Disasters due to ATC misunderstandings

[pilot007]

Hi folks,

since I've a lecture on communication in civil aviation I need a few examples of disasters due to ATC misunderstandings (or communication failures within the crew).

When was the accident with the 747s in Amsterdam? What went wrong? Do you have other misunderstanding/misleading examples?

I hope that you can help me out?!

Thx,
pilot007


P.S: This topic is also posted within the ATC section.

[RRAAMJET]

huh?

I presume you mean the ground collision between KLM and Pan Am in Tenerife, 1975? The only other 747 fatal in Amsterdam was an EL AL freighter in the late 90's.

Must be something in here using the search function....

[West Coast]

It may be a bit of a stretch considering what your looking for...

Look at the Eastern L1011 crash in the Everglades in 1972 and the role ATC played.

[ramsrc]

This probably doesn't really belong in Rumours and News - but then I am not a moderator so I'll post a link to the Pan Am/ KLM CVR transcript which is Here (http://aviation-safety.net/cvr/cvr_kl4805.shtml)

Plus - some information and analysis from the ICAO circular Here (http://www.panamair.org/Accidents/sectenerife.htm)

Another disaster worthy of consideration is the collision of the Adria DC9 and British Airways Trident over Zagreb in 1976.

[Daysleeper]

The Zagreb was more systemic controller overload rather than a communications breakdown.

Try American 757 at Cali, crew misunderstood the controller then struggled to program the FMS.
Or the Dan Air 727 in the Canaries.

[Dengue_Dude]

DAN Air 727, Mount Tidy, Tenerife Canary Islands

Misunderstanding of ATC instructions and wrong actions by crew.

Recent 757/Tu154 over Switzerland and TCAS resolutions

This is a dynamic process, R/T phraseology with confusion between things like 'TO' and 'TWO' are being addressed all the time.

Flight Level 'Wun Zero Zero' being changed to Flight Level 'Wun Hundred' etc is proof that the system does 'care'.

Good on 'em, they've got my vote.

Good luck, the more we understand 'mis-understandings' the safer we'll all be.

[Final 3 Greens]

There are many examples in a book written by David Beatty, called "The Naked Pilot."

It is published by Airlife and the ISBN is 1-85310-482-5.

I lecture on project management and have applied the underpinning theory to show how we are all vulnerable to human factors.

[cribble]

A Flying Tigers B747 freighter got caught out by a communication misunderstanding, on approach to KUL, a number of years ago: "Descend 2400..." vs "descend to 400.." resulted in an impact well short of the Rwy 30 threshold.

Details hazy now but we used to use it as a communications case study.

[Dan Winterland]

Charles de Gaul a few years ago. A BritishShorts 330 crew were given a runway crossing clearance in English and acted on it. Meanwhile, a French airliner was given a take off clearance in French. The aircarft collided killing the British First Officer.

[nitefiter]

I was given the clearance "descend now FL240" a couple of weeks ago and i read back "descend now 240", immediately and after thinking about it, quite rightly,i was asked to confirm flight Level 240,which at the time i was convinced i already had,but I could have read back "descend to 40",big difference.I used to fly with a guy (old school) who said that " The words TO and FOR should never be used on the RT,he has a point!

[Basil]

A recent potential for misunderstanding (due to the introduction of RVSM) is that 330 and 320 can sound dangerously similar on the RT.

[Old Smokey]

Going back to cribble's post -
"Descend 2400..." vs "descend to 400.."
The controller's words "Descend Two Four Zero Zero" (correct in the phraseologies of the time) was the origin of the current use of "Thousand" in the altitude call. In today's words, it would have been "Descend to Two Thousand Four Hundred".

We live and we learn, it's surprising even today to hear many pilots, and some controllers, not using the "Hundreds" component of F/L 200,300 etc., but still using zeros.

Users of Australian airspace will note that there is no Runway 02 or 20 in the country, even if the runway direction indicates that it should be so. 01/19 or 03/21 is used instead, whichever is closer to the actual. This originated from an accident many decades ago when 02 was interpreted (fatally) as 20 by a pilot.

I'd be interested to know if the American practice of not using the preceding zero for runways such as 06, has lead to a significant incident or accident.

[LYKA]

nitefiter:

the words "to" should only be used when descening/climbing to an Altitude. i.e. descend TO altitude XXXX. Omit the "TO" when climbing to a FL, i.e. Clmb FL 240. CAP 413 stuff for those interested.

