Quoting Tangowhisky (Reply 149): Those aircraft are true fly-by-wire not command by wire which the 170/190 family feature.

Whats the difference between command by wire and true Fly by wire? Im not an aviation professional and honestly don't know...googled it with no luck.

Thanks

Murf

Quoting murf (Reply 150): Whats the difference between command by wire and true Fly by wire? Im not an aviation professional and honestly don't know...googled it with no luck.

A pure fly-by-wire system takes pilots cockpit commands, converts them to electrical signals, they then gets fed into fly by wire computers which commands the surfaces to move by respecting various control laws. The control laws have several features including stabilizing the airplane (flight path, speed, etc depending on the manufacturer's philosophy). there are augmentation laws such as gust alleviation so that the wing has lower stress helping to lengthen the maintenance program inspection intervals. And of course there are protections features such as limiting bank angle, pitch angle, stall, and other extreme conditions.

A command by wire also uses electrically converted cockpit commands but only features minor augmentation features.

Command by wire is basically a direct connection to the control surface activators....much like cables or hydraulics, but uses electrical inputs. Think R/C aircraft or trucks. The electronics are dumb...they just do what they're told.

With fly by wire, the control inputs are interpreted by a computer and will apply control input based on programming. It's most useful at the extremes where pilot actions may cause the plane to lose control.

For most actions, the computer basically does what the pilot wants....I think.

I'm no expert but that's how I see it.

FTV4 has it's engines mounted and avionics have been turned on. When it will fly, nobody knows. On the other hand, I would rather they say nothing than keep hearing the, 'in the coming weeks' mantra.

http://www.fliegerfaust.com/ftv4-eng...s-are-installed-bom-715908968.html

FTV2 now in the air for its 3rd flight since return to flying. Took off at 12:20 local time.

Quoting Quantos (Reply 154):

It looks like they are confident in the fix; 2:53 in the air. Now, let's get those other planes into the air.

Yep, I was afraid that they would ramp this up very, very slowly with short hops for numerous weeks. The flights, at the least, are long. I'm unsure how high and hard FTV2 flew so far, there doesn't seem to be any information about this. FTV4's engines are running today as well.

To go from zero to 3 hours in the air so soon after the fix (obviously with P&W ground testing prior), I am hoping that everyone involved can breath a *bit* of a sigh of relief. I look forward to a doubled-up effort on the flight test schedule, in the hopes the EIS isn't going to be severely pushed back...

FTV4 just completed a compass swing.

http://twitter.com/sylvainfaust/status/510855023392460800

FTV2 is airborne right now.

Quoting KarelXWB (Reply 159): FTV2 is airborne right now.

FTV2 flew for 2h39'
FTV4 is working some ground tests on the ex-taxiway B1 (what Sylvain Faust calls route 408)

FTV2 completed today's test flight after 2 hours and 39 minute flight

From earlier:

Videos of the 'CSeries Back In The Air'

www.youtube.com/watch?v=janP7Ih9xt0&...ex=2&list=UUPvyf8tiq_GhyqqJJ8XuBaA
www.youtube.com/watch?v=8jzTn9NVU-4&...t=UUPvyf8tiq_GhyqqJJ8XuBaA&index=1

[Edited 2014-09-14 15:16:59]

Quoting Miami (Reply 161):

So they have turned the ADSB transponders back on?

Quoting golfradio (Reply 163):

Nope, radarsource is T-MLAT2 (MLAT server for North-America)
If an aircraft is being received by 4 MLAT equiped FR24 stations they can triangulate its position  

More on MLAT on the FR24 website:
http://www.flightradar24.com/how-it-works/

And FTV2 is in the air again, it's the 5th flight since Bombardier resumed flight testing.

*Might* be flying in FBW normal mode, seems unclear at this time.

[Edited 2014-09-15 10:58:38]

Quoting starbucks (Reply 164):

Interesting. Thanks for the link.

