The airmet did include a good portion of the proposed route. For the moment, it did not include the airspace for Rick's departure and destination airports. Usually, though, these types of clouds are not much more than a few thousand feet thick but can cover a lot of territory, cutting you off from your destination. For the time being, Springfield was clear and Williamsport was reporting a broken sky at 4,100 feet. The Williamsport terminal forecast kept the broken clouds most of the day, but did imply that the ceiling would improve to 10,000 feet throughout the remainder of the morning and afternoon. Certainly this was something that Rick would have to monitor.
Route and Altitude Planning
Assuming Rick wanted to make this flight, he had four choices: go over, go under, go through or go around. Going around was perhaps the most conservative choice. However, most of West Virginia was expected to fill in with icing, so Rick would have to fly well to the south into Kentucky and Virginia before heading north into Pennsylvania to avoid the icing. That would add time and miles and may force a fuel stop.
Without a certified IPS, any altitude below 10,000 feet on a direct route would place him in probable icing conditions, given rather warm cloud top temperatures and marginal VFR ceilings en route. At some point in time, he'd likely be forced to climb to at least 11,000 feet or higher to make the flight over the weather.
With the ability to climb in clear air out of Springfield, flying on top of the deck wasn't out of the question as long as there was supplemental oxygen on board. While not a certified IPS, his SR22 was equipped with a non-certified TKS "weeping wing" IPS in the event he needed to land short of his destination due to an in-flight emergency. The biggest question would be the cloud cover at Williamsport upon arrival. The Forecast Icing Potential (FIP) showed a good chance of structural icing creeping in that area by the late afternoon despite the optimistic terminal forecast. With only scattered clouds expected in southeast Pennsylvania, this became a solid out if needed.
Rick's Final Answer
Unfortunately, it was still early in the morning and there were only a few pertinent pireps in the system. These reports confirmed that the icing tops were sloped with the highest tops to the north of his optimal direct route and lower to the south. A more direct route would likely force him to eventually climb to 13,000 feet or higher. Rick was hoping to make the flight at 9,000 feet since there wasn't any supplemental oxygen on board his Cirrus.
After we discussed all the options, Rick decided to file a flight plan that was a compromise between a direct route and one that would force a fuel stop. The icing environment was not as deep in southern Ohio, so he shifted his route to the south by 100 miles or so. It was clear that this would eat a little into his fuel reserves, but it would allow him to complete the flight in one leg and minimize his exposure to structural icing. Rick headed to the airport, got his IFR clearance and headed east.
Don't Stay in the Dark
During the summer, ATC can lend a hand helping you to work around thunderstorms. In the winter, don't expect it to be as proactive keeping you out of the ice. There are a few things it can do to help, but you need to make it happen.
As Rick approached southern Ohio, the first clouds came in view. For now, the tops were comfortably below him. As he looked out over the endless sea of clouds ahead, he asked the next controller if there were any aircraft along his route that were also on top at 9,000. A few minutes later, ATC responded that a Baron 50 miles east was on top at 10,000 feet headed in the opposite direction — the pilot of the Baron estimated the tops were around 9,000 feet. That was priceless information that you won't necessarily get unless you ask for it. Pilot reports will certainly allow you to act quickly now instead of reacting when it is too late. This kind of solicitation works well in just about all phases of flight.
Also remember to listen up. If pilots on your frequency are all asking ATC for higher altitudes due to icing, that might be a clue that the icing layer may be creeping up into your altitude. Don't count on the controller to be thinking ahead for you. He likely knows less than you do about the weather ahead.
Perhaps the best information available in the cockpit is satellite-delivered weather. A few years ago, XM WX Satellite Weather added pireps to its broadcast — your portable or panel-mounted system may display them in a text and/or graphic form, allowing you to monitor the route continuously while airborne. With the transitory nature of icing, any pilot report more than an hour old should be used with caution.
When you run out of other options, you can always use the traditional method and ask ATC to leave the frequency to call En route Flight Advisory Service Flight Watch on 122.0 MHz to get the most recent pireps. Flight Watch is organized by the en route center (ARTCC), so don't forget to let it know where you are located relative to a navaid or airport when you call.