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737-400 approach speed

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Old 23rd Apr 2011, 06:41
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Snoop 737-400 approach speed

Has anyone heard of a technique of adding 8kts to the approach speed instead of the recommended 5kts, In conditions where the reported wind speed is Variable less than 10 including tailwind.

I was told that this is a requirement on the 400. I can't find this in the FCOM.

Thanks,

J
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Old 23rd Apr 2011, 10:20
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That sounds odd. So if it was a 10 knot headwind, you'd add 5knots. But if it was variable at 10, you'd add 8 knots?

I've got 734 time and I've never heard of it.
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Old 23rd Apr 2011, 10:52
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I was told for any wind reported under 10 kts the approach speed was to be flown Vref+08kts!

I have never heard of this before, would there be any reason or justification for this?

J
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Old 23rd Apr 2011, 11:07
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Hmmm. That's not in any of the references I have from two airlines. One airline I've flown at used Vref+10 as the minimum for RNP approaches. That was for -4,7,8, and 900s.

Otherwise it's from the FCTM and that is the standard.
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Old 23rd Apr 2011, 11:23
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That's what I thought.

I have flown the 6,7,800 and all my classic time on the 400 and never heard of such a thing! Hence my post here.....

It's in the FCTM and I will be sticking to the +5kts unless the wind dictates different.

Thanks,

J
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Old 23rd Apr 2011, 11:43
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Do you have an Ops Manual?
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Old 23rd Apr 2011, 11:52
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BOAC

Yes and there is no mention of it. I thought that it may be a technique that I hadn't been told about.

It makes no sense to carry extra speed when not required. My company operates into alot of high elev airfields. 5000-6000 ft so this would give a higher GS over the numbers. I wouldn't like to have an over run. Not that the 3Kts would cause that.....

J
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Old 23rd Apr 2011, 11:57
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Should have mentioned hot too!

J
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Old 23rd Apr 2011, 12:01
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Thought I would ask, since most Ops Manuals TELL you how to bug speeds and that is what you should be doing! Traditionally on Boeing it is half the speed plus all the 'gusts' so I guess you could derive + 8 in some circumstances but not as an SOP.
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Old 23rd Apr 2011, 12:12
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No standard Boeing. That is why I wondered about the Vref +08kts in nil wind!

I guess it must just be his own aditive for the wife and kids

Thanks for your input......thought I was missing something somewhere.

J
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Old 23rd Apr 2011, 13:53
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How many wives and how many kids.......? Perhaps particular pilot is 'frightened' by the thought of flying SO SLOWLY..............
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Old 23rd Apr 2011, 14:24
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Traditionally on Boeing it is half the speed plus all the 'gusts'
Presumably you mean half the reported headwind component plus all the gust factor? Not forgetting the FCTM advice to bleed off the headwind component approaching touch down. Many airlines fail to accentuate this point and the result is excess speed over the threshold and long float which is not a Good Thing - especially if runway length limited and its raining.
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Old 23rd Apr 2011, 14:45
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Presumably you mean half the reported headwind component plus all the gust factor?
- indeed - hopefully 'abbreviated' for those who understand
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Old 23rd Apr 2011, 17:55
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Tee Emm

Thanks I understood exactly what BOAC was talking about. The thread was reference to why would you set Vref +8 as standard instead of Vref +5 as recommended inthe FCTM.

I also understand that you have to maintain the gust factor if applied whilst removing the mean wind component.

I guess it's like BOAC says ....this guy doesn't like to fly the recommended speed and would like to use more runway! All good and well on long runways

J
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Old 24th Apr 2011, 03:32
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check your QRH and see the landing distance difference for an increase of 3 kts...cant be that much..maybe 30 m? if you keep it until touch down..
I normally add one kt but thats for my grandma..

Last edited by de facto; 24th Apr 2011 at 03:47.
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Old 24th Apr 2011, 03:50
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D Facto

What TRTO does your grandma work at

Maybe one day that 60m will be required....why fly faster than required?

Do you Increase your V1 because you feel like it? Why not depart with a 13kt tailwind.

We don't have to be so rigid with the numbers but common sense dictates.

J

Last edited by jidder; 24th Apr 2011 at 04:14. Reason: Gash Spelling
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Old 24th Apr 2011, 04:13
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Increased V1 and/or Vr is actually a boeing standard procedure for improved climb out performance. As much as up to 35kts is perfectly normal.
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Old 24th Apr 2011, 04:20
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Yes Denti.....

If the figures tell you that your V1 for an Improved climb is 168kts you don't go adding 3 kts cos you feel like it do you?

That was my point.

My original question was why would you set 3kts faster than the boeing recommended Vref +5kts for nil wind conditions.

End of! Thanks

J
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Old 24th Apr 2011, 04:47
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Do your SOPs dictate to use A/T OFF for app/landing with A/P oFF??
Maybe the guy just doesnt trust you can fly vref+5 so accurately..and believes adding 3 kts to the APPROACH speed (which will be bled off) during flare is a safer option to start with or when you scan and reaction arent as quick as they used to be...

TO answer your question: APPROACH SPEED does NOT affect your landing distance!
You must plan to be at VREF and stay there from 50ft to touchdown...the speed you fly before this gate is irrelevant.

f the figures tell you that your V1 for an Improved climb is 168kts
its not V1 that you increase,,,its V2...but v1 and vr get dragged along...

but thanks for the COMMON SENSE class...

Last edited by de facto; 24th Apr 2011 at 05:06.
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Old 24th Apr 2011, 05:17
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De Facto

Why the attitude? Great CRM...

The chap who advised me to fly Vref +8 also does this himself, so maybe it is just you who thinks I can't fly the aircraft at the command speed.....

I could go on about what speed you should be over the numbers but I think it would be wasted on you.....suffice to say you should not always be at Vref

The sorry thing about COMMON SENSE is it's not very common anymore. You are a prime example!

Have a nice day.....

J
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