Questions tagged [boeing-737]

A short- to medium-range twinjet narrow-body airliner, originally introduced in 1968. With over 10,000 aircraft delivered and over 4600 on order, the Boeing 737 is the most popular commercial jetliner in history.

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Why are the Boeing 737 nacelles odd shaped?

Why is a Boeing 737 NG engine not completely round in shape? It seems to be flat at the bottom and round at the top and sides. Earlier Boeing 737 versions (100 and 200) seem to have a more rounded ...
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What is this wire going from mid-fuselage to the tail on this 737?

In this question the following image is shown, with the question what the two bulges at the aft fuselage are. However, I'm wondering what this wire is that starts somewhere midway the fuselage, and ...
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What is this flange on the engine?

Flying home from the Denver ComiCon, on a 737, I saw an angled flange on the engine. Could you describe its purpose? Photos by CGCampbell licensed CC0
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What exactly are those openings in the bellies of many jetliners?

I have circled the areas (in yellow) under the belly of the 737. What exactly are those? (airliners.net)
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Is the 737-800 a different plane from the 737 MAX 8?

I am flying on March 16 from Barbados to Toronto on a Westjet Boeing 737-800 also referred to as an aircraft type 73H on my ticket. Is this a different plane from the Boeing 737 MAX 8, grounded by ...
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What is the purpose of a dorsal fin such as on the Boeing 737?

I've noticed that the 737 has a rather unusual vertical stabilizer, with an extension at the front. Is the 737 the only plane equipped with such a vertical stabilizer, and what is its purpose?
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What is a “high-bypass geared turbofan,” and why is it so much more efficient?

According to the article Bombardier’s CSeries Gamble Is Facing Longer Odds, this new plane from Bombardier uses a new engine technology that will improve efficiency over its rival 737 series and A320 ...
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What are these spinning discs next to the throttle of the Boeing P-8 Poseidon?

The source video can be found here and the GIF is from 0:21 onwards. What are those 2 spinning things next to the throttle ?
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Is this ferry flight route possible for a B737-800 WL?

Recently a new aircraft, B737-86X (tail AP-BNA) was delivered to a new airline in Pakistan. The ferry flight as reported by planespotters is BFI - BGO - KHI but this seems like a large stretch given ...
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What are these lines on the nose of a Boeing 737?

What are these lines on the radome? You can also see them here: What are they and what is their function? Source: AviaFilms
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What are the advantages and disadvantages of having landing gear doors?

To make comparison easy, let us take the example of B737 and A320, both similar aircrafts with retractable landing gear. As seen on the photo below, the B737 doesn't have gear doors for the wheels, ...
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How is the 737 main landing gear protected from weather?

I really like the 737, it is perhaps my favorite airliner. One curiosity of this aircraft (afaik, it is the only commercial airliner) is that the main landing gear has no cover: Here is another ...
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Would an A320 override the autothrottle due to an erroneous radio-altimeter?

The pilots of Turkish Airlines Flight 1951 had multiple issues with the auto-throttle setting itself to idle during approach: despite manually adding throttle, the plane stalled and crashed before ...
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What is the technique or procedure to disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft? [closed]

With regard to the recent crashes involving the Boeing 737 Max 8 aircraft, where according to preliminary reports, it appears to be related to the MCAS, which is a safety system that pushes the nose ...
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Why does the Boeing 737 have 5 x the passenger fatalities of the Airbus 320?

I thought I'd compare the accident rates of these two similar, competing, very successful aircraft. ...
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Did A320 NEO need an equivalent to 737 MAX MCAS because of its bigger engines?

We read that MCAS on the Boeing 737 MAX was needed because of the new, bigger, heavier engines of the MAX compared to the previous 737 versions. The closest equivalent to MCAS on the Airbus A320 NEO ...
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Has the Boeing 737 MAX MCAS system successfully prevented a stall or approach to stall condition outside testing?

