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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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What is that ceiling compartment of a Boeing 737?

Does somebody know what that big box in the roof of the 737 cabin is?
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1answer
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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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1answer
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Why do the flap maneuvering speed margins to stick shaker depend on altitude?

Why do the flap maneuvering margins to stick shaker reduce with increasing altitude? Ref: It is written in FCTM of the Boeing 737-800:
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What proportion of the component parts of an 1967 Boeing 737 could be fitted to a model built in 2019? [duplicate]

52 years after the first one flew, Boeing 737s are still rolling off the production lines. What proportion of the parts, whether it's more interesting to measure them simply in number or by mass, ...
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1answer
114 views

What short-term alternatives do airlines have to replace their grounded Boeing MAX 8s?

The MAX 8 fleet is grounded: what are the other practical aircraft platform options available to AA, SWA or Continental that ensures that ticketed summer 2019 passengers arrive at their destinations ...
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How did NASA Langley end up with the first 737?

This answer shows N515NA, CN/MSN: 19437 as an early 737, and mentions that it may be the first one. Was this a special design built for NASA, or perhaps a prototype that nobody wanted for commercial ...
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Where do I get the latest 737NG FCOM?

So, I went online to search for the 737 FCOM, but I can only get the FCOM from 2005. Is there a 2019 version? An updated version?
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1answer
139 views

How the stabilizer cutout switch functionality has changed from Boeing 737 NG to 737 MAX?

The Boeing 737 NG has stabilizer trim cutout switches marked as MAIN ELECT (left) and AUTOPILOT (right). Turning off the right switch disables automatic stabilizer trim in autopilot mode and automatic ...
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How much does it cost to ground a B737 max aircraft for an airline?

What are the cost items for which an operator with such an aircraft in the fleet incurs per aircraft because of the grounding of the Boeing 737 max aircrafts and how much is the average cost incurred? ...
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Can the 737 Max autopilot be engaged when some sensors have failed?

If some instruments on the 737 MAX 8 fail on the Captain's side and autopilot stops, can the First Officer engage autopilot (as the instruments on his side are fine)? In the ET 302 crash the Captain ...
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737 ACP GPWS volume control?

So, I was sitting in the front rows of an A320 and could obviously hear the AP disconnect. But I could not hear the GPWS altitude and RETARD callouts. I assume this is because the pilots set the GPWS ...
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1answer
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Is the 737 Max's AOA disagreement warning light an actual light?

The New York Times article Boeing Believed a 737 Max Warning Light Was Standard. It Wasn’t. includes the following: When Boeing began delivering its 737 Max to customers in 2017, the company ...
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Why is the 737 so low?

Why does the Boeing 737 sit so low on its wheels compared to the Airbus A320?
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3answers
319 views

How does MCAS compare to stall protection systems installed in other aircraft? [closed]

How is MCAS in 737 MAX 8 different from the stick pusher in MD80 or DHC8 and from the Airbus alpha protection, in terms of overall safety? All these systems will push the nose down at high AoA and ...
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4answers
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Are Boeing 737-800s grounded? [duplicate]

I’m flying on a WestJet Boeing 737-800 from Honolulu to Vancouver and then on to Toronto in July, returning on the same type of aircraft in August. Are these aircraft still grounded and are they ...
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238 views

Who controls the cabin air temperature?

I understand the B737-800 has two air conditioning packs that handle the temperature of three zones: the cockpit, the fwd cabin and the aft cabin. I understand that which pack is turned on is ...
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Can stored/leased 737s be used to substitute for grounded MAXs?

The 737 MAX was introduced relatively recently. I would have assumed they were replacing at least some older 737 models in operation with the major airlines that took them (eg Southwest, American, ...
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What is the THS deflection speed?

Let's restrict this question to best sellers airliners (A320 and B737). On this aircrafts, the THS is used for pitch trim. The speed requirements may not be has intense as for elevator as it control ...
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1answer
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How to disable GPWS in a 737NG just like how the Airbus can?

The Airbus planes have a feature where the GPWS can be disabled. But I cannot find any switch in the 737NG cockpit to disable the GPWS.
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What do you need to do to bring a 737 Max back in service after 6 months in storage?

What kind of maintenance has to be performed on an aircraft if it has been stored for 6 months? For example, do fluids need to be changed, have the tires become flat, etc.
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Could the Boeing 757 replace the Boeing 737 Max 8/9/10? [closed]

The "Baby Boeing" 737 started life in the 1960s with roughly half the thrust and around 60% of the weight as the 757. In stages the 737 grew into a capacity squarely in the range of the 757. ...
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Which models of the Boeing 737 are still in production?

The BBC is reporting that the production of 737 aircraft has been reduced from 52 to 42 per month due to a loss of 737-Max orders. It isn't clear in the report whether the Max is the only 737 being ...
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1answer
198 views

What does the preliminary report on the Ethiopian B737 MAX accident show? [closed]

In early April the Aircraft Accident Investigation Bureau of Ethiopia released a preliminary report on the crash of Ethiopian Airlines flight 302 that happened on March 10, 2019. There apparently is ...
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1answer
258 views

Is a FAA certified plane allowed to fly everywhere in the world?

Following the debate about FAA and Boeing certification practices, I was wondering whether Europe could potentially require the Boeing 737 Max to be certified by a European agency. Is a FAA ...
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Why are the 737's rear doors unusable in a water landing?

