I'm reluctant to post this link at all, as it seems a little bit too negative to Boeing, and their design efforts. However unqualified Mr. Dominic Gates is to report on Aviation engineering, I thought I'd see what your take is on this article.
I guess what I took away more than anything from the article is that Boeing opens themselves up to a lot of liability every time they sell/deliver an airplane, be it a 737, 767, 777 or the new 787. Virtually everytime there is a lawsuit involving an airplane crash, the manufacturer seems to find themselves on the list of defendants in the lawsuit. That being said, I just don't see how Boeing or Airbus would allow an unsafe aircraft to fly and that alone seems to be enough to point a finger of irresponsible reporting on the author.
BMI727 From United States of America, joined Feb 2009, 16181 posts, RR: 27
Reply 1, posted (4 years 11 months 1 day 4 hours ago) and read 38105 times:
Quoting rgreenftm (Thread starter): Virtually everytime there is a lawsuit involving an airplane crash, the manufacturer seems to find themselves on the list of defendants in the lawsuit.
Yep. And it isn't just airlines either. As I understand it, there is a pretty healthy industry of independent accident investigators and engineering consultants who work with crash litigation. Apparently it isn't bad work if you can get it.
Or regulatory bodies for that matter. The fact of the matter is that the 787 (and all composite aircraft) are certified using the same standards as any other.
And on a final note, even if composite aircraft prove to be somewhat less crashworthy than their aluminum counterparts, I would have to guess that the cost benefit analysis still weighs in favor of CFRP.
Why do Aerospace Engineering students have to turn things in on time?
Not much at all, this came across to me as the sort of story you research and have in your back pocket when you have a slow news week.
The real advantage I see composites have for crashworthiness is the magnitude of kinetic energy that the "aircraft" as a system would have, and the better aerodynamics that result from using a composite wing.
In both cases he mentions, i.e. the BA 777 at LHR, and the AF A340 in YYZ I think the outcomes would have been different if they same aircraft were made from composites.
A composite 777 would have been able to make the runway, not because of the weight saving, but because of the better L/D ratio (best glide angles are independent of weight), also the thermal insulation properties of composites I think would prevent fuel from getting as cold during long flight at cold temperatures.
And for the AF A340, I think they would have had a lower approach speed, and lower total energy that would have made the landing process safer. The most unsafe aircraft in my view from a landing safety point of view are freighter aircraft, they tend to land near maximum landing weight, which normally requires higher approach speeds and sink rates than similar passenger aircraft.
I am also very confident in the engineering and testing that aircraft manufacturers put into their products, while historically new situations do present themselves which make regulators re-examine the certification basis, I am confident when Boeing receives their TCDS for the 787, it is the official stamp of approval to back up the following “Boeing says a key design change and subsequent physical tests prove the final Dreamliner design is now as safe as a metal airplane.”
[Edited 2010-06-27 02:22:30]
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
MCIGuy From United States of America, joined Mar 2006, 1936 posts, RR: 0
Reply 3, posted (4 years 11 months 1 day 3 hours ago) and read 37687 times:
I'd get on 003 for a ride to Farnborough, in a millisecond. I'd say the the test program has been a success so far, with only minor glitches that raise absolutely not red flags when it comes to safety.
757luver From United States of America, joined Jan 2010, 143 posts, RR: 0
Reply 4, posted (4 years 11 months 1 day 3 hours ago) and read 37612 times:
With the way the article seems to attack the idea of composites, it makes you wonder if someone is part owner of an aviation metal supply company. To me there's always a 50% percent survival rate in an accident no matter what mode of transportation you take. It doesn't matter what it's made of, the forces alone can kill you even if the plane remains intact. I myself wouldn't hesitate to climb on board a 787. Just wish the media would get over this whole composites vs. metal thing.
slz396 From , joined Dec 1969, posts, RR:
Reply 5, posted (4 years 11 months 1 day 3 hours ago) and read 37590 times:
Quoting MCIGuy (Reply 3): I'd say the the test program has been a success so far, with only minor glitches that raise absolutely not red flags when it comes to safety
Given the entire fleet is currently de facto grounded due to Boeing's inability to guarantee there are no configuration deviations in key structural parts produced by Alenia which can potentially cause disasterous fatigue damage to the plane's rear fuselage and elevator, I wouldn't say it only has minor glitches.
At the very least I'd say:
The 787 is surrounded by ongoing uncertainties about its long term structural integrity, deep into its now halted flight testing.
EPA001 From Netherlands, joined Sep 2006, 5292 posts, RR: 40
Reply 6, posted (4 years 11 months 1 day 2 hours ago) and read 37517 times:
Quoting zeke (Reply 2): I am also very confident in the engineering and testing that aircraft manufacturers put into their products, while historically new situations do prevent themselves which make regulators re-examine the certification basis, I am confident when Boeing receives their TCDS for the 787, it is the official stamp of approval to back up the following “Boeing says a key design change and subsequent physical tests prove the final Dreamliner design is now as safe as a metal airplane.”
