THUNDERSTORM FLIGHT PROCEDURE

as a pilot approaches the thunderstorm area the flight procedure to be used will depend upon the type of storm the locality over which it lies the type of equipment the altitude and the mission to be performed the storm should be analyzed before the surrounding clouds are encountered as they might obscure the important characteristics study the situation thoroughly before making a decision whether encountering a single storm a group of storms or a line of storms the flight procedures are similar the pilot may circumnavigate the storm centers through a thin spot or clear area or fly at a low level underneath the base of the thunderstorm or fly at a high level over a Saddleback between storm tops always fly around isolated airmass thunderstorms do not try to save time by flying a straight course through the thunderstorms when they can be avoided by circumnavigation the added mileage and the time lost are as little consequence it is a good practice to fly around thunderstorms in mountainous regions when thunderstorms prevail along coastal mountain ranges a fight conducted a few miles to seaward will avoid this activity thunderstorms over islands maybe many thousands of feet higher than those associated with the open sea and should be circumnavigated a wall of thunderstorms caused by a front presents many problems when applying the rule of circumnavigation the storm line is generally too long to fly around it should be kept in mind however that the storm front is a series of individual thunderstorms closely knitted together by intervening clouds it is often possible therefore to fly between these storm centers through holes or thin spots sometimes the hole is obvious with blue sky on the other side and presents no problem to circumnavigation in some cases it is impossible to see through the holes but there is definite evidence of thinness in this case determine the direction in which the line of storms is moving and head in at a right angle this will reduce flying time in the storm to a minimum after you have once set your course and started through don't turn around on account of turbulence rain or hail this will result in flying through the same conditions twice there is also the added hazard of becoming lost it does not take long to fly through if a straight course is maintained a pilot's approaching a line of thunderstorms at a low altitude can fly underneath their base if circumstances permit this procedure is recommended when flying over flat terrain or the open sea in determining a course underneath the storm centers can be identified by the dark rain areas here visibility is reduced and lightning flashes are frequent therefore it is preferable to conduct the flight through the clear areas between storm centers lightning is of no serious concern when flying an all-metal closed cockpit airplane as the craft acts as a perfect conductor however bright flashes may cause the pilot to be temporarily blinded if night nning strikes an open-cockpit airplane it might injure the pilot and cause structural damage to the craft the turbulence under thunderstorms may place heavy stress on aircraft and the inexperienced instrument pilot may have difficulty controlling his plane the closer you fly to the surface of the earth the less turbulent it will be a good rule to follow is to fly 1/3 of the distance from the surface to the base of the cloud for example if the cloud is determined to be 3,000 feet above the surface fly at 1,000 feet on approaching the front of the storm and updrafts will be encountered under the roll cloud region strong up and down drafts will be experienced at the core of the storm a downdraft is usually encountered then an updraft may lift the plane toward the base of the storm finally there is a downdraft before breaking into the clear in a flight under the storm the higher the flight level the rougher the trip care must be taken to prevent being lifted into the cloud forming the storm base when flying under the storm from the rear the pilot will experience a downdraft first this leads to the following rule when entering a storm from the rear enter at a higher level than you would if entering from the front when visibility is bad underneath and contact flight cannot be maintained it is inadvisable to fly under the storm in the case of thunderstorm conditions along mountain ranges never attempt to fly underneath unless a good ceiling exists and the visibility is such that peaks and ridges are clearly defined never land at an airport when the wind shifts in advance of a thunderstorm is approaching the field turbulence and shifting surface winds make this a hazardous procedure since thunderstorms move at a speed of from 10 to 30 knots it is often possible to wait until the storm center has passed before landing when the high-level flight is anticipated the pilot should seek a high-level before approaching the storm getting on top of the protruding shelf of clouds around the storm this will give him an opportunity to inspect the storm line and select his course when thunderstorms are associated with rough terrain high level flight is preferable this procedure is the safest in cases where the pilot is not familiar with mountain ranges and mountain peaks when flying at a high level it is inadvisable to fly underneath overhanging clouds associated with the anvil tops as hail is often encountered in these regions try to pick a spot that has no overhanging clouds lines of thunderstorms Overland generally extend to greater heights than those over the open sea 15,000 feet will usually top the Saddleback's of a storm line over the sea in some cases it is impossible to establish a path which will conform to the three basic flight procedures when you were faced with this problem there are two courses open fly between storm areas as high as possible to miss the greatest turbulence or fly between storm areas as low as possible avoiding the role clouds and staying safely above the highest terrain here's a report of a pilot - encountered a storm and could not establish any one of the three basic flight procedures and was forced to fly through took off from home field on an important mission to a base in the Canal Zone forecast of thunderstorm conditions ahead early in the evening the predicted conditions were encountered a wall of storms appeared extending for hundreds of miles the East and West mountains paralleled the coast from north to south extended up into the clouds at 14,000 feet so later course out to sea the storm extended down close to the water and appeared violent they betting fried under it could not be flown around so crime trying the topic at 16,000 feet the ship became sluggish due to heavy load and as the cloud still towered up beyond this point it was apparent that the plane would not be able to get over there was now no other course but to go through chose a spot which appeared to be between two storm centers checked instruments reduce flying speed and headed in that a right angle turned on cockpit lights to avoid temporary blindness from anticipated lightning flashes first updraft was not strong then encountered very heavy turbulence rain fell in torrents visibility dropped to zero was tempted to turn back in search of a better point of entry but did not want to risk becoming lost and add to flying time in the storm frequent lightning lashes some boats probably struck the craft but discharges were conducted off as the ship was an all-metal closed cockpit job suddenly the plane was rocked by a violent downdraft indicating midway point of the storm ran into hail but fortunately it was soft splattered against the ship without damage after emerging from the strongest turbulence the display of st. Elmo's fire was encountered static electricity was building up on the plane flashes of light jumped across the surfaces of the windshields streamers of electricity played up and down the wings and at the same time fiery blue green circles formed on the periphery of the propellers cut flying speed further to avoid an electric discharge which might damage the radio shortly afterward broke out into the clear rest of flight was uneventful in summary the pilot headed seaward when he encountered a storm condition which had built up along the coastal mountains for at sea he would find the intensity of the storm less severe he did not attempt to fly under the condition since it lay almost on the surface and appeared very violent at that point he was unable to go around the storm wall since the front extended for several hundred miles the storm was too high to fly over so he chose a thin area when forced to fly through to avoid the cores of any of the storms he headed in that a right-angle this was for the purpose of flying a straight course through the storm and reducing his flying time within it to a minimum he turned his cockpit lights on and kept his eyes on the instrument panel to avoid temporary blindness when lightning flashed close to the plane although tempted to turn back upon encountering the heaviest turbulence the pilot chose to continue on his original course knowing that he might otherwise become lost and his flying time in the storm he greatly increased when he found static electricity building up on the plane he slowed his speed to reduce the possibility of a discharge which would produce a blinding flash and possibly destroy radio communication experience has taught that the safest course is to stay away from thunderstorms however due to the urgency of many present-day missions it is often necessary to break this rule the modern airplane is the best for its purpose that human ingenuity can devise when flying through thunderstorm conditions the pilot must have confidence in his knowledge of the structure of thunderstorms and confidence in his equipment remember it is the pilot that loses his head and not the plane