PRECAUTIONS DURING WINTER FLYING

  1. Winter is approaching fast and with it, the associated flying hazards during Winter Season.  Number of accidents/serious incidents have occurred around the world during winter months. The accident of Air India, Air Bus 320, at Jaipur, on 05 Jan 14, which fortunately did not result in casualties, highlights the need for involvement by all stakeholders to prevent any accident/incidents. Unfortunately, no lessons are learnt from the investigation reports of the accidents and history continues to repeat itself.
  2. Aviation Safety Management Society of India, which is dedicated to promote Safety and Efficiency of Aviation Operations in the country, wishes to disseminate certain precautions which should be taken by the Operators/Pilots during winter flying, to prevent any incident/accident.

Hazards During Winter Flying.

  • Fog and low clouds leading to almost zero visibility conditions, wet, slippery runways, frost, icing and snow blindness/white out are a major flight safety hazard during winter months particularly in Northern, North Eastern and to some extent in Western parts of India.
  • Formation of fog, its thickening and improvement in visibility are quite unpredictable.
  • Most of the times, the fog thickens at sunrise and may last for long hours before clearing or may not  clear for hours or even days.
  • Whenever the surface temperature and dew point temperature are very close to each other, dense fog can be expected. And so long the Surface and Dew Point Temperature remain close to each other, the weather may not improve for hours or days.
  • There may be occasions when the fog is very widespread and it may be difficult to find a diversionary airfield in hundreds of kilometers of the destination airfield.
  • Low clouds may form quickly as the fog lifts and cover large areas, particularly in the hilly regions, they can cover the entire valleys, without any gaps for penetration.
  • Lack of Visual reference due Poor Visibility can lead to Visual Illusions, Spatial Disorientation, Loss of Situational Awareness and consequent CFIT accidents.
  • Western Disturbances in Northern India/North East Monsoons in Tamilnadu Region, associated with Thunderstorms, low clouds, poor visibility and wet/contaminated Runways present flight safety hazards.

Precautions during Winter Flying.

  • The Accountable Executives/Managers should  ensure that all the Pilots have gone through the necessary flying and ground training with added emphasis on Low Visibility Operations, as per the:-
  • DGCA CIVIL AVIATION REQUIREMENT, SECTION 8 – AIRCRAFT OPERATIONS SERIES ‘C’, PART I, Issue I, Dated 13th June 2011, Effective, 01 April 2017, All Weather Operations (AWO).
  • OPERATIONS CIRCULAR 09 of 2017 dated 18 Aug 2017 on Approach and Landing Accident Reduction (ALAR) and Control Flight into Terrain (CFIT) reduction tool kit is a very comprehensive document and all the pilots should be made knowledgeable about it.
  • All the pilots should be current in instrument flying, should have undergone Low Visibility Operations Training (LVO) and clearances etc. as per DGCA CAR. Good knowledge of DGCA CAR on All Weather Operations is essential for safety.
  • In depth knowledge about the aircraft, systems, procedures, understanding the phenomenon of visual illusions, spatial disorientation, recovery from unusual situations, strict adherence to SOP’s, rules, regulations and good CRM are key to successful accomplishment of the mission.
  • Operators/Accountable Executives, Air Crew, Ground Crew and Dispatchers should be fully aware about the winter hazards, phenomenon of fog and human factors limitations.
  • The involvement of Accountable Executives, Supervisors and Operation staff in close monitoring of operations during marginal weather conditions is an essential requirement for the safety of operations.
  • Professional planning and preparation for the flight is an inescapable necessity and should not be ignored. Pre Flight briefing for operations during poor visibility conditions should be much more comprehensive and the pilots must plan for contingencies for sudden deterioration of weather/visibility.
  • Thorough weather briefing and knowledge of the terrain and obstructions around the runways must be ensured before undertaking any flying. Briefing from the Met Department and various Weather Sites should be complemented with the experience of having operated in particular area or region. Knowledge of typical weather phenomenon affecting particular areas during winters is of paramount importance.
  • Although most of the time the Met Forecast is reasonably accurate yet there have been  instances when pilots have got caught in very poor visibility conditions, may be due to inaccurate Met forecast or lack of  intelligent weather  analysis on the part of the Pilots. Hence, these aspects must be kept in mind while planning flying during winter months.
  • A very high level of situational awareness must be achieved related to prevailing weather and its trends, terrain, availability and serviceability of Nav, Approach aids,  watch hours and weather conditions at the neighboring airports.
  • Continuous Monitoring of the weather situation at the destination with particular emphasis on visibility and RVR through ATIS, RT communication and other aircraft operating in the general area of your route and destination is strongly recommended.
  • Pilots must be aware about the timings, extent, duration and severity of fog.
  • Special precautions need to be taken while flying during night, Dawn / dusk and Circadian Low. Night flying during winters should be undertaken with extra caution since poor visibility due fog during night flying is a serious hazard.
  • Use of landing lights during approach in foggy conditions should be as per SOP and situation, since it may degrade the visibility, lead to visual illusions and disorientation.
  • Timely and sound decision making based on the overall situational awareness, should be inculcated among the pilots. Overconfidence and complacency must be kept under check.
  • Operations to and from Delhi airport during winter months foggy conditions  are very challenging and pilots need to be very alert, vigilant and plan diversions well in time lest they get caught into complicated situation.
  •  Meticulous fuel planning as per the CAR is of paramount importance and must not be ignored. Contingency fuel to cater for unexpected delays/diversions due weather may be considered. Remember fuel is life.
  • Fuel planning and close monitoring of the fuel state is of great importance since one may be forced to divert due to poor visibility conditions and most of the time a diversion may not be easily available due to widespread fog.
  • Runway condition must be monitored very closely and special care taken during taxiing, takeoff and landing to avoid slipping, skidding, runway excursion and overruns. All Pilots should be fully knowledgeable about conditions leading to Hydroplaning and how to avoid it.
  •  Do not succumb to the commercial pressures, on time performance, passenger related pressures, inconvenience, job demands and always evaluate the factors related to self, aircraft, weather, terrain and the associated risks, before undertaking or continuing the flight.
  • Follow standard operating procedures meticulously and do not hesitate to go around if unstable approach and  divert in time if situation demands.