The Boeing 737 MAX MCAS system has been in the press a lot as it has been implicated as a possible cause of 2 fatal crashes. The MCAS system was put in to prevent a wing stall caused by excessive ...
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Why doesn't the 737 have a fuel dump nozzle?

I was watching a documentary on aircraft incidents which mentioned that the 737 does not have the facility to dump fuel. Instead they're required to fly in circles to burn off excess fuel in an ...
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Why is the 737’s aileron/spoiler authority reduced at low flap settings?

According to the NTSB report on the crash of United Airlines Flight 585, the ability of the 737’s lateral controls (ailerons and flight spoilers) to counteract the rolling forces produced by (say) a ...
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What winglet airfoils are used on the Boeing B737?

I would like to know what airfoils are used for the Boeing 737 winglets.
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When Boeing designed the 737NG, what factors influenced the change in the flap system?

The early Boeing 737 models had wings with triple-slotted flaps that appeared to be derived from the 727. When the 737 was redesigned as the Next Generation series (dash 600 through 900), these flaps ...
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Why evacuate wing at the front side after water landing?

When looking at the following Transavia B737 safety cards, I noticed that after a water landing, passengers who evacuate via the overwing exits should leave the wing at the front, while during ...
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What is the purpose of the small fins on top of the wing surface of Boeing aircraft?

I've noticed on most Boeing aircraft that there are small fins on the upper surface of many of their wings. They are about one inch high and maybe two inches long (it's difficult to judge size from ...
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What is MCAS trying to fix on B737 MAX?

New sources such as Seattle Times and Aviation Week provide a pretty good overlay of the MCAS function on B737 MAX. However, I'm unclear as to the issue that MCAS is attempting to fix. From what I can ...
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Why doesn't a full yoke deflection also change the stabilizer trim on the Boeing 737 MAX?

Various websites have stated that during the 737-MAX crash in Indonesia, the pilots could not pitch up because of a faulty AOA sensor pitching the plane down. The stabilizer has a rear fulcrum and ...
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With the upgrade of the 737 to the Max model, what major changes are incorporated?

The Boeing 737 was originally designed in the 1960's and flew into the 1980's before a major redesign (the 737-700, -800, and -900 models) was implemented. Coming up in a few years will be the next ...
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How many AOA sensors does the 737 MAX have?

How many AOA sensors does the 737 MAX have? Given that it's reported in the media, that one faulty AOA probe activated the MCAS on the Lion Air flight, I was wondering if anybody also knows how an ...
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What is the wing angle of attack of a Boeing 737 in cruise?

I would like to know the angle of attack that a 737 flies at during cruise. I am specifically interested in the wing angle of attack (if you know the cruise nose-up attitude and the wing incidence ...
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Why are there 40 737 Max planes in flight when they have been grounded as not airworthy?

Many countries have already grounded 737 Max planes and as of Mar 13, 2019 the FAA have stated: The FAA is ordering the temporary grounding of Boeing 737 MAX aircraft (PDF) operated by U.S. ...
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Where can I find accurate information about fuel efficiency of Airbus vs. Boeing planes?

I am trying to understand the competitive positions of Airbus and Boeing's large civil aircrafts. I would imagine fuel efficiency would be very important to airline given its large component in the ...
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Is the ground clearance of the B737 engine low compared to similar aircraft?

I'm referring to this other Question. I want to know more about the B737 and the distance between the engine and the tarmac. There are several Incidents reported, on 737 damaging the tarmac. Is the ...
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When was the Speed Trim System implemented on the Boeing 737?

The Speed Trim System (STS) is a speed stability augmentation system designed to improve flight characteristics during operations with a low gross weight, aft center of gravity and high thrust when ...
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What is a (rough) rule of thumb for calculating fuel consumption in a modern jet airliner like Boeing 737 - 300?

I'm wondering what would be a rough rule of thumb for calculating the fuel consumption of a modern airliner like a Boeing 737 - 300. I am not asking for anything from the plane's manual or even a ...
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Why are these windows on some airplanes red?

