I'm scatching my head over that one as well...

-90+270=180 - yes we got that ;-)
 

Thanks to people who pointed out that a 90/270 is a course reversal - that is bleeding obvious to all of us!!! :ugh:

What I had missed, reading N1EPR's tale, was that he overflew the runway first. He mentions descending above the airfield perimeter but that is what you do on a normal approach too. Nor did he give runway headings. It's hard to read such a big block of text, especially when it's fully justified!

Anyway, it was a good read, albeit wildly off topic ;)

If that's the case, then why is it that "the gear" is designed in such a way that it can "break" in any myriad number of ways and leave the aircraft in a flyable state? Or that recurrent training includes scenarios where said systems fail?

Like Clandestino, I have no idea where you got that from - but there's no evidence whatsoever to support that scenario, and a whole load of evidence that refutes it.

Not to mention that even if the shielding were to be defeated - lightning strikes don't "flash" ROMs, all the ADIRUs plus ISIS back-up use data from gyros mounted in the unit and the FDR confirms that at least one attitude reference was working just fine throughout.

Would that be "Douglas strong" like the THY DC-10 where a floor collapse severed all the cables and hydraulic lines? And would this be the same Douglas that swore up-and-down to Capt. Bryce McCormick that it was impossible to lose all hydraulics on the DC-10?

Don't get me wrong, Douglas did make their airframes fairly tough, but they lagged behind badly in the redundancy and survivability stakes going into the jet age. Also, any airliner using direct cable connections can't be much bigger than a DC-6. That means no more widebodies and a rapidly contracting airline industry.

Electronic control connections are much less bulky, easier to route through the more solid sections of the airframe and present a much smaller area prone to damage by debris. An electronic system is also far easier to provide re-routing redundancy if and when such damage occurs.

Different yes, but not more difficult if the current safety record is taken into account. Anyway, pilots have been debating the relative merits and preferences regarding instruments - and altimeters in particular - going back to the E. K. Gann days (specifically the three-needle vs. two-needle plus drum types).

Again, don't get me wrong - Clandestino is absolutely right when he says that unscrupulous management and executives are in some cases cutting stick-and-rudder experience and training too close to the bone. But let's not throw the baby out with the bathwater here - the fact is that these advances have made civil aviation a hell of a lot safer and allowed the industry to grow to a level that was unimaginable even in the '60s. This fact is as simple as it is irrefutable.

As a techie, I'm as prone as anyone to getting the rose-tinted specs out when it comes to remembering the days of bit-flipping on 8- and 16-bit processors versus the highly regimented, abstracted and process-driven methods we use today. I seriously miss the simplicity and the feeling of direct communion with the machine. But if I take those specs off for even a few seconds I realise that I'd be nuts to even attempt what is done these days using those old methods.

from full automation to stalling in direct law on an airbus impossible:suspect:

@PA - The FCOM manuals for Airbus FBW types clearly state that outside of Normal Law, Alpha protections are lost and the aircraft can be stalled. And they always have.

hence the importance of hand flying...all it took was one iced pitot tube...unreliable airspeed is no reason to crash any airplane

Not quite - it took all three.

Specifically at high altitude in that case.

Agreed - but there was a lot more to that accident than overreliance on automation!

regardless of my error....hand flying is imporyant so one can quickly adapt to rapidly chsnging conditions

the most important training is your primary training not your atpl...

And I'm in total agreement with you. But given that, the PF in that case was a highly experienced glider/sailplane pilot and as such probably had more basic stick-and-rudder experience than most of his peers. The training and experience he lacked was specifically on manual handling at high altitude.

As I said, it's a lot more complex than just trotting out the "Children Of The Magenta" meme again...

we are talking IFR

dozy

douglas strong...unlike airbus strong where the vertical tail falls off

douglas strong , you know like all the DC8's that are still flying...and DC3s, and the DC4s which are fire bombers.

how many 707s and comets are still in use (not military)? not many

I stand by what I said...and cables that work hydraulics work just fine in really big planes.

comet...metal fatigue

737 pop top?

yeah...I'll take douglas...esp single digit dougs

@PA - IFR/VFR isn't the issue - the difference is how a swept-wing jet handles at cruise as opposed to at low altitude.

If you want to take a DC-10 up and subject the vertical stab to 1.8x ultimate design load to prove that point, then be my guest - just please understand why I won't be standing anywhere in the vicinity.

Not pressurised in the case of the latter two. And the venerable VC-10 has been flying in RAF service for about as long as the DC-8.

Well - to be fair most remaining 707 airframes have been requisitioned by the military for spares and the Nimrods were set to fly another 30 years before our current government decided to scrap them in favour of buying second-hand Rivet Joints.

Fine, but I respectfully disagree.

Only the first model - and the VC-10 and BAC 1-11 that followed had fuselages machined from aluminium billets - there have been none tougher either before or since.

