New 737
Thread Starter
New 737
The day after delivery from Boeing, 737 SWA9017 left Sky Harbor then immediately declared an emergency and returned to field. "No electric stabilizer trim, autopilot inop..."
Join Date: Jan 2008
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It happened on Feb 24. Not much of an issue. The autopilot wouldn't engage because the autopilot stab trim was inop.
They declared an emergency because they had to hand fly the airplane.
They declared an emergency because they had to hand fly the airplane.
Thread Starter
MAX8
Howdy... ordinarily yes. This model was grounded for trim system issues involving the Stab trim. Delivered fresh from the factory, perhaps final checks of trim motor action involved accidentally turning off the motors and not turning them back on? I would have thought the factory would have been especially careful of a trim issue in the aircraft's first hour of commercial carriage. Couldn't find any buzz anywhere. Got this on YouTube. Thanks for noting the issue here.
Show of hands - likelihood that someone left the trim cutout switches in the "disable" position and no one tried the wheel trim before starting the take-off roll.
Thread Starter
Controls, "free and correct"... my guess? Pre takeoff check list has included the trim motor switches: "On". Maybe even moved them forward. Out of the pedestal...? One hopes there is now a second AoA sensor/resolver... it would be inadvisable to launch without trim?
Ah, other comments indicate a breaker was pulled for other acceptance testing.
"This is apparently exactly what happened. Circuit braker wasn't replaced after an acceptance trial flight. Aircraft was on the ground for a few hours while mechanics ensured that was the only failure in the system, and the aircraft was returned to service later on the same day." by DERP Squad under https://www.youtube.com /watch?v=3FZ5O2SXuFM
(remove the space in the url - it's the comment, not the video that's the focus.)
"This is apparently exactly what happened. Circuit braker wasn't replaced after an acceptance trial flight. Aircraft was on the ground for a few hours while mechanics ensured that was the only failure in the system, and the aircraft was returned to service later on the same day." by DERP Squad under https://www.youtube.com /watch?v=3FZ5O2SXuFM
(remove the space in the url - it's the comment, not the video that's the focus.)
There is a fair share of heightened anxiety related to this plane, it will take some time to get back to treating it like.... a plane. Trim issues will be sensitive. Declaring an emergency is... well, hard to argue against, but the plane would have had normal backup, having the APLT out of service messes up RVSM, RNP etc, but... oh well. breakers in, system OK.. off we go again.
I suppose it's reasonable to "Declare an Emergency" in the USA as they don't seem to do (and distinguish between) Pan and Mayday. Thus unless you do this if needing to return to base, you are put at the back of the stack.
They declared an emergency because they had to hand fly the airplane.
Last edited by Senior Pilot; 12th Mar 2023 at 11:44. Reason: Remove pointless comment
Thread Starter
We don't know the motors were switched off. I couldn't access the YouTube link. There are other malfunctions to consider. INOP can also mean "uncontrollable". PM first asked for "loiter", no? Also, the word "replaced". Replacing a breaker is disconcerting. "Resetting" is the word I would look for to "quickly return the A/C to service ... " What is a "Simple" issue that would damage a CB? Leaving a CB open before launch is a critical mistake...who did it and how did it not get reset? So the switches were "check, on". If on and no trim, well RTB is what pilots are paid to do when an issue cannot be resolved in flight. Hand flying MCAS might not be the correct call... So, "anxiety around this issue", to me, had nothing to do with crew decisions.
Last edited by Concours77; 12th Mar 2023 at 16:46.
Pegase Driver
Not arguing about the actual real technical reasons to declare an emergency , and I agree a trim issue on an brand new Max is probably raising adrenalime more than on another type...It is just this sentence which I find remarkable.
Some would declare a mayday, some would declare a pan and some would return without declaring an emergency. Truth is, it's subjective and none of them are right or wrong. Yes, flying with manual trim is not a dire situation but heat of the moment who knows what was going through their minds and what else they were dealing with. So, ultimately the only one of the three options that shouldn't be criticised by anyone is the mayday.
Thread Starter
Rock/Hard place
That sentence is inappropriate. Unless I misunderstand, it raised the question of pilot competence, that hand flying is somehow scary or thin to justify Mayday....it is the default, without AP. They had no choice but to handfly. Whether to continue to the destination becomes the issue. The other issue is how did they launch, without trim? They wouldn't have if they knew, imo. So, is no autotrim no go? If MCAS is required equipment for takeoff, is it on the checklist? Also, wouldn't TRIMFAULT (sorry) be on ECAM in position?
Last edited by Concours77; 12th Mar 2023 at 20:36.
That sentence is inappropriate. Unless I misunderstand, it raised the question of pilot competence, that hand flying is somehow scary or thin to justify Mayday....it is the default, without AP. They had no choice but to handily. Whether to continue to the destination becomes the issue. The other issue is how did they launch, without trim? They wouldn't have if they knew, imo. So, is no autotrim no go? If MCAS is required equipment for takeoff, is it on the checklist? Also, wouldn't TRIMFAULT (sorry) be on ECAM in position?
Thread Starter
No sir, I was replying to ATCwatcher's post regarding hunbet's post about hand flying. Your post popped up after mine and I missed it....my apologies. Conc
