Aircraft Technical

Commercial aircraft usually fly at high altitude to get advantage of fuel economy and calm weather. As the aircraft climb, the atmospheric pressure falls with increase in altitude. The low pressure at high altitude is created the unsafe environment for passengers and crews. Aircraft operating at high cruising altitude is typically equipped with pressurized cabin to protect the aircraft occupant against low atmospheric pressure. Aircraft cabin pressurized with constant pressure is usually maintained 8000 ft cabin altitude.  The cabin internal pressure is regulated by automatic cabin pressure control system. Cabin pressure also regulated by flight crew through manual control if automatic cabin pressure control system failed. When cabin pressure is lower than atmospheric pressure negative pressure differential condition developed which is dangerous for aircraft structure. Positive pressure condition is developed when cabin pressure is greater than atmospheric pressure which is hazardo...

Aircraft structural components is the main load carrying member. How efficiently structure will take load depends on its structural components design and material.Thus , primary consideration in aircraft design is placed on structural components. Generally,  three different types of  design philosophies used in designing of structural components which are such as safe-life , fail-safe and damage tolerant design. Please read below article on  safe-life and fail-safe design philosophy. https://aircrafttechnicalinfo.blogspot.com/2021/08/aircraft-structural-components-design.html Damage Tolerant Design Concept ;  As we know fail safe structure so designed that after failure of one part there is still sufficient strength in the reminder part to prevent catastrophic failure until damage part found by routine inspection.The inspection criteria developed for fail safe design failed to specify inspection technique and inspection frequencies were not sufficient to detect discr...

  Engine nacelle strake is vortex generator which enhance aerodynamic performance of an aircraft. It is mounted on engine nacelle. Encircled part in this picture is engine nacelle strake.Many aircraft engine have strake only one side and that will be on inboard of nacelle but few aircraft have strake on both the sides. Fig 01 Engine Nacelle Strake  Fig 02 Strake View from Cabin The purpose of nacelle strake is to generate vortex which energize the low energy airflow over the wing when aircraft operating at high angle of attack and low speed condition such as takeoff and landing phase of flight. We have seen many modern aircraft have their engine mounted beneath of wing and inlet of engine nacelle  forward of wing leading edge. There are many advantages of installing engine below the wing but there are some disadvantage and one of the disadvantages is engine nacelle /wing assembly interaction which disturb the airflow over the wing and it affect the lift production capabil...

An aircraft structural components is the main load carrying member. How efficiently structure will take load depends on structural components design and material.Thus , primary consideration in aircraft design is placed on structural components. There are generally three different types of  design philosophies used in designing of structural components which are such as safe-life , fail-safe and damage tolerant design. Safe-Life Design ;        Original or initial accepted theory of structural components design was safe-life design.According to safe life design concept, the structure designed for finite fatigue life and on reaching this fatigue life structure should be retired from service.A safe life structure components must be remain crack free during their entire time in service.  Safe life structural components service fatigue life is normally consider 25 percent of average life but this consideration of life will not ensure safety of aircraft througho...

The function of aircraft gas turbine engine spinner is to direct air radially outward from the center of fan blade hub into fan blade assembly so that blade can accelerate the air. Aircraft gas turbine engine operated under temperature and humidity condition which could promote formation of substinitial layer of ice on the surface of engine spinner , thereby seriously disturbing  incoming airflow to compressor which cause stall or surge and this lead to engine flame out.The anti-ice or de-ice system is used to prevent spinner from ice . The formation of ice depends on shape of spinner. Thus , the method which is used to prevent the ice formation also depends on spinner shape.The normal spinner shape used in modern aircraft gas turbine engine are  elliptical, conical and coniptical .  Elliptical Spinner : Fig 01 Elliptical Shape Spinner An elliptical spinner is more efficient than other spinner but ice formation start at a lower humidity as compared to other spinner design...

  The purpose of painting an aircraft is to provide pleasant appearance. Apart from this, protect the integrity of airframe against corrosion and deterioration. Airlines operator usually select two- or three-color combination for painting of an aircraft. Out of these two or three colors one of the colors is majority use for painting an aircraft such as white paint. Due majority use of one color on most parts of aircraft, sometimes it’s difficult to locate different parts of an aircraft specially for rescue crew in crash condition. To watch the video of this blog please click on below link https://youtu.be/Vrzue1c21jI   Have you notice thick solid line on the edge of passenger door or emergency exit door? The color of this thick solid line is different from aircraft door color. The purpose of painting of aircraft door edge with single solid line is to easily locate and open door quickly in emergency condition by rescue crew. Fig 01  Solid Line Color on Door ...

Aircraft Entry Door Scuff Plate An aircraft structure carry different load during different phases of flight.The modern aircraft structure design are  based on semi monocoque construction. In semi monocoque construction  all structural member of structures such as stringers,frame ,bulkhead and skin carries the loads.Fuselage skin is the principle load carrying member of semi monocoque construction design.All the loads acting on fuselage is  transferred from skin to internal member of fuselage structure.The integrity of fuselage skin is important for transferring the load efficiently from fuselage skin to internal member of fuselage structure.         Fig 01  Entry Door Scuff Plate Fuselage has number of opening in the fuselage structure for window,door,servicing panels,inspection access hole etc for access and servicing.Passenger/cargo door opening for passengers boarding/deboarding, cargo loading / off loading and inspection access hole for carry...