Aviation Safety
- Thread starter Buy1Sell2
- Start date
Subject T-tail
The main advantage of a T-tail is that during normal flight conditions the elevator is above most of the effects of downwash from the propeller (in case of a propeller-driven aircraft) and the airflow around the fuselage and wings. Elevator operation in undisturbed air allows control movements that are consistent throughout most flight regimes.
The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. Seaplanes and amphibian aircraft (e.g. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible.
The main hazard with this design is the possibility of entering a Deep Stall. While this can occur on other aircraft as well, the risk is greater with T-tails as a high AOA would likely place the wing separated airflow into the path of the horizontal surface of the tail. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. Loss of Control).
The main advantage of a T-tail is that during normal flight conditions the elevator is above most of the effects of downwash from the propeller (in case of a propeller-driven aircraft) and the airflow around the fuselage and wings. Elevator operation in undisturbed air allows control movements that are consistent throughout most flight regimes.
The t-tail is a popular design in aircraft with aft fuselage mounted engines (e.g. MCDONNELL DOUGLAS MD-82) because it removes the tail from the exhaust blast. Seaplanes and amphibian aircraft (e.g. BERIEV A-40 Albatross) often have T-tails in order to keep the horizontal surfaces as far from the water as possible.
The main hazard with this design is the possibility of entering a Deep Stall. While this can occur on other aircraft as well, the risk is greater with T-tails as a high AOA would likely place the wing separated airflow into the path of the horizontal surface of the tail. This may result in loss of elevator authority and consequently, inability to recover from the stall (i.e. Loss of Control).
It’s Been 20 Years Since the Last Catastrophic U.S. Plane Crash
https://www.dcreport.org/2021/11/12/its-been-20-years-since-the-last-catastrophic-u-s-plane-crash/
We made it. I had my doubts, but we pulled it off.
Nov. 12 marks the 20th anniversary of the crash of American Airlines flight 587 in New York City. We have now gone 20 full years since the last large-scale crash involving a major U.S. carrier. This is by far the longest such streak ever.
https://www.dcreport.org/2021/11/12/its-been-20-years-since-the-last-catastrophic-u-s-plane-crash/
We made it. I had my doubts, but we pulled it off.
Nov. 12 marks the 20th anniversary of the crash of American Airlines flight 587 in New York City. We have now gone 20 full years since the last large-scale crash involving a major U.S. carrier. This is by far the longest such streak ever.
The Evolution of Aviation Safety
https://aerocrewnews.com/aviation-news/safety-matters/the-evolution-of-aviation-safety/
Aviation Safety’s inauspicious beginning probably started on September 17, 1908 a mere four years and nine months after the Wright Brother’s first flight and only five months after the first passengers were carried by airplane. This less than momentous occasion also included the Wright Brothers when Orville Wright crashed with passenger Thomas Selfridge during a demonstration flight for the US Army. Wright was seriously injured and Selfridge was killed, leading to aviation’s first fatality. Of course, as aviation grew and more planes were built, more flights were conducted and more people began to push the boundaries of the technology, there were more accidents and more fatalities until eventually industry leaders believed that some form of oversight would be needed to help aviation really reach its full potential as a mainstream form of travel; as endless crashes would not be acceptable to the traveling public. This trend of increasing travel with an expectation for a decrease in accidents has continued to this day.
https://aerocrewnews.com/aviation-news/safety-matters/the-evolution-of-aviation-safety/
Aviation Safety’s inauspicious beginning probably started on September 17, 1908 a mere four years and nine months after the Wright Brother’s first flight and only five months after the first passengers were carried by airplane. This less than momentous occasion also included the Wright Brothers when Orville Wright crashed with passenger Thomas Selfridge during a demonstration flight for the US Army. Wright was seriously injured and Selfridge was killed, leading to aviation’s first fatality. Of course, as aviation grew and more planes were built, more flights were conducted and more people began to push the boundaries of the technology, there were more accidents and more fatalities until eventually industry leaders believed that some form of oversight would be needed to help aviation really reach its full potential as a mainstream form of travel; as endless crashes would not be acceptable to the traveling public. This trend of increasing travel with an expectation for a decrease in accidents has continued to this day.
Can you believe that airplanes used to be made of wood and fabric?
https://www.britannica.com/technology/airplane/Materials-and-construction
Aircraft made of wood and fabric were difficult to maintain and subject to rapid deterioration when left out in the elements. This, plus the need for greater strength, led to the use of metal in aircraft. The first general use was in World War I, when the Fokker aircraft company used welded steel tube fuselages, and the Junkers company made all-metal aircraft of dual tubing and aluminum covering.
