Diverse Departure Question/concern

[James Hines]

It is my understanding that an airport which has been assessed by the FAA for an instrument approach will also be checked for an ODP/diverse-departure.

The Obstacle Clearance Surface (OCS) or 40:1 ratio applies if no ODP or SID are assigned, yet there is an IAP assigned.

Based on that I am confused how the airport N14 checks the diverse departure assessment. When I look at FAA Take off mins, I see that this airport notates 'Rwy 19, trees beginning 16’ from DER, 1’ left of centerline, up to 136’ AGL/152’ MSL.'

To me, that sounds like there is a tree which is 136 ft high, 16ft from the end of the runway. How could this airport pass the assessment?

Just looking to learn. TIA!

 

[luvflyin]

It is my understanding that an airport which has been assessed by the FAA for an instrument approach will also be checked for an ODP/diverse-departure.

The Obstacle Clearance Surface (OCS) or 40:1 ratio applies if no ODP or SID are assigned, yet there is an IAP assigned.

Based on that I am confused how the airport N14 checks the diverse departure assessment. When I look at FAA Take off mins, I see that this airport notates 'Rwy 19, trees beginning 16’ from DER, 1’ left of centerline, up to 136’ AGL/152’ MSL.'

To me, that sounds like there is a tree which is 136 ft high, 16ft from the end of the runway. How could this airport pass the assessment?

Just looking to learn. TIA!

AIM 5-2-9 e. 4.

 

[pb172]

guessing you have to know your planes takeoff distance to clear that obstacle. thats the procedure. also, you can have an IAP w/ODP. Note, "T" on approach plate.
though in this case, it does seem odd a tree right at the DER. Thinking at a standard rate of 152ft/nm, that would only get you to 36FT clearance at 16FT from DER.

 

[Trogdor]

The issue here is that the trees are probably closed-in obstacles which are not part of the ODP’s guarantee (I believe pilots are still responsible for see and avoid of all closed-in obstacles). The “T” in the approaches is suppose to give you a clue about it.

If you can depart 35 DER and maintain a 200 ft/nm climb gradient and not penetrate the 40:1 OCS, the airport is eligible for a diverse departure.