[atcea.com]

I once cleared an aircraft (using incomplete phraseology) "turn left three-one-zero"

vs the correct:

"turn left heading three-one-zero." Pilot read back: "Roger, three-one-zero" . . . and started a climb to FL310.

There's no substitute for proper phraseology. "Shortcuts" can be dangerous!

[bookworm]

Try Cushing's Fatal Words (http://www.amazon.com/exec/obidos/tg/detail/-/0226132013/) for a number of examples.

[Airbubba]

>>Users of Australian airspace will note that there is no Runway 02 or 20 in the country, even if the runway direction indicates that it should be so. 01/19 or 03/21 is used instead, whichever is closer to the actual. This originated from an accident many decades ago when 02 was interpreted (fatally) as 20 by a pilot.<<

Sounds like a lysdexic urban legend <g>. Is this really true?

>>I'd be interested to know if the American practice of not using the preceding zero for runways such as 06, has lead to a significant incident or accident.<<

What would they confuse it with, runway 60? We try to keep things simple in America for safety's sake. Of course, we don't always succeed...

I'm always worried about those conditional clearances to taxi onto the runway that you get in many countries: "Behind landing traffic, line up and wait". I've seen this eagerly given as one aircraft is just touching down and another is on fairly short final. You could sure guess wrong in this case.

Perhaps just as bad is the U.S. practice of issuing multiple landing clearances on the expectation that the preceding aircraft will be clear of the runway in time.

One that gets some U.S. crews is "taxi to holding position runway 05". If you haven't flown overseas it sounds a lot like "taxi to hold in position runway 05".

Of course, my favorite taxi clearance is in SIN, "taxi on the greens..."

[Old Smokey]

Airbubba,
No, the Australian convention for 02/20 runways is not "lysdexic urban legend", it is policy. There's plenty of examples to prove the point, e.g. Townsville RWY 01 is actually 017 degrees. We don't seem to have the same problem in Singapore where there is an abundance of 02/20's.

My query regarding any history of incidents and/or accidents in the U.S. with common use of single digits for runways, was a query in reverse to what you may have thought it to be, if there's no problem then why doesn't the rest of the world use it as well, in the interests of simplicity. The only area that I could conceive of a problem would be at an airport with another runway ending in 6, e.g. Runway 26 at an airport also with a Runway 6.

And yes, "Taxi on the greens" in SIN does make life simpler, for pilots anyhow, it must be like working a train set up in the tower.

.

[bookworm]

Brisbane and Townsville both seem to have 01/19s that would be more geometrically labelled as 02/20s. But Ayers Rock has a 13/31. Why avoid 02/20 but not 13/31?

(from Cambridge, UK, which used to have both 02/20 and 13/31 :))

[JABBARA]

In Kuala-Lumpur, a final approach course CFIT.

747 is cleared to descent to 2400 feet as being transmitted "clear to descent TWO-four-hundred feet".

Acknowledeged as "descending TO four-hundred feet"

[Sick Squid]

A contributory factor to the Kegworth BMI 737 accident were the ATC requests made on the crew during a period of very high workload. Should be seen in context with the well-known inter-cockpit issues in that accident; prioritisation, clarity of decision making processes, use of SOP's and more.

Agree with the Naked Pilot recommendation above, also check out Stanley Stewart's book on accidents, the name of which escapes me right now.

[ramsrc]

That'll be "Emergency - Crisis on the flight deck"

Cheers! That's the one... Squid.

[EastCoaster]

Quote:

"In Kuala-Lumpur, a final approach course CFIT.

747 is cleared to descent to 2400 feet as being transmitted "clear to descent TWO-four-hundred feet".

Acknowledeged as "descending TO four-hundred feet"


Why not "Descend "TIL" two tousand four hundred feet"? No ambiguity there!

[Cornish Jack]

Re the KUL CFIT - we used to use this incident as part of the CFIT training input. The video re-construction, which includes the actual CVR tape, is exceptionally powerful in getting the message across.
What is even more worrying than the misreading/mishearing is the fact that three experienced crew members accepted, without query, a descent clearance which they understood to be to a specified FOUR HUNDRED feet. Can anyone point me to ANYWHERE which would issue such a clearance to an aircraft operating IFR????
Additionally worrying was the TOTAL lack of any response to the repeated 'PULL UP' warnings.
This video ought to be an essential part of any initial and recurrent training - as, indeed we used to.

[JABBARA]

EastCoaster,

Why not "Descend "TIL" two tousand four hundred feet"? No ambiguity there!

