Issues landing - help needed

Capitanfuturo
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Issues landing - help needed

Post by Capitanfuturo » 15 Nov 2018, 15:14

Hello All,

My typical landing on the 737 800 with clear sky are manual usually from 1000 feet, however I very often find myself gliding over the runway at about 50 feet as if the aircraft just does not want to touch down, this is probably to do with the fact that I get a bit scared at the last moment and I flare too much… I am not sure.

My question is basically to do with procedure, what would a flight school training teach as check a sequences? What I mean is as an example what I try to do:
As I am landing I do, very quickly the following checks:
Speed Check, PaPi lights, center runway alignment and vertical speed, and again, and again, and again till touch down.
I seem to feel like I always am about to hit the runway nose first, before flaring, how many degrees should my nose be pointing up? Or are we looking at the vertical speed? Where should it be? Mine seems to be around 1000.

Thanks for any suggestions that I can than practice.

Regards
Nic

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willow
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Re: Issues landing - help needed

Post by willow » 15 Nov 2018, 22:47

Greetings

Sounds like ground effect

http://www.flaps2approach.com/journal/2 ... ation.html

In other words your airspeed may be too high.

A vertical speed of 1000 is a very hard landing.... Final approach vertical speed is dependent on airspeed, however, is usually no greater than 750-500 feet per minute - usually lower. Flare altitude is variable but is usually between 30-10 feet along with throttle retard. As you flare vertical speed reduces to around 200-300 feet per minute.

The NG should be landed with a bit of a bump as this aids in tyre adhesion, effective breaking, reduces lift, and minimises any possible ground effect. I would rate a landing with a vertical speed around 100-200 feet per miniute as very good.

Writing everything in a post is lengthy as there are many variables, and often the information is subjective, so I hope this helps.

Luck to you, WilloW
Last edited by willow on 11 Jun 2019, 13:42, edited 1 time in total.
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egkkman
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Re: Issues landing - help needed

Post by egkkman » 15 Nov 2018, 23:48

Nic,

I'd suggest combining Willow's great advice with the info in this video: https://www.youtube.com/watch?v=6qnriMf ... dex=2&t=0s

I watch all this guys videos and have learnt a lot.

Good luck

Dave

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willow
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Re: Issues landing - help needed

Post by willow » 16 Nov 2018, 00:33

egkkman wrote:
15 Nov 2018, 23:48
Nic,

I'd suggest combining Willow's great advice with the info in this video: https://www.youtube.com/watch?v=6qnriMf ... dex=2&t=0s

I watch all this guys videos and have learnt a lot.

Good luck

Dave
Hi Dave

I forgot about those videos! He does a great job producing them and they are an excellent learning resource!

Best, WilloW
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Lapi
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Re: Issues landing - help needed

Post by Lapi » 16 Nov 2018, 02:33

willow wrote:
16 Nov 2018, 00:33
I forgot about those videos! He does a great job producing them and they are an excellent learning resource!
Nice video!
I was rolling on the floor when it was "explained" that why with a flp-30 landing instead of 53% N1 the actual N1 was 44% on the video...
Saying that because I did many related tests during the years and unfortunately pmdg is way off by handling those basic numbers of the flight-model.
But no problem, when someone does it with the ProSim model, he/she will get 53% N1, not less and not more than that...

regards
Lapi

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portanav
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Re: Issues landing - help needed

Post by portanav » 16 Nov 2018, 11:56

Lapi wrote:
16 Nov 2018, 02:33
Nice video!
......when someone does it with the ProSim model, he/she will get 53% N1, not less and not more than that...
Hi Lapi;

I agree "nice video", with good instruction.

However with regards to the N1 setting on final, I can verify (in Prosim) for me personally, nothing less than 60% N1 with flap 30 and Vref +5, unless the aircraft is very light. In Caribbean Airlines during sim training we were taught that the magic ball park number was 60% N1, and frankly that number was spot on. Both in the circuit (base training) downwind and on final, in the real world and in the sim.

Density Altitude and aircraft weight will always play a part in the final figure, as well as the surface wind, since the rate of descent (700-800 fpm) used to maintain the GP is GS based. But 60% was always fairly close to what was the final figure.

As I said, using Prosim I personally have never used an N1 less than 60% (OAT 32C RH 70% W/V .../15k). The video speaker's figure of 57% N1 seems more likely realistic to me, especially with an OAT of 24C as he remarked.

Just my 2 cents worth based on my real world experience.

Best regards,
Regards,
Michael :)
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Capitanfuturo
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Re: Issues landing - help needed

Post by Capitanfuturo » 16 Nov 2018, 12:04

Thanks everyone for your feedback, I just did a test, I guess knowledge aside, practice makes better and that is what I need,
I very often find myself to be too slow on approach, my speed can go to 120 knots, trying to look at speed, vspeed , PaPi, RW Alignment and now N1 it's a lot of work :-)
But after testing today I notice already improvements, even if I struggled with 53% N1, my 737 definitely wanted a little more, close to 60%
But I need to keep practicing, that was probably me still doing something wrong.

Will try again tomorrow.

Thanks again

Nic

Lapi
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Re: Issues landing - help needed

Post by Lapi » 16 Nov 2018, 15:37

portanav wrote:
16 Nov 2018, 11:56

However with regards to the N1 setting on final, I can verify (in Prosim) for me personally, nothing less than 60% N1 with flap 30 and Vref +5, unless the aircraft is very light. In Caribbean Airlines during sim training we were taught that the magic ball park number was 60% N1, and frankly that number was spot on. Both in the circuit (base training) downwind and on final, in the real world and in the sim.
Hi Michael,

It's easily possible in practice that you are actually around 60% N1.
BUT please mind it that the data quoted on the video is NOT flap 30 Vref +5 but it is FLAPS 30 (VREF30 + 10) at 1500ft MSL. N1 will be slightly above the value above 1500ft and a bit less lower.
That makes a lot of difference...

The "by the book" N1 value can only be tested without any weather and preferably with the given 60T GW, strictly 3 deg glide and AUTOLAND.

regards
Lapi

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portanav
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Re: Issues landing - help needed

Post by portanav » 16 Nov 2018, 18:37

Lapi wrote:
16 Nov 2018, 15:37
The "by the book" N1 value can only be tested without any weather and preferably with the given 60T GW, strictly 3 deg glide and AUTOLAND.
Agreed.

But for all practicality, especially when training, simplicity is the best approach and the ball park figure 60% gives the student something to work from and still allows good airspeed and altitude control.

The "by the book" values are usually good for the engineers, scientist and pencil pushers, and to keep the authorities happy; but rarely works online in reality with all the many variables affecting the aircraft. Especially when hand flying.

Hope you have a great weekend. It's raining cats and dogs here in the Caribbean for the last week; It's like monsoon season in India. Looking out for the sunshine and some dry spells :D .

Regards,
Regards,
Michael :)
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Lapi
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Re: Issues landing - help needed

Post by Lapi » 16 Nov 2018, 18:56

portanav wrote:
16 Nov 2018, 18:37
The "by the book" values are usually good for the engineers, scientist and pencil pushers
Naturally.
But those are also good for any flight-model-designer... :lol:
It's like monsoon season in India
I just loved to be in India in the monsoon season, specially if I didn't have to go anywhere. But the mood and feeling of the monsoon is just great - inside the house that is...

regards
Lapi

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