT TO A POINT I NEVER MADE. I never said I want pitch to read zero ALL THE TIME, ridiculous strawman argument. Your AOA is is indirectly related to your indicated pitch (we have no direct AOA indication unless you add one). WE FLY PITCH. AOA is one factor of LIFT.
Equation of LIFT: Coefficient of lift (the airfoil), Air density (yes dmspilot altitude), airspeed and AOA (indirectly pitch on AOA). Of course it changes. So what?

What does this have to do with wanting my G5 to read closer to zero than 3 degree in TYPICAL level flight? Nothing. A C152 has a very narrow operating range.

EVERY FLIGHT PITCH CHANGES? OK how much. If you start with a typical weight, typical cruise speed, typical altitude? Not much. I can assure you we are not taking our C152 IFR trainer to 14,000 ft. If you did get it up there you would expect to see 3 degrees. So what your point/ You are not logical and following the plot, Topic calibration of the G5. This is the Avionics forum...

NO WHERE DID I SAY OR IMPLY I WANT IT TO READ LEVEL IN ALL FLIGHT CONDITIONS... OK. Just closer to zero, 1 degree is fine in TYPICAL level flight. 3 degrees is not on any index. We are trying to fly +10 feet +0 feet in simulated or actual IMC. OK. This is precision flying. We are making fraction of degree pitch adjustments. I want level to be close to that BIG WHITE HORZ LINE. Got it.

Again Thread has run it's course. If you have COMMENT about the G5 and calibration great. You want to lecture me how planes fly, don't please. Thank you

George,

There is a name for what you want. It's called a flight path vector. When the flight path vector is on the horizon line, the aircraft is in level flight. That's what's shown in the image below; the little circle on the horizon line is the flight path vector. It shows where the aircraft is going.

The exact pitcha angle required to be in level flight is variable and changes with airspeed and aircraft weight.

Many electronic attitude indicators these days have a built-in flight path vector. The example below shows level flight as confirmed by the VSI, and by the flight path vector symbol being on the horizon line, while flying with a slight nose-high attitude pitched up about 4 degrees. If this airplane increases airspeed, the pitch angle to maintain level flight would be lower. There is some airspeed where the pitch for level flight would be zero.

It's a simple matter of physics. For lift to exactly offset weight, the angle of attack has to be adjusted when airspeed changes (because lift is proportional to the square of airspeed), and obviously also when the weight changes. And we change angle of attack in level flight by changing pitch. So there cannot be one pitch angle which always results in level flight.

Regards,
Martin

Martin thanks. Cool stuff. I have used flight directors for 3 decades at airlines, but frankly we fly on autopilot, not hand fly to the flight director, unless we are doing recurrent. I have a "synthetic flight path" and two axis autopilot in my personal experimental plane with glass panel (not Garmin).

Plane I am talking about is a BASIC IFR trainer, bare bones C152. It actually flies very nice and has everything you need and are required to have for IFR flight. Needless to say there is NO FLIGHT director, synthetic flight path, terrain avoidance, autopilot. GNS430W and second G5 in HSI mode does Nav. Everyone know planes fly just fine without Glass? Ha ha. I learned to fly pre GA glass and GPS. This is club plane and have no say what gear it has.

I supplement student training with a RedBird LD G1000 ATD Sim (which cost almost as much per hour as the airplane wet). The Sim has G1000 panel, but does not truly have all the bells and whistles of a G1000 or G1000NXi. It is actually a generic copy of a Garmin, but it is a hardware panel, with screen, buttons knobs. It does not have any flight path, vector, wiz-bang features. It is basic G1000 simulation, enough to do what we need.

My students will get their instrument ratings for less than half cost of what an FBO charges (around $10K). We are a non profit flying club. They are getting good training. A C172 would be better, but the IFR C152 is surprisingly stable IFR platform, slow but stable. It does what you tell it to do with the flight controls. Our other club plane is a C182 with Garmin GTN750 fully functional features, two axis auto pilot. That would be very expensive to use as an IFR trainer. I just flew that round trip 540NM total. Very nice, averaged 135 kts, but under 11 gal/hr. Thanks for your LOP video. I knew about this technique, but your LOP Lean of Peak video was great.

 

[asicer]

Martin thanks but I have used flight directors for 3 decades at airlines, but frankly we fly on autopilot not hand fly to the flight director, unless we are doing recurrent. I have a "synthetic flight path" and dual axis autopilot in my personal plane with glass panel. This plane I am talking about is a BASIC IFR trainer, bare bones C152. It actually flies very nice. There is NO FLIGHT director, synthetic flight path, terrain avoidance, autopilot.

The GI275 does not need a flight director or autopilot to give you the FPM.

 

[fly4usa]

The GI275 does not need a flight director or autopilot to give you the FPM.

Did I say that? What is a GI275? Google says MFD. OK. I have G5's. I can't keep up with every variation of avionics. Other GA aircraft I fly Aspen, Dynon, Grand Rapids, I can't keep up. Frankly I like flying my partners J3 with no glass and Nav by pilotage and dead reckoning.

 

[Groundpounder]

Holy smokes.

 

[Bell206]

Did you read or understand this thread?

Ha. I was replying to what you stated in your post. Maybe you should read and understand what you post?

I need to convince my A&P of this, point of this thread

And one way to "convince" your mechanic is to get additional info from the approved data holder regardless the type of STC or approved data. An EO is merely one method. As to cost I've never paid for an EO for a specific S/N aircraft before. But thats my experience. Perhaps you should become better acquainted with actual mx processes before making general statements. Its not very becoming.

 

[Clip4]

Thank you. Note
"In flight level cruse attitude is not necessarily the same as the leveling points provided by the manufacture. Adjustments to the pitch and roll offsets can be made to compensate for the aircraft flight characteristics." Garmin told me the same thing, and it does not violate the STC.

As far as the other comments that they also have 3 degree pitch up that is good info. A&P's are great, keep the planes flying but they are not pilots. The instructions to install them work, but with fancy electronics we can dial them in. May be Garmin did not want the liability and used the KISS method. The calibration takes a minute of button pushing, not a difficult thing.

It is harder on students to make small pitch changes and maintain precise altitude. If I can get the A&P to adjust it, based on note and calling Garmin, adjusting for "aircraft flight characteristics", it will indicate ZERO pitch (+/-) in level cruise. Why "get use to it". I was using a G1000 the other day. They seem to have adjusted that properly to real zero pitch in level flight.

Actually the students adapt to it very quickly, the pilots who seem to struggle a bit are the pilots with lots of Vac AI time.

The other issues are the adjustment is only valid at the gross weight/CG/TAS condition you make the adjustment for. Your student who transitions to other aircraft are not going to be able to demand adjustments because many PFDs are not adjustable or they are going to be told to grow up.

 

[chemgeek]

That is a lot of percent.

Did it 10 times(?), just like he repeatedly raled about the G5 not conforming to an unrealistic vision of flight physics. I hope the OP is not disappointed that his G5 is not going to read zero degrees in level flight at both cruise and approach speeds, or with different passenger loadings. No matter how many times he has his mechanic readjust the offset on the ground.