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DUSdude
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Re: Plane Crash in Waller County, Texas

Thu Oct 21, 2021 5:25 am

Western727 wrote:
DUSdude wrote:
FlyingViking wrote:
The ABC13 feed has a very short view from the right rear down. I think I can just catch the trailing edge of the right wing. Looks like flaps were extended.
https://abc13.com/plane-crash-katy-toda ... /11143371/


I don't see flaps in that footage from the rear angle. I only see the flap track fairings or whatever they are called under the wing. The MD80s have a pretty massive leading edge slat that would be quite prominent and would reflect a lot of light as it is unpainted aluminum. I'm not seeing that in any footage either. So the plane looks not configured for takeoff to me. Other question is why the thrust reversers are stowed.


The TE flaps and LE slats look extended to me. The LE looks too "thick" from the front to be clean. Further, on the taxi out segment at 1:31 we see the port spoilers going up as part of the usual pre-takeoff check, and the TE flaps are clearly down at that point, indicated by the angle of the TE flap vs the fuselage with the stowed position on the fuselage exposed. The slats look extended at that point as well, evidenced by the shinier part of the upper LE of the wings that gets exposed when the slats are out.


I don't know which pre taxi video you are referring to. I can no longer make sense of the ABC videos, they seem to have shuffled some stuff around. But you may be right. It is starting to look like a left engine failure started the sequence of events.
 
IAHFLYR
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Re: Plane Crash in Waller County, Texas

Thu Oct 21, 2021 2:05 pm

wjcandee wrote:
Interesting, though not necessarily indicative of anything, that they brought a mechanic along for the ride.


A very unfortunate day at KTME, but grateful day that all survived except the airframe.

While interesting regarding the mechanic onboard, I know of three different corporate flight departments that fly G550's and G650's and they take a mechanic on each trip regardless of where they are flying, short domestic flights or 10 hour international flights and the mechanic also acts does the flight attendant duties. So my guess would be similar type of operation.
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Thu Oct 21, 2021 5:41 pm

Some observations (assuming the pertinent videos were taken of the actual accident flight):

  1. While taxiing from the terminal, a momentary rising of spoilers seems to indicate a "Flight Control Check" was accomplished,
  2. A flight control check is also a "freedom of movement" check. Obviously in aircraft where the position of the flight controls can also be checked (either visually or by EFIS Flight Control page), it serves the purpose of verifying operation of the system, but it also verifies lack of binding, whether mechanically or due to, say, ice build-up.
  3. The observed puff of smoke occurs at the beginning of the takeoff roll and if any significant thrust reduction had occurred, it would be both negligent on both pilots to not note it - especially the PF due to having to counter that with steering/yaw control, which...
  4. ...is unlikely since:
    1. The tracks appear to be pretty much on center line at the end of the runway, not what might be expected with an engine failure, and
    2. Ignoring an asymmetric thrust situation until well beyond V1 is also unlikely by a professional crew.
  5. By process of elimination, and also evidenced by an abort that exceeded the aircraft's ability to stop within the required runway distance (thrust reversers are not required for balanced field calculations) as well as early passenger comments, we can be pretty sure this abort happened well after V1 and likely due to the inability of the crew to rotate the nose [high enough] to generate enough lift in the aircraft's configuration to leave the runway and therefore boils down to:
    1. A wing improperly configured for the conditions, or
    2. Horizontal Stab configuration (trim and/or malfunction) incapable of rotating the nose high enough.
 
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DL_Mech
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Re: Plane Crash in Waller County, Texas

Thu Oct 21, 2021 9:34 pm

OldB747Driver wrote:
Obviously in aircraft where the position of the flight controls can also be checked (either visually or by EFIS Flight Control page), it serves the purpose of verifying operation of the system, but it also verifies lack of binding, whether mechanically or due to, say, ice build-up.


The DC-9/MD-80 does not have an indicator showing flight control position (other than flaps and a spoiler deployed light/message). Even if an indicator was provided , the tab driven flight controls would not show movement until there was airflow across the surface.

