September 12
Looks like “Captain Obvious” material. Anyone that has ever read “Fate is the Hunter” by noted author Ernest Gann realizes that icing has been a problem since the early days of air mail–about the last 100 years.
Quote: “However, the FAA’s recent tests show that modern deicing boots, from aircraft manufactured after 1960, are not prone to ice bridging.” REALLY? I’ve been flying IFR in Minnesota for the past 58 years–flying freight in singles and twins, flying corporate in light twins to jets–28,000 hours. Yes, I’ll tell you that “engaging the boots when icing begins” WILL eventually lead to “ice bridging”–as boots work by expanding and cracking off the accumulated ice. If you don’t allow an accumulation to build first, you can’t crack it off–and premature operation of the boots will allow the ice to “Bridge” over the expanded boot–leaving NO WAY TO CRACK IT OFF.
The best way to “fly ice” is to go where the icing ISN’T–stay in warmer air, or climb quickly to an altitude where there isn’t enough water in the clouds to accumulate ice in the first place.
I have over 12,000 hours in King Airs and other turboprops–they are not immune to ice (even with “known icing”) but the ability to climb and descend rapidly through icing layers keeps icing accumulation and boot use to a minimum, as there is not enough accumulation to crack it off. Increased indicated airspeed also helps–it keeps the “stagnation point” on the airfield in a fairly narrow band–any accumulation is easier to crack off.
Note: Some aircraft carry ice better than others. The fat wing on an Aztec, for example, tends to accumulate ice in a fairly narrow band on the leading edge–somewhat mitigating the effects of a buildup–BUT–look at the tail leading edge surfaces on the same airplane–they are thinner, and accumulate ice faster.
The best way to handle ice is to simply MINIMIZE EXPOSURE to the altitudes and conditions where it occurs. Ask for an expedited climb or descent–and always have a “plan B” to escape icing conditions. In years of flying people and freight in Minnesota (where icing occurs at least 6 months out of the year), I’ve rarely had to cancel a flight, as long as I’ve had a diversion option–but I won’t launch UNLESS I HAVE A PLAN FOR ESCAPING ICING CONDITIONS.
September 12
Good comment. Have personally witnessed ice bridging in a Shorts 360, I can’t believe the NTSB is still sticking with this line.
September 13
The comment on staying out of icing conditions is spot on! Deicing equipment buys you time to find a way out, not to continually fly in icing. I agree with the NTSB as far as the Cessna Caravan is concerned. Never saw any ice bridging in that airplane. On the other hand I never stayed in icing in that airplane for long due to the Caravan not carrying ice very well. Most of my Caravan flying was done in the Great Lakes area. Until the icing AD that came out in 2006, there was an average of one pilot per year getting himself into ice that overwhelmed the airplane resulting in a crash. The one that crashed in Wisconsin in 2002, that pilot was a friend of mine. The Caravan has so much unprotected surfaces, and little extra power, that collected ice can easily bring one down if remaining in icing too long. When I moved up to jets I found all that excess power available at low altitudes helps keep those planes in icing a little longer, but still would prefer to minimize staying in those conditions. I suppose older planes might have the ice bridging issue but I have no experience in any of those so I can’t directly comment on that.
September 13
These alerts are like the road signs “Bridge may ice in cold weather”.
Basically if you do not already know about ice, then you have no place driving or flying in the first place.
September 13
The NTSB has lost all credibility. Get a former freight dog to lead it, whose seen the real world and can make revommendations worth heeding.
September 15
Ice bridging is real. I’ve observed it flying cancelled checks and other freight in pistons and turboprops. When it comes to advisory factors I can actually support the NTSB guidance as published if they got rid of statements that bridging isn’t a factor on modern planes.
In the late 90s and early 2000s there was a misconception around bridging that lead to some faulty analysis describing ice as having some plastic, bendable qualities. This lead to some now superceded statements regarding bridging and the idea that pilots didn’t know what they were looking at. In reality, we were dealing with artifacts of language. Nobody thought ice could bend like rubber, but if tiny cracks in ice fill in during an inflation cycle, the remaining shell will appear to bend even though something more complex is occuring.
There’s a counter argument to be made. If we acknowledge that no guidance is perfect for everyone should we teach people complex strategies to fight bridging and other icing encounters? Would it be better to teach them a few, simple habits that are mostly survivable and lead to early escapes? I can see the value in this. It’s not 1994 anymore. There aren’t fleets of Cessnas, Pipers and Beechcraft crossing the Great Lakes filled with checks. There aren’t Jetstreams, Saabs and ATRs clogging up the STARs into O’Hare. The people encountering icing will be doctors and corporate CEOs seeing “real” weather for the first time. Why should we teach them to fight their way into a bad position?
