Donald Cook’s Post

I had already heard that repairs to the fuselage near the static ports (and the air data sensors, in general) should be designed and carried out with greater care, following some of the premises of the SRM, essentially on the primary sensors. Depending on the damage and the proximity of the primary static port, the plane may no longer be certified for RVSM. The reason is easy to understand; disturbances in the air near the sensors can lead to "inaccurate" readings, extremely necessary for this type of operation. A few days ago, I came across this repair near the alternate static port (secondary sensor). I was curious to know what the minimum distance was and which area was treated as critical, and I found out that there are several areas called "extra critical aerodynamic surfaces", such as the leading edges of the wings, the horizontal and vertical stabilizers, the engine intake, the positive pressure relief valves and the areas near the air data sensors. The extra critical areas have special specifications, different from other areas of the plane, even the height of the exposed rivet head outside the fuselage is taken into account. In the case of this photo, the repair is at the border of the extra critical area, which forms an area 30 inches in front of and behind the sensor, and 15 inches up and down, forming a 60 x 30 inches rectangle. The existence of an extra critical area does not mean that there should be no repairs in this space, but rather that these repairs must meet special criteria.

This is a piece of a larger video showing a mandatory test of a fire suppression system in an aircraft hangar. When I first saw it, I thought it was just #water pouring out of the roof, but then upon further research, I learned a few interesting things: 1) What's coming out of the roof is a foam that quickly expands. Here's a 5-minute video showing about 1/3 of that hangar being filled in about 4 minutes - https://lnkd.in/gRZ9t6pk 2) The synthetic foam has #PFOS in it. That's one of the forever chemicals you can't get out of the water system once it makes its way into it. They're at best, bad news. https://lnkd.in/gzx8c32v) Thanks to Adam Feffer for teaching me about PFOS and PFOA many years ago. I still remember that presentation!

An examination of the movement of dynamics of jet engines through lillustrative diagrams provides a comprehensive understanding of their operational intricacies.

PSE(Principal Structure Element) & SRC(Structural Removable Components) A PSE is an element that contributes significantly to carrying flight, ground, and pressurization loads, and whose failure could result in catastrophic failure of the aircraft. Caution: any defects on a PSE must be reported to the manufacturer. A PSE can possibly be located on or inside Structural Removable Components (SRC) •Doors, Flaps, Slats, Horizontal Stabilizers, Rudders, Ailerons,Engine mounting,…etc. may be transferred between aircraft. SRCs are generally not listed in MPD unlike landing gears. •When they are PSEs they are by definition limited to the airframe DSG limit Traceability It is important to: •Know the history of your components and the components you purchase. •Keep records of component history while they are under your control. •Establishing a statistical method for CSN calculation applicable to SRCs is necessary.

For the #AirForce #crater #repair (or Airfield Damage Repair, #ADR), there are typically seven distinct steps. These steps are: 1) debris removal, 2) crater marking, 3) damaged area cutting, 4) upheaval removal, 5) backfilling, 6) crater capping, and 7) curing/cooling of repair material (if applicable). This animation shows the deflection response of a 15 ft. by 15 ft. area repaired using granular materials as backfill material (simulated using #ILLISLAB), under one-half the main gear of C-130 aircraft (Approx. 37 kips/tire). The surrounding (i.e., original) pavement consisted of concrete slabs having significantly higher modulus (4,000 ksi) than the backfill material (120 ksi). As somewhat expected, the repaired area (with significantly lower modulus) shows excessive deflection when the 2 tires are near the center of the repaired area. Also notice the shearing action when the tires travel over the joint(s). The repaired area is typically covered up with a capping or cover (not modeled herein) to avoid any debris flying all over the place, anchored at a few feet (approx. 3 ft. or less) from the joint. How are these cover materials and anchors going to behave under such extreme shear at the joints and significant deflection at the center of the repaired area? What are your thoughts? 😃