A fight control check of the elevators would feel normal even if maintenance left a screwdriver jammed in the elevators.
 
freakyrat
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Re: Plane Crash in Waller County, Texas

Thu Oct 21, 2021 10:52 pm

wjcandee wrote:
cat3appr50 wrote:
Not sure how the aircraft proceeded to 150 kn GS without liftoff, but in any case with normal flaps and takeoff thrust and calc. TOW it would have lifted off way before 150 kn GS (est. 120 KN +/-). Possibly inadequate flaps setting may have occurred, stabilizer trim way off relative to what was needed, or a jammed elevator situation. One engine failure being asserted as a potential cause...then how did they get to 150 kn GS and not have rejected the takeoff way before this point if that occurred?


Agreed. I think the puff of smoke is going to be a red herring. The passenger who spoke to the media did not mention anything about the pilots saying it wouldn't accelerate. Instead, she said that the pilots told her the one pilot tried to rotate and it wouldn't, so the other tried, and when he couldn't get it to rotate, they aborted. That could explain the 150; the acceleration of the aircraft continued as they attempted to rotate her, maybe taking longer than optimal to call a high-speed abort. That also may explain why the tire marks seem to come a lot further down the pavement than one would expect for an abort just after V1.


My take on this now that they are bringing up the puff of smoke and the fact that the aircraft hadn't flown in 10 months is this is possibly a case of contaminated fuel however most of that fuel burned up in the accident.
 
nm2582
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 12:12 am

Notes from today's briefing.
* aircraft last flew in December 2020
* 1200 feet of heavy braking tire marks at the end of the runway
* the flight mechanic is the one who opened the cabin door that everyone evacuated through
* CVR media appears intact/good condition, although they had to repair data transfer hardware on the CVR.
* FDR is older tape recorder and recording media does not appear heat damaged, but they aren't sure how many parameters are recorded, could be as few as 8.
* Optimism was expressed for both the CVR and FDR data recovery efforts.
Image
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 12:24 am

Am I getting this right, this is the first flight after being on the ground for ten months?
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 12:58 am

GalaxyFlyer wrote:
Am I getting this right, this is the first flight after being on the ground for ten months?


How interesting that NTSB says December 2020, when ADSBExchange shows all sorts of data from a trip southwest across Mexico to points unknown in April. Out on April 21, return on April 26, each way with a stop in Nuevo Laredo. Transponder lit up numerous times in the two weeks before this flight, but always on the ground. Presumably preparing for this trip.

PS NM2582 -- great update!!

Interesting to see that the investigators out there today were up on a lift looking at the elevator and control tabs.
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 1:33 am

DL_Mech wrote:
The DC-9/MD-80 does not have an indicator showing flight control position (other than flaps and a spoiler deployed light/message). Even if an indicator was provided , the tab driven flight controls would not show movement until there was airflow across the surface.

A fight control check of the elevators would feel normal even if maintenance left a screwdriver jammed in the elevators.

Thanks for that, and yes, I do understand the system although I have no direct experience with the type.

The reason for including the statements regarding the flight control check were to those who speculated that *because of the way the system operates* they would have no reason to do a flight control check as well as to further address that even if they did do a flight control check, it would not actually verify they had elevator control as you stated.

I know its been awhile since Delta had the MD's but maybe you would have some info on whether a nose down trim setting could completely override any nose-up control input? Or what procedure would be used by a flight crew to verify that the elevator surfaces moved freely after start-up?
 
TokyoImperialPa
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 2:48 am

The white puff of smoke from engine number one indicates a compression stall. The scorch marks at the crash site behind engine number two might mean that engine number one was not working at the time of the crash, but engine number two was, or that both engines had failed and engine number two caught fire.

The thrust reverser was found in the stowed position BUT skid marks reminiscent of those from wheels whilst braking, would mean that the pilot was trying to brake but something when wrong with the engines? If there is a compressor stall then the main response would be to reduce thrust to the engines anyway so thrust reversers may have been useless.

Would it not also cause the plane to turn/bank? It seems odd to me that you would keep engine number two running while engine number one was failing when you are trying to brake and not using thrust reversers.
 
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DL_Mech
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 3:12 am

OldB747Driver wrote:

I know its been awhile since Delta had the MD's but maybe you would have some info on whether a nose down trim setting could completely override any nose-up control input? Or what procedure would be used by a flight crew to verify that the elevator surfaces moved freely after start-up?


