G5 numbers question

murphey

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murphey
For those of us with older cherokees, and possibly others, the airspeed indicator is mph on the outside of the ring, kts on the inner ring, and a knob to adjust the mph for temperature.

The G5 can be set to use either mph or kts. I've set it for mph and loaded all the V speeds for mph and it works fine. If I then set for kts, will the gadget automatically convert the V speeds into kts or do I need to reset everything by hand? There's nothing in the Pilot's Guide. I can't find anything in the Install manual (v 18) about it, either.

Will head out to the hangar later today and see what happens. Fortunately, I have all the V speeds in both mph and kts on a 3x5 card I keep in the airplane so resetting everything by hand won't be a big deal. But I dither over mph or kts on the unit.
 
I've gone back and forth on this with my eFIS. I eventually settled on MPH because my backup ASI is MPH on the outer (easier to read) ring, and I wrote my POH in MPH. So it just made sense to stick with that UoM.

Nav planning and talking to ATC I use Knts, which I get from the GNS.
 
I ran into the same issue. The G5 installer set it to read in mph because that is what the 1969 Piper Arrow 200 owner's manual uses for the operating airspeeds. I changed the G5 to display indicated airspeed in knots and had to re-do the V speeds manually. IOW, the G5 didn't "convert". G5 groundspeed is in knots since it comes from the GNS 530 WAAS navigator. My ASI is a "true airspeed" unit with 2 scales with mph in the outer scale like the OP stated. But when ATC wants to know airspeed I use the G5 reading rather than squint to read the smaller numbers on the ASI inner scale.
 
Pretty sure it isn't "legal" unless the unit of measure matches the placards in the airplane. All my placards are in MPH
 
Mine is in MPH as well. Curious as to whether it will automatically change all your speeds if you select knots.
 
Mine is in MPH as well. Curious as to whether it will automatically change all your speeds if you select knots.
IMNSHO software should recognize the Kts/Mph setting and do it automatically. Maybe in a future release? Of course pilot confusion could be a big issue. Who would notice the tiny indicator as to kts/mph on the little display?
 
Pretty sure it isn't "legal" unless the unit of measure matches the placards in the airplane. All my placards are in MPH

My installer said the ASI is in MPH, the G5 has to be MPH.
 
Funny how this forum gets wrapped around the axle. He didn't say he was going to convert to knots per hour but rather if the G5 automatically changed all his V speeds to knots if he selected it.
 
No, the G5 won't "automatically" convert but it is easy to change from one to the other in the setup procedure. It is correct that if the POH specifies mph then the installer must set the G5 to mph. Odd that the G5 would then be displaying IAS in mph and right below it would be GS in knots. Could be confusing???
 
No, the G5 won't "automatically" convert but it is easy to change from one to the other in the setup procedure. It is correct that if the POH specifies mph then the installer must set the G5 to mph. Odd that the G5 would then be displaying IAS in mph and right below it would be GS in knots. Could be confusing???

I assume if you change GPS to display MPH, then it will come across that way to the G5.


Tom
 
Gee, I have no idea! I never thought about that neither do I know if my GNS 530W can do that. All my flight planning and dealing with ATC has to be in knots so I never think in terms of mph. My ASI color markings (mph) are the "quick reference" for gear speed, flaps, etc. The plethora of different units in flying is just short of ridiculous anyway...e.g., temp in C, QNH in inches of Hg (except outside of CONUS where QNH is in mb), wind direction in degrees true EXCEPT on the ground, distance in nm, speed in knots (except in my POH), altitude in feet, etc. The only constant is $$!!
 
Follow-up: I just reviewed the manual for the GNS 530W and it does allow for changing the units of position and speed to statute miles and mph. So I guess the ground speed reported to the G5 could be in mph. Never thought about that before! Seems like it would place a BIG workload on the pilot to mentally convert from those units to the "standard" of nm and kts when dealing with ATC.
 
When I was a brand new pilot <20 with a 1962 cessna 150 I didn't like the "impurity" of the 150 being in MPH and everything else I flew and aviation references in knots. I'm 35 now, and could not care less. Its silly, I mean MPH x 1.2 is close enough to knots for gross estimating, for actual calc 1.15.

Nowadays all my flight planning is knots using apps, GS on the GPS is in knots, all weather data is knots. airspeed references are just another # really. No one says "climb at 65 miles per hour" they just say "climb at 65"
 
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I assume if you change GPS to display MPH, then it will come across that way to the G5.


Tom

My G5 is in MPH indicated and ground speed. My 530 still shows kts. There is probably a way to change GS in the G5 settings.
 
Interesting because that implies that the G5 is converting the GNS 530 kts to G5 mph...curious...
 
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