New ASI - MPH / KNTS or KNTS / MPH

[rodney]

Well, need to replace my Airspeed Indicator in my 65 M20E.  Old one is leaking, original to plane apparently, and not repairable.

Two questions:

 

1) What brand?  UMA or United.  United a little more expensive but my Instrument shop likes them best.

2) My current ASI has MPH on outer scale and Knots on inside.  I have the opportunity to reverse this and put Knots on the outside scale.  I am considering this.  Has anyone done this?  

 

Thanks for any comments.

 

Rodney

[jetdriven]

Aircraft Quality Instruments in Wichita can rescreen your ASI however you want and OH it.  IIRC the cost was <200$.   I prefer knots on the outer scale.

[garytex]

All the POH on my F is MPH, so I put MPH on my outside ring.

Gary

[DaV8or]

Quote: garytex

All the POH on my F is MPH, so I put MPH on my outside ring.

Gary

[flight2000]

I came to the same conclusion as Dave.  Easier with everything in the owners manual being in MPH for my 67E.  Still have the knots on the inner ring though.  

Brian

[Oscar Avalle]

Same with me too. I just added and ASPEN to my panel and decided to keep the MPH. Just simpler.

[cujet1]

You will have to use the markings and limitations originally intended for your aircraft.

[Marauder]

You will have to use the markings and limitations originally intended for your aircraft.

This has been an interesting challenge since I bought my 1975 F in 1991. My entire POH has the speeds listed in both MPH and Knots. My airspeed indicator is labeled the same as well. The outer ring is in MPH, the inner is in knots. And it has caused me problems over the years. If I do a BFR/IPC i need to know whether i am dealing with a "knots" Or "MPH" CFI. I am in the process of having an Aspen installed. This will force me to pick one. Thoughts?

[carusoam]

Prior to Js, most speed information was transmitted in mph. It sounds faster...

The IFR world seems to have restandardized on KIAS. Approach plates are all in knots

If you fly in the system, knots is probably better.

If you fly VFR it won't matter.

Either way, stick with one system. Otherwise landing long or short becomes an inherent distraction.

Consider this as an amateur opinion...

Best regards,

-a-

[rodney]

Just reporting back...

I ended up getting a ASI from Aircraft Quality Instruments as suggested above. I did buck the initial advice and switched to KNTS on outside, MPH on inside. I always fly within the system and previously found myself thinking in terms of knts most of time anyway, and knts is what my GPS, etc. is displaying so I was constantly doing the conversion, looking at the small scale anyway.

Even so, having flown with the new ASI, I am surprised at how ingrained the landing speeds, gear down speeds, and flap speeds were in my head. I have had to retrain myself and bit, even though the new ASI still has both scales on it. That said, I think it will just take a few more flights to adjust.

Rodney

[Marauder]

Just reporting back...

I ended up getting a ASI from Aircraft Quality Instruments as suggested above. I did buck the initial advice and switched to KNTS on outside, MPH on inside. I always fly within the system and previously found myself thinking in terms of knts most of time anyway, and knts is what my GPS, etc. is displaying so I was constantly doing the conversion, looking at the small scale anyway.

Even so, having flown with the new ASI, I am surprised at how ingrained the landing speeds, gear down speeds, and flap speeds were in my head. I have had to retrain myself and bit, even though the new ASI still has both scales on it. That said, I think it will just take a few more flights to adjust.

Rodney

I know what you mean! I fly IFR and being in the system you are always speaking in "knots". I learned my Mooney in MPH and still think that way when I am flying. Keep us posted how the transition goes! My ASI needs a facelift after 37 years of faithful and I am thinking of sending it in to have it overhauled while my plane is in for the avionics upgrade. The ASI will still be required even though I will have the Aspen PFD/MFD. I opted to stay with the internal battery, not because it saves me $1k, but there is something comforting about seeing things mechanical gauges, even if they will be relegated to a backup role.