I’m not a pilot, but I would hope Douglas would not design a plane that would not rotate due to a poorly trimmed stabilizer. Hopefully someone will have some info.

I am surprised at the amount of 737NGs without any surface position indicator. I’ve seen them on military versions and a few foreign operators, but there are a lot of planes out there without an indicator. I guess standard operating procedure is free moving flight controls during pre-flight checks?
 
nm2582
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 3:36 am

wjcandee wrote:

How interesting that NTSB says December 2020, when ADSBExchange shows all sorts of data from a trip southwest across Mexico to points unknown in April. Out on April 21, return on April 26, each way with a stop in Nuevo Laredo. Transponder lit up numerous times in the two weeks before this flight, but always on the ground. Presumably preparing for this trip.


Makes one wonder if the logbooks for the aircraft are missing that flight.
 
lx2iah
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 4:14 am

NTSB says planes engines in “great condition” + 1,200 ft. of skid marks on the runway + no debris field near fences at north of runway.

NTSB says engines from plane crash in ‘great condition,’ providing information
https://www.click2houston.com/news/loca ... formation/
 
lx2iah
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 4:16 am

Here’s more coverage from KHOU CBS 11 Houston

https://www.khou.com/article/news/plane ... 738dfa761d
 
lx2iah
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 4:18 am

And coverage from ABC 13 KTRK Houston

https://abc13.com/ntsb-waller-county-pl ... /11152128/
 
lx2iah
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 4:24 am

NTSB- plane had not been flown in 10 months.

NTSB: Plane that ran off runway in Brookshire had not flown in 10 months
https://www.click2houston.com/news/loca ... -accident/
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 7:57 am

nm2582 wrote:
wjcandee wrote:

How interesting that NTSB says December 2020, when ADSBExchange shows all sorts of data from a trip southwest across Mexico to points unknown in April. Out on April 21, return on April 26, each way with a stop in Nuevo Laredo. Transponder lit up numerous times in the two weeks before this flight, but always on the ground. Presumably preparing for this trip.


Makes one wonder if the logbooks for the aircraft are missing that flight.


I sent the ADSBExchange links to the NTSB witness line. They'll figure it out. Am I wrong? Seems like lots of data points using this aircraft's code.

Accident flight: https://globe.adsbexchange.com/?icao=ad ... 1634655596

April 21, 2021 flights: https://globe.adsbexchange.com/?icao=ad ... 1634655596

April 26, 2021 flights: https://globe.adsbexchange.com/?icao=ad ... 1634655596
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 1:48 pm

DL_Mech wrote:
I’m not a pilot, but I would hope Douglas would not design a plane that would not rotate due to a poorly trimmed stabilizer. Hopefully someone will have some info.

I am surprised at the amount of 737NGs without any surface position indicator. I’ve seen them on military versions and a few foreign operators, but there are a lot of planes out there without an indicator. I guess standard operating procedure is free moving flight controls during pre-flight checks?


If I'm not mistaken, most EFIS-equipped aircraft will have a status page for the flight controls, which is typically selected prior to performing the check in question - it used to be a "primary display" on older aircraft but with the level of automation increasing, it seems to be unnecessary as a primary (always visible) display.

Anyone out there have experience with the "Flight Control Check" procedures on the MD-8X series aircraft? All of the aircraft I've flown have either had instrumentation which monitored the position of the control surfaces or were mechanically (cables) linked such that if the cockpit controls were free to move to normal limits, they performed as expected.

On a side note, on any Part 25 type aircraft I've flown, the control forces required to rotate the aircraft could be substantial (although maybe possible???) if the the trim was significantly out-of-trim. TG I never had an opportunity to confirm that...
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 2:33 pm

OldB747Driver,

If you're interested, Juan Browne's latest update on this accident on the youtube Blancolirio channel includes a section where he's going through pages of an old Continental Airlines MD80 checklist, which is very-illuminating. He also explains the MD80 pedestal, and how the controls work and interact, and what issues the takeoff warning system addresses. It's pretty-comprehensive.