Optimizing Trim of the vessel to reduce Fuel of Consumption With the stringent IMO guidelines, the shipowenrs and operators are under tremendous pressure to reduce Fuel oil consumption of the vessel. Trim optimization is one of the low hanging fruits for them. However, analysis points out that trim of the vessel affects the following parameters. ·      Geometrical parameters: It changes the Length of waterline & Wetted surface area of the ship, in turn, changing values of the actual form coefficients and the form factor of the vessel. ·      Wave Profile: The alteration of flow around the hull changes the wave pattern around the vessel inturn changing the wave making resistance of the vessel. ·      Viscous Resistance: The alteration of Length of waterline & Wetted surface area of the ship changes the actual Reynolds number of the vessel and in turn changes the frictional resistance & Viscous Pressure drag of the vessel. ·      Wake Profile: The alteration of flow around the hull changes wake behind the vessel altering the values of Wake fraction & Thrust deduction factor. This in turn will have a detrimental effect on the Hull Efficiency of the vessel. ·      Propulsion: With the trim & the alteration of flow around the hull, both the propeller shaft and the propeller will be at an angle, affecting values of the Thrust and Torque coefficients of the propeller. ·      Air Resistance: Although marginal, however, with the entire superstructure and other items on the main deck are at an angle, affects the Air resistance of the vessel. Above suggests that CFD analysis of the bare hull alone can’t guarantee the returns expected from Trim optimization. Indeed, it is fascinating to develop a code to optimize trim of the vessel by considering the above parameters. #MEPC #TrimOptimization #FOC #EnergyEfficiency #VesselPerformance #IMO

#Rogers #IsoClad 917 laminates are non-woven fiberglass/PTFE composites. It achieves exceptionally low Dk and Df within their class by utilizing a low ratio of non-woven fiberglass/PTFE. The non-woven reinforcement also allows these laminates to be used in applications where the final PCB may require bending or shaping, such as in conformal or wrap-around antennas. It is commonly used in conformal antennas, stripline and microstrip circuits, guidance systems, and radar and electronic warfare systems.#PCB

ATA 78 refers to "Engine Exhaust " in the ATA 100 system. This category covers various components and systems related to the aircraft engine's exhaust Here are some common topics: 1. Exhaust Nozzles 2. Thrust Reverser Components 3. Thrust Reverser Actuation Systems 4. Cascade Systems 5. Thrust Reverser Hydraulic Systems 6. Thrust Reverser Locking Mechanisms 7. Thrust Reverser Ground Deployment Systems 8. Thrust Reverser Indicating Systems 9. Thrust Reverser Door Mechanisms 10. Thrust Reverser Inspection Procedures 11. Exhaust Nozzle Position Sensors 12. Thrust Reverser Ground Handling Locks 13. Thrust Reverser Control Levers 14. Thrust Reverser Feedback Systems 15. Thrust Reverser Hydraulic Fluid Checks 16. Thrust Reverser Safety Interlocks 17. Thrust Reverser Warning Systems 18. Exhaust Plenum Systems 19. Thrust Reverser Rigging 20. Exhaust Cone Assemblies These topics ensure the proper functioning, maintenance, and safety of the engine exhaust and thrust reverser systems, which play a critical role in controlling thrust and enhancing aircraft performance during landing and ground operations.

#The_Classification_of_Power_Systems(type 5) #Hydrostatic Power Systems: In the hydrostatic power systems, the power is transmitted by increasing mainly the pressure energy of liquid. These systems are widely used in industry, mobile equipment, aircrafts, ship control, and others. This text deals with the hydrostatic power systems, which are commonly called hydraulic power systems. Figure 1.8 shows the operation principle of such systems. The concepts of hydraulic energy, power, and power transformation are simply explained in the following: Consider a forklift that lifts a load vertically for a distance y during a time period Δt (see Fig. 1.9). To fulfill this function, the forklift acts on the load by a vertical force F.

#DailyDose #Day1 Blankets :- Aircraft fuselage insulation blankets are an important component of the aircraft's thermal and acoustic management system. They are designed to provide insulation and soundproofing, as well as to protect the aircraft's structure from temperature changes and external noise. The specifications for aircraft fuselage insulation blankets can vary depending on the specific aircraft and its intended use, but here are some general considerations: 1. Material:typically made from lightweight, fire-resistant materials such as fiberglass, aramid fibers, or other composite materials. These materials are chosen for their thermal insulation properties and ability to withstand the rigors of aviation environments. 2. Thickness: vary based on the areas where they will be installed. 3. Fire resistance: Aircraft insulation blankets must meet stringent fire safety standards to ensure the safety of passengers and crew in the event of a fire. The materials used in the blankets should be able to withstand high temperatures and should not contribute to the spread of flames. Why we let corrosion inhibiting compounds (CIC) fully dry before we install the blankets!!!? #CabinTechnician #AircraftCabin #Maintenance #Aviation #CabinMechanic