Macho-ism

[poadeleted20]

If you have a radio failure (as in your stack goes tits up), don't land in a field lol, sometimes I forget some people don't have any damn common sense. What you SHOULD do is, in VMC fly to the nearest AIRPORT and call in on the phone.

Nearest suitable airport. No need to wedge your Baron into an 1800-foot grass strip in this account.

 

[Captain]

To those that wouldn't declare an emergency if they lost their attitude indicator;

Would you also not declare if an engine quit as that is trained for too? Any time the safe outcome of the flight is in question you declare an emergency. I'm a pilot who flies IFR for a living, log 800'ish hours a year and do two check rides in a level D Sim per year. I guarantee you I'd declare an emergency if I lost my primary attitude indicator. I even have a backup peanut gyro...

If you think you're better than me partial panel by not declaring an emergency then this thread title is for you...

 

[Captain]

Nearest suitable airport. No need to wedge your Baron into an 1800-foot grass strip in this account.

I agree with all you've said on this. Only thing I'd add is initial altitude is also a factor. If you're at 37,000 feet a normal descent makes an airport 100 miles away just fine for 'nearest suitable'. Overflying a bunch of 7,000 foot runways is okay. You CAN spiral down if you want, or you can descend straight. Nobodies going to question you either way. The problem. Comes when you fly straight and level past good airports to get to some special place tying up the system and resources.

 

[Palmpilot]

Re: Machismo

I've forgotten what the circumstances were in the enforcement case that Cap'n Ron mentioned. Anyone remember the details, or have a link?

 

[denverpilot]

Nate, there is a big difference between temporary loss of comms due to reception range and atmospherics in an area where ATC expects it and having a radio failure.

Yeah but the example used was an inane one about someone continuing NORDO into LAX. There's plenty of places where "land when practicable" will just be your final originally planned destination. The world isn't all Class Bravo hubs.

 

[azure]

Would you also not declare if an engine quit as that is trained for too? Any time the safe outcome of the flight is in question you declare an emergency. I'm a pilot who flies IFR for a living, log 800'ish hours a year and do two check rides in a level D Sim per year. I guarantee you I'd declare an emergency if I lost my primary attitude indicator. I even have a backup peanut gyro...

I don't know what a "peanut" gyro is, but serious question: if you have a backup gyro then presumably you would not be partial panel at that point, so why would the safe outcome of the flight be in doubt?

Speaking only for myself, what I said has nothing to do with being macho. I learned the hard way not to ask ATC for anything I don't really need. The rules require that I tell them about the equipment failure, otherwise I wouldn't do that either. Losing an engine is a completely different issue, so is losing an important flight instrument such as the HSI, or altimeter, or really ANYTHING other than the AI. There is no comparison. Flying with my AI covered up is NOT partial panel. The DPE had to fail BOTH my AI and HSI to simulate partial panel.

 

[Captain]

I don't know what a "peanut" gyro is, but serious question: if you have a backup gyro then presumably you would not be partial panel at that point, so why would the safe outcome of the flight be in doubt?

Speaking only for myself, what I said has nothing to do with being macho. I learned the hard way not to ask ATC for anything I don't really need. The rules require that I tell them about the equipment failure, otherwise I wouldn't do that either. Losing an engine is a completely different issue, so is losing an important flight instrument such as the HSI, or altimeter, or really ANYTHING other than the AI. There is no comparison. Flying with my AI covered up is NOT partial panel. The DPE had to fail BOTH my AI and HSI to simulate partial panel.

Sounds like a good story there.

Here's a link to an article talking about partial panel. In the picture, to the upper right of the main flight display is a small 2 inch AI. That is a peanut gyro. The same style that I have.

I have flown approaches in the Sim with it alone and I promise you it isn't pretty. If I had to rely on that and shoot an ILS to mins it would be a class A emergency. I speak for all professional pilots on that I think.

 

[azure]

Sounds like a good story there.

I've posted about it quite a few times already. I had a flaky-acting fuel gauge, told ATC I was diverting to check it out (this was on VFR flight following), ATC declared for me and I had to answer some rather unfriendly questions from a FSDO inspector.

Here's a link to an article talking about partial panel. In the picture, to the upper right of the main flight display is a small 2 inch AI. That is a peanut gyro. The same style that I have.

