Blocked !

[Jet A1]

What's with this phrase 'BLOCKED' by acft on the radio these days. We can all hear the garble when two or more stations try to call. What really gets up my nose is this 'BLOCKED' reply from us UK pilots. (The Brits and Nigels especially guilty.) Not standard RT and although may be deemed as using a bit of airmanship, it does nothing else but to miff people off !!!

Rant Over !

[ETOPS]

Jet A1

I think you are a little out of line here. The most frequent use of this helpful aside is in North American airspace where I have heard it for the 5 years I have been operating there. Next is the Eurozone where our freunden in LH are always ready to help out.

Remember that although you can hear the garbling through your airband scanner, the poor ATCO can't - thus the quick "Blocked" promts him/her to re-transmit.

It's a safety thing..........

[NoseGear]

Been using "Two at once" down under for years now. As ETOPS said, its a safety issue as the transmitter doesn't know that the call has been stepped on. ;)

Nosey :D

[White Knight]

I find it very helpful. After I've called up and get no reply I wonder if the ATCO's busy on the phone. If I hear "blocked" or "two at once" I know that's not the case.
ALSO, JA1, if another crew in Tenerife back in 1977 had said those short words when the Pan Am, KLM and tower controller had all stepped on each others transmissions some 570 people may not have died. I have to say you must be in a very small minority on this with the way you see it.

[5milesbaby]

As ATC being told you have been blocked can be such a vital aid, however gets more interesting when even this transmission becomes stepped on :bored:

[Wee Weasley Welshman]

Saved me once when followed by an Avoiding Action. If it ain't in the book then it should be. "Blocked" would be my nomination.

WWW

[foghorn]

In my experience (GA where it happens a lot) it's quite common for ATCOs to respond to a a situation where one aircraft transmits over another's transmission by prefixing his response with with 'two together'.

In GA I also find that the term 'stepped on' is used most often by pilots to describe when an ATC message gets transmitted over by someone else. Useful from a safety perspective, IMHO. Agree with the Welshman, 'blocked' probably better as less syllables and it should be in CAP413 (mine's out of date so it might be now).

[DrSyn]

I agree with all after "Rant Over !" Blocked is a short, sharp word understood by all, and therefore useful on a busy freq. It's actually been around for decades, so I am surprised at the sudden interest. The alternatives mentioned seem perfectly reasonable, if longer.

The advent of Contran has certainly reduced the incidence of cross-transmissions but unfortunately is by no means a universal fit. No doubt it will eventually become mandatory only after another tragedy, just like CVR, FDR, SSR, GPWS, etc, etc.

[forget]

Dr Syn. How right you are. I hope I'm not blowing your anonymity but I assume that you fly with the one and only operator, world-wide, with the wit to have installed Contran. Apart, that is, from Airbus Belugas - despite Airbus Industrie saying 'Quelle Problemme??'

It's beyond belief that, decades after Tenerife and the Netherlands DCA Director General urging the CAA's and FAA's of this world to come up with a certified/approved fix for blocked transmissions, those same people just ignore the issue.

Worse yet, the UK's very own CAA (Campaign Against Aviation) has spent more money and effort in discrediting Contran than it would have taken to equip a substantial fleet - including a trial of Ground Contran at Stansted (full marks to Stansted ATC!). What I hadn't reckoned with was the NATS attitude that, if the trial worked, they'd have to spend money fitting the kit. The NATS solution - sabotage the trial. I imagine this may raise hackles somewhere, but the owners of those hackles can reach one of two conclusions. Either the trial was deliberately sabotaged - or NATS (Not Stansted!) employ engineers of breathtaking incompetence. Unlike the real world of Bournemouth who have been operating the world's only Ground Contran for some six years - without missing a beat.

I suppose I'd better a declare an interest; www.contran.co.uk is my baby, but I imagine you've guessed this by now. Anyway Dr Syn, lets hope your predictions are proved wrong, and I'm very pleased that you find the system useful.

[saudipc-9]

Flying in Saudi with guys from 5 different Air Forces, the term "stepped on" is what we use most.
I really don't see what the problem is about using this term. It really is just being helpful to your fellow aviators. What I do find annoying is people who don't listen out before they transmit and thus require me to say "Stepped on":p

[Little One]

Here in SA we say "double Transmition" instread of Blocked. I think its important to be told if there has been a double tx so that no info is lost or misunderstood. We have a side tone on our Headsets which means that we hear the Tx as we make it and if someone blocks us whilst we tx we hear that annoying whining and whistling that goes with a double tx and generally release the foot switch and wait for the idiot that wasn't listining to get off the freq.

Personally my pet hate is when an acft is handed over from one sector to the next and they just hit the comms button and start Tx with out listening 1st. Bad radio etequite (Can't spell).

Having not heard of contran till this forum I used the link above to see whats it was about. I think the best feature is the stuck PTT problem quote
"The secondary function of CONTRAN® alerts the flight crew to an onboard unintentional transmission or ‘stuck-microphone’. If the fault cannot be rectified then automatic termination of the transmission follows."

This I think is great as almost daily some idiot sits on his Ptt and we hear all about his meal etc nothing worse than trying to get acft to miss when you can't speak to them cause all they hear is WOOOOOPPP

About using Blocked It is shorter than Double transmition so I think I will try it out

[B767300ER]

Whiteknight...that 'two at once' or 'blocked' transmission at Tenerife was definately the most fatal aftemath of such an incident. Not sure if the KLM Captain would have stopped, though. He seemed determined to go that day.

583 fatalities actually; still the most tragic accident in aviation history. I was 12 years old when it hapened, and will never forget it, nor its lesson to me as a pilot.