UK CAA ban B737 MAX8 operations in UK
Their schedule is 2 deliveries in May and 2 a month after that. So lets see they have 437 738s in operation and 2 Aircraft is going to make such a huge difference NOT. As a disposal program to sell on some of their older 738's was in place this just gets delayed for a couple of months. May need to hire in a couple of leased aircraft but see little or no impact.
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Agree, but there may well be a further complication if even a small proportion of the travelling public can't or won't distinguish between the 737 Max and the thousands of others without the particular model suffix. Very difficult to predict or quantify but it's difficult to believe that there won't be some collateral damage to the 737 brand. I imagine the PR and Commercial departments of "old" model 737s will be giving this some thought and will be looking for any signs of avoidance.
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At least two US flights have reported that an automated system seemed to cause their Boeing 737 MAX 8 planes to tilt down suddenly.
In reports filed last year in a database compiled by NASA, the pilots said that soon after engaging the autopilot on their planes, the nose tilted down sharply.
In both cases they recovered quickly after disconnecting the autopilot.
Remember Boeing developed the MCAS to give the 737MAX the same handling qualities in turns as the 737NG, ie eliminate the nose-up tendency that the LEAP engines create. The aircraft should be flyable with out it, and is most definitely flyable with the electric stab trim disabled (this would have been a test case). The issue is that it will fly differently. Systems that allow two different aircraft to handle the same are quite common these days. In fact the modern FBW systems are design to do just that. The 737 is a legacy and so any systems that does this will have been built on top of other systems which may not have been designed with that function in mind.
There are a number of questions that are not answered in the public domain, but should be asked
- Why does the MCAS system only make use of one of the two AoA sensors? – You don't have triple redundancy, i.e. you can't tell which one is right if they disagree, but you don't actually need the system to fly the aircraft so a disagree could have made the system go INOP
- Why is the 'AoA disagree' flight-deck alert an option on the MAX? If the airline doesn't buy that option you get things like 'IAS Disagree' instead. This can confuse the flight crew as to what the issue is. Note: In the case of the Lion Air accident the MTC log has the AoA disagree, but the crew only saw IAS disagree. This makes diagnosing issues more difficult
- Why was there not a limit on stabiliser travel on MCAS? – In the extreme Boeing could have relied upon the stick-pusher to counter critical AoA deviations
- What was Ethiopian's stab runaway training regime and had it incorporated MCAS failures in light of the LionAir accident? – Note: most airlines that already had 737NGs have not ordered/received MAX specific simulators, so training in that area would have to be 'kludged'.
- What was the actual basis for suspending operations of 737MAXs? Keep in mind 737s were not grounded after the spate of rudder hard-overs in the 1990s. Training and procedures were updated and over time a modification was developed and installed that minimised the likelihood of a hard over occurring. Also, Airbus FBW aircraft were not grounded after Air France and Air Asia crashes that while that had different initial faults had almost exactly the same human factors failure modes. Again training and procedures have been modified and the US (others?) has mandated training specifically in high-altitude stall recovery to minimise the chance of those accident chains from happening.
This article sounds damning, but plausible:
https://www.seattletimes.com/busines...ion-air-crash/
Other than the author's fixation with "high speed stall" when he actually just means "stall", it sounds as if he could have talked to the right people. But if it IS true it's pretty damning about the state of engineering governance in Boeing IMHO.
PDR
https://www.seattletimes.com/busines...ion-air-crash/
Other than the author's fixation with "high speed stall" when he actually just means "stall", it sounds as if he could have talked to the right people. But if it IS true it's pretty damning about the state of engineering governance in Boeing IMHO.
PDR
Being serious as Boeing will have to rework every single plane and everything will need recertifying so it could be 6-9 months. In addition nobody will be taking deliveries of them either so your production schedule is shot for 2 years. Boeing will be lucky if cost is under $2 billion because of delays, rework and compensation. Every single plane will need this and they haven't even started yet hence my timetable may be too short. Just updating a piece of software like a laptop will not bring confidence back.
In this article it isn't Boeing that's pushing the idea of a bird strike. US administration blames foreign pilots for 737 Max crashes