Q400 Problems Get Worse

Accidents/Incidents, SAS

Last week I wrote about SAS’ two accidents involving landing gear problems on the Q400. This story keeps getting stranger.

On Thursday, Horizon Air announced that they had completed inspections of all their Q400s and everything would be back to normal Tuesday, Sep 24. 07_09_24 q400They took ads out in local papers reassuring customers that inspections were completed, but they made no mention of finding anything wrong.

Meanwhile, a report came out this morning saying that SAS found corrosion of the landing gear on 25 of the 27 planes inspected. They were fixing the gear and then they would put everything back into service.

As if that wasn’t enough, there was yet another incident this weekend. Augsburg Airways, which flies regional flights for Lufthansa, had a Q400 land with its nosegear up at Munich over the weekend. The SAS incidents both involved the main gear, but this still has to have many people thinking about the connection, not to mention how this relates to the ANA nosegear problems from March.

I wish I had more answers than questions at this point, but I don’t. What the heck is going on here? Why is it that Horizon would seemingly find no problems (unless they just aren’t telling us) yet SAS would find some on almost every plane? It’s not like they operate in very different climates. I’d argue that the environment is about the same for both operators. Anyone else have any theories?

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12 comments on “Q400 Problems Get Worse

  1. Differences? Most likely maintenance procedures. Did SAS follow all procedures correctly, or at least the same way as other operators? The investigation will likely find this out, but these things, of course, take time.

  2. Could this just be a SAS problem and not a Q400 problem? From the brief research I just did, the Q400 uses the same basic landing gear as the CRJ700, and I haven’t heard of any similar problems with those aircraft. The only other report I found regarding the inspections of the Q400 is this one from Australia saying they found some loose nuts:


    I wonder if the two problems are related? Have there been any other reports from the other 19 operators of this type?

    Awkward postscript: I found this report of a Jeju air Q400 that also had a landing gear failure:


  3. It might be that Horizon Air has a more complete maintenance program, being that they are owned by the same company that owns Alaska Air and Alaska Air flies into some of the harshest mainline airports in North America.

    Alaska Air got into trouble over that jack screw issue when their MD-88 when down off California, so they had to make changes to their maintenance programs. Those changes would likely have affected Horizon Air as well.

  4. Not that I really know anything about this, but the one major difference between Horizon’s Q400 fleet and SAS’s Q400 fleet is that with one exception Horizon flies the 401 variant, and SAS flies the 402 variant. What exactly the difference is and if it is relevant I have no clue. The one 402 that Horizon flies is about 4 years younger than the general SAS Q400 fleet. I haven’t dug through the data extensively, and I’ve made the major assumption in looking at the data on Horizon and SAS, is that they were the original operator of the airplane..

  5. I thought about maintenance, but is Horizon really doing something to prevent corrosion that SAS is not? I could understand if SAS just wasn’t fixing corrosion when they found it, but that would still mean that Horizon would have seen corrosion somewhere before and I don’t think they have. So that would mean that Horizon would have to doing some sort of preventative corrosion treatment, and that seems unlikely.

    And to your point, Joe. Though SAS is the only one that has had main gear problems, we know that ANA and now Augsburg have had nosegear problems. These could be completely separate issues, I suppose.

  6. Try this link if you would like to see the video.
    And I do know it is not a maintenance problem but a design problem. Bombardier has made a press relaese in Danish media, that SAS has made (fufilled) all the correct maintenance procedures.
    The 2 a/c invovled had more then 20.000 cycles.
    Why right gear, since the planes allways make a right turn (180 degress)out of stand/gate in CPH. (more stress on right gear)

  7. am a retired flight controls engineer. I have been following the Q400 accidents that occurred in Denmark and Lithuania very closely and consider these accidents to be very critical situations. These failures are giving the aircraft industry a subtle, but urgent warning that must be addressed. I found a report, dated September 15, 2007 online re – Preliminary Report on I am a retired flight controls engineer. I have been following the Q400 accidents Danish SAS Q400 accident that included a very useful drawing for analyzing the failure mode. It would also be very useful to review a drawing or sketch of the main landing gear retract/extend actuator, manufactured by the Goodrich Corp. in Tullahoma, Tennessee in order to confirm my analysis of these failures. Please note that a nose gear incident occurred on a Q400 in Japan on March 13, 2007, and I suspect that it is probable that it contains a similar actuator design as the main landing gear system. Another nose landing gear accident occurred in Munich, Germany on September 21, 2007. If this is true, it would be very important to inspect the nose landing gear actuator as well as the main landing gear actuator. In my study of the main landing gear reports, some investigators noted the fact that the jam nut backed off and the lockwire was missing. This condition, could eventually cause a disconnection of the rod end, which was also stated by investigators in preliminary reports. This failure may have actually occurred after 10,000 cycles while coupled with severe impact upon landings. This scenario seems very plausible. Most of the hydraulic actuators used in the aircraft industry contain a locking device to prevent rotation of the actuator piston, and are secured by a jam nut, and lockwired to prevent the jam nut and the locking device from backing off. Early discussions regarding this failure were stated that corrosion in the linkage probably played a major role in the accident. I don’t believe that corrosion played a significant role in these failures. My intention is not to interfere with the official investigation of these accidents, but to offer a feasible scenario to help solve the problem.

  8. Now let me get this straight???

    SAS suspends flying their Q400s while the rest of the airline world continues to fly them without incident. Then just yesterday, SAS flies one again and the landing gear collapses again. Today SAS announces they will discontinue using their Qs.

    Who are we kidding? This is a SAS problem.

  9. SAS mechanics hate to work on the Q400. According to pilots here in norway.
    Widerøe uses Q400 and are the regional airliner for SAS in Norway,
    they have had no problems with the Q400. But since they are owned by SAS,
    they will discontinue the Q400. Widerøe uses Dash exclusively, from 100 to 400.

    Keep in mind Widerøe flies in much harsher conditions than what SAS does.

    Though I don’t think it’s a maintenance procedure failure, most likely a bad batch of planes.

  10. I truly believe this problem is related to SAS or airlines that have poor maintenance policy or control. I found this bit of information on the web:

    16 JAN 2006 SAS aircraft flew without inspections
    Scandinavian airline SAS said it was tightening up the inspection and servicing of its planes after Swedish authorities identified gaps in its safety checks on 10 aircraft. The aircraft hadn’t been inspected according to international regulations after engine installations. The Swedish CAA reported that the company`s international operation permit could be limited or withdrawn as a result of the misconduct. SAS said the problem could partly be due to the fact that some of the maintenance had been outsourced to other companies. (AP, Reuters)

    It seems odd that most of the landing gear problems is coming mainly from one airline-SAS!

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