Originally Posted by
2StgTurbine
Yes I am. For example off of runway 7 at KDEN, APG gives a flap retraction altitude of 7,331 ft MSL which is 1,897 ft AGL. As far as I can tell, there are no close in obstacles.
As far as you can tell? APG performs a runway and obstacle analysis, and your assessment is "as far as I can tell?" That settles it, then. It seems you know more than APG. You might be able to make a small fortune supplanting their business and your overhead will be quite low. Where as they must spend a great deal of time and expense to make those determinations, you can simply look and say "nothing there as far as I can tell." You've got it nailed. Congratulations.
Close-in obstacles may not be the reason, and an analysis isn't just looking at immediate obstacles. There are a number of reasons that a level off altitude may be assigned as part of a runway analysis. Not all of them are next to the airport. That doesn't matter, because as far as you can tell, there are none, and that's good enough.
Have you looked at the takeoff minimums and gradients for runway 7 at KDEN? Have you noticed that for each departure, runway 7 is cited as NA-ATC, and that there are departures depicted for each runway, including 26...except runway 7? The takeoff minimums and obstacle departure procedure for runway 7 simply says "
Climb on a heading between 315 clockwise to 220 from DER. All other courses, climbing right turn, thence direct DEN VOR/DME holding pattern (hold South, right turns, 343 inbound) to 16,500 before proceeding on course."
Where is the route description for runway 7 for the BAYLR3, BRYCC3, CONNR3, COORZ3, EEONS5, EMMYS5, EPKEE3, EXTAN4, FOOOT3, JMPRS2, RIKKK3, SOLAR3, SPAZZ3, or STAKR3 departures? You won't find it. It's per ATC, in which case ATC takes responsibility for your path. ATP publishes a minimum for your own use, for safety. Ignore it at your peril, as your published procedures give you no guidance in that regard.
The DENVER 8, PIKES7, PLAIN7, ROCKI2 uses radar vectors, for which ATC takes responsibility, and in which case your analysis will still provide your minimum cleanup altitude for an engine-out. Altitudes provided are for more than just trees and rocks. Departures are assigned for more than just noise. Traffic flow and congestion are also applicable, and runway 7 blasts off a number of directions, dependent on ATC assignment and vectors, and crosses the departure path of a number of other runways. There's more to the designing of your runway and obstacle analysis than what you see out the window, or think you see...but then as far as you can tell, it's no big deal, right?
Originally Posted by
2StgTurbine
The way I comply with this is to keep my flaps at takeoff until 7,331 ft MSL in order to ensure I have the required climb performance if I have an engine failure after V1, but below the APG flap retraction altitude.
As you should.
Originally Posted by
2StgTurbine
Since this differs greatly from our SOPs, it requires a lot of extra briefing and modifying of our after takeoff flow in order to prevent the PM from retracting the flaps too early, or the PF from doing our normal two engine acceleration which would cause an undesired aircraft state with our stabilizer.
SOP means standard procedure. If you're given something which is not standard, then the SOP is irrelevant. Simply because you do something in Jamaica or Miami doesn't mean you do the same thing in Denver or Lima, Peru. You fly the departure for the location where you are. This is obvious, is it not?
A "lot of extra briefing?" Your'e briefing the material that you're given for the departure. This isn't rocket science. You're given a nonstandard value for cleanup on an engine-out on departure; that's what you brief. If you have an immediate left turn after takeoff, even though you don't normally do that, you brief that, too. Brief what's appropriate for that specific runway on that specific day. If your company subscribes to data that tells you to climb to 7,331' before cleaning up the airplane, then do that. Not really that complicated.
It's too difficult for the pilot flying to refrain from falling back on habit and retracting flaps at 400? Even though the pilot has briefed the departure? A pilot can't brief a departure and fly it as briefed? Truly amazing. What is such a pilot doing in the cockpit in the first place??
You assert that the pilot monitoring might retract the flaps too early? Your monitoring pilots don't retract flaps on command, but simply to it on their own at 400'? What kind of a show are you running, there? People simply act willy-nilly, doing their own thing, freelancing in the cockpit? Who is in charge? You're actually worried that the PNF/PM might actually go off on his own, retracting flaps at 400' even though 7,331 has been briefed, because that's what he does at some other airport? You have bigger issues than simply using APG's data. You have a major breakdown in cockpit discipline. Apparently no standard, either.
Originally Posted by
2StgTurbine
For example at KDEN, the BAYLR 3 RNAV departure off of runway 8 requires a climb gradient of 400 ft/nm until 5,934 ft MSL. That climb gradient has nothing to do with clearing obstacles since the non RNAV Denver 8 departure off of that runway simply requires the standard 200 ft/nm.
What altitude does your APG program give you for a departure off runway 8 on the BAYLR3, with an engine-out? Let's stick to the discussion, shall we? You're attempting to drift far afield. What pilots might want to do for any other reason is irrelevant. The thread, and your question regards your "SOP" cleanup altitude of 400,' vs. runway and obstacle analysis data provided for you by APG.
Originally Posted by
2StgTurbine
Since I have to make this briefing for every departure, it would seem that the SOPs should be modified so I don't have to constantly brief this and so that all of our pilots understand that the APG runway analysis dictates our flap retraction altitude, not what the manufacture used to meet the certification standards.
Is it difficult for you to "constantly" give a briefing that addresses actual takeoff conditions? Rather stick to a canned one, would you? Sounds tough.
You do understand that what was used to meet certification standards is irrelevant with respect to where you bring the flaps up for a departure at a given airport, don't you? Every bit as much as demonstrated crosswind has nothing to do with what the aircraft can actually handle. That's a value used at the time of certification, but in no way was ever intended to imply that the aircraft should be operated in that manner. In fact, V2 for certification purposes is provided to 400 feet as a MINIMUM. It's not a fixed or hard altitude, and it's fullly expected that where a higher altitude is appropriate given terrain or other reasons for cleaning up later, that you'll do that. It's what you're paid to do; fly the airplane safely in real world conditions, not living in the past based on an arbitrary minimum number used to demonstrate minimum performance before the airplane ever went into production.
Then again, all that briefing, all that flying, all that wranging of the PM to keep him or her under control, is clearly a difficult burden on you. Perhaps you should blindly stick to a 400' flap retraction altitude, ignore the data that's given you, and move on with your life. Probably, nothing untoward will happen. Probably.