Specific to the way Aloha used them - if they'd used DC-9s the same would have happened.

Fine, but given the choice, I wouldn't.

Anyway, as fun as this willy-waving is, it's somewhat beside the point. The undeniable truth is that even with the myriad problems facing the industry, it is statistically far safer than it was when DC airliners ruled the sky. I agree with you that there needs to be more attention paid to handflying skills by the industry, but to blame technological advances for this state of affairs is putting the cart before the horse.

IMC vs VMC is a huge difference!

I flew that Aloha 737 over 100 hrs I am sure before Aloha got it from us. Mostly over FL330. We had an incident where the crew got low landing at ONT and hit high voltage power lines and diverted to LAX. The power lines caught their landing gear causing faults that caused an overun. Reinforcement to the belly of that ac might have kept the aircraft intact with the upper skin torn off.
I always trusted Boeing aircraft so stayed with them for 25years with no major problems and about 16,000 hrs in Boeing aircraft. I flew the MD80 for a bit also.

dozy...now I know you are wrong...the DC9 had something the 737 didn't have...take a look at the upper fuselage and the finger like metal...then look it up.

heh.

I know - but *in that case* the more problematic lack of experience was high-altitude manual handling, where the aircraft's response in the 3 axes will be far more sensitive due to the lower-density air. That crew's only manual handling experience was takeoff to a couple of thousand feet and approach/landing.

Possibly, but if the corrosion had occurred either before or at the apex of the finger lap, then you might have had a scenario which was the same or worse, due to pressure buildup along the finger laps that were holding.

mainly it's about reduced aerodynamic damping...mean one must be gentle with the flight controls...in IMC...at night in turbulence....there are six axes

Sure. Or, (as in the case of AF447) leave the controls alone* and monitor aircraft behaviour until such time as a correction needs to be made.

* - but cover them and be prepared to use them

I have never flown an Airbus...but I don't think that that is the procedure for unreliable ASI.

with no AP the plane will enter a spiral dive without manual intervention

dozzy...possibly the sun will explode.

possibly I will be elected POTUS

now look up the finger laps/joints and how they would SHOW a problem if there were one...

douglas used more rivets

@PA - The Airbus UAS procedure is posted in the AF447 threads. And here:
http://www.bea.aero/docspa/2009/f-cp...nexe.06.en.pdf

The aircraft will not spiral dive for some time if the trimmed pitch and power are OK, which at that point they were.

Hi - yes, I know. I did look things up as you requested and found a very interesting academic paper on the subject here:

http://xa.yimg.com/kq/groups/1451308...wift_Comet.pdf

Admittedly the equations go over my head, but the prose explains it well. It transpires that Douglas's approach on fatigue was very much informed by the information shared from the Comet 1 investigation.

Now - the problem in the Aloha case was not with the design so much as it was the way the aircraft was maintained by the airline (though the NTSB stated that the airline were not to know that their methods may be problematic). It was the disbonding, re-bonding and re-riveting performed as part of an overhaul that caused greater opportunity for corrosion and fatigue. In fact one of the passengers did see a small crack before she boarded, but did not speak up as she assumed it was known about.

Additionally, sometimes making things tough is not the way to do things - witness the MD-11 hard landings that sheared the spar at the gear attachment location.

The autopilot had to be disconnected on Apollo 11 to prevent a crash. Apollo 13 would have been a loss without pilots.

No autopilot today can even handle something as routine as mountain wave. That's just one of many examples. No autopilot today can get an airplane out of an unusual attitude reliably. They can however put you in one.

Drones are not pilotless, they are remotely flown and still crash a lot.

Airliners still on the drawing board are still based on the 2 pilot concept .

You guys thinking large commercial jets will be flying pilotless in 20 years are smoking the funny stuff.

To be fair, that was triggered because Buzz Aldrin (reasonably, though contrary to procedure) left the rendezvous radar on standby during the descent in the event of an emergency abort. What he didn't know was that leaving it on would steal cycles from the guidance computer in the early stages of descent. This resulted in the LEM ending up somewhat downrange of its original intended landing point.

That point aside, I completely agree.

one gust and you can be spiraling in short order...all planes want to spiral but it's is indeed. ususually a slow process if in trim in smooth air...the point is one has to handfly routinely in oorder to be better equipped to deal with more exotic flight conditions...

I'm not arguing that second point PA, I agree!

However - looking at the DFDR traces shows the yaw damper working overtime to successfully keep the aircraft upright during even the most extreme gyrations.

I'm not saying leave the controls alone entirely, just that the first point of order should be to see if the aircraft will remain relatively stable without encouragement - which in most cases it should!

but you get your hands in the flight controls and eyes on the instruments immediately...but in most cases there are no fast hands in a jet...on that point you are corrrect

Yes - as I said about controls - "cover them (meaning get your limbs in a ready position) and be prepared to use them". If you start making inputs without assessing the situation then you're more than likely to get it wrong and end up fighting yourself - as happened with AF447.