Also, as I know you know, one issue with the MD80 that is illuminated in the Ameristar NTSB report is that there is the possibility that you can move an MD80s controls freely, which will mean, as to the elevator, that the control tabs are moving, but the elevator itself could still be jammed, and you can't detect the jammed elevator without getting on a lift and going up and looking. https://www.ntsb.gov/investigations/Acc ... AR1901.pdf In the report, the very-first safety issue identified by the investigators is: "Lack of a means to enable flight crews of Boeing DC-9/MD-80 series and 717 model airplanes to verify before takeoff that the elevators are not jammed." (Page x).

Indeed, the NTSB Press Release on the subject is titled "Undetectable Flight Control Malfunction Cause of Jetliner Runway Excursion; Flight Crew’s Actions Praised". https://www.ntsb.gov/news/press-release ... 90307.aspx
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 2:43 pm

Thank you, wjcandee - and while I'm at it, thanks for your many pertinent and cogent posts in these forums.
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 3:27 pm

Hmmm... this is starting to come into sharper focus.

This is starting to look like at least two critical problems have occurred consecutively:
  1. A horizontal stabilizer/elevator issue, followed by...
  2. "Something" pushing the power up on that number 2 engine, with the most likely candidate being an autothrottle that re-initiated power after manually pulled back by the PF, thereby not only negating the efforts to bring the aircraft to a stop on the runway surface, but also not allowing the thrust reversers to deploy (engines not at an idle setting).

The bare area behind the number 2 engine -but not the number 1- seems to imply a much higher than idle setting, and I have a hard time believing any crew would not have pulled the power back while doing a rejected takeoff. I suppose the thrust lever could have been pushed forward during the shutdown/egress, but that doesn't seem to pass the sniff test, given the amount of cleared grass; it seems as though the number 2 was running at a pretty good clip for some time, although how loose the soil was with overgrown grass would be a factor.
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 9:08 pm

SPEED mode engaged, not THRUST? Why one would be in SPEED, I can’t fathom, but I see that in our FOQA parameters in RTO. Not MD-80 or any airliner.
 
Thrusty69
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 9:39 pm

If the #1 engine failed, could the ART (Auto Reserve Thrust) have activated and commanded max power+ on the #2 engine? And maybe went unnoticed?
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 10:29 pm

This is what I was referencing:

In an exclusive interview with CBS sister station KHOU in Houston, passengers shared details of the crash.

“One pilot pulled up on the, whatever you call it, the steering wheel, and it wouldn’t go up, so the other one did,” the passenger who wanted to remain anonymous said. “This is what the pilots told me and it wouldn’t go up so they tried to stop it and there just wasn’t enough runway left.”

https://boston.cbslocal.com/2021/10/20/ ... n-hanscom/
 
OldB747Driver
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 10:48 pm

Again, without a operative knowledge of the MD-8X, can only one side of the autothrottle disconnect? It's not too hard to imagine that the flight crew's attention was riveted outside and on braking, especially on an "after V1 abort", without noticing the number two thrust lever creeping up in response to a still-connected autothrottle - if that's even possible.

Maybe an Air/Ground logic switch that "thought" it was airborne? In types I've flown, this switch is typically in the nose gear strut, so is it possible that after attempting to rotate and extending the nose strut without enough to rotate the nose to a flight position and a rapid response to abort activating ATR? Spitballing here, for sure, but that #2 was definitely pushing out high volumes of hot air at the accident site.
Last edited by OldB747Driver on Fri Oct 22, 2021 10:50 pm, edited 1 time in total.
 
trnswrld
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 10:48 pm

IF it is true that the aircraft had not been flown in 10 months, is that normal for its first flight to be done with passengers? I’ll be honest if I boarded an aircraft and they told me this thing hasn’t left the ground in nearly a year I’d be a little concerned.
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Fri Oct 22, 2021 11:01 pm

trnswrld wrote:
IF it is true that the aircraft had not been flown in 10 months, is that normal for its first flight to be done with passengers? I’ll be honest if I boarded an aircraft and they told me this thing hasn’t left the ground in nearly a year I’d be a little concerned.


Not in an operation I ran.
 
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Aaron747
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 12:02 am

trnswrld wrote:
IF it is true that the aircraft had not been flown in 10 months, is that normal for its first flight to be done with passengers? I’ll be honest if I boarded an aircraft and they told me this thing hasn’t left the ground in nearly a year I’d be a little concerned.


