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Search: Posts Made By: MurphyWasRight
Showing results 1 to 35 of 38
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Forum: Rumours & News
24th Nov 2019, 13:30
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Actually 2 questions: How will MCAS be...

Actually 2 questions:

How will MCAS be disabled for the test, simplest would likely be a software load but that might raise questions of what else changed. Might also be possible by a HW/wire mod....
Forum: Rumours & News
20th Nov 2019, 22:00
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

There is a sticky post at top of tech log that...

There is a sticky post at top of tech log that points to those as well. (Have not followed it but from name looks to be same).
Forum: Rumours & News
20th Nov 2019, 17:16
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Or had the AD stated that suspected MCAS runaway...

Or had the AD stated that suspected MCAS runaway could be held at bay by momentary blips (up or down) of the trim switches at < 5 second intervals but warned to expect it to re-engage 5 seconds after...
Forum: Rumours & News
5th Nov 2019, 12:25
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Boeing on using redundancy to the max

Statement after the otherwise successful Starliner spacecraft pad abort test.
Forum: Rumours & News
2nd Nov 2019, 01:47
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

What I read: A "normal' MCAS activation would...

What I read: A "normal' MCAS activation would unwind the applied trim when AOA returned to within range - unless it was interrupted by pilot input.
In the broken AOA case it would never unwind since...
Forum: Rumours & News
1st Oct 2019, 23:39
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

If I follow that it seems possible, although a...

If I follow that it seems possible, although a bit complicated at least to describe without pictures.

The implementation of the trim wheel overide clutch really does not matter, the point is that...
Forum: Rumours & News
9th Sep 2019, 20:44
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

A few possibilities, not of course mutually...

A few possibilities, not of course mutually exclusive:

A: One or more did but their concerns were brushed aside and they did not feel they could safely escalate. This brushing aside is more likely...
Forum: Rumours & News
5th Sep 2019, 22:03
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

My bold in quote, main point is things are not...

My bold in quote, main point is things are not necessarily as simple as it seems;

1:AoA sensor is not active until enough airflow to move the vane, so position with zero airspeed is meaningless....
Forum: Rumours & News
5th Sep 2019, 02:09
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Not exact match to MCAS, at least in Lion AIr...

Not exact match to MCAS, at least in Lion AIr case the AOA value was in range..
The "bad packet check" is not possible in this case since there is (with a singe input) no way to check the data.
...
Forum: Rumours & News
4th Sep 2019, 19:35
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

It is useful to keep in mind that as far as we...

It is useful to keep in mind that as far as we know the MCAS software worked exactly as specified/designed/implemented.
No amount of SW process can catch a system level specification error so while...
Forum: Rumours & News
25th Aug 2019, 13:10
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

My bold in above. The above does not mention...

My bold in above.
The above does not mention the need to first get the aircraft in trim -before- cut off of electric trim which appears to be the fatal action by Ethiopian crew. Although not...
Forum: Rumours & News
23rd Aug 2019, 12:42
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

One can hope that the Lion air and Ethiopian...

One can hope that the Lion air and Ethiopian investigators did such testing early on before it became widely known and discussed.
In fact the Ethiopian accident suggests that the crew was not fully...
Forum: Rumours & News
6th Aug 2019, 11:57
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Also before getting deep into probabilities of N...

Also before getting deep into probabilities of N bits flipping it seems to me that the '5 bit flip' test is also a rational stand in for "something happens we have not though about",

In other...
Forum: Rumours & News
28th Jul 2019, 12:32
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

This is getting to be depressingly similar to...

This is getting to be depressingly similar to Challenger shuttle disaster where the historical "prove it is safe to fly" mandate to engineers was inverted to "prove it is not safe to fly" due to...
Forum: Rumours & News
22nd Jul 2019, 17:59
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Now you've done it, the price will jump due to...

Now you've done it, the price will jump due to Prune interest and Boeing will take a further earnings hit :)

There are vendors that specialize in supporting old ICs, they sometimes even buy the...
Forum: Rumours & News
22nd Jul 2019, 17:44
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

The report is very interesting reading, ARIANE 5...

The report is very interesting reading, ARIANE 5 Failure - Full Report (http://sunnyday.mit.edu/nasa-class/Ariane5-report.html) the 3.1 findings summarizes a series of assumptions that led to the...
Forum: Rumours & News
17th Jul 2019, 01:10
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

For the NG there is probably an out by revising...

For the NG there is probably an out by revising the checklist to re-incorporate the use of 2 (auto and all) cutout switches.

Can probably make the case that non auto instigated trim runaway is...
Forum: Rumours & News
12th Jul 2019, 22:07
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

(From memory) From discussion on older threads...

