SAX Q400 farming expedition

[i-Robot]

The Beeld reported yesterday that a SAX Dash Q400 taxied off the taxiway at George into the grass and got stuck. Anyone with further info?

[Woof etc]

Wannabe SAA A340 driver?

[GULF69]

heard the same for someone in the NIA yesterday...

[whiskeyflyer]

Click on
http://www.avcom.co.za/phpBB2/viewtopic.php?t=27876
It is in Afrikaans with a photo (I know only english posts allowed here so you'll have to click)

[reptile]

who then ran off the runway....

Actually the taxiway after vacating the runway.

[Aspen20]

Guys, play nice. There are those who have and those who are still going to.

[Avi8tor]

Anybody know why it didn't stay on the black stuff?

[grjplanes]

Saw this morning that it's still standing at GRJ, any idea what is going on, I suspect something must have been damaged if they couldn't get it flying up to JNB again...?
In the meantime SAX is using the "Community Airlines" 737-200 in it's place to GRJ...which is actually good for them, having extra capacity and cashing in on "Nationwided" pax.

[TwinJock]

Nose-wheel steering failure. Bombardier must be pulling their hair out with the Q400. SAS canned them because of all the problems - seems that the problems are ongoing!:E

[Q4NVS]

Not related at all...

Infact, there is no real difference between the Nose Wheel Steering System on the Q400 Series versus that of the 300 Series, as well as many others et al.

Nosewheel Steering System (Q400):

The tiller turns the nosewheel up to 70 degrees (60 degrees for 300 Series) either side of centre for low speed taxi. Steering with the rudder pedals turns the nosewheel up to 8 degrees (7 degrees for 300 Series) either side of centre.

Here is also initial proof that SAS eventually and possibly grounded their Q400 fleet due to their own inabilities to properly maintain the Type...

Preliminary Investigation Report - SAS DHC8-Q400 LN-RDI Accident
Published by Michael November 4th, 2007 in Aviation Safety.

Denmark’s Accident Investigation Board reported that the landing gear accident of SAS Dash 8 - Q400 LN-RDI at 27.10.2007 in Copenhagen was caused by a piece of rubber O-Ring trapped in the landing gear, preventing it from extending accurately.

This cause is not related to the two previous accidents which occurred in September 2007. According to the preliminary investigation report, this accident might have happened because of a fault by maintenance personnel and not because of a possible design fault of Bombardier’s Q400.

Summary
During the examination of the retraction/extension actuator assembly from the right main landing gear of the occurrence aircraft, an O-Ring was found blocking the orifice in the restrictor valve.

The blocked orifice within the actuator assembly prevented the normal extension of the right main landing gear.

The O-Ring was similar to that O-Ring for the door solenoid sequence valve (SSV). The only component in the landing gear system that incorporated this O-Ring was the SSV.

An SSV on the right main landing gear system had been replaced on 16 October 2007.

In the past occurrences, O-Rings (situated adjacent to the filter) from the SSV´s are not known to have migrated into the landing gear hydraulic system.
The O-ring found blocking the right main landing gear actuator restrictor valve, was from the SSV that was previously installed on the occurrence aircraft.

The rogue O-Ring could not have traveled from the SSV to its final location in the right main landing gear retraction/extension actuator restrictor valve.
The MSV of the right main landing gear was replaced on 22 October 2007.
According to the maintenance records, the replacement MSV, was initially configured for installation into the nose landing gear hydraulic system. Prior to installation on the occurrence aircraft, the supplied MSV was reconfigured by maintenance personnel. To make it compatible with the installation requirements for the main landing gear, the unions from the replaced MSV were used.

During the replacement of the MSV, the rogue O-Ring could have unknowingly been transferred from one side of the MSV to the other side by maintenance personnel.

Following a possible transfer of the O-Ring, it could travel through the hydraulic lines towards the main landing gear retraction/extension actuator restrictor valve causing the blockage of the valve.

:oh:

[SAASFO]

Can anyone confirm that this was a landing gear related failure?

[reptile]

Can anyone confirm that this was a landing gear related failure?
The SAX incident was NOT a gear failure, but a failure of the hydraulicaly actuated nose wheel steering system combined with cold brakes.

[Avi8tor]

Cold brakes?

George in the summer? At the end of the landing roll? Hmmm.....

[Q4NVS]

Ever the expert...