ICAO Annex 10 and ICAO DOC 4444 prescribes how to speak altitude and flight level. That is exactly what you said, thousands and hundreds are spelled seperately:

2400 feet: "Two-thosand-four-hundred"
11500 feet: "one-one thousand -five hundred"

Cornish Jack,

Remember in this particular disaster "fatigue" is also a major contributing factor. But you know still we dont have SUBPART Q (FLIGHT AND DUTY TIME LIMITATIONS AND REST REQUIREMENTS)
in JAR OPS1

I do not know what they are waiting.

[Micky]

Stanley Stewart book is called air disasters ( try amazon), it is I think number two next to Emergency- Crisis on the flight deck (only storys were crews saved the day...)and flying the big jets...
Regards
Micky

[visibility3miles]

Although hardly examples of disasters, as a student pilot making my first (required) long distance solo flight, someone burst on the frequency for the uncontrolled (no tower) airport in a panicked voice IN FRENCH just as I was taking off.

I am not trying to make negative comments about the French, but whoever it was sounded like there was a major problem. I couldn't see any other plane, and still have no idea what it was about, but it got my attention as a student pilot.

Another non-event at an uncontrolled airport occurred when I was calling downwind for runway XX at airport xyz, when another aircraft announced that they too were landing at runway XX, but failed to mention the airport. Basically, whoever they were (they never identified their aircraft or the airport they were landing at) kept calling the same positions for a landing at a runway with the same heading as I was landing at, yet I never saw them, despite looking VERY carefully. (And, in fact, no other plane landed at that airport at the time.)

I don't know if it was someone landing at a different airport with the same runway heading (a possibilty), or if it was someone just having fun.

[EastCoaster]

Jabbara,

Think you might have missed my point. Wasn't the actual enunciation of the levels or the fact that the hundreds and thousands of feet are separated, it was the til in parentheses that I was trying to highlight.

Not much chance of getting that mixed up with an index in any clearance or instruction.

On the up-side though, nice to know that my knowledge of standard phraseology is still up to scratch!! Cheers Jab :ok:

[enicalyth]

Think altimeter in a Piper, say. Think of two nationalities. Hear the words a) Set 29 92; b) Set to 992. Pilot a) sets 29.92" Hg direct; pilot b) looks at a card reads 992mb = 29.29" Hg. Roughly 600ft difference? Now that's one to avoid through explicit RT procedure.

Also wasn't there a case once where a ground vehicle asked permission to cross xxx but someone cut across the transmission? Next he heard was his callsign and the words "Go ahead.." Handbrake, clutch, bang!

[MachD]

"Taxi on the greens" in SIN does make life simpler.

How about in BKK, does QF get the instruction "Taxi on the fairways?"

Only jokin' ;)

[Frangible]

Tenerife (1977) was not down to controller misunderstanding. It was down to taking off without clearance. ATC was cleared in the Dan air too.
Uberlingen mid-air July 02 was a classic of ATC versus TCAS, as was Jan 31, 2001 JAL incident (DC10 and 744 with 677 total souls missed by 10 metres, and 100 injured in violent avoiding action) which was also ATC versus TCAS (and five other very close calls in Europe alone in 2000/1, according to a Eurocontrol survey).

The best example of true misunderstanding between cockpit and tower was Avianca 52 in January 1990 at JFK, where the co-pilot repeated he was running out of fuel and tower paid not attention because he did not hear the magic word "emergency". They flamed out and crashed on Long Island, killing about half on board.

[bookworm]

Tenerife (1977) was not down to controller misunderstanding. It was down to taking off without clearance. ATC was cleared in the Dan air too.

It's plausible, perhaps probable, that the crew misinterpreted the controller's instructions for "after take-off" as a clearance to take off. That makes the acciedent clearly relevant to the issue of misunderstandings between ATC and crew. It does not mean that ATC was in any way to blame.

[Semaphore Sam]

It seems "Descend & Maintain 2 thousand 4 hundred" or "FL zero two four" does the deed sufficiently...no strange 'til's', no ambiguity.

As for altimeters, reporting an altimeter setting isn't an order to set it. "Altimeter two niner decimel five seven" , or "Altimeter two niner point five seven" would do; a controller should just report altimeters (and Transition Levels, when 'by ATC').

"Descend to" and "Set to" are inherently dangerous; other choices are available, AND non-ambiguous. Unfortunately, many don't use them (especially in F-Land, where they also hate to ID fixes/beacons phonetically, requiring 4 or 5 calls where 2 would do).