They vibrate like crazy. The fasteners they use are actually better than safety wired fasteners. Safety wire only prevents the fastener from falling off, not from loosening. Critical auto fasteners are designed not to loosen.
Cars have not used safety wired fasteners, as far as I know, since the 1930’s Bugattis.
Fasteners falling off of car or even loosening is a near non-existent event so there is no need for it.
Using safety wire would add a lot to the cost of every vehicle manufactured and production costs drive everything. The cost per hour to assemble a car is in the hundreds of dollars.
That is exactly why the OK City GM plant shut down not many years ago. It was stated that Ford and Chrysler could assemble an SUV for instance in around 17 or 18 hours. To assemble a GM SUV they were chewing up 27 hours of labor time. It’s not difficult to see when that train wreck was going to happen.
At least 27 hours when sabotage wasn’t going on or another strike not happening.
If the wires are slow learners they need to be taught. Otherwise, taut is probably good enough.
A private plane was repaired at the local airport and a fuel line was removed and reinstalled when accessing a cylinder but the fuel line vibrated loose at take off and the plane crashed killing the pilot. The investigation determined that the fuel line was reinstalled without cleaning and reapplying a locking sealant or properly torquing the nut. No mention was made regarding safety wires. That would tend to indicate that not all threaded connections require wire but it does indicate that proper procedures are critical. Personally I would guess that the safety wires are a dated and unnecessary step that has remained a standard operating procedure because no one important has taken it on themselves to question the procedure. I say that because I once had to get up before day break and guard an engineer carrying a metal detector for 6+ miles checking for mines in a road that had been paved for more than a year. The government is SLOOOOW to change.
I flew private airplanes decades ago. I know that airplanes incorporate “redundant systems” that don’t exist in automobiles. Airplanes have back-ups of critical components, such as fuel pumps, fuel tanks, ignition systems, etcetera. These back-up systems are checked prior to take-off.
When cars have system failures and no “redundant” back-up systems they coast to a stop in the break-down lane of a highway until the driver calls AAA.
When airplanes have a system failure they rely on a back-up system to stay in the sky. Otherwise, the pilot becomes instantly homesick and needs to change under garments and could possibly die, taking innocent passengers along.
I’m pretty sure that airplanes would function without safety wiring of fasteners, but it is a back-up system. It probably won’t come into play, but would be worth its weight in gold when the pilot and passengers are bombing along in adverse weather conditions and the ground is not in sight when a fastener lets go.
Airplanes are designed to give humans a leg up when push comes to shove, even adding extra stuff to do it. There is no break-down lane at 10,000 feet!
Feeling lucky?
CSA
Some mechanics would not bother to replace them just like some don’t bother with a torque wrench. The safety just has to be built into the fastener.
True with auto mechanics and automobiles. I’ve had lug nuts left loose by a mechanic (And discovered by me before the car ever started. Walk-around inspections are my norm whenever anybody else touches my vehicles.) and there were no consequences other than that of losing a customer, me!
Aircraft must undergo (very) costly, periodic FAA inspections, annually for certain private aircraft, and more frequently (sometimes, much more frequently) for “commercial” aircraft. Missing safety wires would not pass inspection. Everything is recorded in log books. An FAA certified mechanic with any inkling for shoddy or sloppy work will be featured serving coffee at Mickey D’s before her/his next pay check.
CSA
It’s not that they’re outdated. It’s that they’re unnecessary on cars. If my oil filter falls off (which, in nearly 30 years of driving, has never happened btw) I can pull over as soon as I see the oil pressure light come on. I can turn off the engine before the car’s even stopped. I don’t really have that option at 20,000 feet in a Seneca, so it’s more important to have a (most likely unused) backup system to keep that filter in place in an airplane than it is in a car.
I miss the 727. Best looking tubeliner ever made.
Cars don’t have safety wire for the same reason that your daily driver doesn’t have titanium rods. The cost/benefit number is poor.
I suppose so. And, speaking of tubeliners, I suppose some miss the MD-88 which is still in use (not by me), I avoid them.
But, that should all be soon forgotten when one flies in an A-320.
CSA
727s were reasonably comfortable to ride in. 707s were even more comfortable.
But my experiences flying in those was back in the 1970s and 1980s.
Did not like flying in a DC10 nor in an MD80. Nor in whatever Southwest flies these days.
