747 inplane loading system

[744rules]

Can someone let me know what are the differences between the boeing system and the telair system (both maindeck and lowerdeck). :)

[CR2]

Very different systems, but work in the same way.
The Telair system is more modern, though unfortunately not mature yet.

All the large PDUs in the constant section have been replaced by little (3") ones which are fixed into the lock rails. The disadvantage of this is that you can no longer move locks around for non standard loads. Similarly, these things no longer have a clutch; if the thing fails, you have to replace the unit (...and they fail often). Freewheeling the pdu is no longer an option.

All the castors common on the TRW designed (standard Boeing) system have been replaced with Ball Transfer Units (BTUs). We've had a lot of trouble with these. They simply break.
All locks & guide rails, door sills have been replaced - they function in the same way, just made out of lighter materials.

PDUs 1-5L/R and 17/18/19L/R are of a new design. No longer pneumatic but solid with a rubber covering (which wears off very quickly). They do turn faster though.

The whole system was supposed to be lighter than the original system; due to various modifications (eg strengthening the BTUs), system weight has increased.

Given the choice, I'd go back to the original system. This is unfortunately no longer offered by Boeing.

Some other points - the 3 inch pdus have electronic eyes; they only drive when the pallet covers these eyes - takes a little getting used to; you initially think the system is malfunctioning. There is also a neat little computer system at the sidewall at position RL. This thing can test each and every pdu, giving you a status message (eg operative/inop, overheated....)

Hope enough for now.

[744rules]

thanks for the reply. Just wanted to know what to expect, as Singapore will be using telair on their 6 latest 747-400f (first delivery in march 2003)

[707]

If they are like those used on most residents of LHR whatever brand, they are usually only properly functional for the first few months after which it is down to effort. Maybe Singapore maintain theirs.

[CR2]

707

I fortunately work for a company that takes good care of the loading system. The whole thing is checked every A-check; anything inop is replaced/fixed. Same if something fails during a turnaround at home base; quick call & our maintenance people come out.
At the end of the day, malfunctioning equipment leads to a longer turnaround. Time is money etc etc. Matter of company attitude.
Take a look on the AFX thread to get an idea of what I mean.
Merry Christmas

[Buster Hyman]

Never use them down here! We just chuck it in & hope we don't get a telex from the next station! ;)

[CR2]

Big bruvva is watching yers aussie peeps :p

[Buster Hyman]

Yes, but the ones that REALLY watch are squinting...if you get what I mean!:rolleyes:

[tinyrice]

The other problem you run into with the small diameter Telair style wheel is that if the board is bent or damaged the wheel doesn't grip. Not a big problem is you're lucky enough to work with an airline that looks after its gear. Likewise if the wheel is wet, the solid tyre has a hard time gripping, although I thought they changed their compound to improve that. For the main deck posn 1-5( I think ) and 17-19, Aero-Union out of California used to make a drop in replacement that had a better wheel drive system ( ramp up torque v on-off ) and self contained cables and limit switches so you didn't have to adjust the damn things on the ramp. The Aero-Unions in positions 19 alone, gave NWA virtually delay free performance when compared to the Boeing PDU's.

[CR2]

True, but AeroUnion pdus don't stop when you release the joystick (continue 1/4 turn or so). Considered unsafe and therefore not accepted on our 74s - break a frame with an overhanging 20ft.

[tinyrice]

CR2. Never came across that problem with our Aero-Unions and we had all union loaders.

[africa10]

anyone used the aero systems pdu's?