fish314
Well-Known Member
The short answer is it means "Or STANDARD", which for civil aircraft is 1/2 statue mile for airplanes with more than 2 engines, and 1 statue mile for airplanes with 2 engines or less.
For MILITARY airplanes, it depends on your command. USAF Air Education and Training command requires 300'-1 or landing minimums, whichever is higher (in most cases). USAF Air Mobility Command required 1600 RVR or 1000 RVR for operational missions.
SOME MORE GOOD IFR TAKE OFF stuff:
Before the first instrument approach into an airfield is approved by NOAA they conduct a survey to determine if an IFR departure is possible. The TERPS guy goes out to the end of the runway and measures a rising slope from the departure end of every runway that goes UP 1 foot for every 40 feet it goes OUT. That's called an Obstacle Identification Surface (OIS).
If nothing penetrates that 40:1 OIS then a diverse departure is authorized, which means that an aircraft can depart the runway using standard take-off weather minimums and maintaining a minimum climb gradient of 200 feet/Nautical mile on departure. Upon reaching 200' AGL and passed the departure end of the runway, the aircraft can turn in any direction on course.
SO WHAT ABOUT IF THERE ARE OBSTACLES THAT PENETRATE THE OIS?
The first option that the TERPS guy has is called a "screen height". At US Army or Civil fields, the terpster can raise the starting point of the OIS slope up 35 feet from the departure end of the runway. From that point the OIS still goes out 40 feet for every 1 foot up, but since it began 35 feet higher, the obstacle might not penetrate the OIS using a screen height. If it doesn't penetrate NOW, then the terpster doesn't have to publish alternate take-off minimums or departure procedures, which means there will be no "trouble T" at the front of the book (using NACO/DOD/NOAA style books). At US Air Force or US Navy fields, the TERPSter isn't allowed to use a screen height without publishing it. So the upshot is that at a civilian or army field you must always cross the departure end at 35' AGL. (At a JOINT USE field, which has both USAF and civilians, like Charleston, SC or Honolulu INTL, it depends. If any of the approaches were created by USAF or USN, then they will have to list the screen height in the trouble T section if it is required on ANY runway, but if the approaches were all created by the FAA, then no trouble T is required, even if a screen height is used).
The next option that the TERPSter has is requiring a climb gradient greater than the standard 200 feet/NM.
Another option that the TERPSter could use is increasing the take-off weather minimums for that runway. For example, for Part 91 aircraft with 2 engines or less, the STANDARD take off minimum (IFR) is 1 statue mile. But the TERPSter may require weather of 2300-2 to take off on that particular runway. These weather minimums assume that the pilot will see and avoid the obstacle visually BEFORE entering the weather, and are sometimes refered to as SEE AND AVOID MINIMUMS.
The third option for the TERPSter is for him to publish specific departure procedures. These can be published several different ways. They can either be found at the front of the book (NACO style books), or sometimes you'll see a graphical OBSTACLE DEPARTURE PROCEDURE published for a field that will graphically depict how they want you to depart. The graphical ODP will look very similar to a Pilot-Nav SID, except that it will have the words (OBSTACLE) on it.
The fourth option for the TERPSter is to publish a list of low, close in obstacles under the title of TAKE-OFF OBSTACLES. With these, there really is no procedure that the TERPSter could design that would guarantee that you don't hit them, due mostly to the inaccuracy of the navaids, but generally they aren't considered a safety hazard due to being so close to the field and so low. So the TERPster just lets you know that they are out there and then it's up to the pilot to not hit them.
The last option that the TERPster can use is a combination of ANY or ALL of the above methods.
So for example, here's the trouble T at Buckley AFB, in Colorado:
BUCKLEY AFB (KBKF)
AURORA, CO
Rwy 14, 700-1*
* Or standard with minimum climb of 240/NM to
5700.
TAKE-OFF OBSTACLES: Rwy 14: Rising Terrain 5685’
to 5700’ MSL 975’-1355’ from departure end of rwy,
210’-270’ right of centerline.* Or standard with minimum climb of 240/NM to
5700.
TAKE-OFF OBSTACLES: Rwy 14: Rising Terrain 5685’
to 5700’ MSL 975’-1355’ from departure end of rwy,
If you take off on RWY 14, you need to have at least 700-1, and you need to be advised of the rising terrain to the right of centerline for the first third of a mile. USAF users (and possibly some others, I'm not an expert in Part 121 or Part 135 operations) aren't allowed to use the alternate take off minimums (SEE AND AVOID MINIMUMS), so they HAVE to be able to meet 240'/NM instead. They are allowed to do this because of the phrasing "OR STANDARD". In fact, part 91 users could take off with less than 700-1 if they could meet the 240'/NM instead.
And if you couldn't take off IFR on RWY 14, nothing in the above prevents you from departing VFR or departing on the opposite runway. The restrictions are ONLY for IFR DEPARTURES from the LISTED runway.
Now check out MEEKER, CO:
MEEKER, CO
MEEKER
TAKE-OFF MINIMUMS:
Rwy 3, 2000-2.
Rwy 21
,1000-1¼.
DEPARTURE PROCEDURE: Climb visually within 3
miles southeast of airport to depart to 7400. Climb on
EKR R-113 to 9000, then climbing left turn direct EKR
DEPARTURE PROCEDURE: Climb visually within 3
miles southeast of airport to depart to 7400. Climb on
EKR R-113 to 9000, then climbing left turn direct EKR
VORTAC. Depart EKR VORTAC at or above 10500.
In this case, there is no "OR Standard with.." so you MUST have the required weather to take off on that runway, AND you MUST comply with the departure procedure.
Sometimes instead of listing alternate take-off minimums and the phrase "Or standard with minimum climb of ..." it will just say "minimum climb of ..." In that case you must be able to meet BOTH the minimum climb gradient AND the required weather. (AND in that case USAF aircraft wouldn't be authorized to depart from that runway IFR since they aren't allowed to use SEE AND AVOID MINIMUMS!)
