PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 2
Old 2nd Mar 2012, 17:19
  #20 (permalink)  
RR_NDB
 
Join Date: Feb 2011
Location: Nearby SBBR and SDAM
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
1st question

Hi,

HazelNuts39,

Not sure that I understand the question.


Is the power being applied to the AS probes enough in order to their proper operation?

The power UNDER STEADY STATE CONDITIONS (operating at MAX POWER) is enough?

Operating at MAX power there is no delay, i.e. you are in a "open loop" mode wasting energy and stressing materials when not necessary.

I guess the max available power is enough. (Just guessing).

And i suspect the amount of heat are not being sufficient when encountering ice. This "encountering" was mentioned to be heard on CVR.

I took into account PJ2 post when formulating all 6 questions,

The problem of momentarily blocked pitot tubes is extremely rare. Appendix 7 of the BEA Second Interim Report, which see, lists the events which occurred to Airbus. (...) but given the millions of ice-crystal-cloud-penetrations that occur each year without result, "avoiding all cloud" isn't realistic.
The recorded data show the opposite of a temperature drop. At 02:09:30 the temperature was ISA +10.6°C, trending downwards (Interim #3, p.48), and at 02:10:00 it was ISA +15.6°C (p.86).
I am talking in the transient, just after noise increased in CVR due ice crystals "collisions" to windshield an nose cone surfaces.

I also took into account the recorded temperature, (higher than expected and imposing a FL375 REC MAX) not relevant to my rationale. I am looking to the transient, the so called t0+, just after encountering ice crystals when the heat MUST BE PRESENT immediately to assure proper AS sensors operation.

Last edited by RR_NDB; 2nd Mar 2012 at 17:31.
RR_NDB is offline