The FAA recently issued a directive to ground all Boeing B-17E, F, and G models over concerns related to wing issues.
There are 18 registered B-17's in the USA and which three are still flying. there is one in operation in the UK
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The FAA recently issued a directive to ground all Boeing B-17E, F, and G models over concerns related to wing issues.
There are 18 registered B-17's in the USA and which three are still flying. there is one in operation in the UK
It was bound to happen. These old birds can't fly forever.
Remember the N9M catastrophe. Last survivor of 4 built, and now gone, along with a seasoned pilot. My son and I were able to see it at the Chino Air Museum on a father son trip 1999.
2019 Northrop N-9M crash - Wikipedia
Yes, too bad but they're 85 years on now? How much longer can they safely fly? More important to have them prefect on the ground than maybe destroying things when they crash.
The B17 can stay flying in the same way the B52 and the A10 is still in active service Jim. Regular inspection and maintenance schedules that are strictly adhered to and they can fly conceivably forever.Quote:
Originally Posted by browningautorifle
I find it very hard to swallow that after 85+ years they suddenly find a defect in the design of the wing spar grounding all flying examples? A week before the Memorial Day air shows kick off? Not trying to do wrong by the site here but it reeks of dirty politics.
OK, possibly dirty pool as you say. I do know about the B52, have seen them do runs over me. I know there's guys flying aircraft their grandfathers flew.Quote:
Originally Posted by oldfoneguy
Going with what I've heard from the B-17 group on Facebook: This isn't a wing spar issue, it is a wing attachment issue. Apparently the EAA's Aluminum Overcast was discovered to have a two-inch gap between the port wing and root while out on tour! To find the problem they had to disassemble the plane and ship it home. They told the FAA what they discovered and the FAA issued an Advanced Directive for the rest of the survivors involving disassembly, advance imaging, and remediation if necessary. It isn't a hard inspection.
https://www.milsurps.com/images/impo...71269566-1.jpg
These are the parts in question, forward mounting plates and pins. The arrows point out where the pieces were relieved at service depots when they wouldn't reassemble after a service. Apparently one side had to be heated and the other had to be frozen before it could be done and some service depots didnt' know so the parts griped too much to be reassembled. The result over time could be hidden fracturing leading to the wings becoming loose! The parts aren't hard to find or fabricate. Aluminum Overcast and Sentimental Journey have been inspected and are back in the air already. Others are completing the process right now. The directive indicates that this may end up being a recurring 120 mo/2500hr inspection cycle for B-17s. More, HERE.
Bob
Those items in the photo posted are the items related to the previous AD issued back in 2001.Quote:
Originally Posted by Bob Womack
The new AD is in relation to the bolts that fix through the steel spigot that fits inside the tapered alloy spar tube, the end of this spigot is what attaches to those steel plates.
This updated article from aerovintage shows photo's from the items in a current dismantled B-17 being restored.
https://www.aerovintage.com/2023/05/...e-may-25-2023/
The big potential problem, will be if any NDT shows up any corrosion or cracks in the tapered ally tube section, rather than the steel spigot, as its impossible to reproduce these tapered spar tubes.
The steel spigot can be replaced, although to do so means taking the wings off.
So how do they go with the Spitfires main spar as its assembled then cranked at which point you cannot separate it to inspect it!
Spitfire spar beams can be reproduced, in fact pretty much everything for a Spitfire can, or has been reproduced, and is a very different form of construction.Quote:
Originally Posted by CINDERS
Please forgive my ignorance but why is it impossible for them to reproduce the tapered spar tubes?
The tooling no longer exists to do it, so the expense of building new bespoke tooling to draw the tubes with an internal taper, for the small run of tubes needed, is just cost prohibitive. Some of the restoration shops that have worked on B-17's in the USA started looking at this issue several decades ago, and they eventually found that the tooling may have been sold off to China back in the 70's, but the trail basically ran cold after that. Back in the 90's when there were double the number of B-17's still airworthy, it was cost prohibitive to make new tooling, and now with less aircraft, its very much cost prohibitive.Quote:
Originally Posted by jond41403
So after 80 years they well may just become desirable trophies...at least we'll have them to see.Quote:
Originally Posted by GeeRam
Well, two of the B-17's have now been checked as per the FAA directive, and passed clear, and are now back flying again. CAF's Sentimental Journey returned to the air again on the 10th to join Madras, Oregon based Ye Olde Pub, which was passed clear to fly again recently.
I was a volunteer at the Vintage Flying Museum in Ft. Worth and helped Chuckie regain her Airworthiness Certificate after the wing spar AD in 2001. We volunteers were very unhappy when a few years later, after Doc Hospers passed away the estate sold Chuckie to the Military Aviation Museum in Virginia Beach.
Speaking of Ye Olde Pub, Franz Stigler was an associate of mine and a fellow member of the R.C.A.F. Association in Abbottsford, B.C. Canada. Franz and Charlie Brown (Ye Olde Pub pilot) were finally able to meet but Unfortunately I had been deployed overseas. Franz, knowing how much I would have liked to meet Charlie Brown got him to sign a copy of the print, "The Ultimate Honor" by R. Harper who was an Intelligence Officer at the time. Franz signed it too and it now resides in a place of honor in my study.Quote:
Originally Posted by GeeRam
She was out here a few years and got a ball turret and some restoration and was sold to Erickson Aircraft Collection where she became “Madras Maiden”. Ericson leased her to the Liberty Foundation, had her painted olive drab, removed the chin turret and Cheyenne tail turret position, and renamed her "Ye Old Pub."Quote:
Originally Posted by Sapper740
Bob
Well, the Sally-B team have just confirmed that the inspection on their B-17G has been completed at Duxford, results sent to CAA and FAA, and both have sanctioned her return to the air, and she should be flying again this weekend.
So, that's 3 of them back flying now.
Now seen confirmation that the last of the four currently flyable B-17's, Yankee Lady has now also passed inspection as per the new AD, and will be returning the air shortly. So, that's now all 4 back in the air, with none showing signs of the issues as seen on the EAA's Aluminum Overcast back in 2021, which lead to this AD being issued.
:)
I didn't know he lived in the area... Adolph Galland didn't know about the incident until several decades later during a televised interview when Franz told the story. Galland turned and said "I'd have SHOT you"...Quote:
Originally Posted by Sapper740
A tapered spar tube?
There are several ways to produce a tapered tube, on any scale.
If the tube, be it steel or of some interesting aluminum alloy, is ductile enough, it cam be run into a gigantic "sizing" die, or "spun" with traveling dies", squeezing the parallel tube into a "conical" tube. This process will ado elongate the tube, in much the same way the starting blanks for hammer-forged barrels "stretch" as they are hammered.
NOT ALL ALLOYS are equal. Choose wisely and get opinions from several actual metallurgists.
IF the spar is readily removed and replaced, IFF replacements are available, then do it.
Failing that; perpetual hangar queens. Wreckage-strewn craters are a "different" sort of "interesting".
The tubes are constant OD, with an internal taper reducing the ID over part of the length, which is why 20 years of investigation has drawn a blank to getting them remade in the correct material that is commercially viable for the amount required.Quote:
Originally Posted by Bruce_in_Oz
There has been a lot of investigation done on this by the various B-17 restoration specialists, and they've drawn a blank.
Saw the pilot and mechanic working on this ship in Chino the week before he augured in. We were at Fontana for NASCAR. PAXQuote:
Originally Posted by limpetmine
Over the decades I've been privileged to see Evergreen, Sentimental Journey, Nine-0-Nine, Aluminum Overcast, Texas Raiders, Thunderbird, and of course, Chuckie.