During the period from 1919 through 1934, there was a gradual trend to all-metal construction, with some aircraft having all-metal (almost always of aluminum or aluminum alloy) structures with fabric-covered surfaces, and others using an all-metal monocoque construction. Metal is stronger and more durable than fabric and wood, and, as the necessary manufacturing skills were developed, its use enabled airplanes to be both lighter and easier to build. On the negative side, metal structures were subject to corrosion and metal fatigue, and new procedures were developed to protect against these hazards. A wide variety of aluminum alloys were developed, and exotic metals like molybdenum and titanium were brought into use, especially in vehicles where extreme strength or extraordinary thermal resistance was a requirement. As aircraft were designed to operate at Mach 3 (three times the speed of sound) and beyond, a variety of techniques to avoid the effects of aerodynamic heating were introduced. These include the use of fuel in the tanks as a “heat sink” (to absorb and dissipate the generated heat), as well as the employment of exotic materials such as the advanced carbon-carbon composites, silicon carbide ceramic coatings, titanium-aluminum alloys, and titanium alloys reinforced with ceramic fibres. Additionally, some designs call for the circulation of very cold hydrogen gas through critical areas of aerodynamic heating.
https://www.britannica.com/technology/airplane/Materials-and-construction
Aircraft made of wood and fabric were difficult to maintain and subject to rapid deterioration when left out in the elements. This, plus the need for greater strength, led to the use of metal in aircraft. The first general use was in World War I, when the Fokker aircraft company used welded steel tube fuselages, and the Junkers company made all-metal aircraft of dual tubing and aluminum covering.
During the period from 1919 through 1934, there was a gradual trend to all-metal construction, with some aircraft having all-metal (almost always of aluminum or aluminum alloy) structures with fabric-covered surfaces, and others using an all-metal monocoque construction. Metal is stronger and more durable than fabric and wood, and, as the necessary manufacturing skills were developed, its use enabled airplanes to be both lighter and easier to build. On the negative side, metal structures were subject to corrosion and metal fatigue, and new procedures were developed to protect against these hazards. A wide variety of aluminum alloys were developed, and exotic metals like molybdenum and titanium were brought into use, especially in vehicles where extreme strength or extraordinary thermal resistance was a requirement. As aircraft were designed to operate at Mach 3 (three times the speed of sound) and beyond, a variety of techniques to avoid the effects of aerodynamic heating were introduced. These include the use of fuel in the tanks as a “heat sink” (to absorb and dissipate the generated heat), as well as the employment of exotic materials such as the advanced carbon-carbon composites, silicon carbide ceramic coatings, titanium-aluminum alloys, and titanium alloys reinforced with ceramic fibres. Additionally, some designs call for the circulation of very cold hydrogen gas through critical areas of aerodynamic heating.
Where does an airplane store its fuel
https://airplaneengineeringblog.wordpress.com/2017/02/28/where-does-an-airplane-store-its-fuel/
Because the wings have all this space available, and because usually the biggest if not always the only consumers – the engines – are hanging on the wing anyway, it’s only logical to use this storage for fuel.
The weight of the fuel also counteracts the force of the lift bending the wing upwards in flight, so storing fuel in the wings is also good practice to help against the fatigue of this bending. That’s one reason why there are often at least two different tanks inside a wing: one on the inside – the inner tank – and one on the outside – an outer tank. Fuel is kept in this outer tank for as long as possible just because its weight helps counteract the upward bend in the wing the most.
I invite you to look at the wingtip on your next takeoff to see how much it actually bends upwards; and if you can, then compare that to how much more it is bent up just before landing, when most fuel is used. It may scare you to see how flexible a wing actually is.
As the airplane flies along, the weight of the fuel that is spent to achieve this feat leaves the ship and is pumped into the atmosphere as H2O (making those contrails high in the sky) plus CO2 and some other not so nice byproducts. The resulting shift in weight may spell balance trouble if the center of gravity would move too far away from the wings. So the wings are an ideal storage space to avoid this consequence as well.
https://airplaneengineeringblog.wordpress.com/2017/02/28/where-does-an-airplane-store-its-fuel/
Because the wings have all this space available, and because usually the biggest if not always the only consumers – the engines – are hanging on the wing anyway, it’s only logical to use this storage for fuel.
The weight of the fuel also counteracts the force of the lift bending the wing upwards in flight, so storing fuel in the wings is also good practice to help against the fatigue of this bending. That’s one reason why there are often at least two different tanks inside a wing: one on the inside – the inner tank – and one on the outside – an outer tank. Fuel is kept in this outer tank for as long as possible just because its weight helps counteract the upward bend in the wing the most.
I invite you to look at the wingtip on your next takeoff to see how much it actually bends upwards; and if you can, then compare that to how much more it is bent up just before landing, when most fuel is used. It may scare you to see how flexible a wing actually is.
As the airplane flies along, the weight of the fuel that is spent to achieve this feat leaves the ship and is pumped into the atmosphere as H2O (making those contrails high in the sky) plus CO2 and some other not so nice byproducts. The resulting shift in weight may spell balance trouble if the center of gravity would move too far away from the wings. So the wings are an ideal storage space to avoid this consequence as well.
Spirit Airlines cancels dozens of flights to inspect some of its planes, disruptions will last days
https://nypost.com/2023/10/21/spiri...ens-of-flights-to-inspect-some-of-its-planes/
Spirit Airlines canceled about 100 flights on Friday after pulling some planes out of service for inspections, and the airline expects the disruptions to last several days.
Spirit did not describe the nature of the inspections and did not respond when asked for further information, but the Federal Aviation Administration said it involved inspection of brackets on the planes’ airframes.
https://nypost.com/2023/10/21/spiri...ens-of-flights-to-inspect-some-of-its-planes/
Spirit Airlines canceled about 100 flights on Friday after pulling some planes out of service for inspections, and the airline expects the disruptions to last several days.
Spirit did not describe the nature of the inspections and did not respond when asked for further information, but the Federal Aviation Administration said it involved inspection of brackets on the planes’ airframes.