Aeronautical Insanity: switching to secondary tolerances

The Something Awful Forums > Discussion > Automotive Insanity > Aeronautical Insanity: switching to secondary tolerances

mustard_tiger: Nov 8, 2010

I know this is a stupid question, but did the drone land on the aircraft carrier after? I remember a saw a post earlier of a test with an arresting hook that proved it could be done.

# ¿ May 16, 2013 08:00

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# ¿ Apr 30, 2024 10:00

mustard_tiger: Nov 8, 2010

There was a plane crash in western russia today.

http://rt.com/news/passenger-plane-crash-kazan-866/

# ¿ Nov 17, 2013 21:54

mustard_tiger: Nov 8, 2010

Eej posted:

Boy, 16, hitches ride from California to Hawaii in plane's landing gear

Truly a boy dedicated to Aeronautical Insanity. Is the wheel well even pressurized?

e: wait that's a dumb question, how did he survive

Why is nobody concerned that he made it onto the flight? This seems like a major security breach to me.

# ¿ Apr 21, 2014 08:06

mustard_tiger: Nov 8, 2010

Cross posting this from the cold war airpower thread:

Red Crown posted:

Russia is going to build a fleet of supersonic stealth mega transport planes capable of each carrying three of their notional uber tanks which have a 152mm gun and self defense AAA.

Putin has crossed the border into cartoon megalomania.

What do you guys think?

# ¿ Mar 20, 2015 05:49

mustard_tiger: Nov 8, 2010

Hambilderberglar posted:

http://www.theguardian.com/world/2015/may/09/spanish-air-force-cargo-plane-crashes-near-seville-airport

An A400M crashed near a Coca Cola plant in Sevilla. Up to 10 may be dead. Aircraft was meant for the Turkish Airforce.

How many Spanish Air Force crashes have there been in the last year, seems like I read something about them fairly recently (maybe a fighter jet crash)?

# ¿ May 9, 2015 19:50

mustard_tiger: Nov 8, 2010

I use imagus and it works for me. Chrome.

# ¿ Dec 28, 2015 07:36

mustard_tiger: Nov 8, 2010

slidebite posted:

Yeah, I understand they didn't mean to kill anyone but destroying evidence because it would have "made them look worse" makes it, well look worse.

but we were just having fun

Yea seriously, this would be like a Nascar driver killing a family in a street racing crash and then destroying the dash cam footage. I'm sure he feels very sorry for his actions being that he stood up and announced that to the class. Like many people before me said "gently caress that guy".

# ¿ May 7, 2016 00:54

mustard_tiger: Nov 8, 2010

vessbot posted:

[Quote]and long endurance seats that will enhance field of view in the cockpit and reduce fatigue over longer missions[/q]

I like how they danced around saying the seats are comfortable in fear of making it look wimpy.

Also they are kinda calling the old seats uncomfortable with bad sight lines.

# ¿ Dec 18, 2016 04:04

mustard_tiger: Nov 8, 2010

a patagonian cavy posted:

So let me get this straight.

1. An AoA sensor (not plural) goes crazy and indicates a stall.
2. Based on only this sensor and due to the negative stability induced by the larger engine relative to the 737 NG at high AoA, the computers automatically trim nose down with a significant portion of the total % of horizontal stabilizer trim.
3. If you apply manual electric trim against this input, it will stop MCAS but AoA will be re-checked and MCAS re-activated 5 seconds after manual electric trim is released. Repeated use of trim can allow repeated MCAS activations up to the trim stops. (this detail is at the bottom of the Ethiopian inital report, page 32/33).
4. Yoke control inputs have no input on if MCAS is functioning or not, so pulling back on the control column does nothing to address the root issue.

Now we have the branching chain based on what happened to the Lion Air flight and the Ethiopian flight.

