Langkau ke kandungan utama

PITOT TUBES AND PLANE CRASHES


credit to : http://voices.yahoo.com/plane-crashes-pitot-tubes-2447529.html


Most of us are aware of the devastation a bird strike can have on an aircrafts structure or engines. But what about an insect? Or a few ice crystals? A surprisingly trivial substance can bring down even the largest aircraft.
All avionics systems rely on devices called "pitot tubes." These measure the force (impact) of oncoming air. The "pitot-static" system compares this impact pressure to the neutral (static) air pressure. The information is fed to three of the most critical instruments: Airspeed, Altitude and Rate of Climb. A blocked static port affects all three instruments, while the pitot tube itself will only involve airspeed.
The simplicity of the pitot tubes makes them vulnerable to blockages. The elaborite system of avionics, gauges and computers can be deceived by any number of blockages. Dead insects, mud wasp nests, and ice are the most common.
The most hideous aspect of this malfunction is the way a pilot, or even worse, computer, can be fooled. The flight instruments can provide wrong or conflicting information with a potentially tragic outcome. A pitot system failure is considered to be the worst possible malfunction of an aircrafts avionics.
Even a small amount of moisture can wreak havoc as in the loss of a $1.4 billion stealth bomber. This crash, the most expensive in the history of military aviation, was the result of not switching on the pitot heat system prior to air data calibration.

An X-31A crashed in 1995 after a pitot tube was blocked by ice. Many military aircraft are too unstable to control without automated avionics. In some situations the plane is not recoverable.
Austral Lineas Aereas Flight 2553 was lost, along with 74 lives, when a pitot tube froze solid. The DC-9's instruments fooled the pilots into believing the plane was stalling. Pilots are trained to trust the instruments and computers, especially in darkness and poor weather. Spatial disorientation prevented the pilots from making proper decisions. Structural failure was the result of adding full power and lowering the flaps at high speed. Flight 2553 impacted the terrain at 1,200 kph.
In 1996, Birgennair Flight 301 crashed shortly after takeoff. Mud wasps built a nest in one of the Boeing 757's pitot tubes. The captains airspeed indicator showed 350 knots and triggered the autopilot to pull up and reduce power. The actual airspeed was much slower. The pilots heard contradictory overspeed and stall warnings. Although the co-pilots seperate pitot system was working the pilots could not know which to believe. The stall warning was very real but was ignored to withing 8 seconds of the ground. 183 people were killed. Ground crews could have saved Flight 301 by installing pitot tube covers while it sat idle.
That same year Aero Peru Flight 603 was lost because ground crews failed to remove a piece of duct tape from the static ports on another 757. The computers issued overspeed, underspeed and "too low, terrain" warnings. Again, the pilots had no way of knowing which warnings were correct. They asked Air Traffic Control for the correct airspeed and altitude. With this information they confidently flew the aircraft into the ground. All 70 on board were killed.
This crash illustrates just how deadly a failed pitot-static system can be. The simple devices are the source of the entire system. The failure of even one of the two or three can circumvent the whole concept of redundancy. Besides feeding nformation to the gauges and computers, the faulty readings were also relayed to the air traffic controllers. The aircrafts computer fooled the controllers into confirming horrifically wrong speed and altitude.
It's hard to believe how many aircraft and lives have been lost to such trivial events. It's unsettling to realize they wil not be the last.

Catatan popular daripada blog ini

COLLATERAL LIGAMENT TEAR : PATIENT'S GUIDE

A Patient's Guide to Collateral Ligament Injuries Introduction The collateral ligaments are commonly injured parts of the knee. An injury to these ligaments usually involves a significant force, such as a fall while skiing or a direct impact to the side of the leg. This guide will help you understand where the collateral ligaments are locatedhow a collateral ligament injury causes problemshow doctors treat the condition Anatomy Where are the collateral ligaments, and what do they do? Ligaments are tough bands of tissue that connect the ends of bones together. There are two collateral ligaments, one on either side of the knee, that limit side to side motion of the knee. The medial collateral ligament (MCL) is found on the side of the knee closest to the other knee. The lateral collateral ligament (LCL) is found on the opposite side of the knee. Together, the collateral ligaments also work with the posterior cruciate ligament (PCL) to prevent excessive motion of the tibia posteriorly…

