by | 2021-05-30
Long turboprop aircraft that sustained extensive fuselage damage inflight due to a collision.
Metroliner involved in a midair collision. One can attest to the airframe solidity. (Photo: The Aviation Herald)

A hard wake-up call

The May 12th 2021 midair collision between a Metroliner and Cirrus on approach at Centennial airport (KAPA, 20 nm, SSW KDEN) shows a couple of staggering points. 

First and foremost that no one was hurt, never mind killed is a welcome change from the norm under similar circumstances.

The other point that stands out like a sore thumb freshly crushed by an out of control hammer is communications.

Evidently, there is no accident report issued so soon after the event. Nonetheless, an important element that will surface are the communications between ATC and the Cirrus involved.

No one has the right to offer an explanation for this accident. Like any case like this one, no one was sitting at the flight controls other than the concerned crew members.

Regardless, coming from the already well public comms, one can easily understand the exchanges between ATC and the Cirrus pilot. The controller advises the right base for 17R Cirrus that he has a Metroliner traffic, final, landing on 17L. The Cirrus pilot acknowledges the traffic insight.

Vital tool

Communications cannot be clearer.

Within CRM training, a wide array of points deserve to be mentioned regarding communications. One can spend literally hours of training on communications alone, this not for public relation personnel but for aircrew and ATC controllers.

An « aviation certified » definition of communication can be: « Communication is the more or less efficient transfer of vital information for the safe conduct of flight between two or more individuals. »

The quality of the message, which has nothing to do with its critical nature, depends largely on the transmitting and receiving individuals and their own perceptions.

In respect to the KAPA accident, the critical message transmitted by the controller to the Cirrus pilot is that there is an incoming traffic landing on the parallel runway. The controller’s transmission is crystal clear: No static on the radio, clear language is used with mumbling, the microphone is close to the mouth. Above all standard phraseology is used and understood by the two aircraft crew.

We can assert with confidence that no one wishes to witness an accident from within.

The response to the controller from the Cirrus pilot is also clear coming from a good quality radio: «  Traffic in sight. »

Common sense would dictate that the Metroliner traffic threat indicated by ATC would become a priority to be avoided. The critical message is recorded and will be used to maintain safe spacing.

This is the point where the accident investigation will take its bulk of work:

  • Did the radio transmission permit the pilot to react adequately and in time?
  • Was the transmission perceived as sufficiently relevant for both aircrew?
  • Can either pilot in command become complacent with traffic so close?

A multitude of questions will be asked before concluding. However, at the root of the accident will be communications.

Closer to home

Another situation, definitely less spectacular, no less consequential and certainly at the opposite end of the spectrum occurred a couple of days following the KAPA event.

Close by Montreal (Canada)in class G airspace within an ATF (aerodrome traffic frequency – the equivalent of CTAF in the USA), this instructor was busy practising stop and goes with a student. Traffic was non existent for at least 30 minutes. Comms were maintained with standard call-outs all along the circuit.

The surprise was complete when a traffic suddenly reported on short final asking when if we were to take-off soon! 

Dear reader, should you have any emotion to let out, I totally understand, since this instructor had just formulated in his mind a few colourful metaphors that were definitely lacking in elegance. 

Two extremes are in play in these two cases. First standard radio communications incomplete in their intended outcome. Second, inexistent communications despite the regulatory requirements, perceived with reason as a flagrant case of voluntary non-compliance.

Without any doubt, we can all recall Class G « adventures » despite our best efforts to avoid them.  

Considering that the vast majority of midair collisions occur near an airport and that communications are a major contributing factor in those accidents, it would be appropriate to consider flight management in this domain.

The vital importance of clear and procedural communications is to reduce known risk. « Known » since obviously air traffic is not so predictable as to its arrival within one’s safety bubble, one know’s that it will eventually occur.

Communications are the corner stone of CRM. As a reminder, CRM is without any doubt one of the best tools science has provided to our industry to reduce accidents. Good CRM requires that communications must be optimized. 

Matters are troubled from the start when regularly, traffic comes in with downright pitiful radios which sprinkles quantities of ambiguity in the proximity or straining phonetic intonations, difficult to decipher add another layer. Forget standard phraseology many times it is scant annoyance. 

When operating within class C or D airspace, controllers for evident reasons, always maintain standard phraseology. Moreover, should a transmitting aircraft radio quality be mediocre, controllers will mention the fact. When in rush hour an aircraft may be denied entry in controlled airspace (risk management) for having bad comms unless an emergency exists of course. 

What is the case within Class E (VFR) or class G? It is a fair understatement to mention the legendary « Far-West ».

In Canada, we have never ending, yet essential, position reports on 126,7, this has become problematic. Understandably well meaning, many transmissions have become too wordy. Typical example after stating one’s position one adds the very implicit: « conflicting traffic please advise C-XXXX on one twenty-six point seven ».

On a sunny Saturday morning, the heaviness, length of those reports have many out there tuning out at their own risk and peril to others. We all recognize in this country that different traffic frequencies should be attributed for different reason. Unfortunately, the authorities administrative comfort forbid such an innovation.

Is it so difficult to review procedures?

Another « good one » is the aberrant creative interpretation of our AIM RAC 4.5.2. This section deals with traffic patterns in uncontrolled airports. In our part of the world an increasing number of pilots report themselves approaching an airport on the « inactive side ». This artistic call implies for the transmitting party that they feel safe and secure away from all those “nasties in the circuit. Alas, the upwind sector is everything but inactive. Buckets of traffic transit there descending, slowing, checking windsocks to eventually join the circuit in the downwind leg.

Last week, one has even overheard « dead side of the runway», really! Nah, thanks I will come back later! Even more troubling are some instructors from a big respectable nearby flight school using this kind of non-standard phraseology along the admiring and attentive students.

It appears that for many instances while in discussion, complacency et even worse smugness in our procedure obscures good flight discipline.


Flying in class G airspace should be safe thanks to well established rules and procedures. Who would ever think of transmitting loud and clear ambiguous or creative communications in class C or D airspace. Air traffic controllers discipline help us allot to put in perspective proper communications. This writing’s intention is not to praise the excellent work of ATC but to bring to light communications that are a capital part of the now basic James Reason Swiss cheese model. In class E (VFR) or G, ATC support is non-existent unless requesting flight following should time allow it for the regional sector.

We all know that some pilots will avoid altogether controlled airspace by inability to submit themselves to basic rules and procedures. We can state that it is perhaps wise to not exceed one’s limitations. However, those very same pilots with limited communication capacities will evolve in their very own right everywhere else.

Class G airspace now becomes the legendary Far-West where rules and procedures apply only when convenient for the operator.

A long time ago, I thought that flying was a calm, relax and agreeable « activity ». Hey! We are all proud to demonstrate that we can beat the laws of gravity with great ease when mingling in large living rooms. Well, approaching an aerodrome it is everything but this!

A long time ago in the industry, we have understood that standard operating procedures is the strict minimum technique to allow safe flying. Handling the flight controls comes second.

The agreeable aspect will always remain of course, forget the calm and relax and part!

Aviators have to manage numerous known risk factors. Why do some create new ones with mediocre communications requiring yet more transmissions to clarify:

  • Unreadable: « Traffic mumblemumble GXXX groblegroble. »
  • Imprecise: « Traffic Whateverplace FXXX 30 miles out inbound. » 
  • Useless: « Traffic ABC, I have you visual, you are at my 3 o’clock. »
  • Completely inexistent (especially when required): «       . »

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2 thoughts on “Communications

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