The 737's rear exit doors cannot be used to evacuate the aircraft in the event of a water landing, as shown, for example, in this safety card: (Image from flight-report, via Jordy here at AvSE.) In ...
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Why can't the 737 MAX's horizontal stabilizer autotrim be cut out by control yoke inputs?

According to this article, a horizontal stabilizer runaway on the 737 MAX, unlike with all other 737s, cannot be countered with yoke inputs: Older 737s had another way of addressing certain ...
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Can airlines choose whether or not to enable MCAS on their fleets, and if so, have US airlines chosen to do so?

I've been told that, although all 737 Max aircraft are equipped with MCAS, the system can be deactivated by the individual airline. I've also heard that US airlines never activated MCAS in their 737 ...
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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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If the updated MCAS software needs two AOA sensors, doesn't that introduce a new single point of failure?

Regarding the 737 MAX story, the New York Times writes: "Boeing’s software update would require the system to rely on two sensors, rather than just one, and would not be triggered if the ...
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Why do the in house Boeing 737 max tails have a drag chute? [duplicate]

In the recent videos of some in-house (tagged as Boeing instead of some airline), at the top of the aircraft's tail, there is a rope with a small drag chute attached to it. What is the purpose of this?...
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How are these flywheel-like devices used in the Boeing 737 Max? [duplicate]

The recent news video CNN's exclusive look inside a Boeing 737 Max simulator shows a 737 Max simulator cockpit. There are a pair of what look like large black flywheels on the console, shown spinning ...
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Is it possible to selectively deactivate alarms? [duplicate]

My question is restricted to Airbus an Boeing's best sellers, namely the A320 and the B737. If relevant, answer can be extended to other types. In those aircraft, there are multiple possible alarms (...
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610 views

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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Is the physical MAX8 design bad because software is required for the aircraft to stay airborne? [closed]

I'm not an aviator by any means, but one thing that has come up in recent conversations with friends is that the MAX8 is inherently unsafe because alone, unpowered, the craft is not 'aerodynamically ...
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1answer
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Is it normal ops to dispatch an airplane after a stick shaker was on throughout the previous flight (Lion Air 610)? [closed]

I've been studying Figures 5 and 7 of the Lion Air interim report and cannot understand why the airplane was dispatched on the "Loss-of-control" flight when the Left stick-shaker was on throughout the ...
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Why do the stabiliser trim wheels not move exactly in sync?

I've watched a few videos about the Boeing 737, and in particular because it's a bit of a current topic, about the stabiliser wheels in the cockpit. On some of these videos, which are often in ...
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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 ...
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When extreme yoke movement cuts out stab trim on a 737-NG, does it stay off after yoke returns from limits?

I've read that the 737-NG has logic built into the stab trim system that will cause stab trim to cut out if the control column (yoke) is pulled/pushed far/hard enough (it's not clear to me if it's ...
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Is the in flight emergency manual of a Boeing 737 Max 8 available to read online? [closed]

I frequently read about pilots going through manuals/checklists/procedures in an emergency situation in an airliner while in flight. Is there an online resource where the public can actually read it, ...
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How does the 737 MAX MCAS differ from stab trim in other 737 variants? [closed]

I have the following questions: MCAS will not cut out from excessive control column movement as non-MAX 737 aircraft stab trim does. Is that correct, and is this cutout permanent or does it re-...
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Will the Boeing 737 MAX 8's software update require recertification of the aircraft?

Will the upcoming software update for the 737 MAX require the plane to go through a new certification like a new plane?
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413 views

Why is this 737 MAX 8 still flying? [duplicate]

I just saw a plane overhead that was flying unusual low and it turns out it was a 737 MAX 8 that left from the Boeing factory in Renton. https://fr24.com/BOE867/1fdcadbf Are planes that are not yet ...
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what type of sensors does the Boeing 737 MAX use for MCAS?

I can imagine there are several different ways to measure angle of attack (accelerometers, relative pressure measurements between pitot tubes, etc), but I'm curious which sensors the 737 MAX uses for ...
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Is the Boeing 737 MAX 8 MCAS exceptional in operating when autopilot is off?

To the uneducated reader it seems strange the Boeing 737 MAX 8 MCAS system only operates when autopilot is off. I understand the reasoning behind why it was implemented to operate when autopilot is ...
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3answers
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Why can’t more older 737s be retrofitted with more newer winglets?

Some background: there are four different types of winglet that have been used on various 737s over the years. The mini winglet is used to retrofit 737-200s (one of the two 737 Original variants, the ...
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Why do newer 737s use two different styles of split winglets?

All new 737s use split-tip winglets, which are more efficient than the simpler blended winglets previously used. However, for no clear reason, they use two different types of split-tip winglet: New ...
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What does 'in-trim speed' mean with respect to Boeing 737 mis-trimming correction?

This question was prompted by discussions of the recent Boeing 737 MAX crashes, but it is not specifically about that variant. In Boeing's 737 NG Flight Crew Training Manual, in Chapter 8 (Non-Normal ...
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How is device control software checked for quality?

Many, many reports on the now infamous MCAS suggest a software patch is forthcoming in the next several weeks that will address the confounding single point of failure with the two AOA sensors that ...
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1answer
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Which was the last Boeing crash that didn't send its black boxes back to the US?

I couldn't find an answer online, so I am asking the community. The real question is how frequent it is for a Boeing crash not to send the black boxes back to the USA, and a reply to title's question ...