Posts Tagged 'Boeing 737'

Plane Slides Off Runway in Denver

Continental Airlines flight 1404 scheduled to fly from Denver, Colorado to Houston, Texas on 20 December, 2008 slid off the runway at Denver International Airport at around 6:18 pm.

Click for full picture on Airliners.net

The Continental Airlines Boeing 737-500 as seen at the crash site, one day later - C by Ben Remy on Airliners.net

The Boeing 737-500 (registration number N18611) that first flew in 1994 had 115 people on board of flight CO 1404 (110 passengers and 5 crew), who ALL disembarked the plane through emergency slides that have been deployed on both sides of the aircraft. 38 of them were taken to hospital, with 4 having “moderate to serious” and one person reported as having “serious” injuries. Most injuries are broken bones and fractures. Most of the passengers escaped through the emergency slides and were climbing up the small hill immediately after the accident as the fire fighters arriving to the scene have seen passengers walking or running away from the plane, coming out of the smoke that covered the wreckage.

It is not yet confirmed whether the plane had actually taken off by the time it caught fire, but according to reports runway has was littered by wreckage – which indicates that the plane may have lifted off and then practically fell back on the runway before sliding off into a small ravine on the side 200 yards away. (If this is true, the accident itself seems to be similar to that of Spanair in Madrid earlier this year, where most of the passengers died…) One passenger story tells us: “the plane started to take off, came back down and skidded off“, but this will have to be investigated. After skidding off, the plane came to rest on its right hand side, and the cabin was filled with smoke. After the evacuation the fire had entered the cabin as well, as firefighters were reporting that the overhead luggage bins have melted onto the seats.

by balint01

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Aircraft Winglets

Many of us who fly regularly have most probably seen a so-called winglet or wingtip device at the end of the wing of an airliner at least once. It is showing up more and more often on more and more types of aircraft, thus we felt it’s time to give an overview to our readers about these sometimes funny, sometimes cool and stylish looking aircraft parts.

Winglet on Virgin Atlantic A340-600 - c by Dan Valentine on Airliners.net

Winglet on Virgin Atlantic A340-600 - c by Dan Valentine on Airliners.net

History, Reason and Benefits

The initial theoretical concept goes back to times before even the Wright Brothers first took to the skies in 1905, but it was picked up and developed by Richard T. Whitcomb of NASA after the 1973 oil crisis – in order to reduce fuel consumption. The first tests were carried out in 1979/80 in cooperation with the U.S. Air Force. At almost the same time, but independent of any U.S. military organization, a private jet producer, LearJet exhibited a prototype in 1977: the LearJet 28 that featured the first winglets on a jet and a production aircraft. Flight tests made with and without winglets showed that the winglets increased range by about 6.5 percent and also improved directional stability for the LearJet- these two factors are the major reasons behind using this facility at any fixed wing aircraft ever since.

Airflow around the wingtip with or without a wingletA winglet is a (near) vertical extension of the wing tips. The upward angle of the winglet, its inward angle as well as its size and shape are critical for correct performance – this is why they can look quite different. Air rotating around the wing strikes the surface of the winglet that directs it in another direction – thus creating an extra force, basically converting otherwise wasted energy to thrust. This is a small contribution but can save a lot for an operator in an aircraft’s lifetime. Another potential benefit of winglets is that they reduce the strength of wingtip vortices, which trail behind the plane. When other aircraft pass through these vortices, the turbulent air can cause loss of control, possibly resulting in an accident.

Winglet Types

In general any wingtips that not end the wing simply horizontally are considered as some kind of a winglet. Even though in strictly technical terms Wingtip Fences are not real extensions of the wing, and Raked Wingtips do not have a vertical part, they are still widely considered as winglet variants.

WINGTIP FENCES are a special variant of winglets, that extend both upward and downward from the tip of the wing. Preferred by European plane-maker Airbus, it is featured on their full product range (except the A330/340 family and the future A350). The Airbus A300 was actually the first jet airliner to feature this kind of solution by default, but it was a very small version of the tool. Provided that most of the Airbus planes (including all A320 family jets) feature such wingtip fences, this may be the most seen and most produced winglet type. Even the new Airbus A380 double-decker features wingtip fences.

Airbus Winglets as seen from the outside

Airbus Winglets as seen from the outside

Airbus Winglets seen from onboard

Airbus Winglets as seen from onboard

BLENDED WINGLETS (the real “Winglets”) are the most popular winglet type, leveraged by Airbus, Boeing, Embraer, Bombardier but also by Russian Tupolev and Iljushin. Blended winglets were first introduced on the McDonnel Douglas MD-11 aircraft in 1990 with launch customer Finnair (it also features a smaller winglet at the bottom side of the wing). In contrast to Airbus who applies the wingtip fences by default on most of their aircraft (and the winglets on the A330/340 family), blended winglets are considered by Boeing for example as an optional extra feature on their products, except for the Boeing 747-400. For some of the older Boeing jets (737 and 757) such blended winglets have been offered as an aftermarket retrofit, these are the newer, tall designs and do not connect to the tip of the wing with a sharp angle, but with a curve instead. These winglets are popular among airlines that fly these aircraft on medium/long haul routes as most of the real fuel savings materialize while cruising. Longer flights mean longer cruising, thus larger fuel savings. And they also server as marketing surface for airline logos or web addresses usually.