If you're flying with a glass PFD then I really don't have much experience to draw on for comparison. I have little doubt that any serious PFD failure requiring use of backup instruments would be an emergency situation. All I can tell you is that in my airplane, the AI is nothing like the large, exquisitely sensitive attitude display on a PFD. It's small, shows a slight bank when wings level, is fairly insensitive to small attitude changes, and is prone to transient errors after turns. I rely much more on my HSI and TC to control bank, and my altimeter and VSI to control pitch. If I had a DG instead of an HSI, especially a vacuum driven DG, it would be a very different situation.

 

[NineThreeKilo]

Nearest suitable airport. No need to wedge your Baron into an 1800-foot grass strip in this account.

I think that goes without saying, don't you??

Also don't land your plane on the anchor looking airports on the chart unless you have floats, don't try to land your Lear jet on a heli pad, be sure to land on the runway longways, not from the side to side, don't put your fingers in the prop, and yes, your Starbucks coffee is hot when heated

 

[poadeleted20]

I don't know what a "peanut" gyro is,

Many turbine aircraft have a small 2-1/8 inch standby AI with internal backup battery power good for 30 minutes or so. As it's kind of peanut-sized compared to the big AI's most turbine aircraft have (much bigger than the standard 3-1/2 inch instruments light planes usually have), it's called the "peanut gyro."

but serious question: if you have a backup gyro then presumably you would not be partial panel at that point, so why would the safe outcome of the flight be in doubt?

You are still "partial panel" in the sense that you have lost your primary flight instrument, which may have additional functions/displays beyond just attitude. For example, the big "8-ball" primary instruments we had in the RF-4C and F-111E included heading and lateral/vertical steering bars in addition to basic attitude information. Lose that instrument, and it's harder tofly precisely even if you still have the peanut gyro and a CDI somewhere else in the panel.

Speaking only for myself, what I said has nothing to do with being macho. I learned the hard way not to ask ATC for anything I don't really need. The rules require that I tell them about the equipment failure, otherwise I wouldn't do that either. Losing an engine is a completely different issue, so is losing an important flight instrument such as the HSI, or altimeter, or really ANYTHING other than the AI. There is no comparison. Flying with my AI covered up is NOT partial panel. The DPE had to fail BOTH my AI and HSI to simulate partial panel.

That may be your definition, but the Task in the Instrument PTS is "Loss of Primary Flight Instrument/Display", not "partial panel", the latter term having no official definition.

 

[poadeleted20]

I think that goes without saying, don't you??

You'd think that, and I might, too, but the NTSB files suggest otherwise. I've learned over the last five decades that there are a lot of folks out there with pilot certificates but not much in the way of good judgment.

 

[NineThreeKilo]

You'd think that, and I might, too, but the NTSB files suggest otherwise. I've learned over the last five decades that there are a lot of folks out there with pilot certificates but not much in the way of good judgment.

Indeed this is true.

Lack of common sense in the air tends to work it selfout rather quickly as the NTSB can demonstrate.

 

[gismo]

Sounds like a good story there.

Here's a link to an article talking about partial panel. In the picture, to the upper right of the main flight display is a small 2 inch AI. That is a peanut gyro. The same style that I have.

I have flown approaches in the Sim with it alone and I promise you it isn't pretty. If I had to rely on that and shoot an ILS to mins it would be a class A emergency. I speak for all professional pilots on that I think.

I think part of that is due to the airplane the peanut gyro is in (the other part might be your vision, I know mine have a harder time seeing small movements on the AI). First you're probably coming from a 4-5 inch AI or glass AI presentation so that 2 incher would seem a lot smaller than it might to someone who was switching from a 3" AN gyro. Second, a half degree pitch change in a 172 probably results in a 50-100 FPM altitude change rate, vs a lot more in a jet.

That said, I have no objection to anyone declaring an emergency if one of their primary flight instruments fail regardless of what they've got for backup. Heck in a G500/600 equipped Bonanza, "partial panel" means reverting to a 3" AI, ASI, and heading gyro but that's enough of a change to make for problems if you're not used to it.

 

[NineThreeKilo]

.... Heck in a G500/600 equipped Bonanza, "partial panel" means reverting to a 3" AI, ASI, and heading gyro but that's enough of a change to make for problems if you're not used to it.

Poor babies... are you F'n kiddin me, reverting to full analog gyros, if that makes problems, well you had problems before you started your flight.

If the above type of situation resulted in someone declaring a emergency, I wouldnt question their decision, I would however STRONGLY question if they should be allowed to have a instrument ticket after they were safe on the ground.

Furthermore I would consider if they were reckless operating a aircraft that they were not qualified to operate, I'd vote for immediate and perminate revocation of all airman certs.

