34 votes

What should I follow, if two altimeters show different altitudes?

The G5 is not certified as a primary altimeter- its information is advisory only. From a legal standpoint, your primary altimeter is always the certified one- in your case, the steam gauge one.
Chris's user avatar
  • 14.5k
22 votes
Accepted

Why aren't PFDs made as robust as the Integrated Standby Instrument System (ISIS)?

The value of the Integrated Standby Instrument System (ISIS) is not that it is infallible. Its value comes from its failures being unrelated to the primary system. ISIS can and will fail from time to ...
abelenky's user avatar
  • 30.7k
21 votes

Should turns always be standard-rate?

The Turn Coordinator index marks denote a standard rate turn. Standard rate is 3 degrees per second, meaning it takes 2 minutes to fly a full circle. It's also called a "2 Minute Turn" or &...
John K's user avatar
  • 130k
21 votes

Why does a sudden tailwind/headwind change IAS?

Why that happens is due to the aircraft's inertia. Consider a fairly simple case: an aircraft is flying due north, straight & level, with a constant 100 knots of indicated airspeed (KIAS) and a 10 ...
Ralph J's user avatar
  • 50.6k
19 votes

Why do most light aircraft not have AoA indicators?

Historical inertia, mainly. AoA indicators aren't too terribly expensive to install anymore, but they were until very recently. We are now in a period where AoA indicators are fairly inexpensive and ...
Chris's user avatar
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18 votes
Accepted

At what point is the input data to glass cockpit PFDs converted to digital?

Glass cockpits are modular systems, and not all of them are exactly the same. But many/most include a module called an Air Data Computer (ADC) which performs the digitalization function for the ...
TypeIA's user avatar
  • 14.2k
16 votes

At what point is the input data to glass cockpit PFDs converted to digital?

On smaller aircraft, the conversion is done within the Air Data Computer (see TypeIA's answer). This makes replacing older steam gauges with a glass cockpit relatively simple because you just send the ...
Bianfable's user avatar
  • 55.4k
14 votes

What should I follow, if two altimeters show different altitudes?

Garmin itself says: With the Auto Calibration feature turned on, the altimeter accuracy can range from +/- 50 to 125 feet (same as GPS elevation). You can draw your own conclusions from this!
TonyK's user avatar
  • 259
14 votes

Should turns always be standard-rate?

Fly the aircraft however you want to fly the aircraft... if you want a really slow turn, put in a few degrees of bank. If you want to crank it around, roll it to 60 degrees and enjoy the 2 G's. ...
Ralph J's user avatar
  • 50.6k
14 votes

Why do most light aircraft not have AoA indicators?

One reason is just that it is hard to build as a console instrument for light aircraft. Just having an indicator on the side is easy, but having it show up in instrument cluster requires measuring an ...
GremlinWranger's user avatar
9 votes
Accepted

The instrument that show the attitude in the F-16 cockpit in a dive glide slope but nose up attitude what will show?

If the nose of the airplane is above the horizon the ADI will show more sky than ground. Rate of descent, AoA, and power setting are all irrelevant. The ADI displays only attitude with respect to the ...
Michael Hall's user avatar
  • 25.6k
7 votes

How was altitude calculated before the invention of the altimeter?

By triangulation. Knowing where the airplane is above the ground and knowing what the angle is between horizontal and the sightline vector pointing towards the plane, you can solve for the height of ...
niels nielsen's user avatar
7 votes

Why do most light aircraft not have AoA indicators?

Chris's answer is spot on, but I'll add a bit. Retro-fitting is expensive, and getting airframes included in a cert (if the airframe is no longer in production) is a calculated risk. AOA sensors are ...
Dave's user avatar
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6 votes
Accepted

Why is this Cessna flap position indicator marked so irregularly?

Because it was the analog world and no other (easy) solutions exist. Providing an exhaustive answer will require too much space here, but I'll give the idea with the help of some figures. So, this is ...
ocirocir's user avatar
  • 1,954
6 votes

Why are pitot-static measurements preferred over other velocimetry techniques?

