I think the smart pilot uses this technology with one eye on its shortcomings and one eye on the aspects from which he can benefit.
None available within the GA market is yet perfect.
For example. I am very impressed with the electronic approach charts that Avidyne provided as part of their Integra system. The charts enable the pilot to combine the best of the paper world with the best of the virtual world on the same screen. Garmin's approach technology is not as good in that it does not interpolate the plate with the approach as well as Avidyne. Combine the moving map with the plate and terrain awareness and the pilot not only has the ability to verify that he is where he intends to be in the procedure but also to avoid potential hazards when he departs from the procedure for some reason.
Why anyone would feel the need to rely on TAWS outside a published procedure escapes me unless it was part of a home made procedure in which you had personally surveyed the entire area whilst in VMC to ensure your procedure and the terrain correlated with the real world!
Was TAWS designed to provide en route terrain clearance whilst scud running - I dont think that charge sits well at Garmin's door. After all if you are in VMC you going to be looking out the window, if you are en route in IMC you are presumably ignoring every shred of your training if you rely on TAWS to keep you clear of the ground. The vast majority of FITs involving IMC qualified pilots occur during the approach procedure usually because of a loss of situational awareness or control during the approach phase or on the go around. Whilst I suppose it is possible TAWS is also inaccurate in the area surrounding a published approach couple TAWS as I indicated above with the published procedure and you are going to have to get some aspect of the approach or go around horribly wrong if you end up colliding with the terrain for no other reason than a loss of situational awareness.
Last edited by Fuji Abound; 17th June 2008 at 07:53.