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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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Compare the engines of old Boeing 737 and new 738max, is the begger engine the culprit? [on hold]

They say installing the new bigger engines on Boeing 737 Max has created the pitch up torque which could lead to stall and hence the need for the software to control the nose pitch, which contributes ...
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1answer
160 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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Leasing costs engines and aircraft dry lease [closed]

What would be the cost of a 3 year operational lease for two Boeing 737-800ng aircraft? Will this include the engines? question 2. What would be the cost of leasing two cfm56-3c1 engines to have the ...
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Do you guys agree that we must have at least 3 sensors to detect the angle in 737 max? [closed]

We should keep odd number of sensor that similar to Paxos pattern. Here is how it helps in preventing false positives. For example let’s assume that we have 3 sensors sensor-1, sensor-2, and ...
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361 views

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 fluid need to be changed, have the tires become flat etc.
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416 views

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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954 views

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
157 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
180 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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1answer
227 views

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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2answers
504 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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2answers
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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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218 views

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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1answer
250 views

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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2answers
381 views

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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290 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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1answer
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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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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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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 ...
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How difficult is it to simply disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft?

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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1answer
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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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1answer
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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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1answer
687 views

Has the number of angle of attack sensors been reduced in Boeing 737 Max, in comparison to the older models?

Boeing 737 is flying since 1967. I would like to know first how many ' angle of attack sensors' does it have, and has they number been reduced for Boeing 737 Max, in comparison to the older models ...
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Why is Germany not able to read data from the Boeing 737 MAX black boxes?

It is my understanding that Germany stated it does not have the capacity to read the new software, declining Ethiopia's request: "The French announcement resolved uncertainty over the fate of the ...
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1answer
317 views

Why is Boeing being blamed for the recent 737 Max crashes? [closed]

Boeing has received more than 5,000 orders for the aircraft, it has delivered 350 so far and only 2 of them have crashed. That's not a very high crash rate. The FAA, until just a day ago, was very ...
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1answer
129 views

What happens when an aircraft type is grounded while in flight? [duplicate]

Over the past few days, many countries have decided to ground the 737 MAX. Among these, several have also decided to deny passage to the affected models through that country's airspace. How does this ...
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1answer
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Are the Boeing MCAS and Airbus Alpha Protection systems the same?

I have a little question concerning MCAS from Boeing and Alpha Protection from Airbus. I think these two systems are the same, if I'm wrong please tell me. If the two 737 MAX crashed because of the ...
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Where are the grounded 737 Max planes being kept?

With various countries grounding the 737 Max, where are they (their carriers) keeping the grounded planes? Are they simply being kept at Gates of various airports (which I doubt since gates are ...
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1answer
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How unusual is the 737 MAX 8's crash history?

The Boeing 737 MAX 8 is getting a lot of bad press at the moment, but people's instincts when it comes to probability are generally terrible, especially when it comes to risk assessment. Compared ...
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Why wasn't the Boeing 737 grounded in 1991 after a crash's cause remained unknown? [closed]

Why weren't 737-200s (and other variants): grounded immediately after UA 585 crashed, out of precaution and risk avoidance? The crash's cause was unknown then. remained grounded in 1992, after the ...
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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 ...