How to make a kiss landing like Jan

[stefans85]

Your landing looks good but: your speed was at VREF+5 I think. Don't let it go unter VREF+5 on final. It can be more, but not slower (because of some wind change). I'll target at VREF+10 normally. Also you were too high over threshold (100ft so double as high as you should have been) and you ditch down the nose at <100ft. Don't do that! The Pax would be screaming.

Trim down a bit for let's say 1second at 200ft and "hold the plane on the yoke" so you can counteract the ground effect and winds on short final. Saw it on a maintenance flight and love it in the sim since then.

[Alpha Floor]

1 hour ago, stefans85 said:

Trim down a bit for let's say 1second at 200ft

I don't know about 200 feet, but you certainly should NOT be trimming during the landing itself (flare and touchdown).

I don't like trimming below 500 feet anyway. At this point (latest) the approach should be stable. 1000 feet for precision approaches.

[Alpha Floor]

1 hour ago, stefans85 said:

your speed was at VREF+5 I think.

And that's fine. The speed never went below the bug.

1 hour ago, stefans85 said:

Also you were too high over threshold (100ft

I re-watched it, and he didn't cross the threshold at 100. At 100ft you can clearly see the threshold in front of him. Minute 1:29 in the video.

I'd say it was 70 (or even 65 feet, see minute 1:33). A little high, yes, but nothing too serious. He touched down in the touchdown zone without floating anyway.

[stefans85]

I rounded the values a bit.

Before flare you won't trim right. But at 200ft you have plenty room and can make it.

[cmbaviator]

On jeudi 26 mai 2016 at 8:10 PM, Litjan said:

Your KLAX looks ugly! Why don´t you have at least the default KLAX showing? Is your X-Plane updated to 10.45??

Jan

 

 

lol Jan, thats the default one for 10.45 (Steam Version); how should Klax look ? My setting are on high and that's with a gtx 980ti

[cmbaviator]

regarding Vapp, i normally use :

 

Vref + 5kts ( mandatory) + 1/3 of HD wind component = Vapp

[Alpha Floor]

5 hours ago, cmbaviator said:

Vref + 5kts ( mandatory) + 1/3 of HD wind component = Vapp

That's interesting, I always thought that:

Vapp = Vref + 1/2 the head-wind component + the full gust. Vapp should not be less than Vref+5 nor exceed Vref+20

On the Boeing 777 (and newer Boeings too probably), if AT is used, Vapp is always Vref+5. It's claimed that the AT is more than capable of adjusting against winds or gusts. If AT is not used, the above definition of Vapp applies.

However, I found this "newer" document in which they mention the 1/3 component you said. This one is an Airbus document and they use Airbus terms, so I guess the "VLS" or "minimum selectable" is analogous to the "Vref" of a Boeing. The "minimum selectable speed" and the Vref are not exactly the same thing, though. VLS is the top of the amber band which in a Boeing is called "minimum maneuvering speed", the speed that grants 1.3g maneuver capability (40º of bank at level flight). But Vref on a Boeing is usually somewhat higher than the minimum maneuvering speed, it's not exactly on the top of the amber band. Maybe VLS and Vref are conceptually the same and it's just the definition of the amber band that's different between manufacturers.

This whole discussion is for the "no-failures" scenario.

 

 

 

Edited May 30, 2016 by Alpha Floor
Definition of Vapp

[cmbaviator]

4 hours ago, Alpha Floor said:

That's interesting, I always thought that:

Vapp = Vref + full head-wind component + 1/2 the full gust. Vapp should not be less than Vref+5 nor exceed Vref+20

On the Boeing 777 (and newer Boeings too probably), if AT is used, Vapp is always Vref+5. It's claimed that the AT is more than capable of adjusting against winds or gusts. If AT is not used, the above definition of Vapp applies.

However, I found this "newer" document in which they mention the 1/3 component you said. This one is an Airbus document and they use Airbus terms, so I guess the "VLS" or "minimum selectable" is analogous to the "Vref" of a Boeing. The "minimum selectable speed" and the Vref are not exactly the same thing, though. VLS is the top of the amber band which in a Boeing is called "minimum maneuvering speed", the speed that grants 1.3g maneuver capability (40º of bank at level flight). But Vref on a Boeing is usually somewhat higher than the minimum maneuvering speed, it's not exactly on the top of the amber band. Maybe VLS and Vref are conceptually the same and it's just the definition of the amber band that's different between manufacturers.

