Tailplane Dihedral
Joined: Dec 1999
Posts: 27
Likes: 0
From: Approaching DANDI FL240
As tailplane force acts downwards ( 
hopefully ), the lower pressure should be on the lower surface. It could thus be a question of an anhedral effect, decreasing spanwise flow and improving tailplane effectiveness.
But who am I to speak of such complicated matters
hopefully ), the lower pressure should be on the lower surface. It could thus be a question of an anhedral effect, decreasing spanwise flow and improving tailplane effectiveness.But who am I to speak of such complicated matters
Joined: Feb 2000
Posts: 120
Likes: 0
From: New Zealand
That's the one. TP Dihederal is not a stability thing in most airliners.
Our two Welsh and Two Chinese friends who are responsible for lateral stability (Di Hedral, Sweep Baack, Hi Fin and Hi Wing [you will remember that now - huh? - lol]) have more than enough effect on the mainplane and fuselage. You do get some Lateral Stability from DH on the tailplane - but usually you are looking at a cleaner airpath solution on the approach...
MG
Our two Welsh and Two Chinese friends who are responsible for lateral stability (Di Hedral, Sweep Baack, Hi Fin and Hi Wing [you will remember that now - huh? - lol]) have more than enough effect on the mainplane and fuselage. You do get some Lateral Stability from DH on the tailplane - but usually you are looking at a cleaner airpath solution on the approach...
MG
Do a Hover - it avoids G
Joined: Oct 1999
Posts: 2,201
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From: Chichester West Sussex UK
Agree with Master Greens comments, but would add that more than one design office faced with the wrong dihedral EFFECT from the whole aircraft has found it cheaper to redesign the tailplane spar than the wing one....
Certainly if a design has an anhedral tailplane (like some military types) it is likely that it is an attempt to reduce an otherwise excessive overall aircraft dihedral effect.
Certainly if a design has an anhedral tailplane (like some military types) it is likely that it is an attempt to reduce an otherwise excessive overall aircraft dihedral effect.
Joined: Oct 1999
Posts: 398
Likes: 0
From: United Kingdom
I understand the anhedral on the Phantom's stabiliser is because it should ideally have been lower down on the fuselage
This was impractical due to the position of the engine outlets so it was effectively made lower by adding anhedral. This may also be true for other military types
This was impractical due to the position of the engine outlets so it was effectively made lower by adding anhedral. This may also be true for other military types
