PPRuNe Forums - View Single Post - AF 447 Thread No. 5
View Single Post
Old 19th Jul 2011, 00:25
  #475 (permalink)  
john_tullamarine
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,194
Received 105 Likes on 69 Posts
Could you comment on the inclusion of "damaged or missing" radome?

I don't think I saw any comment on this question.

Pitot static performance is dual input - pitot and static.

Apart from blockage pitot performance generally is pretty robust and doesn't give too much in the way of problems.

Static performance, on the other hand, is a bit of a prima donna.

- in the certification phase development of PEC data is a major part of the flight testing program.

- we even go to the trouble of using trailing drogue (cone) static sources to get out of the aircraft's interfering flow fields

- modifications forward of the static source can be a nightmare for PEC effects. I recall one tale about a B52 program where a mod up forward made a BIG difference to IAS during the takeoff - fortunately, the TP had a feeling in the water during the first takeoff and rejected.

- in routine operations, the easiest way to get a massive airflow disturbance which will always cause an effect on the PEC is to have the radome disintegrate ...

For those who like some arithmetic and lots of fancy mathematical symbols, you might like to read reports like this one. (Everything you wanted to know about pitot statics but were afraid to ask ...)
john_tullamarine is offline