 

[wabower]

Have you ever flown jets or turbine-powered planes? Do you know their definition of "raw data" for partial panel approaches?

Poor babies... are you F'n kiddin me, reverting to full analog gyros, if that makes problems, well you had problems before you started your flight.

If the above type of situation resulted in someone declaring a emergency, I wouldnt question their decision, I would however STRONGLY question if they should be allowed to have a instrument ticket after they were safe on the ground.

Furthermore I would consider if they were reckless operating a aircraft that they were not qualified to operate, I'd vote for immediate and perminate revocation of all airman certs.

 

[Captain]

Poor babies... are you F'n kiddin me, reverting to full analog gyros, if that makes problems, well you had problems before you started your flight.

If the above type of situation resulted in someone declaring a emergency, I wouldnt question their decision, I would however STRONGLY question if they should be allowed to have a instrument ticket after they were safe on the ground.

Furthermore I would consider if they were reckless operating a aircraft that they were not qualified to operate, I'd vote for immediate and perminate revocation of all airman certs.

You clearly do not have the experiences to form the position you have taken.

I swear on all that is holy that any Airbus operated out there or 737-800 would declare in an instant if they lost their PFDs and had to land on a peanut gyro. Are you as willing to throw every UAL, DAL, SWA, B6, and AAL pilot into the 'poor babies' category?

If so well then I don't know what to say.

 

[NineThreeKilo]

Have you ever flown jets or turbine-powered planes? Do you know their definition of "raw data" for partial panel approaches?

I fly turbines, 6 days a week, average 80-100hrs a month, no autopilot, no copilot.

Also I didn't realize a Bonanaza is a turbine or is in the transport category.

 

[wabower]

Then maybe you should limit your rants to things you know more about.

I fly turbines, 6 days a week, average 80-100hrs a month, no autopilot, no copilot.

Also I didn't realize a Bonanaza is a turbine or is in the transport category.

 

[NineThreeKilo]

Then maybe you should limit your rants to things you know more about.

What are you jibbering on about lol

I replied to a bonanza with glass and a backup mechanical AI and DG, well within my scope of practice!??

Still stand behind what I said, if some dude flying his Bo looses his glass and can't cope with a full mechanical AI and DG, he probably shouldnt be flying that plane.

So with near 10,000 posts how do you find the time to fly anything other then your keyboard? How many hours you logging a month Wayne?

 

[azure]

You are still "partial panel" in the sense that you have lost your primary flight instrument, which may have additional functions/displays beyond just attitude. For example, the big "8-ball" primary instruments we had in the RF-4C and F-111E included heading and lateral/vertical steering bars in addition to basic attitude information. Lose that instrument, and it's harder tofly precisely even if you still have the peanut gyro and a CDI somewhere else in the panel.

Absolutely, if you've lost a primary flight instrument (or worse, a multi-function primary display), that's an emergency, I've never argued otherwise. My point was that what constitutes your primary flight instrument(s) depends on your instrumentation. What you're saying actually supports my point.

That may be your definition, but the Task in the Instrument PTS is "Loss of Primary Flight Instrument/Display", not "partial panel", the latter term having no official definition.

Now you're quibbling about terminology. What's the point? To review, I said that in my airplane, I would not consider losing the AI to be a true partial panel situation, and therefore not an emergency. Translated into your better defined terminology, losing my AI does not constitute losing my primary flight instrument/display. Evidently my DPE was of the same opinion.

One thing is for sure, if someone said I could have my AI or my HSI but not both, I know which one I would pick. YMMV as always.

 

[poadeleted20]

Now you're quibbling about terminology. What's the point?

To understand the FAA's position as regards instrument training and testing.

To review, I said that in my airplane, I would not consider losing the AI to be a true partial panel situation, and therefore not an emergency. Translated into your better defined terminology, losing my AI does not constitute losing my primary flight instrument/display.

What is your primary flight instrument for attitude if not your AI? Keep in mind that an attitude instrument is a requirement for instrument flight, and if you've lost the only one you have, your aircraft is no longer legally airworthy for instrument flight, which pretty much implies it's now an emergency situation. Of course, if you have a backup AI, it's not that big a deal.

 

[azure]

What is your primary flight instrument for attitude if not your AI? Keep in mind that an attitude instrument is a requirement for instrument flight, and if you've lost the only one you have, your aircraft is no longer legally airworthy for instrument flight, which pretty much implies it's now an emergency situation. Of course, if you have a backup AI, it's not that big a deal.