Just recently the Boeing 767-300ER has received 3.4 m high (!) winglets produced by Aviation Partners Inc. with American Airlines as the launch-customer with Air New Zealand and Hawaiian Airlines following with orders of 5 and 8 aircrafts respectively. 141 shipsets have been pre-sold already as the forecasted fuel savings range around 4%-6% for medium/long-range flights. Airbus earlier tested similar blended winglets designed by Winglet Technology for the A320 series, but determined that their benefits did not warrant further development and they stayed with the wingtip fences instead. Aviation Partners Boeing claims that winglets on 737s and 757s have saved a collective 1.2 billion gal. of fuel since they were introduced and 11.5 million tonnes of CO2 while reducing those types’ noise footprint by 6.5%. It has sold winglets to 140 airlines and 95% of all 737NGs are fitted with them. It is working on four winglet concepts for the 777 and hopes to finalize a design for that aircraft type by December, 2008.

Blended Winglets on Several Aircraft Types

Blended Winglets on Several Aircraft Types

RAKED WINGTIPS are the most recent winglet variants (they are probably better classified as special wings, though), where the tip of the wing has a higher degree of sweep than the rest of the wing. They are widely referred to as winglets, but they are better described as integrated wingtip extensions as they are (horizontal) additions to the existing wing, rather than the previously described (near) vertical solutions. The stated purpose of this additional feature is to improve fuel economy, climb performance and to shorten takeoff field length. It does this in much the same way as “traditional” winglets do. In testing by Boeing and NASA, raked wingtips have been shown to reduce drag by as much as 5.5%, as opposed to improvements of 3.5% to 4.5% from conventional winglets. Airliners to use raked wingtips: Boeing 747-8, Boeing 767-400ER, Boeing 777(-200LR; -300ER; and freighter versions) plus the new Boeing 787 Dreamliner and the Airbus A350. The 747-8, the 787 and the A350 will have special, new kind of wings, which do not have a separate winglet, but have raked, and blended wingtips integrated – without a sharp angle between the wing and the winglet.

Raked Wingtips on the new Boeing 787 and Airbus A350

Raked Wingtips on the new Boeing 787 and Airbus A350

As you can see, wingtips/winglets have developed and changed very much over the last 30 years, but are becoming the standard, which is not proven better by anything else than the wing designs of future aircraft by the largest airplane-makers that feature a built-in winglet at the tip of their new, revolutionary wings.

(Most of the winglet pictures in the montage images taken from airliners.net taken by several photographers.)

by balint01

88 killed in Aeroflot Boeing 737 crash – with pictures

Aeroflot Nord’s flight 821 was on its way from Moscow to the city of Perm, when it blew up in the air during its descent to Perm. Local residents told the media they heard a huge blast, then the plane rocketed towards the ground like a comet. Fragments of the plane were scattered over an area of four square kilometers and it even destroyed a part of the Trans-Siberian railway.

According to the official statement of the airline radio contact with flight SU821 was lost at 1,100 metres as the plane was descending for its landing at Perm; at the same time the plane’s signal was lost on air traffic controllers’ displays. Wreckage of the plane has been found within the boundaries of the city of Perm. The plane was totally destroyed and had caught fire.

82 people and 6 crew members were onboard. According to the news nobody survived the crash. Among the passengers there were seven children and 21 foreigners including Ukrainian, Swiss, Italian, Latvian, French, German and Turkish citizens.

General Gennady Troshev, a former commander of Russia’s war in Chechnya, was named among the victims. He was accused of permitting soldiers to commit vicious abuses of human rights during the campaign and was sacked by then President Vladimir Putin in 2002.

The list of passengers is available now on the website of Aeroflot.

Aeroflot is Russia’s flag carrier, Aerflot Nord is a subsidiary that operates flights domestic Russia. Aeroflot had a bad accident statistics in the mid 90s, but after they modernized their fleet, they had no serious accidents. According to Aviation Safety Network this was the first accident of Aeroflot Nord.

Spokesman of the airline said the 15-year-old plane was in a good condition and it had a full safety check this year. The plane was registered as VP-BKO with Aeroflot Nord since 14MAR2008 and first flew on in 08SEP1992 in Braathens colors for about two weeks before moving to China and beginning operations with Xiamen Airlines on 24SEP 1992, where it remained for 15.5 years.

We will follow up with the news and updates of this accident.

Update September 15: according to the first results of investigation, engine problems may have caused the accident of Flight 821.

Alexander Bastrykin, head of a federal committee investigating the accident, said the crash “was apparently connected to technical failure and a fire in the right engine” but did not provide evidence to support the claim.

Aeroflot officials said the plane was circling at about 3,600 feet in “difficult weather conditions” — including low cloud cover and rain — when it suddenly crashed.

Flight controller Irek Bikbov who was in contact with the doomed aircraft prior to the crash told Russia’s Channel One television that the plane’s pilot was behaving in a strange way, disobeying orders to go lower on the final approach and instead taking the jet to a higher altitude. He said the aircraft also turned left when he instructed it to turn right.

When he asked the pilot whether things were normal on board, the pilot answered positively but his voice was strained as if under stress, Bikbov said.

He was behaving in a strange manner and wasn’t following my orders,” Bikbov said.

The plane’s flight recorders have been found, and officials said it will take three to four weeks to analyze them as they sustained “serious damage” and are in “poor condition,” adding that “additional work using special equipment” would be required before any information could be extracted.

Read more on Aviation.com

By Szafi

68 Dies In Kyrgyzstan Air Crash

Shortly after a sad accident of Spanair at Madrid Barajas airport, another aircraft crashed shortly after take off. This aircraft was a Boeing 737-200 operated by Itek Airline of Kyrgyzstan.

The charter plane operated for Iran Aseman Airlines took off for Tehran at 20.30 local time and according to Aviation Safety Network, the captain attempted to get back for an emergency landing, but unfortunately it crashed and burst into flames. 68 people died and 22 survived the crash.

See a short video about the facts by Airsafe.com

And another one by CNN

Itek Air is among the blacklisted airlines, so we do not recommend anyone to fly them.

By Szafi


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