Winter Edition 5 November 2006

Transcription

1 Safety Corner Winter Edition 5 November 2006 The Safety Corner newsletter will be periodically published when covering topics of safety interest and importance. Any suggestions please contact Scott Olson at msolson@hotmail.com. Once again old man winter is knocking at our doorstep so it is time for our pilots to begin the Company s instrument training program. Instrument training should include the following: 1. Basic Instruments a. Level standard rate turns b. Standard rate climbs/descents c. Unusual attitude recovery 2. Inadvertent instrument meteorological conditions (IMC) recovery a. Maintain aircraft control b. Transition to instrument flight c. Contact Air Traffic Control (ATC) d. Select transponder setting 3. Instrument approach procedures a. VOR approach b. LOC approach c. GPS approach d. Radar approach e. Missed approach 4. Emergency procedures a. Engine failure All instrument training will be conducted at night. Training should consist of 1 hour per pilot per month; however, if a pilot feels like they are weak they should see Matt and request addition training. Medical personnel are highly encouraged to fly with the pilots conducting instrument training to get a feel for what is actually going on. There is no hourly time limitation so it is up to each pilot to get the most out of his training. If a pilot feels like they are weak they should see Matt and request addition training. Medical personnel are highly encouraged to fly with the pilots conducting instrument training to get a feel for what is actually going on. Staying proficient in instrument flying is no easy task, however, staying prepared is. The following steps will aid pilots in making a successful recovery from instrument meteorological conditions when the event occurs.

2 Safety corner page 2 What is inadvertent instrument meteorological conditions? Inadvertent IMC is a flight under visual flight rules (VFR) that inadvertently flies into visual obscurants such as clouds, fog, etc., which results in the loss of outside visual references. Helicopter control is then solely maintained by aircraft instrument visualization. According to an NTSB, unplanned entry into IMC is the single most common factor in fatal crashes involving emergency-medical-service helicopters. Because most of the inadvertent IMC accidents result in pilot fatalities, accident investigators can learn little about the events that lead to the accidents. In cases where pilots lived to tell their stories, it's like the Safety Center has been telling us all along: they tried to fly VFR in IFR conditions. They also felt pressure to accomplish the mission, in spite of deteriorating weather. 1. Assess the weather before take off. Just because the weather at departure and the arrival destination is VFR doesn t mean that it will be VFR in between. 2. Have the instrument approach plate out for a recovery in case of inadvertent IMC after take off. a. Brief the crew on what actions you will be taking and what you expect them to do to assist you. b. Tune and identify the VOR approach to be used. 3. In the event of inadvertent IMC Fly the Aircraft! a. Admit to yourself that you are IMC! b. Develop a good scan! c. Announce to your crew inadvertent IMC/Sterile cockpit! 4. Once IMC conditions are encountered remember the following steps: Attitude, Heading, Climb and Airspeed. a. Attitude Level the wings on the attitude indicator b. Heading Maintain a constant heading using the directional gyro. c. Climb Establish a positive rate of climb on the VSI. d. Airspeed Establish the appropriate climb airspeed. 5. Only after aircraft is under control or if there is a known immediate obstacle turn the aircraft and attempt to fly out of the condition. 6. Declare an emergency if you can t get out of the weather and request ATC help! 7. Medical crewmembers must understand that inadvertent instrument meteorological conditions (IMC) is an emergency and that patient care comes secondary. It is each crewmembers responsibility to assist the pilot by looking for clearing in the weather in which the pilot might be able to land the aircraft.

3 Safety corner page 3 WEATHER Precipitation and Visibility - When it comes to accident statistics, low ceilings and visibilities rank as the greatest weather hazard to the VFR pilot. Not thunder, not ice, not high winds or turbulence nothing seems less threatening, or is more dangerous than condensed water vapor. Learn to respect it? Precipitation occurs both liquid (rain) and solid (snow, hail) forms. Precipitation type and intensity affect your visibility. In weather reports and forecasts, a minus sign (-) usually means VFR or marginal VFR (MVFR) visibilities. Moderate precipitation may reduce visibility to MVFR or IFR, while a plus sign (+) most likely means IFR visibilities will prevail. Chances of precipitation and its forecast level of intensity can be found in aviation area forecasts. Visibility is a critical part of flight safety. Water in the atmosphere might appear as precipitation or fog, or hold suspended particles that cause haze. The amount of water the air can hold rises with the temperature. As the temperature goes down (such as in the evening), it may reach the temperature at which the air mass just can t hold any more water. That s called the dew point. The difference between the temperature and the dew point is called temperature-dew point spread. When the temperature and dew point meet at altitude, water appears as rain, clouds or snow. When they meet near the ground, water condenses into fog. Winter weather also brings us another hazard that if not prepared for can cause serious injury. Wind Chill while working in and around an operating helicopter can cause serious injury if you are not dressed appropriately. Wind chill is the apparent temperature felt on exposed skin due to the combination of air temperature and wind speed. Rotor Wash - up to 120 mph while the helicopter is hovering. The wind chill factor may be significant. Make sure that you are dressing appropriately for the weather conditions. Remember it may be nice in Page; however, it can be extremely cold in other locations only a short distance away from base. Below is a wind chill chart that shows the effects of wind and temperature on exposed skin.