FTV2 has landed, FTV4 in the air   Still no confirmation on FBW status.

Today's updates as per Sylvain Faust:

- FTV2 flew for 2h10, perhaps in "normal" FBW, although that seems to be unconfirmed.
- FTV4 flew for about 1h10, up to FL390. This was FTV4's 5th flight overall.
- FTV4 will move to KICT soon.

Quoting Quantos (Reply 169): perhaps in "normal" FBW, although that seems to be unconfirmed.

Flying in normal law would be a major milestone. I'm sure Bombardier will issue a press release when it happens.

Quoting KarelXWB (Reply 170):

Given how the folks at BBD likes to keep things close to their chests, I imagine they'll wait until they are pretty sure the test had positive results before making an official announcement.

FTV 2 and 4 are now both in the air (according to Faust).

A steep increase of flight activity.

Quoting KarelXWB (Reply 172): FTV 2 and 4 are now both in the air (according to Faust). A steep increase of flight activity

There is going to have to be a dramatic increase in flight activity to get the hours needed for certification.
While I realize they are coming off the engine incident they only accumulated 3hrs 20min flight time total with 2 frames yesterday.
I expect the pace to pick up dramatically as I would expect the engine issue should be resolved.
The delay to fly in normal law is a little concerning.

Okie

Quoting okie (Reply 173): There is going to have to be a dramatic increase in flight activity to get the hours needed for certification.

Agreed, the whole fleet must log some 130 hours monthly to meet the certification schedule.

Quoting KarelXWB (Reply 174): the whole fleet must log some 130 hours monthly to meet the certification schedule.

May I ask you to compare this 130hours/month (is that for all aircraft combined, or per aircraft?) with the A350 campaign that you have so carefully and pleasurably (for us) followed.

It seems to me just from a mathematical POV, 130 hours in a 20-day month is 6.5hours/day. If that is spread over 4 aircraft, well, that's just over 1.5 hours/day each

Again according to Sylvain Faust, FTV2 is flying in normal law today. He seems pretty sure of himself. No confirmation from BBD so far, however. I do agree that this is perhaps something that they would announce only after the fact, probably in a video update from Rob Dewar.

I tweeted "Is normal FBW mode 100% confirmed? If so, that's a big milestone!" to Sylvain. He answered: "if you ask me, I'll say yes...".

[Edited 2014-09-16 08:56:36]

Also, concerning the flight hours required for certification. Remember that actual flight hours are not equal to what BBD considers testing hours. BBD combines flight and ground testing hours into a single number. It's hard, if not impossible, for us to conclude that X amount of flight hours are required for certification.

[Edited 2014-09-16 08:59:40]

[Edited 2014-09-16 09:00:26]

Quoting KarelXWB (Reply 170): Flying in normal law would be a major milestone. I'm sure Bombardier will issue a press release when it happens.

While not an official Bombardier release. https://twitter.com/sylvainfaust/status/511891225918832640 He seams to have some good intel

Quoting okie (Reply 173): While I realize they are coming off the engine incident they only accumulated 3hrs 20min flight time total with 2 frames yesterday.

Longer flights would be preferred I'm sure but I'm sure Pratt is downloading the Fadecs to ensure all is well before really ramping up the flight test program again.

Quoting Quantos (Reply 169): - FTV4 will move to KICT soon.

I recall an FTV in KICT for avionics testing...anyone know if this is the same one and returning or is another still there from the grounding and awaiting the updated engines.

Quoting murf (Reply 177): I recall an FTV in KICT for avionics testing...anyone know if this is the same one and returning or is another still there from the grounding and awaiting the updated engines.

As far as I recall, FTV3 is already in KICT, but hasn't flown since the grounding. FTV4 will join it, but has only flown six times in total (including today), only from CYMX.

