Another Country Grounds The 737-MAX

[tamada]

... Airbus also did the same thing with their A320 Neo. ...

Yes but the original A320 already had taller undercarriage and higher-mounted wings than the 737 and could readily accept the larger circumference engines without the need to shorten the pylons or 'squash' the bottom edge of the engine nacelles.

A320Neo

737 Max

[sometimewoodworker]

Good posts. For the layman traveler, take-off ends when the seatbelt light goes off and the plane is (almost) at cruising altitude. Deployed flaps disable MCAS but depending on how quickly the aircraft is being taken through climb-out, the flaps will be retracted sooner, no? Do you know if MCAS automatically senses the amount of flap and kicks-in unannounced or does it only activate once the flaps are fully retracted? The Lion Air flight had issues during climb out and the same issues may have affected the Ethiopian flight which, due to the altitude of Addis, thinner air and other aerodynamics, may already have been on a more accelerated climb-out?

MCAS does not function while the flaps are extended. It only activates once the flaps are fully retracted.

As you can see from the graphic I posted it is the airspeed that governs the retraction of the flaps.

The hight and time into climb out at which flaps are retracted is dependent on the plane, noise abatement procedures, airport, takeoff direction, wind speed, wind direction and company fuel conservation policy. It is typically between 1,000' and 3,000’

I haven't found any noise abatement procedures for Bole airport which may mean that the Max reached total flap retraction speed quickly.

The most efficient is a full power climb with minimum flaps for the airspeed according to

Fuel Conservation Strategies: Takeoff and Climb

By William Roberson, Senior Safety Pilot, Flight Operations; and James A. Johns, Flight Operations Engineer, Flight Operations Engineering

[pipoz4444]

Watch this, if true, it just makes you wonder even more, about Boeing's design

Alternating from one side to the other after each flight or in this case after a Test/Check, back to a defective one??

https://www.youtube.com/watch?v=4koccb8suOQ

pipoz4444

[sometimewoodworker]

Watch this, if true, it just makes you wonder even more, about Boeing's design

Alternating from one side to the other after each flight or in this case after a Test/Check, back to a defective one??

https://www.youtube.com/watch?v=4koccb8suOQ

pipoz4444

As you say, if true, and if what is claimed about the non documentation of this in the maintenance information, it makes the fault even more clearly a Boeing one. I know that writing maintenance manuals is not easy and is expensive but there is no conceivable reason for the omission.

[Jing Jing]

“U.S. air-safety regulators have tentatively approved sweeping software and pilot-training changes for Boeing Co.’s grounded 737 MAX jets, aimed at fixing problems with a suspect flight-control system, according to internal government documents and people familiar with the details.” NY Times

Boeing appears to be fixated on slapping together a quick fix rather than waiting for the final crash reports or reviewing the whole flight system. I don’t think Boeing has enough information at this point to say MCAS software tweaks are all that is needed.

Again more pilot training is based on an iPad application not actual flight simulator training

[papafarang]

"Boeing appears to be fixated on slapping together a quick fix rather than waiting for the final crash reports or reviewing the whole flight system"

they don't need the report , they knew the MCAS system was dangerous , that's why they update software. who has not seen their computer crash because of a software issue...mind you a home computer with software problems don't ditch you into the ground at 450 miles an hour and then incinerate you with jet fuel

[tamada]

Good summary here.

https://www.vox.com/business-and-financ ... -explained

[fdimike]

You certainly won't find me on one of these 737s. Why would anyone trust anything Boeing has to say about the safety of these planes?

[tamada]

I think we are lucky over this side of the planet as outside of Lion Air and their local offshoots, most local and regional airlines seem to have bought into the Airbus A318, A319, A320 and A321 variants. ThaiSmile, Bangkok Airways, VietJet and AirAsia gets my business. For long haul, the 777 is immensely safe but note that in the fallout from the Ethiopian crash, Boeing had to 'bury' the roll-out of the 777X which is a (even more) stretched version of the 26 year-old air frame.

Are we seeing a trend here?

[Udon Map]

I think we are lucky over this side of the planet as outside of Lion Air and their local offshoots, most local and regional airlines seem to have bought into the Airbus A318, A319, A320 and A321 variants....

Don't forget Nok. Nearly all 738s.

For long haul, the 777 is immensely safe but note that in the fallout from the Ethiopian crash, Boeing had to 'bury' the roll-out of the 777X which is a (even more) stretched version of the 26 year-old air frame.