It is possible (not just by luck), when landing the Q400 at less than one ton below MLW (and at George), to have the aircraft come to a complete stop 2/3 down the runway by using Discing only.

Been there and seen it ten's of times :E

[Shrike200]

Don't worry, he's just forgotten what it was like to fly turboprops!

[grjplanes]

George in the summer?

That day was actually the first sunny and warmer day of the two weeks preceeding it...

[Avi8tor]

aircraft come to a complete stop 2/3 down the runway by using Discing only
That I doubt. With reverse, I would believe. But small matter of blade erosion. Also I think its good airmanship to try the brakes at the end of the landing roll, before you NEED them. Specially taking a high speed exit. Don't think that would require power application.

Yeah, a few yrs since I flew things with unducted fans, except choppers and tail draggers.

I was commenting on the fact that if that deep sea Canadian trawler seems to have NO brakes on a 20 deg day, what do they do in the deep European winters?

And please guys, NOT a dig at the crew involved, I know how easy it is to sit in the pub with loads of lagers and comment.

[Ibhayi]

What they did was they took the firetruck and its hose and attempted to pull it out. The hose is rubber and it stretched, then when the aircraft snapped back onto the run way the hose being stretched pulled the aircraft into the fire truck damaging the pressurised hull.

It will most likely be flown to JNB unpressurised.

The side wheel went off and the front set of wheels got stuck behind a runway/taxi way light.

[mactheknife]

You cannot be seriaaas!

If so - what a bunch of plonkers.
:=:=:=

[Romeo E.T.]

It will most likely be flown to JNB unpressurised.

I heard this all to be true...aparantly took 4 hours, unpressurized and gear down ferry flight back to JNB

[4HolerPoler]

Priceless! What a great story. :ugh:

I can see the headline - SAX Dash bungees into fire-truck!

Next, they'll try & extingusih a fire with a seriously stretched fire-hose and find out it doesn't work as well as it did pre-bungee.

Palookas.

[Avi8tor]

I can just hear the 'EEEESSSHHH' as it hit the fire truck. I do miss home sometimes.

[Bozo Nightmare]

Sounds like Mr. Bean organised that rescue!

[rouge]

It actually took 2:40 to ferry the aircraft back. unpressurised, due to a tempory patch, and with the gear down as a suggestion from Bombardier. 180kts indicated.

[Trawler]

Quite possible to stop on George Runway 11 (uphill) by only using discing and not reverse. brake philosophy different betwwen 300 and 400. 400 with carbon brakes needs heat and 300 not. Pilot's in brake saving mode did not apply enough heat to the system.

[El Lobo Solo]

Reverse does almost nothing in the 400. Disc is all you need to slow down. Unless there's a total hydraulic loss, no flaps and a short, wet runway, it shouldn't be too difficult to stop. Although, the brakes do take some getting used to. If you don't get on them it won't slow down the same.

How short is the runway in question?

[Avi8tor]

carbon brakes needs heat
Carbon brakes work fine cold, but the wear most when cold. Most flight manual's recomend slow, progressive application through the landing roll. There was a LONG discourse on the subject in the 'Tech Log' a while back.

Never having flown a canadian fishing trawler, but in do have 4000hrs in turbo props. My 4X4Xfar wont coast to a halt from 180kph in 1400m, that has the frontal area of of a block of flats. Be interested to see what the torque gauges say when the props are in 'beta' range.

[Q4NVS]

Carbon brakes work fine cold

Excuse my ignorance, but whatever...

That is the same reason why F1 Cars do a warm-up lap while at certain sections of the track, accelerating against a depressed brake pedal :uhoh:

Never having flown a canadian fishing trawler, but in do have 4000hrs in turbo props

Of which all had propeller rpm's of 1550+.
Ever flown a Turbo Prop that is certified to climb at 29 257 Kg's with the propeller spinning at 850 rpm? If you did, you would know and understand the Aerodynamic Forces/Efficiencies available when pulling those Six Bladed Dowty R408's into Discing... As mentioned before (on another thread), they are so efficient that if care and finesse is not used, you can yank the passengers forward (shoulders away from the seatback), without intending to...(using Discing only)

Your 4x4xFar does not have those!

Be interested to see what the torque gauges say when the props are in 'beta' range.

If it is any consolation, the Torque is at a Max of 35% when in Full Reverse.