Quoting Quantos (Reply 178): As far as I recall, FTV3 is already in KICT, but hasn't flown since the grounding. FTV4 will join it, but has only flown six times in total (including today), only from CYMX.

Thx Quantos

Even though the flight test campaign hasn't been as smooth as a lot of us here may have hoped, it is worth noting that today the CSeries turned 1 year old!
A happy birthday is due and hopefully the second year will be a lot more successful.

Quoting okie (Reply 173):

I don't think 'normal law' is a big deal yet. There are a couple of thousand hours yet to fly before certification and the CSeries seems to fly to the edges of its envelope in 'direct mode' without any trauma. They do need to find the actual limits without the aid of 'normal mode'.

Remember, until the 320, every plane ever certified was in 'direct mode'. Civilian aircraft have to be flyable without the aid of envelope protection in case the FBW system fails.

I think not flying in 'normal law mode' is more of a problem for the PR department than the flight test department.

Quoting JoeCanuck (Reply 181): I don't think 'normal law' is a big deal yet. There are a couple of thousand hours yet to fly before certification and the CSeries seems to fly to the edges of its envelope in 'direct mode' without any trauma.

It was my understanding that Flight Testing is done in the 1500 to 1700 hours in the air. Does the C-Series require more hours for some reason other than what you feel is needed?

Quoting YxwatcherMKE (Reply 182):

I think 2500 flight hours is the number tossed about. Bombardier doesn't like to publicize much about the flight test hours required for the CSeries certification program. What we do know is they have a lot more to go.

Quoting murf (Reply 147): Moog will be supplying FBW for Embraer's E2's cause of this.

Quoting YxwatcherMKE (Reply 182): It was my understanding that Flight Testing is done in the 1500 to 1700 hours in the air. Does the C-Series require more hours for some reason other than what you feel is needed?

The issue is Bombardier cannot receive credit for certain flight testing hours until the FBW software is proven safe in the testing labs prior to that flight test.

It isn't just flight hours, it is proving system functions in the air. If the software isn't ready to test a function, a flight test might be performed but certain artifacts wouldn't be collected, so that it means the flight test must be repeated at a future date to close out all the artifacts. Or... the flight test cannot be performed until the software is ready.

Flight testing is so much more than it used to be. e.g., the NEO's flight test program will be *more* complicated than the original A320 flight test program due to the greater understanding the regulatory agencies now demand. Some of what is now tested in flight test is easily 'proven OK' in a few years of commercial service, but every certification agency has realized there are a large number of scenarios that weren't flight tested before that do indeed need to be tested.

This is one reason Boeing and Airbus keep around flight test aircraft years after an aircraft enters service. In some cases, if the added flight testing hadn't been conducted, the insurance companies would have raised their rates. It is now at the point were a majority of the flight testing is to satisfy demands other than the regulatory agency. e.g, LH is responsible for adding *hundreds* of flight test scenarios for Boeing, Airbus, and Bombardier. Why? They feel more confident buying an aircraft that has undergone certain flight tests. If they are a launch customer (as they are with the C-series), those test scenarios are part of the purchase contract. JAL, UA, and a few others are known to do this too. (But AFAIK, LH is the most strict.) But this isn't a bad thing. Both Boeing and Airbus have learned many of these airline scenarios 'add value' and thus have consolidated the testing to be extremely economical which cuts the added hours of flight testing dramatically.



Lightsaber

Confirmed again this morning by Sylvain Faust; the last two flights of FTV2 have indeed been in normal law FBW.

Quoting YxwatcherMKE (Reply 182):

Quoting JoeCanuck (Reply 183):

Though there is no breakdown, they did say that 2500 hours included both flight and ground tests combined. They have already flown some 100 odd hours. Even assuming another 2000 hours to be completed in a year, they need to fly about 5.5 hours each day. Split between the 4 FTVs, each needs to do about 1.4 hours each. Though in reality may not be that straightforward. FTV2 and FTV4 were supposed to test the systems integration including the jet’s avionics and fly-by-wire flight control systems certification program. FTV3 was supposed to be for aircraft and engine performance and FTV1 was supposed to be for aero tests.