Depends on how cheap the owners are. If they are, that's 'normal' to them. But as GF said, this is indicative of a crap safety culture.
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 12:16 am

In the USAF, 7 days on the ground on a deployment, it gets a local flight before continuing on the deployment. I’ve flown C-5 on the ground 8,000 to 10,000 hours, lots of prep, long crew pre-flight, local only, up to altitude for an hour or two, before some landings. Not an FCF, just a check-out.

We did the same for bizjets that had been grounded for whatever reason—awaiting transfer to customer, extensive work being done, interior rerag. It’s only fair to the passengers to make sure everything works.
 
trnswrld
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 2:12 am

Ok that’s pretty much what I assumed. Thanks for the info. So this one apparently didn’t fly for 10 months, and had significant work done somewhat recently. That seems downright negligent for this aircraft to attempted to be flown with passengers, some of them children? Wow
 
B757capt
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 3:34 am

The big question will be “what happened to the aircraft while it didn’t fly for 10 months?”

Was it in a storage program? Was it undergoing any maintenance?

If it was in a storage program then it wouldn’t be required to test fly or Functional Check Flight the aircraft. If it had some significant maintenance it might not have been required either but finger pointing to best practices will absolutely happen.
 
IAHFLYR
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 1:57 pm

As mentioned previously, I also had seen N987Ak on the ground at KTME quite a few times in the last month or so via the ADS-B Exchange site and wondered, what the heck is an MD87 doing on the ground at KTME. Also, the owner is a huge home builder in the North/Northwest Houston area so why base your plane so far from Spring which is where most of his business has been happening? Why not use KIAH other than cost structure, traffic at the airport and who knows what else?

Yes we are all Monday morning QB at this point, but think of this:

1. Not flown according to reports for 10 months. Why not have maintenance flights as GalaxyFlyer and others have mentioned?
2. Where did the pilots come from as they must be contract pilots?
3. When did they last complete recurrent training on the aircraft type?
4. CRM?
5. If that puff of smoke was indeed a compressor stall why continue the takeoff?

Fourth and ten, let the NTSB figure this out.
 
airplanedriver6
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 2:38 pm

IAHFLYR wrote:
5. If that puff of smoke was indeed a compressor stall why continue the takeoff?

Good question, but in fairness not all compressor stalls are noticeable from the flight deck.
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 3:01 pm

Using contract pilots is already being investigated courtesy of the Tahoe accident. Lots of issues there—vetting, training standards, CRM, knowledge of the operations. An MD-87 looks cheap to buy, but the cost of operating is likely beyond the airline’s costs, it’s still an expensive plane. A $60 million bizjet costs about 10% or $6 million a year to operate. Buy a 10-year old plane of the same model, it’ll cost $6 million plus some—no longer under warranty, more wear and tear to fix, etc. 200 hours a year on an MD-87 could easily cost $3 million a year.
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 4:00 pm

GalaxyFlyer wrote:
Using contract pilots is already being investigated courtesy of the Tahoe accident. Lots of issues there—vetting, training standards, CRM, knowledge of the operations. An MD-87 looks cheap to buy, but the cost of operating is likely beyond the airline’s costs, it’s still an expensive plane. A $60 million bizjet costs about 10% or $6 million a year to operate. Buy a 10-year old plane of the same model, it’ll cost $6 million plus some—no longer under warranty, more wear and tear to fix, etc. 200 hours a year on an MD-87 could easily cost $3 million a year.


But here it looks like they're getting about 20 hours a year... :D
 
IAHFLYR
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Re: Plane Crash in Waller County, Texas

Sat Oct 23, 2021 4:32 pm

airplanedriver6 wrote:
Good question, but in fairness not all compressor stalls are noticeable from the flight deck.


Correct from what guys/gals I know who have flown MD80series, though you'd think someone would have noticed something was wrong before V1.
 
ryanov
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Re: Plane Crash in Waller County, Texas

Sun Oct 24, 2021 4:16 pm

The Ameristar accident would seem to prove that that's not true, if I remember the facts correctly. It seems unlikely to me that this is the exact same cause, so soon after and when it has been studied closely, but it's just an example.
 
wjcandee
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Re: Plane Crash in Waller County, Texas

Sun Oct 24, 2021 5:54 pm

ryanov wrote:
The Ameristar accident would seem to prove that that's not true, if I remember the facts correctly. It seems unlikely to me that this is the exact same cause, so soon after and when it has been studied closely, but it's just an example.