This whole discussion is for the "no-failures" scenario.

 

 

 

I was a pro airbus so I used the airbus Vapp philosophy:

Vls ( is the stall speed under 1G with a scurity margin of 23%)

I thought boieng used the same philosophy, ie +5 kts was mandatory, guess i'm wrong.

so for <B737Ng, you only add the full HD component ? so if no wind, Vapp = vref ?

 

Maybe some B737Cl pilots can shed some lights on the matter

Edited May 30, 2016 by cmbaviator

[Litjan]

4 hours ago, cmbaviator said:

 

lol Jan, thats the default one for 10.45 (Steam Version); how should Klax look ? My setting are on high and that's with a gtx 980ti

It should look like this:

 

Jan

[Litjan]

6 minutes ago, cmbaviator said:

I was a pro airbus so I used the airbus Vapp philosophy:

Vls ( is the stall speed under 1G with a scurity margin of 23%)

I thought boieng used the same philosophy, ie +5 kts was mandatory, guess i'm wrong.

so for <B737Ng, you only add the full HD component ? so if no wind, Vapp = vref ?

 

Maybe some B737Cl pilots can shed some lights on the matter

This is how the manufactures wants you to do it:

You calculate Vref. This is 1.3 times the stall speed at 1G.

Now you add:

1.) At least 5kts

2.) Maximum of 20kts

3.) half the steady headwind component

4.) the full gust factor

You fly with this speed until 50 feet (crossing the threshhold), then you bleed off the everything, except of the gust factor. Touchdown with Vref + gustfactor.

Example: Runway 36, Wind is 300/20G30. Vref is 130kts

130 + 0.5x20x0.5 + 10 = 145kts. Touchdown with 140kts.

Jan

[Alpha Floor]

28 minutes ago, Litjan said:

You fly with this speed until 50 feet (crossing the threshhold)

It's also interesting to note that this is the point at which the approach phase ends and the landing itself begins.

The take-off on the other hand ends at 35 feet above the runway, point at which the 2nd climb segment starts (the first climb segment is from lift-off to 35ft, a bit misleading, but yeah).

[Litjan]

8 hours ago, cmbaviator said:

 

lol Jan, thats the default one for 10.45 (Steam Version); how should Klax look ? My setting are on high and that's with a gtx 980ti

Hi cmb,

I just checked - due to some internal FU at Laminar Research, the airport I submitted in December 2015 was not included with 10.45.... so what you are seeing is correct.

You can download the package here, though: https://gateway.x-plane.com/scenery/page/KLAX

Cheers, Jan

 

[cmbaviator]

29 minutes ago, Litjan said:

Hi cmb,

I just checked - due to some internal FU at Laminar Research, the airport I submitted in December 2015 was not included with 10.45.... so what you are seeing is correct.

You can download the package here, though: https://gateway.x-plane.com/scenery/page/KLAX

Cheers, Jan

 

Ah okay, thanks for the info, i'll wait until it gets in xplane 10.50 if that's correct

[frumpy]

Hey guys,

long time, no fly - I've had the chance to fly a 737-800 as a passenger. Runway was supposed

to have some wet patches, so the pilot flared pretty hard. When I asked the copilot afterwards

what his V/S was on touchdown (yah, I'm one of THOSE people  ), he said it was

something around -500 ft/min. He said he wanted the spoilers to deploy for sure, thats why

he chose the high vertical speed.

I wondered if there was something like a 600ft/min limit for structural reasons? I read it somewhere,

but it also depends on the weight of the aircraft, so I am not sure.

He said even -2000ft/min wouldn't break the plane. I'm a bit sceptical about that, but I didn't argue anymore.

 

Jan knows for sure, but perhaps anyone else wants to step in?

 

Edited September 27, 2016 by frumpy

[J.M.G.]

To meet certification, all aircrafts must at least fulfill these limits:

• 360ft/min at MTOW and
• 600ft/min at MLW

Source: Certification Specifications 25, §473 "Landing load conditions and assumptions"