If you look at my previous posts in this thread, I said that I would request a clearance to the nearest large field (i.e., field likely to have mx services), and have it fixed before flying again IFR. I'm well aware that the airplane is no longer legally airworthy for instrument flight. What I wouldn't do, because there would be no reason for it absent other signs of trouble, is to declare an emergency. Of course, the rules require that I report the failure to ATC and they might very well "declare" for me (i.e., treat the event as if I had declared) under the circumstances. I have no control over that.

 

[azure]

The FAA expects the pilot to use ADM in the event of equipment loss to safely terminate the flight. That does not always mean landing at the next available
airport. Where pilots get in bad with the FAA is ignoring a failure, not evaluating options and just plowing on to their destination.

Agree 100%.

 

[poadeleted20]

You two agree may with each other, but I think your judgment in this regard is less than outstanding, and I think anyone in FAA Flight Standards you ask would agree with me. Further, I think anyone who espoused your position during an instrument rating or instrument instructor practical test (and I've sat through a lot of them, both as applicant and observer) would have a deep hole out of which to climb vis a vis the Judgment Assessment Matrix. But, you're the PIC, so when you're flying, you do what you want and if nothing bad happens, nobody will care. OTOH, if something bad does happen, the title of this thread may be your epitaph, either on a tombstone or an FAA/NTSB report.

 

[Palmpilot]

The consequences of disagreeing with Cap'n Ron are dire!

 

[Velocity173]

So Ron how is loss of primary flight instrument taught then? If you can lose a primary AI and revert to a secondary AI, then how is that partial panel? I thought the whole point of simulating flying without an AI is to use supporting instruments to make up for the loss of the primary. And according to the PTS those supporting instruments should be part of the installed equipment in the aircraft. There are a bunch small IFR aircraft that don't have a separate "peanut" gyro.

 

[poadeleted20]

So Ron how is loss of primary flight instrument taught then?

It varies with the system. It's a lot different for a Cirrus with G1000 and dual AHRS and dual ADC than it is for a vacuum 6-pack 172 with two VOR's and nothing else.

If you can lose a primary AI and revert to a secondary AI, then how is that partial panel?

As I said, the Task in the PTS is "Primary Flight Instrument Inoperative," not "partial panel". In terms of testing, it's up to the DPE to create an appropriate scenario, but generally speaking they will not simulate a triple or quadruple failure to get there. In addition, with planes something like a single-AHRS/ADC G1000, most examiners choose not to pull c/b's, with the result that this task becomes simply dimming down the PFD and hitting the red button to go reversionary on the MFD.

Of course, this scenario doesn't disable the autopilot, and many examiners don't deny autopilot use in that situation, not to mention that you still have basically everything you have "full panel" -- you're just required to fly "cross-cockpit" and that's really not much of a challenge. When I give training, I do kill the AHRS and ADC by pulling the c/b (one at a time, not both together), and that is rather more challenging, especially with the AHRS out. It's also, I think, much more realistic training, as well as killing the a/p so the pilot is faced with the real-world scenario of having to hand-fly truly "partial panel" with the G1000 system -- they don't usually do very well on their first tray, although doing it first in the sim helps them a lot.

I thought the whole point of simulating flying without an AI is to use supporting instruments to make up for the loss of the primary.

The point of this Task is to see if you can handle any single-point instrument system failure and get it on the ground safely. It is not a challenge to see who can fly with the least number of instruments remaining. Note in particular that the FAA is very insistent that you be tested on the aircraft you provide, and if it has multiple backups, you don't get tested on every possible scenario.

And according to the PTS those supporting instruments should be part of the installed equipment in the aircraft. There are a bunch small IFR aircraft that don't have a separate "peanut" gyro.

Agreed, and if the plane you show up with for the test doesn't have such a backup AI, you have to get along with the primary AI out, i.e., with the three pitot/static instruments plus TC/T&B and mag compass. But if you show up for the practical test with full pilot/co-pilot instruments plus the third independent AI mentioned in 91.205(d)(3)(i), you get to skate on no-AI flying, just like most folks do when the DPE does the reversionary mode deal I mentioned above with a G1000.

