PPRuNe Forums - View Single Post - Maritime Patrol Aircraft - Best/Worst Features
Old 29th Sep 2016, 14:47
  #16 (permalink)  
PDR1
 
Join Date: Nov 2015
Location: Mordor
Posts: 1,315
Received 54 Likes on 29 Posts
Absolutely - for journey distances much below about 5,000 miles, anyway. It's like putting out requirements for ever faster carrier pigeons when someone is selling telephones!

I once read a Fast Jet URD which included the phrase "the aeroplane must be able to retract its undercarriage".

A few seconds of thought and you realise that this isn't a requirement at all - it contributes nothing to the mission objectives. It's actually a system solution to the operational requirement:

"Shall operate from CVS-class carriers"

and the performance requirements

"Shall deliver death, mayhem and Xmas presents to a target 500 miles away within 80 minutes of mission tasking"

"Shall have a mission radius (with reserves) of at least 800 miles"

and the operating constraints:

"Shall fit down a standard CVS lift"
"Shall fit in a standard CVS Hangar space allocation" [yes I made this up to keep it simple]
"Shall not require external refuelling support to achieve standard missions"

Within these constrains and requirements most of the available solutions will use a wheeled undercarriage, and it's highly unlikely that the drag of a non-retracting undercarriage would be tolerable. So the undercarriage is a system solution, not a requirement.

QED

PDR
PDR1 is offline