Western727 From United States of America, joined Jan 2007, 872 posts, RR: 4 Posted (14 years 4 months 5 days 1 hour ago) and read 1184 times:
According to my Instrument Ground instructor, the term "Obstacle DP" is the official terminology. And I'm not talking about the former SIDS, now known as "DPs" (routes that you can file in a flight plan). According to the person who sits next to me in one of my aviation classes, "Obstacle DP" is a term unique to Jeppesen, and ATC will get upset if you use it over the radios. I'm confused. Which is the correct?
Incedentally, my instructor filed an IFR flight plan, and in the remarks section he put "No DP, No STAR." Flight service didn't know what he was talking about.
Jetguy From , joined Dec 1969, posts, RR:
Reply 1, posted (14 years 4 months 3 hours ago) and read 1155 times:
I believe that your instructor was referring to the "Takeoff & Obstacle Procedures" that are located with the airport diagram at those airports whose departure procedures require something other that the standard TERPS gradiants. They can be quite complex and convoluted, but it is imperative that they be flown precisely if you want to keep from putting your nose into the dirt when departing these airports under IFR conditions. I've never heard them referred to as "Obstacle D(eparture) P(rocedure)s" on the radio, but rather by the phrase "Standard Departure Procedures" As far as the folks at FSS not knowing what you were talking about when he used the the phrase "No DP, No Stars" just be patient and give them some time to get used to this recent change. Just explain to the briefer that you want "No Sids or Stars" and he'll know exactly what you mean. Some of us are still annoyed with the airspace and weather reporting changes a few years ago. Talk about the tail wagging the dog. Hope this helps.
Sunken_Lunken From United States of America, joined Jul 2001, 87 posts, RR: 0
Reply 2, posted (14 years 4 months 1 hour ago) and read 1139 times:
I seem to recall hearing the term "obstacle DP" before, but I don't know where I heard it. I have not seen it printed on anything though, so maybe it's an unofficial term?
I have a guess though. Is it possible this term refers to the non-standard takeoff procedures (like Jetguy said)? I am thinking of the "T" printed in a black triangle on the bottom of NOS plates. This refers you to a page that describes an IFR takeoff procedure.
For example, I departed IFR out of Williamsport, PA once (KIPT) from rwy 9 in IMC. Though there is not a published DP with a name (as would have been called a SID in the past, like REDSS FIVE out of CVG), there is a procedure listed. I don't have a copy with me now, but the procedure called for runway heading departure to something like 2500 MSL, then a climing left turn to a VOR before proceding on course. The reason for this procedure is to keep you away from the 2000 ft. mountain ridge on the south side of the airport.
My guess is that procedures like the one I described above are what some call "obstacle DP's". They were created to keep you from hitting something (just like a published DP with a name), but were not invented because of a need to organize departing traffic from a busy airport.