For that matter, never did like flying in and out of LaGuardia in NYC.
MD80. Maddog! I found them more comfortable than the much larger 757, at least the way AA did the seating arrangements. And they were kinda fun because the engines were probably more powerful than they needed to be, and so were the speed brakes, so the sense of acceleration was a lot more intense than other planes.
They’re old, outdated, slow, guzzle fuel, and I still do not understand why they don’t issue ear plugs for any body seated anywhere near those rear engines. My hearing mostly recovered in fewer than 6 weeks after a flight. Delta is scrambling to get the rest of them (and it’s a lot) out of their fleet. Other than that, they’re terrific.
CSA
Well, yeah, they are. Though not all that slow compared to your A320 – the Airbus cruises at M0.78 and maxes out at M0.82, whereas the MD is 0.76 and 0.8 respectively. If you’re looking for speed, you need to go private. The Gulfstream G650ER cruises at Mach 0.9
It’s kind of fun here, to watch the planes on final approach to SRQ Sarasota-Bradenton (straddles county line) International Airport, going over us, gear down, fairly low, when the wind direction is favorable.
I can spot the pencil-liners and usually pick out the large sun logo on the tails of Allegiant’s A-320s on final. If I knew more logos I could sort out some others, too.
My friend from High School, living in Clearwater, just north of here, just recently retired from a career flying corporate jets. He was presented a special Safety Award from the FAA when he retired. I know he’s flown DH-25s (DH-125s? can’t remember) and the BH version of it, Gulf Streams… I’ll have to ask him what he flew toward the end of his career.
I worked with him at a little private airport when we were in High School. We pumped gas, cut grass, washed planes, etcetera. His dad was a corporate pilot with Holley carburetors and later Burrough’s at the close of WW2. I believe he flew a P-39 or P40 (can’t recall)? during the war. So, he had connections for my friend to transition into professional aviation.
I learned to fly in a Piper Cherokee PA-140 when they were brand new. I think the first one built was N6000W. We had N6012W at the airport and I flew it and it’s in my logbook. My boss, a fixed base operator, was a Piper dealer and ran a little flight school. He was an FAA examiner, a very tough one.
CSA
Oddest fact to me about current airliners - the 737’s main wheels are exposed when retracted.
I’d be interested to know the thinking behind that. I’d be pretty sure that the reason makes sense,
Cooling? Air keeping wheels turning? Doors aren’t necessary for drag reduction, saving weight?
CSA
Some aviation brain farts…
It was the sixties when I worked at that little airport and an executive had a manufacturing shop on the edge of the airport.
He had a twin Cessna based there, but also had a couple of “hobby” antique planes. One was some kind of Ryan monoplane with an "inverted Monasco (sp.??) engine.
The other plane was a Stearman biplane (WW2 trainer) with a radial and tailwheel. It was like new and I earned honors of being his “go to” crew for starting it as he sat in the cockpit.
I’d get up on the lower wing and lean forward against some “flying wires” to steady myself so I wouldn’t fall. At his signals I’d pump a primer on the side of the engine cowl and lock it in place. Then I’d insert a crank handle and slowly begin cranking a flywheel, slowly at first and gaining speed, until he gave the signal to remove the crank handle (I recall handing it to the pilot?) and pull a chrome T-Handle to engage a mechanical starter. The prop on the old radial would slowly turn, the engine would sputter, hit & miss until it came to life and the billowed smoke (from inverted cylinders on the radial) and the prop wash hit me. What a beautiful sound! What a magnificent beast.
I was kind of proud when it started and enjoyed helping. What an experience… so much so I still remember it (even if a few details are screwed up in my head).
Of all the aviation thrills, though, the one they say "you’ll never forget," has to be my first solo flight. I can replay that in mind in excruciating detail and full color, like it was yesterday! I’ll never forget it! I have to find my log, but it has to be over 50 years ago, now. And they’re correct too, your first landing is your best landing.
CSA
I agree with @VOLVO_V70 ‘s very first response in this thread.
Hehe
But keep those thoughts flowing man…
Geez! Mach .90? Our B727’s had a Mmo of .90mach. We cruised at .82 . A smaller plane, the CRJ200 , a commuter plane, has a Mmo of .85 mach. What IS it with the Scarebus and its low max speed?