5. Lion Air- This system repeatedly detects high AoA from the faulty sensor and repeatedly trims nose down, broken only by the pilots trying to use the manual electric trim. This is not detected mentally as a trim runaway because there are several "checks" against MCAS such as flaps (have to be zero), autopilot (has to be off), and timer (can't have used manual electric trim in the last 5 seconds) which wouldn't apply if the trim motor bugged out. Also, the pilots were distracted by the fact that one stick shaker (left) went off for most of the flight, but not the right side one. Eventually, the airplane trimmed itself so nose down that it became unrecoverable, exacerbated by the high airspeed which made the trimmed horizontal stabilizer more effective relative to elevator inputs.source, parameters page 14

6. Ethiopian- The system repeatedly detects high AoA (74.5 degrees to be specific) from the left AoA sensor starting shortly after takeoff, and trims nose down once the flaps are up. After this happens once or twice, the crew follows Boeing recommended practices and disconnects the electric trim using the cutout switches. However, due to the excessively high airspeed from the nose-level attitude and high thrust, manual use of the trim wheel was ineffective.

Additionally, control loads against the high levels of nose down trim were extremely high and exacerbated by the very high airspeed, because the horizontal stabilizer which is trimmed is a much larger surface (and therefore a much more effective control) than the elevator which is controlled by the yoke. Towards the end of the flight, they did turn electric trim (and therefore MCAS) back on, because otherwise they had no control over the pitch attitude due to the high loads on the horizontal stabilizer making manual trim physically extremely difficult, if not impossible. data here, pages 26/27

So Boeing created a system that can, if you cut the electric trim immediately upon realizing MCAS is on the fritz, puts the airplane in an borderline unrecoverable situation. The only way you can correct for the high levels of nose-down trim is to turn the malfunctioning electric trim system back on. This is because at very high indicated airspeeds (trimmed to nose level or nose down at takeoff thrust), manual trim becomes impossible because of the high aerodynamic loads on the horizontal stabilizer. All this can be caused by a single AoA sensor getting stuck or sending bad data.

The absolutely correct course of action appears to be to use manual electric trim to neutralize all control forces at the desired pitch attitude and then hit the electric trim cutouts, otherwise MCAS will re-trim nose down in 5 seconds. Also, you now have no stall protection- protection against possibly unrecoverable stalls.

Am I missing something?

This is one of the dumbest causes for multiple crashes I've heard of and Boeings design/business practices should be raised to the ground. What an unbelievable cluster gently caress. All this because they couldn't be arsed to put in a third AOA sensor like every other critical flight system for the last 30 years. gently caress Boeing.

# ¿ Apr 5, 2019 07:28

mustard_tiger: Nov 8, 2010

Does anyone have the video with the caption "Not today MCAS" and the pilot kicks the manual trim wheel? I think it was in this thread.

# ¿ Apr 5, 2019 17:34

mustard_tiger: Nov 8, 2010

Jonny Nox posted:

Wtf they did it again!

Air Canada left a blind wheelchair user alone on an empty plane, the 2nd similar incident to emerge in less than a week https://a.msn.com/r/2/AADwcek?m=en-ca&referrerID=InAppShare

Ok. Carry on water landing chat.

Air Canada once left my 95 year old wheelchair bound, non English speaking grandma on a plane for 5 hours after it landed. She couldn't walk and the flight attendant/Air Canada representative that was supposed to bring the wheelchair forgot about her. A crew came to clean the plane sometime during those 5 hours and I guess just cleaned around her without saying anything? They turned the lights off on their way out. Anyways my obviously worried uncle who was supposed to pick her up questioned the Air Canada desk and was given repeated answers along the lines of "we always check our planes after we land, it is impossible she is still on the plane." Eventually he got so irate with these answers that the desk got security to throw him out of the airport. At no time did anyone from Air Canada actually attempt to look in the airplane or call someone to check. They only found my grandma when the next air crew got on the plane to get ready for the next flight and wondered why this old woman was sitting near the front of the plane. That's my story god bless.

:e according to this thread my grandma should have just pulled herself up by the bootstraps and crawled her way out.

mustard_tiger fucked around with this message at 07:53 on Jul 23, 2019

# ¿ Jul 23, 2019 07:51

mustard_tiger: Nov 8, 2010

slidebite posted:

Holy poo poo when did that happen?

It was a while ago, I'd say around 8 years. They sent her a bouquet of flowers after and a free round trip flight from Pearson to Heathrow as an apology.

