When Local Altimeter Not Received

It’s easy to become a little bit complacent about briefing an approach plate.  We look at the big ticket items, so to speak – the altitudes, fixes, missed approach procedures, etc.  But it is all too easy to let a little item slip through the cracks.  This came to mind recently when I was working in the G1000 sim with a customer who was planning a vacation to the Pacific Northwest area and wanted to rent a plane while out there.   I was looking at the available procedures for Renton (RNT) and saw this in the notes.

“When local altimeter setting not received, use Seattle-Tacoma Intl altimeter setting.”  It’s a note that is present on many approach plates.  But how many of us would take the time to find the frequency for ATIS at the Seattle airport?  I’d wager most of us don’t, and as you can see, it is clearly not provided on the approach plate.   Yes, you could use your GPS to find the information, but there is actually a far easier way to get the information, and it involves the now-ubiquitous iPad. 

The example detailed here utilizes an iPad2 and the very popular ForeFlight application.  From the Map page, with IFR enroute low chart type selected, you can clearly see the Seattle airport (SEA), to the west of Renton (RNT).  

If you put your finger on the SEA airport symbol, ForeFlight brings up a dialog box that looks like this.

We don’t want to add KSEA to the route, but we would like to get the frequency for its weather information.  Selecting the “>”  symbol to the right of the airport accomplishes this.  The first page displayed is the METAR, which has the altimeter setting. 

But you can also get the ATIS frequency by selecting the “Info” tab at the bottom of the dialog box. 

So now you have the SEA altimeter setting and can proceed to your destination at Renton.  ForeFlight gives a convenient way to get the information, but you could have also included it in your briefing of the approach plate.