PPRuNe Forums - View Single Post - Speedbrakes on a Cessna 172...
View Single Post
Old 25th March 2002 | 14:02
  #30 (permalink)  
john_tullamarine
Fleet Manager
25 Anniversary
 
Joined: Apr 2001
: ATPL
Posts: 7,448
Likes: 310
From: various places .....
Post

May I throw in a few comments, please ... ?. .. .(a) door open (ajar) in a flying tailplane aircraft is no fun .. the pitch oscillations, initially, are quite alarming. Quite interesting if you are by yourself on the other side of the aircraft. Not the time for rapid and ill-considered actions. The one time I found myself in this situation, I got to a suitable height, rolled left, let go, and closed the door .. and then recovered from the right roll .... after about the third or fourth attempt. I don't know that I would prefer to land with the pitch oscillations, though .... .. .(b) on unpressurised aircraft, the doors' more usual function is to keep out the rain and the drafts ... hence their routine removal for dropping operations ... the possibility of airflow induced vibration should mean that an appropriate review and test program is effected prior to such operations. Pressurised aircraft normally have a structural aspect to the doors.. .. .(c) large flap deflection with aggressive sideslip may present a problem if there be a significant fuselage flow separation. This may cause a significant disturbance in flow field around the tailplane with a consequent reduction in tailplane download and ... an uncommanded (and definitely undesired) nosedown pitching moment ... might not be good fun on short final. Of course, we all have done just this in youthful ignorance and stupidity .... .. .(d) don't know that I would like to find myself in an inadvertant spin in a Cessna unless the CG were well and truly inside the Utility envelope .... it is illustrative to note the very significant reduction in aft limit between Normal and Utility Category envelopes.. . . . <small>[ 25 March 2002, 10:09: Message edited by: john_tullamarine ]</small>
john_tullamarine is offline