I often marvel at how much aviation has changed in the twenty-odd years since my very first lesson. Just in my experience as an instrument-rated pilot, there have been several game-changing developments.
The first was GPS, which revolutionized navigation. Long before I ever saw a panel-mounted GPS navigator, I was among the early adapters whose flight bag wasn’t complete without the latest hand-held moving map wonder.
Next came datalink. It’s hard now to imagine that I ever willingly operated in instrument meteorological conditions (IMC) without the kind of weather situational awareness that this technology provides.
A related development was the proliferation of online weather and flight planning tools, complete with graphics (e.g., color-coded station models) that vastly simplified tasks such as weather analysis and selection of a legal and appropriate alternate.
Now, of course, we are in the midst of the tablet/ app and ADS-B driven shift to anytime, anywhere mobile capability for instrument flight planning, risk analysis, and all aspects of flight monitoring. The most popular apps even include information about the ground facilities and services you might need if the weather data they provide persuades you to divert.
All this information is great, but it can improve safety only if we pilots use it in the context of overall critical thinking about what we realistically can – and can’t – safely do in a typical GA airplane. That requires asking and, of course, answering several important questions.
Is there convective activity?
There is no category of airplane certified to fly in or through thunderstorms. If the forecast calls for convective activity along your intended route of flight, you need to dig deeper, develop a solid understanding of the situation, and ensure that you have both a plan for, and a commitment to, diverting to a safe alternate destination. If you conclude it’s safe to launch, appropriate use of weather technologies such as ADS-B and datalink can help you monitor developments and stay well clear of convective activity.
What’s the freezing level?
We associate icing with winter operations, but it can occur at any time of the year. ADS-B, datalink, and even radar are all “blind” to icing, so your best defense against this peril includes a very careful preflight analysis of forecast and actual conditions (including any PIREPs on icing), and then disciplined in-flight monitoring of the outside air temperature . My personal policy is to never launch into the clouds without knowing that I can stay below the expected freezing level without hitting anything. It’s also important to have at least one gold-plated escape plan in case the ice finds you anyway.
How low is too low?
Your instrument rating allows you to legally shoot an approach to minimums, but “legal” and “smart” are not synonymous. Here’s where it pays to have well-established and frequently-reviewed personal minimums that account for your actual proficiency and comfort level in IMC. My personal rule is to avoid low IFR (LIFR). Even with another pilot on board, LIFR conditions add more risk to single-engine GA operations than I care to assume.
Do I have options?
The existence of “real” options (not just “legal” alternates) is another important factor in my preflight planning for a trip in IMC. In my book, widespread IMC strongly indicates a “no-go” decision, especially if there isn’t even a marginal VFR airport in range.
More trigger points?
Now that I’ve shared a few of my trigger points for deciding whether to launch into IMC, I’m curious to hear yours. Write to me at the address below, and we’ll consider publishing a list of the best IFR safety ideas in a future issue. (FAA Safety Briefing – SepOct 2015)