Now signing off on this thread, as it has become as boring and stereo type as trying to "Watch the Paint fall off the Mona Lisa..."

:E

[rouge]

Bravo Q4NVS!!:D

[El Lobo Solo]

Nicely done. The Q400 is still the greatest turboprop airplane ever in my opinion. (minus the :mad: gear issues)

[PAXboy]

Non-pilot speaking
Are you really serious that they tied a fire hose around the gear?? Any fire truck has ropes, surely?? And I'll call you Shirely until I hear for sure that they used a hose and not a rope.

I have lived in ZA, my nephew drives 738s and I have paxed at GRJ a dozen times AND paxed on Q400s in the UK but ... I still find this hard to believe!!

[reptile]

Avi8tor.............What exactly is your point? Trying to prove that that the Q400 is a poor product or that the pilot in question is a bit shaky?

Either way, you are completely off the mark (you did state that you are completely unfamiliar with the Q400, and had you known the pilot you'd be dishing out apologies about now). This is a simply a case of very bad luck: Steering fails as the aircraft vacates the runway onto a taxi way with an angle in excess of what the rudder can handle. Add cold ceramic brakes and you end in the sand.

Speaking of sand..........I believe there's a camel with your name on it. Now be a good boy and go play.

[Avi8tor]

Steering fails as the aircraft vacates the runway onto a taxi way

Of that I have NO doubt. As I have said before, my comments are in NO way aimed at the crew involved. I have no doubt they did the best under the conditions. I have the highest regard for the trainers in the Dash late fleet, as I know most of them.

I just take exception to the 'dodgy science' of some of the posts. However, 'none so deaf as those that will not hear'.

[TwinJock]

Here is also initial proof that SAS eventually and possibly grounded their Q400 fleet due to their own inabilities to properly maintain the Type...


Q4NVS! You serious! If SAS can not maintain the Q400, what makes you think that SAX can? I think Bombardier has hit a dud with this type - just too many incidents for my comfort. The -300 is however, a marvelous machine!

By the way - not sure what the speed limit is for taxing at SAX. The speed at which some drivers taxi, their is no way that they can stop on a taxiway if any failure occurs - let alone a steering failure.:=

[Avi8tor]

Even the best are not perfect.

Steady on here. I agree, the crew are not here to defend themselves. Lets leave it as a steering failure. Its a GENERAL discussion about props and brakes.

[Avi8tor]

the statement "and had you known the pilot you'd be dishing out apologies about now" smacks of arrogance.
Speaking of sand..........I believe there's a camel with your name on it. Now be a good boy and go play

Yeah, I know, but you learn to ignore the kids that still function like there in grade 2. I am not gonna go down to there level. It says more about them than us.

Also with a 'no blame' culture that should be in aviation these days, we should be learning from mistakes, if any are made. Hence this discussion.

[nugpot]

not sure what the speed limit is for taxing at SAX

In SA you can get taxed at any speed...................

[El Lobo Solo]

I think Bombardier has hit a dud with this type - just too many incidents for my comfort.
You cannot be serious. Have you flown the 400? It makes all the other Dash models look like rubbish trucks. Whatever the gear issues are, they'll figure it out. It's a little buggy on the electronics side, but it will snap your head in the headrests on takeoff. Try that in a 300 (what headrests?).
Q400----best turboprop ever! :ok:

[Biff99]

Suitcaseman, differential thrust will only help to turn the plane not stopping it in time when the nose wheel steering fails. When the nose wheel steering fails it makes for interesting times and it can happen so quicley...aspesialy in sharp turns. I know the pilot in question and hold him in high regards and if it can happen to him, boy ,it happen to any body. For the argument about carbone brakes operation when cold, yes at low speed and low thrust setting it will function but higher speed and higher thrust settings while cold....will be interesting to say the least. Carbon brakes optimum efficiency is at higher temps, why do you think the are taxi speed limits on larger aircraft? Its not only a function of tyre wall limitations!
So for all the professors out there, don't judge and condemn, especially if your not rated on the plane or know all the facts involved:oh:

[Avi8tor]

For the argument about carbone brakes operation when cold, yes at low speed and low thrust setting it will function but higher speed and higher thrust settings while cold....will be interesting to say the least.
What are you on about???? Do you care to explain???

COLD carbon brakes will stop the aircraft at V1 PLUS 2 seconds at max take-off mass. Its called an RTO. There is NO minimum brake temp for take off.