Now, is that right? An examiner can only test so much in an hour and a half of flying. I figure it's up to me to make sure during the 30 or more hours of flight/sim training before I sign off the trainee for that test that they can handle pretty much any reasonably foreseeable failure mode appropriate to the aircraft in which they train. But at the same time, I'm not going to try to make someone in a G1000 fly with all the AI's out (AHRS and backup AI) since a) that's a pretty darn unlikely scenario (even with the single-AHRS DA40 set-up, you have an emergency-use only 90-minute independent battery for the AI and flood lights), and b) that would leave them with zero gyro-based instrumentation (no separate TC/T&B in those planes), and that's pretty much an unflyable situation no matter what you try.

And I'm not ready to sign on for making folks do some certain minimum amount of training in a vacuum 6-pack just to torture them with that drill before they take the test in their G1000 plane which they'll be flying thereafter. Steve Ritchey said, "You fight like you train," but then Duke Cunningham correctly added "...so train the way you want to fight." If they're going to be flying glass panel planes with multiple backups, I'll train them appropriately. Think of it like the ME practical test -- we don't do the engine failure/emergency landing or 180 power-off approach Tasks in twins, and you can go from PP to ATP all in twins without ever doing those tasks -- and I've not heard anyone suggest we should change that, either.

 

[Captain]

Agree or disagree the man puts effort into his posts.

From my perspective I saw nothing flawed in Ron's post.

 

[Velocity173]

Agree or disagree the man puts effort into his posts.

From my perspective I saw nothing flawed in Ron's post.

I agree. Thanks Ron. I didn't realize it could be taught / evaluated differently depending on aircraft. I did training in a little Liberty XL with one AI. I was under the impression that any backup AI wouldn't be allowed for loss of primary instrument task. Now I wish I would've trained in a DA-40XL.

 

[Jaybird180]

I had thoughts that Ron nearly took away with his all-encompassing post.

What about separate endorsements for glass vs 6-pack? It would get my vote.

 

[peppy]

I had thoughts that Ron nearly took away with his all-encompassing post.

What about separate endorsements for glass vs 6-pack? It would get my vote.

Where you are heading is towards a type rating for every plane which I think would put a further damper on GA. There are plenty of differences between glass panels. Dual vs. single AHARS is one example. Also there are differences in reversionary capability between Avidyne Entegra (none), Garmin G1000 (special reversionary mode) and Avidyne R9 (full duplication). Do you propose separate ratings for each of these?

 

[RotorAndWing]

Where you are heading is towards a type rating for every plane which I think would put a further damper on GA. There are plenty of differences between glass panels. Dual vs. single AHARS is one example. Also there are differences in reversionary capability between Avidyne Entegra (none), Garmin G1000 (special reversionary mode) and Avidyne R9 (full duplication). Do you propose separate ratings for each of these?

Where I live that's exactly what goes on. If you have a Private or Commercial rating you must have the "type" aircraft printed on your license, i.e. C-172, PA-28-151, etc. And you are only allowed 4 aircraft "types". The Civil Aviation Authority considers a C-172 with a glass panel different from one with a six pack analog.

Be careful what you wish for.

 

[Captain]

A regulation requiring pilots to have a minimum number of hours before transitioning to a technology advanced aircraft would get my vote. Some of these systems take more time to teach than getting a student to solo.

There are different levels of mastery for such systems. There's "I have no idea" and "I can fly basic stuff but build a hold I'll need vectors to figure it out" and "I can fly the system competently" and "I can run it like I designed it".

Depending where you train to depends how much time it takes. And no matter where you train to they will most likely step back a notch (or two) within 6 months.

 

[Dave Theisen]

A regulation requiring pilots to have a minimum number of hours before transitioning to a technology advanced aircraft would get my vote. Some of these systems take more time to teach than getting a student to solo.

So far the FAA has let common sense and the insurance companies control this. I think it could get out of hand if the FAA instituted regulation for each and every avionics system out there.

 

[redtail]

Good discussion guys. I love the G1000!
Really wish I could start my instrument training, just can't swing it right now

I'd love to be a student of Cap'n Ron!

 

[peppy]

Where I live that's exactly what goes on. If you have a Private or Commercial rating you must have the "type" aircraft printed on your license, i.e. C-172, PA-28-151, etc. And you are only allowed 4 aircraft "types". The Civil Aviation Authority considers a C-172 with a glass panel different from one with a six pack analog.

Be careful what you wish for.

I'm with you.

What is missing today is a glass system easy to stay current on for the 70 hour per year pilot. Avidyne R9 comes close but has a few areas that need fixing. Garmin G1000 is a different story and takes a lot more effort for the low time pilot to stay current.

