8.33 Problems

[forget]

Has anyone else heard of a problem which appears to be 757/8.33 unique where reception on one VHF is killed stone dead when another onboard VHF transmits.

[spannersatcx]

No, but I've had it on a 744 where only one VHF appeared to be working, VHF1, and you couldn't use 2 or 3. Answer, VHF 1 was at fault the only way to get it back to base was to physically remove the transceiver and fly with an empty hole where no 1 VHF should of been. Hope that helps......

[redtail]

That must have been a fun bit of troubleshooting. :)

[spannersatcx]

It was I can tell you, it happened on pushback as well which didn't help. Swopped boxes around etc etc checked ant and cabling for moisture etc. I think it was more by luck than anything else in the end after much head scratching and 'expert' advice. I remembered from something similar from many moons previous and it worked. Got told off by QA a week later because I should of had a dispensation to fly with no transceiver installed although you can go with 1 vhf inop under the mel, still with 300+ pax grateful it was worth it.

[GotTheTshirt]

Spannersatcx,
Like your comment re QA - this is what its all about now. No logic! just get all the bits of paper right! As you say what on earth is the difference in flying wihout it or inop if you pull the CB's in both cases??

Had similar incident with a worn brake unit in India. We blocked and blanked the brake off per the MEL and had 3 days to clear the MEL. Usual India problems of customs etc finally got the brake on the 3rd day. By this time another brake was down to limits. So quickest and easiest was to change the newly worn unit and leave the original one blanked and blocked. Operation was the same with one blocked brake. Oh No No No ! we had overrun the MEL on the first brake - what we should have done is unblocked and unblanked the first brake - fit the spare - signed the MEL off. THEN block and blank the second unit and raise a new MEL item!!

As ever BS baffles brains !

[spanners]

I have had experience of this problem on the 757. Getting some VOLMET (for example) weather on one box (RH BOX), whilst transmitting on the LH box interrupts it. If there is a comm test button, pushing this helps, but the further the range the worse the reception, and sometimes none at all.

[This message has been edited by spanners (edited 08 March 2001).]