Interestingly (for avgeeks), the 777X will become the longest passenger aircraft at 76.7 meters, closely followed by the 748 at 76.3 meters and the Airbus 346 at 75.36 meters.

[Jing Jing]

Two minutes after it departed from Addis Ababa's highland airport on its scheduled one hour and 40 minute shuttle to Nairobi, things began to go very wrong, according to the Wall Street Journal. At 8:39, with the jet just 450 feet above the ground, its nose began to pitch down. First Officer Ahmednur Mohamed radioed the control tower to report a "flight-control problem."

No matter how many warning lights there might have been the pilots had no time to react. The problem with MCAS may not only be software but might include mechanical or electrical problems. Other planes that were built at the same time as the Lion Air and Ethiopian Airlines planes should be examined.

[fdimike]

All 737 max planes are now grounded to the best of my knowledge. Are you suggesting that some of Boeings other planes may be affected?

[sometimewoodworker]

Regrettably my post has been edited so it now is not anything similar to my actual posting.

I have therefore deleted the incorrect post

[fdimike]

I certainly have no confidence in Being's ability to correct the problem and train the pilots properly. Boeing knew about this problem long ago but did not include the technology nor pilot training in their 737s unless the airline was willing to pay for it.

[papafarang]

it's a botched design , putting engines on never designed to work with such an old design, and then hoping software will keep it up in the air. How did that work out

[Jing Jing]

Are we seeing a trend here?

I never said that.

The simple software upgrade that Boeing, and the media are focused on may not be the only problem. An example can be found in Air Asia Flight 8501 crash. The pilots and ground maintenance crew kept ignoring a instrument warning light. They never traced the cause of the warning light’s apparent malfunction. That is why I said you need to look at other 737 MAX planes.

[tamada]

I think though that the flying public should force the whole series to be scrapped and make Boeing take the hit to engineer a new plane that is closer in design to the A320 series.

Why? You're saying that the problem cannot be fixed?

As long as Boeing can keep the FAA onside, anything is possible.

[tamada]

Are we seeing a trend here?

I never said that.

The simple software upgrade that Boeing, and the media are focused on may not be the only problem. An example can be found in Air Asia Flight 8501 crash. The pilots and ground maintenance crew kept ignoring a instrument warning light. They never traced the cause of the warning light’s apparent malfunction. That is why I said you need to look at other 737 MAX planes.

My comment on "a trend" relates to Boeing possibly pushing the envelope on extending the life cycle of the 737 AND the 777 beyond what is safe. When the 4-engined A340 became an uneconomical gas guzzler, Airbus voluntarily terminated the program in 2011 rather than try and milk it with patches and modifications through to its original planned program end of 2016. The revolution in aircraft engine design that occurred around the time of the A340's demise and hatched the very practical A320neo triggered Boeing to reverse-engineer the 737 to keep their foot in the narrow-body market.

With regard to AirAsia QZ8501, that was an Airbus A320. It was reported that an intermittent soldered connection that had been sending false but non-critical alarms for the best part of a year may have been a contributing factor. However, there's nothing in the Airbus operations and maintenance manuals that advise a complete reset of the FAC (flight augmentation computer) while in flight which is what the Indonesian Captain chose to do while cruising at around 37,000 feet. The effect of the aircraft being suddenly switched to alternate law mode in the thin air environment where aircraft speed and high angle of attack protections are removed was catastrophic.

[Udon Map]

My comment on "a trend" relates to Boeing possibly pushing the envelope on extending the life cycle of the 737 AND the 777 beyond what is safe.

The airframes themselves last pretty much forever with proper maintenance. Age has nothing to do with it. Various systems and the engines are updated and replaced as necessary. The 747, for example, is two years older than the 737 and 25 years older than the 777, yet it's still going strong. It's a common occurrence for older aircraft to be refitted with new, more efficient engines. For example, Cathay Pacific did it with all of its 747s starting in the late 1990s. The B-52 bomber was first built in 1955, and the last one rolled off the assembly line in 1962; yet they're still going strong.

[fdimike]

Sorry UM you're not looking at the entire picture. These planes are kept in the air with more than simple maintenance. The airframe and it's components all encounter stress related problems Take for example the US B-52 bomber which has been in operation since the 50's. I would be willing to bet very little of the airframe/components are original. Continuous takeoffs/landings take their toll on the airplane.