I totally agree with Zeke on this one. Airplanes and systems keep on getting safer and safer. The very low number on crashed B777 (1) and A330 (2), both airplanes flying since the mid-1990's, is proof for this. But if a crash is severe enough, sadly enough I do not think it will make any difference if the aircraft is made from metal or composites for that matter.
It certainly will not effect my choice of aircraft I am going to fly if I am booking a flight now, or in the future.
pylon101 From Russia, joined Feb 2008, 1620 posts, RR: 0
Reply 7, posted (4 years 11 months 1 day 2 hours ago) and read 37415 times:
I'd say the article is quite positive.
It showed issued - and how Boeing addressed those issues.
In reality we can't judge until 787 is certified and actually flies commercially.
But we are all hopeful.
I agree. Some issues are mentioned, and the steps Boeing took to remedy them are outlined. Indeed we won't know until there is a crash (if there is a crash). But, to a certain extent, this is true for all new airplanes. I agree with Zeke: this must have been in the back-burner for a while. Nothing new. Nothing worrisome.
Rheinbote From Germany, joined May 2006, 1970 posts, RR: 52
Reply 11, posted (4 years 11 months 1 day 2 hours ago) and read 37155 times:
Quoting 757luver (Reply 4): With the way the article seems to attack the idea of composites,
While providing nothing new, I think this article is well researched and well balanced. It raises critical questions, but also tells the story how these critical questions were adressed and how the fuselage design has been changed since then. I wouldn't be too susprised to find that A and B are collaborating on this topic, because safety is their common number one concern. Perhaps here's were the article is falling a little short: Dominic could have asked how this is addressed with the A350 or any other composite aircraft, like the Raytheon Permier One, Hawker Horizon, V-22 Osprey etc. Also, NASA did extensive drop-tests using a real Learfan 2100 and the Sikorsky/Bell ACAP composite helicopter airframes. It's not like the problem is new, it has been worked on for at least three decades.
zainmax From Pakistan, joined Jul 2009, 109 posts, RR: 0
Reply 12, posted (4 years 11 months 1 day 1 hour ago) and read 36918 times:
Boeing has only conducted the wing stress test in order to check the strength of the wing.
But these documents have raised questions and may be now FAA is looking in the matter because hardly 4-5 months are left when its expected that B787 will get FAA certification. Hope all gets well soon ...... !
Why all the negativity about Dominic Gates? I think the current article about 787 composites is a reasonable and balanced report on the back story behind the concerns of survivability of a 787 composite fuselage in a crash.
The best time to plant a tree is 40 years ago. The second best time is today.
tdscanuck From Canada, joined Jan 2006, 12710 posts, RR: 80
Reply 16, posted (4 years 11 months 23 hours ago) and read 35515 times:
Quoting rgreenftm (Thread starter): I guess what I took away more than anything from the article is that Boeing opens themselves up to a lot of liability every time they sell/deliver an airplane, be it a 737, 767, 777 or the new 787.
Yes. I think it's a matter of course to sue the airframer as part of any crash these days.
Quoting slz396 (Reply 5): The 787 is surrounded by ongoing uncertainties about its long term structural integrity
No more so than any other airliner. The current tail issue is a manufacturing error (it wasn't built per drawing). So ver is zero evidence that, if built correctly, the 787 has any more long term structural integrity issues than any other aircraft. There's actually a lot of evidence that it will have *less*.
Quoting zainmax (Reply 12): Boeing has only conducted the wing stress test in order to check the strength of the wing.
Boeing has conducted *far* more tests than that, including all of the fuselage and empennage and the fuselage drop (crash) test.
Ltbewr From United States of America, joined Jan 2004, 13413 posts, RR: 16
Reply 17, posted (4 years 11 months 22 hours ago) and read 34895 times:
It is an interesting question raised by the author. We are going into a major change in aircraft structures with majority non-metal structures, new territory with new and unique risks. Computer testing has it's limits, but so does 'hard' testing especially as to crash scenrios. What if these composite structure aircraft crashes at or very near an airports and hits various land objects such as fences, radio equipment, small buildings, lighting systems, land berms etc.? Of course, such objects will rip apart a 'metal' bodied aircraft as well - look at the A340 in Toronto several years ago. With composite strucures hitting such objects, they may behave differently.
We also have to acknowlege that crashes have been much rarer over time due to many other changes. It is also possible that composites may be less subject to tempature affected expansion and contraction, thermal transfer (ie: possible factor with BA 777 crash at LHR), less subject to corrosion issues, but on the other hand may raise new issues.
