Duchess_Driver
24th Apr 2006, 09:25
On a precision approach the DA(DH) is the height at which the decision is made whether to continue the approach or not - and that is based having certain visual references at that altitude (height).
If at that altitude (height) those references are not acquired and the decision to go missed is taken, the natural flight path of the aeroplane would then take the aeroplane below DA(DH) before spool-up-pitch-up takes effect.
During a discussion the other day it was advocated that the decision should be made slightly earlier than DA(DH) to compensate for the time taken to get the aeroplane going up again, thus never descending below DA. However, I'm not convinced that this is correct - as by the name chosen, DECISION Altitude is where you decide if you can continue or not. Surely at this point on a precision approach being well within OCA, allowances are made for a transient descent below.
I understand that on a non-precision approach, MINIMUM DESCENT Altitude, MDA(MDH) is exactly that, the altitude below which the aeroplane should never go unless those references are attained, and if we're now saying that is also true of DA(DH), where's the difference?
Comments please...
If at that altitude (height) those references are not acquired and the decision to go missed is taken, the natural flight path of the aeroplane would then take the aeroplane below DA(DH) before spool-up-pitch-up takes effect.
During a discussion the other day it was advocated that the decision should be made slightly earlier than DA(DH) to compensate for the time taken to get the aeroplane going up again, thus never descending below DA. However, I'm not convinced that this is correct - as by the name chosen, DECISION Altitude is where you decide if you can continue or not. Surely at this point on a precision approach being well within OCA, allowances are made for a transient descent below.
I understand that on a non-precision approach, MINIMUM DESCENT Altitude, MDA(MDH) is exactly that, the altitude below which the aeroplane should never go unless those references are attained, and if we're now saying that is also true of DA(DH), where's the difference?
Comments please...