In spite of the obituary being written in the other thread, I remain cautiously optimistic.

Quoting golfradio (Reply 186):

I don't give too much credence to tea leave readers, for good or bad. I don't expect the CSeries to beat the sales of the 737 or 320...but it doesn't have to. All it has to do is make a profit...eventually. Anybody who says it won't is blindly guessing...the same as those who say it will.

I don't know but my guess is that it will be a profitable program in the long run. How long is anybody's guess.

In the meantime, the CSeries program is fine. At the moment, BBD has way too much on its plate; CSeries, Lear 85, Q Combi, Global 7/8000. They also have to worry about slow sales of the CRJ's and Q's.

Countering that is their booming biz jets and trains. Even with BBD's compartmentalization, there is no danger of any program being cancelled....much less the flagship CSeries program.

Aircraft programs are long term...decades long. The CSeries has only been flying for one year. It's crazy early to sound any death knells quite yet...though there is no accounting for crazy.

As the plague victim said in Monty Python and the Holy Grail, "Not dead yet".

And FTV4 is in the air again.

Bombardier also released a video of FTV4 returning to the skies:

http://youtu.be/lLfwV6qIYQo

Quoting KarelXWB (Reply 188): And FTV4 is in the air again.

And hop, FTV2 is also flying again.

http://twitter.com/sylvainfaust/status/512610035915317248

Let's see if they can keep this pace.

Interesting post: http://www.fliegerfaust.com/cseries-...2-is-flying-again-t-724538771.html

Among else, he states that P&W is paying for FTV1 repairs.

Seems that FTV4 is now heading for KICT Airport.

http://twitter.com/sylvainfaust/status/512620442952425472

[Edited 2014-09-18 08:15:23]

Quoting Quantos (Reply 190): Among else, he states that P&W is paying for FTV1 repairs.

From the blog: The repairs on FTV1 C-FBCS are seriously progressing. The Belfast Bombardier Masters in composite wings are in town taking a great care of the repairs!... Did you know the expenses are paid by Pratt & Whitney?

This isn't quite clear.

Is PW paying the expenses for the Belfast Mx crew to be in YMX or is PW paying for materials used to repair FTV1?

FTV4 is now in Wichita, joining FTV3 which is supposedly to fly by next week.

http://atwonline.com/airframes/bomba...s-flight-test-aircraft-move-kansas

Status of FTV1:

Quote: Two of the four active jets have resumed flying, and the damaged lead test plane is nearing re-installation of systems that were removed during repairs. It will fly again this fall, he said.

FTV3 should fly in October.

Source http://tinyurl.com/mbz6d3h

Quoting KarelXWB (Reply 194):

The real nugget in the article is the confirmation that normal mode is on. Game on.

Quoting JoeCanuck (Reply 187):

I'm with you, I'd love to see the C-Series succeed. It applies 787-type technology to short/medium haul jets, which could be a game changer for up-&-coming LCCs.

But it has come to market where it is facing the Embraer E-175/190 E2 series - a tough competitor that has a large installed base with many airlines, making adoption of the type easier. And while the E-175 E2 is A-OK for North American airlines' scope clauses, the CS100 might meet with more resistance as a lift-contract contributor to a major airline (too high-tech?).

Quoting challengerdan (Reply 113): Turns out the engine did in fact not perform good enough for BBD to be confident flying the aircraft again. It is now corrected, at least as far as the tests have shown.

Interesting. I will have to talk to members of my rumor mill to see why I received a much more optimistic (for Pratt) report...


Lightsaber

FTV2 flew yesterday again, 4 hours flight this time (maybe the longest to far, IIRC).

Does anybody know what's going on with FTV 4 ?
Don't think it's been in the air since it arrived in Whichita