B737. Why select bleeds off for Single Engine landing?
The B737 Classic One Engine Inoperative Landing checklist includes a provision for additional go-around thrust if desired by configuring the pressurisation system for a no engine bleed landing.
The "If Desired" part raises a few questions in my mind and perhaps the experts can amplify this term.
I would have thought that at max landing weight for most conditions, the thrust available on the operative engine would have been well in excess of that required to achieve the minimum certified gradient of climb on one engine.
If not, I would have also thought that company performance engineers would have worked out the sums and nominated which specific airports would require the "additional thrust" to make the mimimum airworthiness or operational gradient in event of a go-around. High and hot airports for example?
Thus during the landing briefing, the route manual might require airport A as a bleeds off landing approach, while airport B does not. Currently with some operators, the decision whether or not to configure the bleeds is left to the discretion of the crew.
Similarly other operators require that all one-engine inoperative landings are configured for a no engine bleed approach - regardless of the landing weight.
It seems to me that the decision to configure or not when below max structural for landing is difficult to assess if one engine inoperative climb limit weights are not easily available in the cockpit - which normally they are not - unless one has access to a Flight Manual. Workload will normally prevent access to a Flight Manual.
So apart from a specific direction to configure bleeds off in the company route manual, how does the crew judge whether or not to configure to bleeds off in event of a one engine inoperative landing. Is it a case of when in doubt - configure bleeds off? Or is it a gut feeling to configure bleeds off? Seems a grey area to me.