 

[azure]

You two agree may with each other, but I think your judgment in this regard is less than outstanding, and I think anyone in FAA Flight Standards you ask would agree with me. Further, I think anyone who espoused your position during an instrument rating or instrument instructor practical test (and I've sat through a lot of them, both as applicant and observer) would have a deep hole out of which to climb vis a vis the Judgment Assessment Matrix. But, you're the PIC, so when you're flying, you do what you want and if nothing bad happens, nobody will care. OTOH, if something bad does happen, the title of this thread may be your epitaph, either on a tombstone or an FAA/NTSB report.

The only difference between what you're saying and what I'm saying is that I would not necessarily declare an emergency for a single point instrument failure that makes the aircraft legally unairworthy for IFR flight. What am I advocating that leads you to talk about an epitaph or NTSB report? That seems awfully extreme to me. Everyone here agrees that ATC needs to be informed of the failure, that the flight needs to be terminated as soon as practicable, and that the failed instrument has to be repaired before further flight under IFR. What advantage do you see in declaring an emergency in a case where the failure doesn't significantly impact the pilot's ability to control the airplane?

 

[azure]

The point of this Task is to see if you can handle any single-point instrument system failure and get it on the ground safely. It is not a challenge to see who can fly with the least number of instruments remaining. Note in particular that the FAA is very insistent that you be tested on the aircraft you provide, and if it has multiple backups, you don't get tested on every possible scenario.

And my CFII challenged the DPE on the grounds that no single point failure could cause me to lose both my AI and HSI. I don't recall what the DPE's justification was, but apparently it fell under the "loss of primary flight display" wording of the PTS.

Out of curiosity, is the primary flight display wording a "recent" change in the PTS (i.e. last 10 years or so), or has it always been worded that way?

 

[poadeleted20]

What about separate endorsements for glass vs 6-pack? It would get my vote.

The FAA considered that about 12-15 years ago, but chose to hang fire on it until they saw if a problem developed. So far, they've seen no rash of accidents involving glass-trained pilots in 6-packs or vice versa, probably because insurers are setting enough requirements. They're not going to change that unless bad things start to happen.

 

[poadeleted20]

Out of curiosity, is the primary flight display wording a "recent" change in the PTS (i.e. last 10 years or so), or has it always been worded that way?

The change from "LOSS OF GYRO ATTITUDE AND/OR HEADING INDICATORS" to "APPROACH WITH LOSS OF PRIMARY FLIGHT INSTRUMENT INDICATORS" occurred when the "D" edition of the IR PTS was issued in April 2004 replacing the "C" edition with Changes 1&2 from 1998. That's the same change where they eliminated all the separate basic instrument flying Tasks (stalls, steep turns, etc).

Further discussion on this issue from that PTS:

Emphasis on Attitude Instrument Flying and Emergency Instrument
Procedures​

The FAA is concerned about numerous fatal aircraft accidents involving
spatial disorientation of instrument-rated pilots who have attempted to
control and maneuver their aircraft in clouds with inoperative primary
flight instruments (gyroscopic heading and/or attitude indicators) or loss
of the primary electronic flight instruments display.
AREA OF OPERATION IV requires the evaluation of basic instrument
flight maneuvers under both full-panel and references to backup
primary flight instruments/electronic flight instrument displays. These
maneuvers are described in detail in FAA-H-8083-15, Instrument Flying​

Handbook.

The FAA has stressed that it is imperative for instrument pilots to
acquire and maintain adequate instrument skills and that they be
capable of performing instrument flight with the use of the backup
systems installed in the aircraft. Many light aircraft operated in IMC are
not equipped with dual, independent, gyroscopic heading and/or attitude
indicators and in many cases are equipped with only a single vacuum
source. Technically advanced aircraft may be equipped with backup
flight instruments or an additional electronic flight display that is not​

located directly in front of the pilot.

The instrument rating practical test standards place emphasis on and
require the demonstrations of a nonprecision instrument approach
without the use of the primary flight instruments or electronic flight
instrument display. A nonprecision approach without the use of the
primary flight instruments/electronic flight instrument display is considered
one of the most demanding situations that could be encountered. If
applicants can master this situation, they can successfully complete a
less difficult precision approach. If an actual approach in IMC becomes
necessary without the aid of the primary flight instruments/electronic
flight instrument display, a less difficult precision approach should be
requested, if available. Sound judgment would normally dictate such
requests. However, the instrument practical test requires that a
nonprecision approach be performed without the use of the primary​

flight instruments/electronic flight instrument display.