[AirwayBlocker]

Well put Avi8tor

I couldn't have said it better myself.

Dunno what these guys are on about carbon brakes not working when they are cold.

[TwinJock]

It might be the best turboprop ever built - the only problem is that it features too often on CNN and BBC news! Does not matter if it snaps your "head back into the head rest" during take-off - if passengers loose confidence in the type you are stuffed. No pax with snapping heads - no money for salaries!

Nugs - Eye checd da speling tihs time!!:D

[reptile]

if passengers loose confidence in the type you are stuffed.

Pilots (aircraft spotters, and other nerds, to a certain extend) yap about types. Passengers worry about one thing, and one thing only: PRICE. Newspapers may publish sensational articles, but the passengers are ruled by their wallets.

Thus it has always been, and thus it shall always be!!

[Avi8tor]

Passengers worry about one thing, and one thing only: PRICE. Newspapers may publish sensational articles, but the passengers are ruled by their wallets.
That would imply that SAX is a 'low fare' operator?

Not so sure that the travelling public is quite so uncaring. I rememebr being very young and nobody would fly on Swissair or Iberia cause they had DC10's. 800 helped kill TWA.

[reptile]

That would imply that SAX is a 'low fare' operator?
I don't believe SAX is a LoCo operator as such, but the Q400 allows them to compete very aggressively when it comes to pricing - to the extend that on certain routes they have the ability to under price everyone else, and still make a bit of profit.

[Biff99]

Yes
RTO is a straight line or should be. I was referring to the turn he made the nose gear steering failing then try and stop while the a/c is moving, RTO is worked out taking all factors in consideration and then the oomies with thick glasses come up with fig vs a specific weight. Carbon brakes do work better or More efficient if they have temperature in them

[Avi8tor]

Carbon brakes do work better or More efficient if they have temperature in themThat fact is NOT in dispute
I was referring to the turn he made the nose gear steering failing then try and stop while the a/c is movingAnd that would require MORE brake energy than an RTO?

[Biff99]

All depending where the steering failed and how close to the edge he was, taking turning radius into account and where on the runway the turn was initiated, for eg in the middle. With colder brakes he might for eg. need 5 meters to brake, taking thrust setting and weight and acceleration into account. With a warmer brake or brake at optimum , which will be achieved during brake application in the landing, ref. to the incident, he might need 3m to stop. If he was to close to the runway edge for the given scenario, he wouldn't be able to stop

[nugpot]

You should be looking at this from another angle. The captain was able to turn the a/c using inside brake and bring it to a stop. Unfortunately he was not able to do it (within about 50cm) within the margins of the taxiway. The right main gear just went of the side of the taxiway with no damage to the a/c

.........until the recovery attempt.

[Biff99]

That was my point in the beginning, don't judge and doom until all the facts are know. So a small thing turned into a big one and all the profs are giving there two scents worth

[Avi8tor]

I give up too. Just be assured cold carbon brakes had no factor in this incident.

P.S. This is NOT a comment on the Crew performance.

[TwinJock]

SAS has all the old -400's they will therefore find all the problems and honestly the -400 is a lemon. Beancounters loves it because it sips fuel. Pilots hate it because its unforgiving and just keeps comming up with new problems. Heard a pilot say that he loved the simulator checks because there he had an idea of what would happen, in the air the plane would come up with something new all the time.


Interesting! It seems that the fun has only started!

When, and IF I fly on a -400, I will be very relieved if both main gears are extended, and remains extended during the landing roll.

Then their is the question about the COLD carbon brakes after we vacate the runway!!:p

[Coleman Myers]

Could there be any link between this and the Q400 problems SAS had earlier this year ?.

[nugpot]

Could there be any link between this and the Q400 problems SAS had earlier this year ?.

No, they are not related.

[grjplanes]

Am I correct in saying that the involved aircraft has been fixed? Seeing that SAX is having all 3 JNB-GRJ rotations on Q400s again, since yesterday (25/12)

[grjplanes]

In addition to my previous post...at the moment one of these aircraft is "Indefinately delayed" at GRJ again, landed sort of on-time from JNB earlier at around 15:00, but has not yet departed? Anybody got any info?
Like I said in the previous post, it seems that the one that did the ploughing job a few weeks ago only got back into service yesterday (christmas day).