External Static Air Intake

-

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

Post a Comment

Popular posts from this blog

Customizations

-
Image
Before we started our build we selected  several custom options for our plane. Strangely enough, there is no list of all possible options. We just had to keep asking to find out (HINT: someone at TAF should make a list). Anyway here are a few options we selected as part of our order:  Split Rear Seat - This will allow for three passengers and luggage. We also plan to make the rear seat removable because we most often fly without any passengers and lots of luggage. Extra Long Seat Rails - My family is really tall, so we asked for extra long seat rails. This will allow them to move the seat back a few extra inches to accommodate for those long legs. Foot Pedals - The standard it comes with really cheap looking rudder bars. It turns out there is a option to get custom aluminum Sling branded pedals. They are on backorder. Besides the options from the factory, now that we are building we have learned about many small modifications that other builders are making. Here are some th...
Read more

Floor under Back Seat

-
Image
For some strange reason, there is no floor under the back seat. I guess Sling expects the back seat to cover any cold air leaks and stop stuff from falling into the space below. This seems really sub-optimal, dangerous, and needs to be addressed. Without a floor, the seat belt buckles can be pushed through the seat and fall into the space below which houses many important linkages that are needed to fly the plane, so that could be bad. Also there is a huge amount of cold air leaking into the cabin from underneath the seat. To fix this I decided to add aluminum floor panels under the rear seats, to close up the space. They are mounted with rivnuts, covered in carpet, and easily removed for inspection. The final result shown in the first picture.  It is an easy build; you need a rivnut tool, metal scissors , rubber mallet, and a few others. Measuring, fitting, and installing requires various advanced yoga poses, but it is doable. First I made a cardboard template for the two panels, ...
Read more

IPad panel mount

-
Image
A few weeks ago I got the new Apple iPad mini. The smaller form-factor is perfect for the Sling TSi. However, I don’t want it to be floating around on my knee, so I have been looking for a good way to mount it somewhere so that it is hands-free and does not obstruct the view or the instruments. I think I have found a good solution.  I  got a tablet mount on Amazon (link   here ) with a short adjustable arm and   attached the mounting point to the left of the panel (see below). The panel is made of aluminum, covered in leather. I used self tapping screws with plastic washers, but you could use rivnuts. Here it is with the arm attached.   I don’t like the tablet holder that came with it (too bulky), so instead I used another mounting point (Amazon link here ), and some Velcro to attach the arm to back of my iPad cover. That works great, it does not come off easily, it is height adjustable, and it does not take up much space. I also added a small metal tab to hold ...
Read more