There are quite a few reasons. First off, as everyone has already mentioned, HWAs are quite fragile and somewhat more complicated to decode (though the latter is a non-issue with modern electronics). ...
Kostadinov's user avatar
6 votes

Should turns always be standard-rate?

Are you always supposed to turn with the wings on one of these marks, or is that only necessary when you need to use a clock to measure your turn? In the VFR context, no one ever feels compelled to ...
quiet flyer's user avatar
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6 votes

Static port and drain hole blocked with pitot tube unobstructed

A blocked static port will make the altimeter and vertical speed indicator inoperative. The airspeed indicator will function correctly at the altitude at which it first became blocked, but it will ...
Chris's user avatar
  • 14.5k
5 votes
Accepted

What are Baro-Aiding and Baro-VNAV systems?

Many corporate jets use a baro-aided VNAV system. Before WAAS was so prevalent, many FMS installations were certified to TSO c129 standards allowing the operator to fly RNAV GPS approach procedures ...
wbeard52's user avatar
  • 12.5k
5 votes

What are Baro-Aiding and Baro-VNAV systems?

As mentioned on previous answers, Baro-VNAV system combines lateral GPS position with barometric altitude. The approach is retrieved from navigation system database which includes the MAPt position ...
busdriver's user avatar
  • 3,250
5 votes
Accepted

Is the attitude gyro (artificial horizon) equipment on our DA40NG aircraft powered by electricity?

That attitude gyro is electric, and having a standalone emergency battery power supply, is your last resort to get to VFR conditions if you have a primary flight display failure and/or total ...
John K's user avatar
  • 130k
5 votes

What is the name of the dotted line that shows the predicted turn radius, found on the Navigation display of the 738

The segmented white line is called the “Position Trend Vector”.
Mike Sowsun's user avatar
  • 37.7k
4 votes

What is the name for the spherical type of attitude indicator that also shows heading?

I have never seen such a device with a magnetic heading references integrated into it. Given that it appears to have flight director and autopilot command bars integrated into it, that kind of an ...
Romeo_4808N's user avatar
  • 73.5k
4 votes

How to accurately test glide ratio in given configuration?

It is tricky to do well. First, GPS isn't helpful because it can't account for the effects of wind. You can fly upwind and downwind legs to try to cancel it out, but it will still be there. We ...
Rob McDonald's user avatar
  • 9,161
4 votes

When does true altitude equal indicated altitude?

The first part is one of the many poorly-worded test prep questions in the pilot training world. Yes, standard pressure and standard temperature are the only two conditions they are looking for. ...
Max Power's user avatar
  • 2,584
4 votes

Why does a sudden tailwind/headwind change IAS?

Let's suppose that our airplane possesses a speed of 100kts in respect to earth (speed measured for example via a GPS system) and it's flying into a windy air which has a speed of 20kts (measured for ...
sophit's user avatar
  • 10.9k
4 votes

Why do most light aircraft not have AoA indicators?

One reason is that most of the light airplanes already have one of sorts in the stall warning. The stall warning sensor is basically an angle of attack instrument of sorts, although with only two ...
ghellquist's user avatar
  • 1,586
4 votes
Accepted

Why was the rate of part 121 LPV equipage projected to be so low, and has that projection come true?

Short answer: Money. Part 121 operators, i.e. airlines, are interested in profit and running an airline is a low margin business. Aircraft are very big capital expenses. They cost a lot every day in ...
Gerry's user avatar
  • 19.7k
3 votes
Accepted

Manual or other information regarding Kollsman Instruments B40331-10-276 altimeter

Undoubtedly an encoding altimeter. Ten pins are the encoder output. This is Gillham coded, a 12 bit Gray code identifying altitude in hundreds of feet. D4 is needed above 30750ft which makes ten pins. ...
Pilothead's user avatar
  • 20k
3 votes

Why aren't PFDs made as robust as the Integrated Standby Instrument System (ISIS)?

And since the black boxes (CVR and FDR) can survive a crash, why not make the entire plane out of the same stuff? Airplanes, as with nearly any complex technological system, is a balance between cost ...
manassehkatz-Moving 2 Codidact's user avatar

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