It`s (To borrow a USAF term) HOTAS Hands on stick and throttle no inputs necessary but hands on ...

@ 737er - Apollo
 

The Apollo missions were 40 years ago! The damage was most serious for the life support systems which would not have been fitted if the pilots were not installed! Other systems were there to get the humans home, again not required on an autonomous mission.

If I recall, a Lion Air Indonesia B737 went into a gradual spiral at night with devastating consequences. Seems the crew were having difficulties with one of the to IRS. in fact there were many reported snags on that IRS previously.

Again, from memory, the crew decided to trouble shoot and switched off one of the IRS and in turn this caused the automatic pilot to disconnect. Either the crew didn't realise the autopilot had disengaged or if they did, neither pilot was allotted the task of flying the aircraft manually.

While one pilot read from the QRH about IRS non-normal, the other pilot selected the perceived offending IRS to the Attitude mode. This blanked out the PFD on one side. Meanwhile the 737 wandered around the sky at night with no one watching the flight instruments. It eventually went into a gentle spiral which got worse. By the time someone exclaimed WTF, the aircraft was in an unusual attitude.

The captain didn't have a clue how to recover from a UA and instead pulled back hard on the control column while in the spiral. It doesn't take too much imagination to guess why the aircraft eventually broke up in mid-air.

And therefore the Lion Air crew went in...

interesting about lion air

the solution is obvious

the autopilot controls the plane at all times unless you continuously push a button on the yoke, then you fly it , fly it like the old days with no limiters.

and if the button shorts out, it turns the autopilot off and announces it as loud as a san francisco fog horn.

sound familiar? mooneys used this idea for their wing leveler

Quote:
Are you saying that automation contributed to the Asiana 214 crash??? It sure looks like an automated landing would have prevented the crash.

Quite the reverse: the automatics may have been masking a threat in the system. For that particular approach the outcome may have been better if a higher level of automation had been used but that does not address the fact that there was a crew (and still undoubtedly are still crews) out there who given the wrong set of circumstances could not (and cannot) safely guide a serviceable aircraft to a runway in benign meteorological conditions.

The reality is that airlines are best served by having well rounded individuals in the flight deck and a key part of the necessary skill set is piloting skill. Piloting skill is not acquired and maintained by watching screens with one's hands sitting idly on one's knees.

speedrestriction: :D:D:D:D:D

Very succinct, very logical analysis of the root cause.
Matter of fact, the problem is greatly similar to automation in broadcast radio. When unattended, the system chirps merrily away sequencing music, ads, PSAs and other announcements untouched by human hands.

But when I (as a volunteer engineer/producer) take over manually, the computer is put on HOLD, and manual ops are just the same (almost) as during my student days 50 years ago. And executing a fast-paced audio sequence is not so emotionally different from landing in a crosswind. In a taildragger. :)

Pugilistic Animus
Airbus FBW does not get into spiral even with one engine fail and TOGA on live engine because the computers try to hold the position. Any tendency to spiral is prevented by computers by applying rudder upto yaw damper's authority and bank is prevented by applying opposite aileron and spoilers. Since yaw dampers cannot apply the required amount of rudder the aircraft does a skidding turn with MAX 5 to 7 degrees of bank. Even in Unreliable speed the aircraft is in alternate law so behaves the same way except it can be stalled or get into overspeed. You must disconnect AP, ATHR and switch off FDs and the a/c will maintain its pitch and bank.

vilas thankyou for the airbus AP information..very interesting....my knowledge of Airbus systems is nonexistant:)

OK465
I was talking about A320 behaviour OEI in normal law and AEO in unreliable speed in alternate law.

Hands off, in ALT2, roll Direct, A330 with one engine TOGA and one engine failed, the aircraft will spiral (somewhere in the 70-80 degree bank range). It will not however roll over on its back.

What happened to the A330?? from Toulouse on take off being flown by test-pilots that crashed. Was it not something like this? I never did see the final report.

No - that one *was* automation and interface related if I recall correctly. The mode set in the FCU panel was Altitude acquire, which disabled the *autopilot* pitch protection - the FBW alpha protection was unable to correct in time given the incorrect pitch trim, extreme aft CG and power plus very low altitude. They changed the interface soon afterwards.

Airbus Industrie Flight 129 - Wikipedia, the free encyclopedia

Well yes, no argument there - but the original query was talking about AF447, which had no such asymmetric thrust condition.

I'm not sure at what point thrust asymmetry entered the discussion, and in any case you'd want to determine the direction of the thrust asymmetry before making corrective inputs no matter what kind of aircraft you were flying, would you not?