Let us hope that the testing results are valid, that we never have to see in reality of a crash of a 787 or other composite majority a/c and if it happens, that the results are the best possible or even better due to composite strucures.
I know several people here are going to be shocked here while I say I fully agree with Zeke here.
No, the Earth has not left its orbit around the sun..............
Any airliner crash has a negitive effect on survivability. That said, almost any accident has the potential of no injuries or fatalities up to no survivors. That has nothing to do with the materials the aircraft is made from, but has everything to do with the various dynamics of any crash. Fire, or the time between the fire starts (if it starts at all) and the impact is the number one factor in determining survivability. Most people are killed by fire and not impact forces. Although impact forces, and each person's location within the aircraft, do determine if any one person survives. Look at the CRJ-70 accident in LEX a few years ago, the co-pilot was the only survivor, and then only because he was rescued within a short period of time (that aircraft was burning). The recent A-330 and A-310 crashes each also had only one survivor, and the same has happened on numerous Boeing crashes, too. The AF A-340 and BA B-777 each highlight total survivorability, and few injuries due to impact forces, and in the case of the B-777, parts seperating (the main landing gear) and penertrating the hull. The A-340 crash highlights the time from the final crash impact to the fire getting big enough to become a threat to life. In that crash, there was time for the evacuation. The B-777 crash did not cause a fire, so it would be difficult to determine if a fire would have threatened anyone or everyone.
The geographic location the wreckage also is a factor in determining survivorability. The AA DC-10 crach at DFW in 1994 is a good example of that. The wreckage ended up less than 1/4 mile from DFW Fire Station #1, and started to burn, but the fire was put out quickly. The same happened in the CO B-737 crash at DEN a few years ago, too. Sadly that is not always the case. The DL L-1011 crash at DFW in 1985 was not far from Fire Station #3, but that aircraft hit a million gallon ground level water tank, which killed or drowned most of the people aboard, fire killed more, ending up with some 132 people killed, but those in the tail section survived after it broke away from the main portion of the wreckage.
Each airplane crash is unique. Yes, the causes of the crash may be indentical to one or more crashes in the past, but the way the airplane acts during the crash is unique due to various other things going on, like weather, airspeed, angle of impact, location of the first impact on the aircraft, etc.
To say any aircraft, once it is certified, is dangerous is disingenuous.
Quoting slz396 (Reply 5): Given the entire fleet is currently de facto grounded due to Boeing's inability to guarantee there are no configuration deviations in key structural parts produced by Alenia which can potentially cause disasterous fatigue damage to the plane's rear fuselage and elevator, I wouldn't say it only has minor glitches.
Incorrect. Neither Boeing, nor Airbus, or any other OEM can guarantee each and every part manufactured by a subcontractor fully meets the design specs. This is just the latest example of that. Airbus recently had a problem with seats from a subcontractor. They found the problem and have/are correcting it and did not deliver those few aircraft until it was corrected. Boeing is simply doing the same thing here. All this does is bring into question the quality control or QA/QC of the subcontractors.
It seems that current planes are safer than in the past. Examples: BA 777 crash landing with zero loss of life, AF 340 runway overrun with zero loss of life, US 320 ditching with zero loss of life. I'm sure that there were many reasons, but I guess the design of the new aircraft had something to do with the benign outcome of these accidents.
Stitch From United States of America, joined Jul 2005, 32241 posts, RR: 85
Reply 23, posted (4 years 11 months 21 hours ago) and read 33562 times:
Back on topic for this thread, CFRP and composites in general are here to stay and have been for well over a decade. The 777 uses CFRP in her floorbeams and the A380 has a number of large CFRP and non-carbon composite structural sections. Both aircraft successfully passed their certification tests and the first 777 hull-loss involved no loss of life.
In addition to the 787 and A350, it's pretty clear that the replacements for the 737 and A320 families will employ significant use of structural composites and they will see sales into five figures together. Neither the OEMs nor the operators can risk putting an aircraft they either know or believe to be unsafe nor can the governmental agencies that certifies those aircraft allow such a plane to be certified for passenger operation.
UALWN From Andorra, joined Jun 2009, 3133 posts, RR: 2
Reply 24, posted (4 years 11 months 21 hours ago) and read 33563 times:
Quoting SomePlaneGuy (Reply 19): And yet still manages to thrash A350 and will likely do to A330 what 777 did to A340.
Thrash? Why the violence? 787: 866 net orders in 7 years. 350: 530 orders in 5 years. Since the 350 was offered: 576 orders for the 787, 530 for the 350. In the last two years: -44 for the 787, +47 for the 350. Trashing indeed.
Now, orders for the 330 in the 7 years the 787 has been on sale: 607. In the last two years: +50. So the 787 may one day obviate the 330, but so far the 330 is holding its own pretty well. The 767 on the other hand...