There are some red windows on the 737 and the CS-300 as well. Why are they painted red? Source Source
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Which aircraft type flies the most annual passenger-miles?

Which aircraft type flies the most annual passenger-miles? I understand there are over 4,000 737s in service. However, there are over 1,300 777s in service. These each carry more passengers, and ...
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Why do some commercial aircraft have no landing gear cover? [duplicate]

The B737 has no cover on its landing gear, as may be seen in this picture. Doesn't this increase the air drag? Almost all other airliners have doors that close off the rubber of the wheels, for ...
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Did this aircraft illegally exceed 250kts below 10,000ft?

As far as my knowledge goes: There is a 250 kt speed limit under the altitude of 10.000 feet. This screenshot seem to show an aircraft below 10.000 feet and traveling at 285 kts at the time i captured ...
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How much fuel do the new A320-Winglets burn vs. the B737-800?

Now that the new A320-Winglets have established themselves, I'm wondering if they have better fuel consumption than the B737-800? I was told that Boeing used to be marginally better. Is that still ...
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Is there less vertical space for an engine under the wing of a 737 Max than for an A320neo?

The source of this question is the understanding that the LEAP-1B couldn't fit under the wing of a 737 without changing its longitudinal position. But this wasn't the case with the design of the LEAP-...
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Was the 737-300's wing an early supercritical wing?

I know that the 737 NG borrows the basic wing design of the 777, but I have also heard that BAC 4xx airfoil on the 737 classic (300/400/500) was an early supercritical aerofoil design? Is this true?
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What are these five indicators at the front of the 737 passenger cabin?

As a passenger I noticed set of five indicators on ceiling at the front of the 737 passenger cabin. They are: red, yellow (or white), blue, white, red. Red ones seem to be coupled together (what ...
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Why does the landing gear control have 3 positions (up/down/off) on Boeing 737-800?

I've noticed that Boeing 737-800's cockpit has a 3-position landing gear lever. During takeoff, the pilot moves the lever from DOWN to UP and then to OFF position. What's the point of the OFF position?...
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Why force the nose of 737 Max down in the first place?

Can someone here explain a pretty basic question that I have had ever since this controversy came to light? I don't understand why any aircraft manufacturer, engineer, software developer, would make ...
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Is excess fuel leaking normal during take off of a B737?

When we look over this video it's noted that some fuel is coming off from the left wing during the rotate. This is the position of the fuel vent within the wing, ...
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Is it possible to do a barrel roll in a large aircraft like a B737?

Can the bigger planes like B737 do barrel rolling kind of stunts like fighter jets do? I'm sure if it's full of passengers or cargo it would be very difficult and dangerous, but is it possible with an ...
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Is it normal to take off with limited flaps on a B737?

Is it safe/normal to take off (fully loaded from Cyprus to Kenya - 6 hours) with very small flaps extended? Model of aircraft: Boeing 737-800. He used whole length of the airfield to take off, the ...
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What are the tube shaped structures on the back of the fuselage of this 737?

A previous question asked what the little metal plates between the horizontal and vertical stabilizer were (they are vortex generators), however I am much more interested in what the gray tube shaped ...
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Can computer imposed inputs be overridden on the Boeing 737-MAX?

During Lion Air Flight 610, a Boeing 737-MAX, it seems that the angle of attack sensors caused the software to believe the aircraft was stalling, thus initiating a nose-down pitch to recover from the (...
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Why doesn't the A320 have a dorsal fin like the 737?

The A320 doesn't have a dorsal fin, but the 737 does. If the 737 is more or less a similar aircraft, why doesn't the A320 have a similar dorsal fin? By Bill Larkins [CC BY-SA 2.0], via Wikimedia ...
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What are the checklist items for a runaway stab trim on a B737 MAX 8 and MAX 9?

This is a follow up question to this question. This question is not directly related to the MCAS system in the new B737 MAX aircraft, instead, my question is about the checklist for a runaway stab ...