4 Safety corner page 4 Flying in Flat Light and White Out Conditions With winter comes snow! Although we do not normally see large amounts of snow fall in Page we do fly into areas where snow accumulates. When this occurs we have the potential to encounter flat light and white out conditions. Flat Light Flat light is an optical illusion, also known as "sector or partial white out." It is not as severe as "white out" but the condition causes pilots to lose their depth-of-field and contrast in vision. Flat light conditions are usually accompanied by overcast skies inhibiting any good visual clues. Such conditions can occur anywhere in the world, primarily in snow covered areas but can occur in dust, sand, mud flats, or on glassy water. Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates. As a result of this reflected light, it can give pilots the illusion of ascending or descending when actually flying level. However, with good judgment and proper training and planning, it is possible to safely operate an aircraft in flat light conditions. White Out As defined in meteorological terms, white out is when a person becomes engulfed in a uniformly white glow. The glow is a result of being surrounded by blowing snow, dust, sand, mud or water. There are no shadows, no horizon or clouds and all depth-of-field and orientation are lost. A white out situation is severe in that there aren't any visual references. Flying is not

5 Safety corner page 5 recommended in any white out situation. Flat light conditions can lead to a white out environment quite rapidly, and both atmospheric conditions are insidious: they sneak up on you as your visual references slowly begin to disappear. White out has been the cause of several aviation accidents in snow-covered areas. Self Induced White Out This effect typically occurs when a helicopter takes off or lands on a snow-covered area. The rotor down wash picks up particles and re-circulates them through the rotor system. The effect can vary in intensity depending upon the amount of light on the surface. This phenomenon can happen on the sunniest, brightest day with good contrast everywhere. However, when it happens, there can be a complete loss of visual clues. If the pilot has not prepared for this immediate loss of visibility, the results can be disastrous. Helicopter Performance This is just a friendly reminder that with the onset of colder weather there are a few things that we as pilot need to remember. When utilizing the heater for crew and patient comfort remember to check your MGT after turning on the heat. On average the MGT will increase approximately 20 when the heater is turned on. This increase normally will put the MGT into the takeoff, 5 minute (727 to 779 C) operating range. The same can be noted when utilizing the engine antiice. Failure to check MGT could lead to the dreaded check instrument light with an exceedance. VNE during cold weather is usually higher. Remember to check the placard located forward on the overhead console between the pilot and copilot seats to determine VNE based on altitude and temperature. Additional winter equipment Winter will mean the use of additional equipment. Soon, Pete will be installing the bear paws or snow pads to the aft section of the helicopter skid tube. The snow pads provide support when

6 Safety corner page 6 landing in deep snow thus preventing the helicopter from sinking to deeply. When landing with the snow pads the crew will note that the front of the helicopter will sink deeper then the aft creating a nose low condition. The reverse flow baffles are out and ready to be installed. It is the pilot s responsibility to install the baffles when there is a forecast for snow. The baffles change the direction of airflow into the barrier filter section preventing snow from accumulating and causing an engine flame out due to lack of inlet air. In the cargo compartment there will be an additional cold weather blanket that will be placed in each aircraft. This blanket can be wrapped over the patient and provide addition warmth. New Equipment We have just installed the new GARMIN 496 GPS in both aircraft. The GARMIN 496 has a color moving map coupled with weather symbology. There are several important symbols on the main moving map display the represent weather conditions. These symbols are as follows: - Blue - VFR conditions - Green Marginal VFR conditions - Yellow IFR conditions - Red Less than IFR conditions - White/Grey Undetermined NVG Consideration NOTE: Crewmembers may fail to detect a gradual increase in cloud coverage (fog, haze, or precipitation) and may inadvertently enter the clouds. Occasionally look under the goggles (unaided) and check for indications of deteriorating weather conditions. Indications of Restrictions to Visibility at Night. 1. Loss of celestial lights - The moon and stars may fade or disappear due to overcast cloud cover. 2. Loss of ground lights - The city or rural lights will fade due to obscuration. 3. Reduced ambient light levels - Forecast light levels will be reduced due to obscuration. The exact amount of reduction will vary with conditions. 4. Reduced visual acuity The best visual acuity is based on 100% illumination and clear visibility. Visual acuity may be reduced depending on the type and amount of ambient light and the presence of obscurations. 5. Scintillation - Increase in video noise as a result of low ambient light levels. 6. Increase in the halo effect - Halos will always be present when viewing light sources through NVG'S. However, with an increased saturation density of water molecules (rain, fog, etc.) occurring in the atmosphere, larger halos form around any viewed sources of light.

7 Safety corner page 7 Of all the indicators of restriction to visibility at night the most noticeable indication that I have experienced would be the reduced ambient light levels. Last winter coming back from Flagstaff my crew and I went inadvertent IMC just north of the Cedar Ridge area. Prior to entering inadvertent IMC I noticed a large reduction in ambient light levels. Heavy snowfall or precipitation can cause a restriction to visibility from the left side of the aircraft due to the glare from the red position light reflecting off of the visible moisture. At times the snowflakes or raindrops can look like golf balls thru the night vision goggles. When it is foggy out don t be surprised if you look under the night vision goggles and you won t be able to see a thing! You could be IMC and not know it. The NVGs are capable of seeing through some foggy conditions. It is also imperative that medical crewmembers inform the pilot if they are losing or have lost outside visual references. Conclusion The bottom line with winter flying is to be prepared! If the weather is not legal than don t go! Just because the weather is VFR doesn t mean that you can make the flight in VFR conditions! I know this for a fact, for I have been there and I have the T-shirt! When the weather is marginal continually monitor the weather. There are many websites out there which almost provide up to the minute weather conditions. Remember that you as the Pilot-in-Command are solely responsible for the decision to fly based off of existing weather conditions. Medical crewmembers are equally responsible for if there is any doubt on the weather each member of the flight crew can terminate or turn down a flight.