I think the point of referencing the Ameristar accident is the question of crew response when presented with an unflyable aircraft after V1. (I'm giving the pilots the benefit of the doubt that that's what happened, that the puff of smoke is a red herring and they had adequate thrust and airspeed for takeoff, which seems consistent with the video and with the ADSBExchange readouts. I think the left engine not leaving a mark behind the aircraft may have to do with the left wing being torn off and other structural damage as much as anything else.)

IF what the passenger told the media that the pilots said is accurate (i.e. that one pilot tried to rotate and it wouldn't so the other tried and then they aborted), they were presented with an unflyable aircraft at or after V1. The extra time, even if just a few seconds, while the other pilot tried the controls, would cause the aircraft to have accelerated to an even-higher speed in those extra few seconds before the abort, and to have traveled further down the runway. The immediate response (the abort) of the 10,000-hour Captain in Ameristar was one of the things that saved folks. Here, they were going off the end in any event, and it's a fair question whether delaying the abort by a few seconds caused any additional harm. It's an interesting question whether it was prudent to delay the abort, given the certainty of a runway excursion, and to see how much quicker they would have stopped had they aborted at the first indication of an aircraft that wouldn't rotate. In this case, it's probably moot, but if they could have stopped short of that tree line, then maybe not so. Clearly the issue here is that only the left wing hit a tree; they just as easily could have had the nose go straight into a few trees, at which point the death toll likely would have been higher.
 
F9Animal
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Re: Plane Crash in Waller County, Texas

Sun Oct 24, 2021 9:24 pm

airplanedriver6 wrote:
IAHFLYR wrote:
5. If that puff of smoke was indeed a compressor stall why continue the takeoff?

Good question, but in fairness not all compressor stalls are noticeable from the flight deck.


Good point. The engines are so far back on those planes, they may not have even heard it. I am now thinking it might have indeed been something similar to that Ameristar accident.

Hopefully they will find the cause soon.
 
nm2582
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Re: Plane Crash in Waller County, Texas

Mon Oct 25, 2021 7:07 am

The aircraft achieved an airspeed where rotation and liftoff should have been possible. I am still suspicious about engine #1 (puff of smoke, lack of burn marks behind it at the crash site) but it seems most likely that if #1 did have a problem the crew became aware of, it must have happened after V1. An engine failure after V1 could have increased the workload and/or been a distraction from the RTO efforts/decision making.
 
GalaxyFlyer
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Re: Plane Crash in Waller County, Texas

Mon Oct 25, 2021 1:51 pm

An engine failure recognized after V1 should have gone airborne, not result in a RTO.
 
FlyingViking
Posts: 149
Joined: Tue Jul 26, 2005 12:16 am

Re: Plane Crash in Waller County, Texas

Mon Oct 25, 2021 2:02 pm

It absolutely should, but that didn't happen with Garuda in Japan in 1996. Another abort past V1 was Spantax in Malaga in 1982 (tire failure). Both of them disasterous.
 
Okcflyer
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Joined: Sat May 23, 2015 11:10 pm

Re: Plane Crash in Waller County, Texas

Mon Oct 25, 2021 2:19 pm

nm2582 wrote:
The aircraft achieved an airspeed where rotation and liftoff should have been possible. I am still suspicious about engine #1 (puff of smoke, lack of burn marks behind it at the crash site) but it seems most likely that if #1 did have a problem the crew became aware of, it must have happened after V1. An engine failure after V1 could have increased the workload and/or been a distraction from the RTO efforts/decision making.


GalaxyFlyer wrote:
An engine failure recognized after V1 should have gone airborne, not result in a RTO.


FlyingViking wrote:
It absolutely should, but that didn't happen with Garuda in Japan in 1996. Another abort past V1 was Spantax in Malaga in 1982 (tire failure). Both of them disasterous.


Given the reports of "attempts to pull up" it's highly unlikely they began rejecting after V1 due to some engine issue. Clearly they tried to go flying and when it didn't lift off, they began rejecting. As others mentioned, the engine puff is likely a red herring in this case.

