Probably one of the stupidest things you can do while flying is scud running. Stupid, because you might think ‘It will never happen to me!’.
What is scud running? This happens when a pilot reduces altitude in order to avoid unsuitable weather conditions such as cloud or other instrument meteorological conditions (IMC). As VFR (visual flight rules) pilots are required by law to maintain visual with the ground at all times, the temptation to duck below lowering cloud is ever present. But if one maintains visual with the ground, then what is the danger?
Lowering altitude – If you are flying lower than your plan (which should provide the regulatory terrain clearance of 1500m), then you are putting yourself at risk of flying into terrain.
Forward visual – Flying below low level cloud is risky as it is almost impossible to tell how low it will be further ahead. Before you know it, you could be confronted with a windscreen filled with murk and you can no longer see ahead.
So how do pilots get into this situation? The obvious one, is that they assume that if you are below the cloud you will be able to see the ground, and it won’t close up below you. The next factor is definitely one of attitude. If the pilot is determined to get to the destination, then the probable reaction would be to find a way to get through to that destination. The belief that conditions will improve ‘on the other side’ also drives pilots to continue on. When a pilot realises that forward visibility is in fact becoming worse, then there may be a reaction to think ‘Maybe I should turn around…’ Unfortunately, a look behind may convince the pilot that the clear sky is now too far back, and it may be best just to carry on and hope that it clears further ahead.
Scud running is stupid, because it causes stupid accidents. Fatal accidents have occurred with pilots flying their machines straight into mountains, or power lines, which become invisible in these conditions. By scud running, you are not proving your ‘skill’ by out-witting the weather and finding a way to the destination, instead you are playing roulette with the unknown.
Preventing these situations is all about attitude. Even though your weather forecast says CAVOK, always be prepared for unpredictable local conditions. Have a plan in mind BEFORE you take off as to what you will do if you find something unexpected en-route. In this case, have alternate airfields marked out on your route, in case you need to land and wait out the inclement conditions. See this as an adventure, landing at new airfields could make you some new friends, score you a good cup of coffee and even better, a good story! If you are transporting passengers, it may be a good idea to include the possibility of unexpected weather in your safety briefing (you do those right??). This will ensure that you are not under pressure to either impress your passengers that you have the skills to fly through weather, and it will also prepare them mentally that there could be a possibility of an ‘adventure’ i.e. diversion. Lastly, if you cannot maintain visual with the ground at your chosen safe altitude, then make the decision quickly to turn around, ensuring that you have enough space and visual to execute the turn. DO NOT wait to see if it is improving. Worst case, contact the air traffic information for the area and inform them of the conditions and advise them of your required precautionary movements. No controller will ever reprimand you for confessing a situation or seeking advice!
Be a coward, stay safe and find a different adventure…