External Static Air Intake

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When we finished the build of N333ST, the static air intake was located behind the panel. This has been so for all Slings built so far. However, as we have fixed some cabin air leaks the internal pressure has changed and the airspeed is now clearly reading too high by perhaps 20 knots. That is not a good situation. 


So this week I returned to TAF in Torrance to install the newly released External Static Air intake kit. The kit consists of two external ports, some tubing, an intake switch that is mounted in the instrument panel, and some instructions.




We were the first to install the kit. Shawn completed the installation in a few hours, and that same afternoon I performed a quick test flight with Jean. The airspeed was much more consistent, and noticeably lower than before. 

However, the switch was not installed correctly. Switching to internal static air caused the airspeed to quickly drop.



Jean quickly analyzed the problem, and the next day we hooked up the switch correctly. Now it works as expected. 


Switching from external to internal static air makes the airspeed go up 20kts (as expected). Because the airspeed was reading too high before, we had to fly faster approach speeds, expect higher stall speeds, and we almost never had a tail wind. 

The airspeed is much more consistent now, and I flew home with a tail wind. I'm happy!

Comments

  1. AnonymousSeptember 12, 2022 at 2:04 PM

    Hi, this is Edward H (I don’t know how to get it to say I am me instead of saying I am anonymous). I was starting to wonder about static ports, so this post was timely! Do you just have one external static port or do you have a pair, one on each side? If you have a pair, would you ever expect to use the cabin for static air pressure, or would you still want the option?

    ReplyDelete
    Replies
    1. Arthur van HoffSeptember 12, 2022 at 2:38 PM

      Hi Edward, there are two static ports, one on each side. You need the internal static port option in case the external static ports ice-up.

      Delete
    2. EdwardSeptember 12, 2022 at 4:21 PM

      Triple redundancy in case both external ones ice up, or is it likely that if one ices up the other one will, too?

      Delete

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