Something was wrong with elevator and/or trim system. Contributing factors are likely to be pilot error (delayed RTO after PF pulled up and saw problem), maintenance practices (this is probably an issue for ALL operators of old commercial airplanes), and get-it-there-ism (if this thing didn't fly, they were unlikely to make the game with such a large group of people).
 
nm2582
Posts: 209
Joined: Tue Jun 26, 2007 2:15 pm

Re: Plane Crash in Waller County, Texas

Tue Oct 26, 2021 10:26 pm

The point (idea/conjecture)I was trying to make (but did so poorly) is that - IF there was an engine failure, it may have occurred after v1 but before/during the decision to reject the takeoff due to the (presumed) elevator control issue. It might add a few extra seconds to the decision making process. For example - assume they noticed the engine misbehaving after v1, but before Vr. Vr might have came an extra second or two late (due to reduced thrust), putting them further down the runway. Then, when they attempted to rotate but were unable to - the human mind being what it is, they might have stuck with "we're past v1, we have to go flying despite the engine failure!" for an extra second or two (putting them even further down the runway) before the brain accepted that the aircraft was fundamentally incapable of rotation or flight, and that RTO above V1 was the only option. Swiss cheese model.
 
OldB747Driver
Posts: 140
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Re: Plane Crash in Waller County, Texas

Wed Oct 27, 2021 5:51 pm

We're all participating in conjecture at this point and only more evidence not in the public domain will eliminate those invalid hypotheses.

The white puff during initial engine spool-up from idle to T/O power, while not necessarily typical is not an unheard of phenomenon; it wouldn't surprise me at all if a leaky oil seal allowed a few drops of oil to feed into the compressed air before fully sealing as the engine pressures increased during the spool-up.

A little oil makes a lot of smoke and a small amount of oil passing through the combustion chamber *especially during spool-up* would not necessarily show up on the engine indications...
 
nm2582
Posts: 209
Joined: Tue Jun 26, 2007 2:15 pm

Re: Plane Crash in Waller County, Texas

Wed Nov 10, 2021 8:38 pm

https://www.ntsb.gov/news/press-releases/Pages/NR20211110b.aspx

investigators found that the airplane’s left and right elevators were jammed in a trailing edge down position; neither elevator could be moved when manipulated by hand.

​Both inboard actuating cranks for both elevator’s geared tabs were bent outboard, and their respective links were bent. Both actuating cranks and links were found locked in an overcenter position beyond their normal range of travel.
 
sgbroimp
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Re: Plane Crash in Waller County, Texas

Wed Nov 10, 2021 8:43 pm

Sound like Maintenance missed something pretty basic?
 
nm2582
Posts: 209
Joined: Tue Jun 26, 2007 2:15 pm

Re: Plane Crash in Waller County, Texas

Wed Nov 10, 2021 8:49 pm

https://www.ntsb.gov/investigations/Pages/DCA22MA009.aspx

Preliminary data from the airplane’s FDR showed that both elevators were positioned at approximately 18º to 19º trailing edge down when the flight crew applied power and remained there during taxi. Upon reaching rotation speed, the recorded elevator positions split, but neither moved to a trailing edge up position. The airplane reached a maximum speed of about 158 knots before decelerating. The operating parameters appeared normal on both engines and matched throughout the recording.

The damage observed to the left and right elevator geared tab input rod links is similar to the damage found during an investigation of a Boeing MD-83​, which crashed after a rejected takeoff on March 8, 2017.
 
hivue
Posts: 2154
Joined: Tue Feb 26, 2013 2:26 am

Re: Plane Crash in Waller County, Texas

Wed Nov 10, 2021 9:34 pm

Apparently control checking the yoke for elevator movement only moves the control tabs (to be distinguished from the geared tabs) so a control movement check might appear OK to the crew even if the elevators are jammed. Comments on Blancolirio's yuotube video on this suggests there are other tests/cues/feedback the flight crew needs to be aware of in order to catch jammed elevators before trying to rotate.
 
lx2iah
Posts: 111
Joined: Sat Jul 05, 2014 1:01 am

Re: Plane Crash in Waller County, Texas

Wed Nov 10, 2021 10:17 pm

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