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Re: Qantas 737s in a pickle

Posted: 03 Nov 2019, 18:28
by airboatr
airboatr wrote:
02 Nov 2019, 07:18
Chris? Are you still pumping gas?

Chris Trott wrote:
03 Nov 2019, 12:25
.... having Randy Ball and his MiG-17 fly past the Hot Ramp at somewhere in excess of Mach 0.90 at a distance of approx. 150 feet from me.
.... :| that went right over your head :doh:

Re: Qantas 737s in a pickle

Posted: 03 Nov 2019, 20:29
by cstorey
Chris Trott wrote:
03 Nov 2019, 12:25


The pickle fork structure is attached the front spar, not the rear. Also, my understanding is that it's a secondary "load relief" structure designed to help keep the fuselage located on the wing center section, thus why the repair isn't a major concern (i.e. immediate grounding). The other thing that I don't think has been determined is why these cracks are being found. There is some chatter that these cracks are actually from undetected or improperly assessed heavy landings as the most likely way to get a crack like this is the airplane's nose to be "slammed" down which could stretch the attachment, leading to a crack in the saddle.
As I understand the NG's anatomy , the pickle forks are actually on both front and rear spars, 4 per aeroplane. The cracks have been found, as I understand it, only on those securing straps holding the pickle forks on the rear spars . The front spars, which do not carry the same dynamic loads from the main gear on landing , do not seem to have been affected

Re: Qantas 737s in a pickle

Posted: 05 Nov 2019, 13:59
by Chris Trott
I may have misunderstood what Juan Brown and Mentour Pilot were describing then. Both seemed to indictate it was the pickle forks on the front spar that are the problem. The FAA's AD just says that the pickle forks (plural) must be inspected, but doesn't discriminate front or rear.

Personally, I'm most interested in finding out if they discover why they're cracking at 1/3 of their life span. Heavy landing or not, having a part crack that early in its life is kinda odd, especially (as Juan said) the original testing showed they should make it well beyond 90,000 cycles before any issues.

Re: Qantas 737s in a pickle

Posted: 08 Nov 2019, 11:36
by SkippyBing
Chris Trott wrote:
05 Nov 2019, 13:59
Personally, I'm most interested in finding out if they discover why they're cracking at 1/3 of their life span. Heavy landing or not, having a part crack that early in its life is kinda odd, especially (as Juan said) the original testing showed they should make it well beyond 90,000 cycles before any issues.
I believe the original testing was done on wings without winglets. Conceivably these could increase the bending moment by improving the performance of the outer portion of the wing.