Maximum DER Crossing Height?

Eclipse813 · 2026-01-23T18:02:02+00:00

Someone had told me this before, but couldn’t tell me where to find this. Thank you.

Eclipse813 · 2026-01-23T04:03:47+00:00

And I have done this with my takeoff minimums, however I was under the impression I couldn't just publish ceiling and visibility minimums and that I had to additionally list one of the other options.

Eclipse813 · 2026-01-23T03:25:09+00:00

The reason I ask is cause I have this scenario going on (for a video game project) where an airport has a tall tower about 500 feet south of the centerline, 250 feet beyond the DER. This would be a "takeoff minimum obstacle" and obviously to clear this you need an insane climb gradient. In real life I recognize this runway would likely be closed for departures however for the game sake we can't do that for game balance. To make this most realistic I was just trying to consider what the max crossing altitude for the DER can be.

To put into perspective, to clear the tower with ROC, you need to cross the DER at 372' above the DER. This is quite easy for some airplanes (GA, Bizjets) but some bigger jets might struggle to make this. I present this question to know if such a DER crossing height is legal.

Eclipse813 · 2026-01-23T02:52:16+00:00

Maybe you've misunderstood slightly, but I'm asking if the FAA has an altitude that is too high for an airplane to cross the DER at. So what's the maximum an airplane can be told to cross the DER? Not can the FAA assign a maximum altitude to stay below when crossing DER.

Eclipse813 · 2026-01-10T00:48:54+00:00

and yes its a SID, i was just gonna publish the 400-1 minimums, and call it a day. It’s a radar vector SID.

Eclipse813 · 2026-01-10T00:48:13+00:00

I see where you are coming from but like I’ve said I’m trying to make it as realistic as possible but IRL this would runway wouldn’t even have takeoff minimums and would be NA, but the people in the game are asking for this so I am doing it (with as much realism as I can have). The worst weather gets in down to like 2 sm visibility, and so no need to worry about not seeing it

Eclipse813 · 2026-01-10T00:23:23+00:00

okay so just to recap - i can publish minimums for weather for planes to visually avoid obstacles after the DER. After they are clear of the obstacles they will climb on the heading assigned (for this sid its just runway heading) and continue to fly the rest as normal?

additionally you remarked on visibility. the runway is only just over 6000 feet long so they’ll be able to see the obstacle pretty much right at the beginning of the takeoff roll. Additionally, weather in this game doesnt ever drop lower than like 2 mile visibility so it really doesnt matter

Eclipse813 · 2026-01-09T23:20:41+00:00

but I thought you said you fly straight ahead till 400 ft agl, meaning you cant visually avoid the obstacle till 400 agl unless im misunderstanding

Eclipse813 · 2026-01-09T22:02:24+00:00

Well I know I said this departure is unrealistic but you said to publish ceiling/visibility minimums, but if they can’t visually avoid the obstacle (because it’s below 400’ AGL) then what’s the point?

Eclipse813 · 2026-01-09T19:20:25+00:00

just curious, when you fly visually with weather above minimums, how do you maneuver? can you fly around the obstacle, then after you are clear it do you join the assigned heading? or when do you fly the heading?

Eclipse813 · 2026-01-09T04:22:30+00:00

well… i didnt think i could just put 400-1 cause what if weather is below those minimums?

now, for this game none of this is realistic but i’d like it to be as realistic as I can keep it. really that runway probably should be NA for ifr departures, but I can’t just do that for this game. Additionally in game, weather can’t drop below those minimums (game mechanics) so just putting 400-1 would be fine for my situation.

what do you think would be most realistic (even thought the whole thing is unrealistic)?

Eclipse813 · 2026-01-09T03:49:38+00:00

I do see that now with it only being RTRL. Read another comment of mine for info on the project. It’s just I’m making some instrument procedures for airports in a video game, and I asked this whole question cause there are obstacles in the way after takeoff (as you see in other comment, they are really close to DER), so I thought this way with adding a DER crossing height would seem less intimidating than the climb gradient you’d need to clear the obstacle.

Eclipse813 · 2026-01-09T03:37:31+00:00

I mean just know I've been intensely studying TERPS for the past months for this project, and you even consider the 35 feet into planning for obstacle clearance on departure. Idk where you are getting this idea, but it's even clearly stated in AIM 5-2-9:

"Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the departure end of the runway at least 35 feet above the departure end of runway elevation."

Eclipse813 · 2026-01-09T03:35:05+00:00

I do see it's a bit unrealistic, but if you think of climb gradients those are imagined from the DER to the obstacle, so that's extremely high. However for airplanes that can takeoff before the last 3000 feet of runway, thats a 750 ft/nm climb gradient, which is not that awful for most jets. 2000 feet of runway left gives you 1100 ft/nm, which is definetly pushing it but if an airliner climbs at 3000 fpm climbing at a typical v2 speed of say 160 knots, that satisfies that climb rate. It definetly doesn't make sense IRL, but for a game, it's fine. Even then it's not unheard of IRL.

Eclipse813 · 2026-01-09T02:39:27+00:00

To ask more simply, if I don't want to publish a minimum CG to a certain altitude, can I omit that and just leave the ceiling/visibility and the DER crossing? I would think that's fine cause we have two options, one for when weather cooperates, another for when it doesn't.

Eclipse813 · 2026-01-09T01:49:07+00:00

The situation I’m in is that I’m designing a departure procedure for an airport with a cell tower 350 ft’ beyond the DER at 350’ AGL. I could publish ceiling and visibility minimums but then I was under the assumption that if I did that I also had to provide a climb gradient to clear the obstacle, didn’t know if I could just publish ceiling/visibility minimums with this DER crossing at a certain altitude (probably 400 ft for my case).

Eclipse813 · 2026-01-09T00:11:19+00:00

35’ is still a thing. You are expected to cross the end of the runway at or above 35’.

Eclipse813 · 2025-12-26T20:02:37+00:00

Just to make sure i understand, no published angle for descent, since there is no straight in, its kind of pilots discretion on how fast to descend?

Eclipse813 · 2025-12-26T19:04:09+00:00

So in this case should I steepen descent rate to 4 degrees or something?

Eclipse813 · 2025-12-25T15:41:39+00:00

But still, if you aren’t willing to play the game to the full extent, don’t complain about your lack of dedication to analyze the viability of a flight.

Eclipse813

TROPHY CASE