Put simply, second segment climb finishes at 1500' agl
It absolutely does not. This is demonstration of how badly taught this is. Second segment ends at flap retraction. It has nothing whatsoever to do with height. In the event that you lack sufficient power to accelerate to flap retraction speed your aircraft is certified to use certain acceleration platforms and that varies. The most commonly used is 1500 feet but some aircraft use 400 feet. Because the gradient achieved is better clean than flapped, it is permissible and sometimes essential to reduce the platform from 1500 feet where obstacle clearance is not an issue. Just to confirm. Second segment has nothing at all to do with height and on an all engines operating departure you are final segment when you retract the flaps and enroute segment when you have accelerated to your enroute speed.
with the required gradient being predicated on the worst case scenario, an engine failure at V1.
This is true and your performance calculations are predicated on this case but you have tables in the Hawker AFM for flapless departures. Therefore, if you depart in a flapped condition but make it with both engines to flap retraction you can use the flapless gradient from that point which will outperform the flapped gradient. There is no third (level) segment for acceleration because the excess power of all engines operating has both climbed and accelerated you to the retraction speed.
If an engine fails after V1 but before VFTO then, if you pitch to V2, you will achieve a known gradient starting from a higher point, which is a bonus.
Correct. This is, however, unquantifiable without all engines operating tables which we commonly don't have.
If you have already accelerated to VFTO (around 160kts in the Hawker) and have retracted flaps before an engine fails then the Hawker AFM advises to continue climb at that speed until clear of obstacles. In other words, for the Hawker, second segment climb gradient is assured below 1500' as long as the flaps are retracted at or above VFTO and that speed is maintained until 1500'.
I dont have a Hawker AFM but am hopefully getting one later today. Could you post or email me the reference where I can find that in the AFM?
However, there is no harm in leaving flaps at 15 with all engines running until 1500' if that is what your AOC demands.
If you remain below the declared speed for noise abatement departures and thats what you are doing you are correct.
If you are departing without consideration to noise then you are climbing at an unknown gradient (especially if you have reduced power) and would have calculations to make in the event of an engine failure. For instance, if you are on a departure requiring a SID gradient of 5% and you chose to climb at 1000fpm at 200 kts because its comfortable you are under the required SID gradient. If you then fail an engine you will have an element of "zoom climb" while you reduce speed to V2 but it is unquantifiable. So you are under.
If the resultant deck angle bothers you (max pitch is 20 degrees from the Hawker AFM) then all you need to do is reduce power until you have a happy balance between deck angle and rate of climb. If you pitch for VFTO then you will have a limited drag penalty.
This is sort of true but you will have even less of a drag penalty if you are clean. You also have the advantage of an aircraft thats easier to fly in the event of an engine failure and you have no third segment to pitch for. You are already final segment (in fact, because of speed, enroute segment)
If you pitch for anything less than 220 kts then you won't over speed the flaps.
True, but as discussed before you are potentially degrading the climb gradient to a point where you are below the required.
160-180 kts and 90 per cent N1 works well for the Hawker, giving a good rate of climb and pleasant deck angle.
You are wasting fuel against extra drag and you are making more noise over the ground. There is no benefit to leaving the flaps down at that speed.
I am slightly confused about all these pilots who are allegedly over-speeding the flaps; if both engines are running and you pitch for VFTO, controlling ROC with power, how can you over- speed the flaps?
Nobody has mentioned flap overspeed.
Finally, the Flight Safety manual suggests 400' This is a Flight Safety SOP.
and VFTO as the flap retraction point, presumably as a belt and braces safety measure.
absolutely right - this is a presumption. It isn't, as you said, in the AFM
There is no mention of 400' in the approved AFM,
oh, there you go..
although the two are often achieved at about the same time.
This may or may not be true for your type (I would think it depends a lot on load, temperature, departure elevation etc.
The AFM for your type will tell you how the aircraft should be flown to achieve a desired outcome.
Absolutely right, I'm suggesting we follow it.
Your Authority and company AOC may require a different procedure, possibly for standardisation reasons.
This is also possible but quite how the Authority overides the AFM I really don't know. Right at the beginning of most company operating manuals it says something like:-
Each aeroplane is operated in compliance with the terms of the Operations Manual (OM), its Certificate of Airworthiness and within the approved limitations contained in its Aeroplane Flight Manual (AFM).
All operations personnel involved in the dispatch or conduct of a flight must be familiar with the laws, regulations and procedures pertinent to the performance of their duties, including those of the States in which operations are conducted.
The relevant personnel shall adhere to the rules, regulations, instructions and information contained in the OM at all times. However nothing shall keep the personnel from exercising their own best judgment during any irregularity for which the OM gives no provisions or in an emergency situation.
The rules and regulations laid down in the OM (Part A to D) do not overrule any State law or the instructions of the aeroplane’s manufacturer as laid down in their respective Aeroplane Flight Manual. If there is a discrepancy between this manual and any regulation, the Chief Pilot (CP) must be informed immediately.
If there is a situation whereby the AOC requirements cause your type to be flown outside the limitations of the AFM or in an unnecessarily inefficient manner then you should make this known to your bosses such that the AOC can be amended.
Further to that, if there is a situation where the AOC requires the aircraft to be flown in such a manner the AFM is the manual that your ops manual tells you to follow.