*** Do not use this for flying refer to your AFM and company policy OM ****
One of the more interesting and dare I say important investigation reports was released yesterday by the Australian ATSB (Australian Transport Safety Bureau).
The report is titled “Airspeed indication failure on take-off involving Airbus A-330 9M-MTK” and can be found in the link here.
If you do not wish to read the entire report (and you do not It is very long) read the safety message on page iii and iv.
Another noteworthy section is on page 44 “Study on flight crew take-off monitoring”
The other section worth reading is in the analysis portion titled “Take-off without airspeed information” on pages 86-88.
The highlights of chain of events are as follows:
The Malaysia Airlines A330 took off from Brisbane airport Queensland on a flight to Kuala Lumpur Malaysia.
However, all three pitot tubes were covered by the dedicated covers installed for the layover as a protective measure against mud wasps. This was a regular practice at Brisbane airport which is infested with these bugs. The airport even issued a safety brief on the matter.
The crew did not reject the takeoff even though the airspeed irregularities including flags, started well before reaching 100 knots which is the go/no-go speed for Airbus airplanes.
The crew climbed to 11000 feet worked the relevant checklists activating the Back-up speed scale (BUSS) and were able to land safely in Brisbane.
The report is excellent as it goes deep into analyzing a few very interesting questions and suggest a few points to consider.
The report is one of the first I read that goes into the territory of: things must be written in the various manuals (FCOM, FCTM, AFM AOM etc). That’s a given. But the mere fact that they are there does not mean that the crew will follow them to the letter as there are other factors in play, and this fact must be assumed in almost everything we do.
I wish to use this article to address three questions:
How come five walk-arounds missed the fact that the covers were still there?
How come a fully qualified crew failed to reject the takeoff at slow speed despite all the indications?
If this can happen, what should we do? or change?
The bottom line is that risk management mitigations do not stand alone, they tend to be interconnected. If you put to many assets to mitigate one risk, you might end up being blind-sided by another. The balance of different hazard mitigating must not be neglected. This interconnection must be considered, and priorities put in place, taking into account that we are willing to accept minor incidents so long as our system is built to avoid severe incidents and accidents.
Five times. Five different times someone should have seen the covers.
But they didn’t.
So, what should be done? Should the engineer and pilots be punished or fired? Should we better our procedures?
Well, the fate of the personnel involved is not mine me dt decide nor is it yours.
The thing is that we must assume that on occasion this will happen, the covers will be missed. On a very rare occasion. But this is also true for Mud Wasp nesting in the pitot tube. So, the report says and I agree that the risk management of the wasp nest pitot tube block should be weighed against the risk of pitot covers being left on the tubes. Not only the likelihood of occurrence but the severity as well. We check the Risk management matrix every time we manage a risk. Do we remember to manage the risks caused by mitigation means put in place?
Pilot Monitoring during Takeoff (Captain vs FO).
The study on pages 44-45, shows that we react not as good as we think we do. Half of us made the wrong go/stop call for engine failure 10 knots before V1.
We do not all look at the same places of interest during take-ff.
And all this is dependent on Captain/FO and PF/PM.
As PMs we need to be more focused on what’s going on inside the cockpit. Ending parameters, Airspeed parameters ECAM/EICAS alerts. We react much slower in real life than in the simulator. The PM has almost nothing to look for outside, maybe birds or Kangaroos if you live in Australia. You definitely do not need to monitor the centerline, If your copilot is unable to keep the airplane on the centerline you have bigger problems.
It is very natural to want to look outside, and we should. But to balance the risks of the PF not keeping the airplane on the centerline, late recognition of a seldom encountered problem and late reaction to such a spot. Add to that startle effect, communication, trying to troubleshoot where we are not supposed to and there you have it, it is easy to find yourself airborne while theoretically you were supposed to reject.
Airspeed Unreliable Non-Normal Checklist
Those of the readers that read this website know that I am in favor of changing the Airspeed Unreliable Non-Normal Checklist.
The OEMs have a somewhat different interest in designing checklists, Pilots and management pilots have a goal of zero accidents and zero severe incidents. OEMs on the other hand also have another interest and that is liability in the unfortunate event that an accident will occur. This interest was given a boost following the Air Canada 624 lawsuit against Airbus for “failing to direct crews to monitor altitude vs range during the approach”.
So I for one believe that the risk management in the Airspeed unreliable Non Normal checklist is skewed towards completion of the procedures and fails to take into account the importance of Flight-path-monitoring by the Pilot monitoring.
In a similar fashion to what the industry decided to do with the SMOKE checklist following SWISS 111, i.e., add every three or four lines “a diversion may be needed” we need to add instructions to the pilot monitoring to put the checklist aside and monitor the flight path, energy, and trajectory every once in a while.
The bottom line
Risks are interconnected. We have to consider the effects of managing risk A on risk B.
We must acknowledge our weaknesses such as wanting to be in control of everything and trust the developed system that is designed to address these weaknesses, and our crew members.
It is the management of the airline that is responsible to develop such a system, we as pilots and operation personal should not expect this to be done for us by the manufacturer their interests do not overlap 100%.
The FCOM is more a user manual, than an airline-line oriented-operations manual. It is the legal responsibility of the operator. Not the manufacturer.