Buzz From United States of America, joined Nov 1999, 697 posts, RR: 23 Reply 1, posted (7 years 5 months 1 week 3 days 1 hour ago) and read 7615 times:
Hi B52Murph, Buzz here. about 17 years ago we used the same bar on the DC-10's and L-1011-500's. Yes, UAL had half a dozen L-1011s we bought from Pan Am.
And we use the same bar on the 767 series too.
Tristarsteve From Sweden, joined Nov 2005, 3857 posts, RR: 34 Reply 3, posted (7 years 5 months 1 week 2 days 22 hours ago) and read 7584 times:
Quoting Buzz (Reply 1): And we use the same bar on the 767 series too
Yes the L1011 DC10 B777 and B767 all have the same towbar connection. But be careful. They have different shear pins. If you use a B777 towbar on a B767 it will not shear at the right force as it is much stronger.
We broke our B777 towbar last month, and successfully used a B767 for the pushback. But very carefully, and without the engines running as the shear load is much lower.
N8076U From United States of America, joined Jun 2006, 425 posts, RR: 9 Reply 4, posted (7 years 5 months 1 week 2 days 21 hours ago) and read 7579 times:
[quote=Tristarsteve,reply=3]Yes the L1011 DC10 B777 and B767 all have the same towbar connection. But be careful. They have different shear pins. If you use a B777 towbar on a B767 it will not shear at the right force as it is much stronger.
I figured different airlines would do things differently. We did not have any dedicated 777 towbars. The towbars we had were approved (and placarded as such) for use with several aircraft including the DC-10, L1011, 767, 777, and some Airbus as well (A300, etc). I can only guess the shearpin was the lowest common denominator strengthwise, so to speak, to allow the use on so many aircraft.
I was hoping you wouldnt ask!
I forgot the steering lock out pin, and the driver didnt check. So as soon as we started to push back the shear pins went.
I always put the lock out pin in on arrival, but that day I was not there. I was busy on an A319 so I asked someone else to meet the B777. So I forgot the pin.
I'd say on average, one towbar a week got it's shear pin snapped (and I am being conservative), but keep in mind we had over 100 of them between the gates and maintenance areas, and lots of inexperienced tow personnel.
I've even seen a cheaper "new style" lightweight towbar get bent in half. Sitting between a 450,000lb 747 and a 200,000 tug, it had no choice but to give it's life when the tug driver got going a little too fast crossing the active, and then tried to turn.
ReidYYZ From Kyrgyzstan, joined Sep 2005, 536 posts, RR: 1 Reply 11, posted (7 years 5 months 6 days 15 hours ago) and read 7382 times:
The Tristar bar also fits an A330. The shear pins on our model tow bars were stamped for a/c specific. After a while we just went with the lower strength pin (330, I think) so no changing pins back and forth for different departures.
ReidYYZ From Kyrgyzstan, joined Sep 2005, 536 posts, RR: 1 Reply 13, posted (7 years 5 months 6 days 11 hours ago) and read 7345 times:
Quoting HAWK21M (Reply 12): Is there any Corelation between P/N & Shear load.Where can that be accessed.
It is stamped with a/c type, not part number. The aircraft that can take a higher load gets the stronger pin. Being an aircraft mechanic, don't know, never noticed and don't care about any corelation. Truth be known, our GSE mech doesn't know, never noticed or doesn't care either. Pin gets broke, he fix. Where can it be accessed? I don't have the spare time you do to look up this info, and again, nor do I care. If it ain't an airplane, it really doesn't interest me.
Cancidas From Poland, joined Jul 2003, 4112 posts, RR: 12 Reply 17, posted (7 years 5 months 5 days 3 hours ago) and read 7228 times:
while we're on this topic, how often are shear pins supposed to be replaced? our 737/319 bars are fine and hold up amazingly. the problem we encounter is with our regional jet bars. while we do have a lot of inexperienced pushback-qualified agents, i think that a lot of the shear-pin snappage has to do with the fact that our pins are not maintained and just left in the bars to be abused as long as possible. how long are they supposed to last?
by the way, we've got 167 daily departures and only 4 bars, 2 each for ERJ and CR2.
"...cannot the kingdom of salvation take me home."
TUGMASTER From Northern Mariana Islands, joined Jul 2004, 649 posts, RR: 10 Reply 18, posted (7 years 4 months 2 weeks 5 days 6 hours ago) and read 7051 times:
Here at LHR we have a specific Pushback/Tow Department, so all of are guys are highly trained and do no other work other than push, tow or ride the brakes.thats it.
should they bust a shear pin on a bar, it usually 'cos they been rushing (as agents do).the only exceptions i can think of, are 747 pins steering pins which are put in upside down...(can easily fall out) and A300 bars....(twin side locking) which are crap to push anyway, but seem to have a really low shear tolerance.
Tristarsteve From Sweden, joined Nov 2005, 3857 posts, RR: 34 Reply 21, posted (7 years 4 months 2 weeks 4 days 16 hours ago) and read 7013 times:
Quoting TUGMASTER (Reply 18): 747 pins steering pins which are put in upside down...(can easily fall out
They will if you use a B757/B767/B777 pin with the locking device on the end.
However there is a special B747 lock out pin , which is exactly the same size, with the locking device in the middle. This stays put.
I didn't read the link but during winter months 727s will stink to high hell if they had to be deiced at the previous stop. The APU is in the wheelwell (as you probably know) and the exhaust is near the trailing edge of the right wing root. Glycol runs down into it, and gets burned off when the APU is running.
25 HAWK21M: Interesting & Educational.We never do DeIcing out here,thanks to the Climate,so its nice to know. regds MEL
26 Pilotpip: No problem Mel, you're usually the one with the useful info. Glad to help It's pretty bad when you're fueling. The exhaust is right above that wing ro
27 HAWK21M: I always wondered why the MWW was the chosen location for the APU on this model. regds MEL