Expert: David Bidwell - 11/1/2004

Question
I have 2 questions for you.

1. When I am on precision or non precision approach and I am at the DH or MDA and I see the ALS, I can descend 100 feet lower right, not a 100 feet from the ground?

2. When I am leaving a non-controlled airport and it is complete IFR. And In need to get a IFR clearance to leave because I cant take off until I have the clearance because Im socked in. So, do I get a clearance from WX BRIEF or who would I get it from since I cant talk to anyone on my radio until I am up in the air. And they would give me a block time or a hold for release right?

Thanks,
Korey

Answer
Hi Korey,
For descent below the DH or MDA you should refer to FAR 91.175.  91.175 (c)(2) states in part, "the flight visibility is not less than the visibility prescribed in the standard instrument approach".  FAR 91.175(c)(3)(i-x) refers more directly to your question. At least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:
(i) "The approach light system. except that the pilot may not descend BELOW 100 FEET ABOVE THE TOUCHDOWN ZONE ELEVATION USING APPROACH LIGHTS AS A REFERENCE UNLESS THE RED TERMINATING BARS OR RED SIDE ROW BARS ARE ALSO DISTINCTLY VISIBLE AND IDENTIFIABLE".  The reg goes on.  I strongly suggest that you read it thoroughly.

For clearence at a non-towered field, you would normally contact flight service for the instructions and clearance void time.  However, often, you can contact clearance delivery from the ground.  Be sure to check your AFD and or Jepp plate.  On an occasion FSS will give you a telephone number to the nearest approach for your clearance, also.

I hope this all helped.  Good Luck,
Dave