Additional points for Helicopters.

  • Generally Helicopters fly at low levels below 2000 Ft AGL and Pilots in their eagerness to complete the task, tend to descend below minimum safe altitude when faced with fog or low clouds to stay in ground contact.
  • Most of the Helicopter pilots do not have the advantage of the EGPWS, Auto Pilot, reliable instruments or the Co Pilot.
  • By virtue of their operations at low levels to helipads  particularly in  the hills and over water, the chances of Helicopter Pilots getting disorientated, with consequent CFIT accidents are high.
  • Helicopter pilots should be aware of the limitation of the Helicopter and their own limitations and must plan and prepare thoroughly with particular emphasis on weather, terrain and minimum safe altitude.
  • Ground contact flying should be the rule for helicopter pilots unless the Helicopter is suitable for IFR flight and the Pilots are qualified and IR rated. For IFR flights both the departure and arrival airport should be equipped with suitable IFR aids.
  • Spatial disorientation and loss of Situational Awareness are some of the serious challenges and hazard during poor visibility conditions.
  •     Hill   shadows and flying into sun can result in late siting of obstructions or terrain. Be knowledgeable about these hazards.
  • While flying with reference to instruments, resist the temptation of looking outside while flying on instruments. This can lead to spatial disorientation.
  • Single pilot operations particularly in the hills are much more

 challenging and the need for Single pilot to be very thorough in his/her planning, preparation, knowledge and timely decision making cannot be overemphasized.

  • Know the terrain and route safety altitudes well and plan your levels accordingly. Check, recheck and double check the altitude and make sure the altimeter setting is correct and the readings on pressure and Radio Altimeter are matching.
  • Know the obstructions in your area of operations. Pylons, communication/chimney towers, electric/telephone cables, trolley cables particularly in hilly areas pose a major hazard and knowledge of these is important for helicopter pilots.
  • Trolley cables come up in hilly areas to cart apples from one hillock to  other and vigilance is required to look out for the same. Kindly intimate other operators in your area of operations about the existence of such hazards and mark them on maps.
  • Operations in snow bound areas require special skill levels. Special briefing and training is essential for safe operations in these areas. Snow blindness (white out), blowing snow during pick up, hover and sit down, skids/wheels getting stuck in snow, slippery conditions while on snow or melting of snow during long hours of operations and disorientation (White out) are some of the aspects which need to be taken into account for snow bound area operations.
  • Ice formation at high altitudes is a serious hazard. Anti-icing measures like serviceable and available ice detectors, heating elements, need for frequent movement of controls to prevent jamming of controls due ice formation, knowledge about freezing level and potential of ice formation are some of the areas which require the  attention of the Operators/Pilots.
  • Before takeoff at high altitudes and low temperature conditions, ensure that the main, tail rotor blades and other surface areas are free of ice and frost formation.
  • Check the manufacturer’s instructions about adding anti –icing additives in the fuel and use proper additive as required.
  • Check and ensure the serviceability of wind screen wipers, pitot heaters.

Do not forget to switch on pitot heaters whenever required and switching them off on landing.

  • Be aware that snow fall can change the appearance of the terrain and perspective during takeoff/landing.
  • Helicopter batteries need to be maintained properly and protected during night from extreme cold temperatures by keeping them in warm rooms or wrapping in blankets etc.
  • Cracking of various seals can take place and must be checked periodically.
  • Engineer and technicians should ensure thoroughness during their maintenance and servicing activities. Tendency to take short cuts due to very cold temperatures should be avoided.
  • Low light conditions during winter months may result in minor cracks or other small defects getting overlooked. Ensure adequate lighting for servicing and maintenance work.
  • Maintenance staff should be careful while climbing on the helicopter for maintenance work since surface may be slippery due to frost, icing etc.
  • Take special precautions during taxiing and maintain very good look out for obstructions, aircraft and vehicles.
  • Do not succumb to commercial pressures, VIP pressure, peer pressure, Self-imposed pressure, job demands, and personal convenience. Never take chances with the poor weather conditions and don’t be overconfident or macho. Overconfidence has taken the lives of many pilots.
  • There may be occasions when frustration may set in because of the delays and postponement of departure timings/dates and long wait on ground due prolonged bad weather spells. Number of pilots have taken chances with weather under such conditions and have met with serious /fatal accidents. Please be aware of the grave danger under such conditions and take very considered decisions.
  • For Helicopters, it is always advisable to divert, return or land at a suitable site or even at an airfield beyond watch hours if unable to continue the flight due weather (Air Safety Circular 09/2013).
  • Although efforts have been made to include as many precautions to be taken during winter flying, as possible, yet some points may have been missed out. Operators may like to add some aspects which may be typical to their area of operations.
  • Operators should always endeavor to match the man with the machine, mission and weather conditions. Adequate instrument flying practice, simulator flying, currency, recency in area of operations, comprehensive briefing covering the entire spectrum of the various aspects of the operations, maintenance and monitoring performance are key to the successful conduct of the operations.
  • Respecting the weather and courage of conviction to say no if the safety of the flight is likely to be compromised must be impressed upon the pilots.

ASMSI wishes you all safe and efficient flying operations during winters.

Many Many Happy landings.

Air Commodore BS Siwach AVSM YSM VM

Director General, ASMSI

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