PPRuNe Forums - 737 All flaps up landing -a question on airmanship

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- - 737 All flaps up landing -a question on airmanship (https://www.pprune.org/tech-log/410823-737-all-flaps-up-landing-question-airmanship.html)

Quote:

But in generic terms, and your request re 'Airmanship'. I would suggest that your efforts are best directed at:

Finding the longest into wind runway

That is true of course. But the original post stated clearly that the landing was on a limiting length (for the all flaps up case). All the rest of the stuff you added is superfluous. Sorry about that but that's the budding lawyer in me:ok:

Boeing already answered your questions for you:

Quote:

FCTM, Chapter 8 non-normal operation, All flaps up landing:
Use of autobrakes is recommended. Autobrake setting should be consistent with runway length. Use manual braking if deceleration is not suitable for the desired stopping distance.

Immediate initiation of reverse thrust at main gear touchdown (reverse thrust is more effective at high speeds) and full reverse thrust allows the autobrake system to reduce brake pressure to the minimum level. Less than maximum reverse thrust increases brake energy requirements and may result in excessive brake temperatures.

In other words Boeing absolutely do not recommend that you do not use the wheel brakes upon touchdown (either max manually or with an appropriate autobrake setting for the available runway length). With that in mind I think there is a much greater likelihood that you will blow a tire with manual braking at an approach speed of 180ish kts (NG) than with max auto.

Personally I would choose max auto, to assure a decent stopping power immediately at touchdown (certainly faster application that with manual) and that braking is in progress in the delay time before the reversers deploy.

When the reversers take effect the brake pressure will reduce hence the chance of a blow out will reduce. At this point I would switch to manual braking if needed.

Not using the autobrake at touchdown would be counter productive and against Boeing's recommendations.

Further...

Quote:

FCTM, chapter 6 Landing roll, wheel brakes:
Although immediate braking is desired, manual braking techniques normally involve a four to five second delay between main gear touchdown and brake pedal application even when actual conditions reflect the need for a more rapid initiation of braking. This delayed braking can result in the loss of 800 to 1,000 feet of runway. Directional control requirements for crosswind conditions and low visibility may further increase the delays. Distractions arising from a malfunctioning reverser system can also result in delayed manual braking application.

...supports the reasoning to use autobrakes initially and later switching to manual if needed.

From an airmanship perspective, what should be your greatest fear with a flapless landing on a restrictive runway (say less than 2000 meters)?

1) A very likely overrun into the landing lights, localizer antennas etc. due to insufficient braking?

2) A remote possibility of blow out at some point in the landing roll which may not certainly degrade your braking performance to the point that it will cause an overrun.

Quote:

Originally Posted by kenparry (Post 5610282)

No need to get shirty. My reply was based on somewhat more than 20 years in the front seats of various Boeings, including the B737.

How many flaps up landings did you do on limited runways? Or how many tyres have your burst with max manual braking?:E:E:E

P.S no need for hernia's I am just messing:ok:

Question for the OP, and those who fly the 737: (Nigel, your points are good airmanship points, please bear with me)

IF you have to do a flaps up landing because you don't have a choice
AND your runway choices are limited to "short" per the OP,

is there not a consideration to get light (fuel dump) before you begin your approach to reduce landing distance required? :confused:

OR

are those x thousand pounds, or not, of marginal influence so as not to be worth adding into your pre-landing plan for a flaps up landing? "Get light" seems to me one of the variables you can control, in modest measaure.

(Yes, I realize enviro issues, and an accountant's "What, you threw away perfectly good fuel?" issues arise, but I am asking to understand the airmanship question ... )

No fuel dumping possible, but extending the landing gear and speedbrakes while flying a holding burns off fuel fast. However, consider a possible go-around due to uncommon approach attitude and speed and keep enough fuel for that.