PANTUN CINTA ~~ CILOK FROM MY TWEET

berhias tandu daun selasih raja dewata megah berarak kemarau rindu menghakis kasih goyahlah cinta dicumbu jarak
pena dilarik mengukir kalam kalam ditulis atas suasa wahai angin sampaikanlah salam salam rindu curahan rasa
tumbuh tinggi pohon akasia singgah kelana memahat kenangan pemilik cinta biarlah rahsia silalah tunngu kiriman undangan
Tengah menggeledah arkib twitter, terjumpa pantun ini Kalau dikenang balik, terasa lawak dan kelakar. Waktu tu rasanya tengah jakun lagi dengan twitter. Tak sah kalau tak sehari mengtweet. 
Tak pasti pantun ini tentang apa dan siapa. Tapi bila check tarikh, macam dekat dengan waktu PADU. So, maybe semangat berpantun tiba-tiba datang berdamping. 
Aku rasa mesti waktu tu, follower aku banyak yang muntah hijau. Aku pun sekarang bila baca balik pantun ni, rasa nak hentak kepala kat meja ja. It's so cheesy. 



GOOD LUCK MY SISTER ON YOUR SPM

Dear my sister Najihah, I wish you the best for your SPM;s results. Whatever the result is, never lose faith A good results in SPM  as the people said is the good start for a better future but frankly speaking, its NOT a good results will not guarantee a good future because what FUTURE hold for you is still a SECRET that keep by the ALMIGHTY
So, dear sister I wanna you to keep your head held high never compare the results with others whatever it is your result especially don't compare it among the siblings every one of us have their own hurdles and destiny
and a reminder to you my dear sister you already decide what is your path do not think about what others get try the best what exactly in front of you do the best but keep in mind try to live your life to the fullest STUDY HARD PLAY HARD
 and last but not least, remember always I will always support you you may think that I try to get you into something but I will always try my best to find something that I think is the most suitable for you so, I will always…

OPTICAL COMBUSTION ENGINE~~~~ A BRIEF INTRODUCTION

1.INTRODUCTION  Figure 1 : Optical Single Cylinder Engine Internal combustion (IC) performance is one of the important aspects in automotive industry. The higher the IC performance, the powerful the engine car to be, therefore cause the higher request between the lovers of high performance cars. However, engineers had faced lots of problem in the way to determine the exact and more accurate performance of IC engine. These problems happen due to lots of factor such as the material that IC engine made of from. The IC engine is made of from all-metal materials and this prevent engineers to gain a detailed insight of the mixing, combustion and emissions formation processes occurred in the cylinder of IC engine. Therefore, the Optical Engine has been introduced as the improvement to the original system. High-speed imaging combined with the optical access provided by a optical engine offer the ability to directly image and compare ignition and combustion phenomena of internal combustion engin…

PALAPES

PALAPES.....
apakah itu.. seekor binatangkah atau nama makanan yang sangat enak
actuallty PALAPES is standing for Pasukan Latihan Pegawai Simpanan
and i had joined PALAPES UDARA or its comercial name is Air Force
Palapes di Usm terdiri daripada tiga jenis iaitu Palapes Darat, Palapes laut
dimana kedua-duanya berpusat di USM campus induk
manakala Palapes Udara pula berpusat di USM campus kejuruteraan
kenapa aku terpikir nak masuk yek...
actually since aku kat matriks lagi
aku dah pasang angan2 nak join Palapes ni
yelah seronok mendengar cerita dari Cikgu Fadhilah
tambahan pula pelbagai perkara baru aku boleh balajar
before aku disahkan senagai salah satu ahli Palapes
pelbagai prosedur yang perlu dilakukan
yalah palapes nih bukan calang2 skuad
dengar nama penuh pun ngerikan betul tak....
selepas menerima surat panggilan
kami diminta hadir ke kompleks sukan
untuk menjalani ujian kecergasan
alah macam ujian yang kita selalu buat dekat sekolah time PJ dulu
nasib baiklah aku baru ba…