(From memory)
From discussion on older threads I don't believe we know for sure if the FDR trace reflects the stick tracer request/condition -or- the motor actually running, in other words not 100%...
Forum: Rumours & News
9th Jul 2019, 20:52
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

To be clear there was the same AoA fault on the...

To be clear there was the same AoA fault on the last 2 flights; the recorded values disagreed by a mostly constant 22 degrees.
The AoA system was not touched before the accident flight.
The AoA...
Forum: Rumours & News
8th Jul 2019, 17:17
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Working from memory, since I don't have time to...

Working from memory, since I don't have time to track original posts at the moment, I believe this was reported by Southwest and possibly others.
I don't think we know if this was discovered by...
Forum: Rumours & News
8th Jul 2019, 14:43
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

It is important to remember that the AoA...

It is important to remember that the AoA miscompare alert was not an option.

It is a standard feature that Boeing knew was not working unless the optional AoA display was installed.

Boeing knew...
Forum: Rumours & News
6th Jul 2019, 23:00
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

The unreported stick shaker was on the...

The unreported stick shaker was on the penultimate Lion Air flight, not Ethiopian.

Given that that aircrews are discouraged from failure diagnoses it would have been better to report 'what...
Forum: Rumours & News
6th Jul 2019, 20:55
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Very good point: If raw pitot pressure/speed...

Very good point: If raw pitot pressure/speed matches within a defined tolerance seems that triggering a full UAS warning would not be necessary since it could (as it likely did) distract from the...
Forum: Rumours & News
4th Jul 2019, 12:57
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

(my bold in above) If Boeing is in fact...

(my bold in above)

If Boeing is in fact trying to muddy the waters in a public forum, which may/may not be the case, they are taking a rather unsophisticated approach if the goal is evidence for...
Forum: Rumours & News
3rd Jul 2019, 20:53
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Note that my proposed 'step 6' (NG or...

Note that my proposed 'step 6' (NG or reconfigured MAX switches) is not a memory item, only taken after all electric trim shut down and allows possible restoration of manual electric trim only:

To...
Forum: Rumours & News
3rd Jul 2019, 19:40
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

In no way are the above mutually exclusive, as...

In no way are the above mutually exclusive, as almost always the case in accidents there are multiple factors.
Short view:
Pilots could have prevented the accidents, why did they not succeed ?...
Forum: Rumours & News
3rd Jul 2019, 18:42
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

Agreed that a big question is why (both) crews...

Agreed that a big question is why (both) crews did not effectively control trim when they should/could have since manual electric trim inputs did stop MCAS for 5 seconds, as documented and confirmed...
Forum: Rumours & News
3rd Jul 2019, 15:24
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

For the NG (and theoretically reverted MAX) the...

For the NG (and theoretically reverted MAX) the stab trim runaway procedure memory items could be kept the same, simplistic paraphrase: Trim if possible, both switches to cutout.
The only change...
Forum: Rumours & News
27th Jun 2019, 14:12
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

True, except MCAS is enabled when AP is off,...

True, except MCAS is enabled when AP is off, perhaps another overlooked failure mode/path?
Forum: Rumours & News
27th Jun 2019, 13:34
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

The diagram is missing detail of the electric...

The diagram is missing detail of the electric stab trim motor block.
That is where an absolute override of all automatic trim inputs by pilot inputs "should" be, very simple no computer required.
...
Forum: Rumours & News
17th Jun 2019, 22:18
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

If this thread devolves into a...

If this thread devolves into a 'coulda/shouda/wouda' circle it will most likely get locked like the prior ones. Almost anything conceivable has been said multiple times on those.
To summarize, yes a...
Forum: Rumours & News
17th Jun 2019, 22:07
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

If this thread devolves into a...

If this thread devolves into a 'coulda/shouda/wouda' circle it will most likely get locked like the prior ones. Almost anything conceivable has been said multiple times on those.
To summarize, yes a...
Forum: Rumours & News
17th Jun 2019, 21:23
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

To be practical any mechanical fix would need to...

To be practical any mechanical fix would need to fit in the existing manual trim wheel space and could not involve 'remote' control of anything external such as a gear box in the tail.
It must also...
Forum: Rumours & News
17th Jun 2019, 20:57
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

I suspect your being optimistic with 1/3, might...

I suspect your being optimistic with 1/3, might be as low as 1/4. On the other hand back and forth 'pumping' motion is easier to do quickly and with greater force than rotating a wheel since the...
Forum: Rumours & News
17th Jun 2019, 20:28
Replies: 4,656
Views: 4,791,232
Posted By MurphyWasRight

As I mentioned above a ratcheting handle could...

As I mentioned above a ratcheting handle could provide up to 3X torque for the pilot inputs assuming the handle was full diameter and folded out at the edge, goes from 0.5 diameter to 1.5X diameter....
Showing results 1 to 35 of 38
 
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