# ¿ Jul 25, 2019 02:22

mustard_tiger: Nov 8, 2010

Nebakenezzer posted:

American Airlines mechanic charged with sabotaging plane

It's less bad than the headline says, as the sabotage was to ground the plane so the mechanic could get overtime

A broken pitot tube can apparently crash a 737 so this might be a bit dangerous.

# ¿ Sep 7, 2019 19:52

mustard_tiger: Nov 8, 2010

Is it even possible to fly special VFR when you're in the clouds? Why didn't he change altitude from 1400 when the controller said the ceiling was at 1100? Like wouldn't it just be a wall of white in front of him when he was talking on the radio?

# ¿ Jan 27, 2020 05:48

mustard_tiger: Nov 8, 2010

Sagebrush posted:

No, if you're in the clouds you are flying IFR. In the USA, a pilot can fly VFR over a solid cloud layer with no visual reference to the ground if they can find a hole in the layer to get through while maintaining the proper distance from the clouds (2000 feet away in class E, can't touch them in class G). This is called VFR-over-the-top. It's debatable how safe that practice is -- some countries ban it -- but it's legal. Not legal to fly VFR inside a cloud though.

The ceiling/altitude thing is tricky as ceilings are reported above ground level at the reporting station. Burbank airport has an elevation of 745', so that means the bottom of the overcast layer was about 1845' MSL. Flying at 1400 feet, the helicopter would have been out of the clouds and very close to the legal requirement for VFR in class E airspace that they stay 500' below the ceiling. Realistically the extra 55 feet is within altimeter error and the ceiling isn't always perfectly flat, so they were probably legally okay from that standpoint. However, 1400 feet MSL puts them at only 655' AGL over the airfield, which is below the 1000 feet that is legally required over a populated area and just barely above the 500' general limit -- and the peaks in the area they crashed go up to 1600' MSL so the safe minimum altitude there was 2600'. Even if they skim along the canyon, they can't climb or descend without blowing a regulation, giving no margin of safety -- pretty much the definition of scud-running as hobbesmaster mentioned.

Thank you for explaining this this makes a lot more sense to me now. Do you know how the term scud-running came to be?

# ¿ Jan 27, 2020 07:17

mustard_tiger: Nov 8, 2010

Effective-Disorder posted:

For me it's more that the idea of crowdfunded war is both somehow inevitable and a huge can of worms for us to pick over in the aftermath. I pass no judgement on the people doing these things, because I doubt I'd understand from where I sit. I just wonder if it's a bad thing that we have to crowdfund pretty much everything from medical care to warfare now, and what the hell that means going forward. I strongly suspect it's not so much just bad but entirely awful.

Couldn't war bonds be considered crowd funding? This has happened since the beginning of time.

# ¿ Jun 21, 2022 17:17

mustard_tiger: Nov 8, 2010

EvenWorseOpinions posted:

AirPlane

Its actually Air & Plane.

# ¿ Jul 18, 2022 21:21

mustard_tiger: Nov 8, 2010

Didn't he plead guilty to the obstruction charge because there was a real chance of him being charged with terrorism or something for intentionally crashing an airplane?

# ¿ May 12, 2023 15:59

mustard_tiger: Nov 8, 2010

ImplicitAssembler posted:

Hate crimes.

Also the helicopter pilot lost his job. Not because he didn't anything wrong, but with no machine to fly, the company terminated his contract.

Probably saved his life though.

# ¿ Sep 7, 2023 21:03

mustard_tiger: Nov 8, 2010

Cojawfee posted:

Cue the story of the Russian bomber that didn't set the direction correctly on the navigation and flew the inverse of the actual mission plan, the landmarks all lined up with what they should have been seeing, and they almost started a war with Iran.

The pilots only realised when the sun started rising in front of them. They thought they had been travelling west.

# ¿ Nov 22, 2023 20:18

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# ¿ Apr 30, 2024 10:00

mustard_tiger: Nov 8, 2010

slidebite posted:

The youtube link was for the pilot that tried to shut off the engines inflight (geoblocked in so couldn't see it)

Yeah, that was a pretty good Mentour imho. Really humanized the guy.

I hope he's getting help.

I watched it and I'm in Canada. Weird.

# ¿ Jan 23, 2024 19:52

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