Turbine D But your point does confirm what some of us have believed for sometime, the standard Airbus UAS memory list is poorly written and needs to be changed.
Yes, agree, the Airbus UAS drill, as still published, can be confusing. However, numerous Airbus publications available on the web indicate how the UAS drill and QRH checklist were, and are to be handled and the FCTM notes do reflect this although they could be much clearer still.
Earlier in this thread I pointed out where in the original (now closed) threads that this discussion began taking place. However, if some comments here are an indication of the broader piloting community, then, without blaming anyone as to why this may be so, there remains a great deal of misunderstanding on when and how to apply the memorized drill and when not to and instead proceed directly to the QRH checklist items. In fact, the memorized drill and the checklist are NOT sequential, they are an "if/then" decision point.
First, when loss of airspeed information occurrs, the qualifying condition, "If the safe conduct the flight is affected" is not clearly defined in the drill-checklist, nor is it defined in the Boeing checklist, (there are no memorized items or initial pitch-thrust memorized combinations in the B767/B777 UAS responses). The drill-checklist is not a sequential drill - rather, the "safe conduct of the flight affected" is a primary "if-then" decision point in the UAS response - the safety of the flight IS affected at takeoff, initial climb or descent/approach/landing.
Loss of airspeed information at cruise altitude is not an emergency and because the airplane is, for all intents, stable in pitch and power, then "nothing" needs to be done (except keep the airplane stable), because the safe conduct of the flight is not affected, (in comparison to the takeoff/landing case). The crew, (PF) assumes control of the airplane to maintain aircraft stability by maintaining thrust and pitch at current settings, (Aviate), maintains/alters heading as required, (Navigate) and calls for the ECAM actions, (Communicate), to be done followed by getting out the QRH Checklist to set pitch and power for the remainder of the cruise.
The graphic below illustrates this and I think this is the source of much of the confusion:
The "Pitch/Thrust settings for initial level off" are just below this point in the drill. The balance of the QRH provides pitch and thrust settings for varying weights in cruise, descent, approach, landing and go-around. However, in all cases of a UAS event in cruise, airspeed indications returned within about one minute, including AF447's airspeed indications, but the stall had been entered by that time.
vilas However the wording used is "If the safe conduct othe flight is affected".For cruise you are expected to level off and follow the unreliable airspeed procedure for trouble shooting. Boeing is not much different. It mentions crew should be aware of appx.pitch attitude for each maneuvre and then asks you consult the table.
Yes. This is the way the drill & checklist were always intended to be done. Airbus stated as much in its
December, 2007 "Safety First" magazine (pg 14): in the oft-quoted-in-original-threads Joelle Barthes article entitled, "Unreliable Speed":
1) If the safe conduct of the flight is affected, APPLY THE MEMORY ITEMS, i.e. fly a pitch with TOGA or CLB thrust,
2) If the safe conduct of the flight is not affected, or once the memory items have been applied, LEVEL OFF, if necessary, and start TROUBLESHOOTING,
3) If the affected ADR can be identified, fly with the remaining ADR. 4) If the affected ADR cannot be identified or all airspeed indications remain unreliable, FLY WITH PITCH/THRUST REFERENCES. - Safety First magazine, December, 2007, Joella Barthes
followed by the a graphic, describing what is intended by the above:
- Safety First magazine, December, 2007, Joella Barthes
In fact, in an
Airbus presentation in September 2006, it is clearly stated that what constitutes "safe conduct affected" is defined in training:
Airbus OLM FBW 2006, (Unreliable Speed) - Toulouse - 23-28 September 2006
In my opinion and from what I have researched for a long time now, the UAS response is NOT a sequential drill-checklist - never was.
What is confusing about this is not entirely nor necessarily the Airbus UAS drill and checklist. The large black dot is a decision-point, not a "start here and follow all items" point. Buy down below, the "Level Off..." action item has the same black dot, making the drill-checklist appear "sequential". It is not.
A large part of the problem is knowing the way checklists are written in terms of these "decision points" and the meaning of correct indentations, (which this drill-checklist appears to not have). The decision point regarding safe-conduct-of-the-flight-affected permits/requires that the crew either execute the memorized items OR, (in cruise for example), they do the QRH checklist after stabilizing the aircraft in level flight.
This has all been reviewed and discussed in the original threads (part of which has been pointed out but, I assume, not viewed or referenced by some in the present thread.