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andreadebiase

VSI values for different types of landing

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Does anyone know what ranges of VSI values we are looking at on a 737-800 when the landing is:

 

a- smooth (aka very comfortable for passengers)

b- hard (few sounds of passengers disapproval are heard in cabin)

c- very hard (loud sounds of passenger disapproval are heard in cabin)

d- very hard (where mechanical inspection may be further needed)

e- definitely needs repairs...

 

thank you

 

ps

the categories i made are purely examples I came up with based on my business travel experience,  it's just to give an idea. I had many As, few Bs, and pretty sure I had a C on a A380 landing in Paris where I am 99.9% sure the pilot for what ever reason did not flare (visibility was low).

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Common misconception among non-pilots is that smooth landings are the best. This is false. I'll take a firm solid touchdown any day, certainly any day with any wind.

 

I do remember a few special landings that were real squeakers, about the same sensation as flying over a manhole, but the breeze was light to none and I was showing off. The safest procedure is between don't float and don't bounce, and the windier it is the more important it is to nail it.

 

Ask any Navy pilot about  best landings haha.

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the answer to your question is......who knows.

 

Realistically, the vsi is such a poor instrument, that it wouldnt catch up to the change in v/s in the flare to get a good idea of your actual v/s at the point of touchdown.

 

Also, i would say about 50 fpm for a nice soft landing. At the end of the day, its a computer game, just get it too look good and youll be ok!!!

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Such a good topic to discuss.

 

If I recall right, other Boeing FCTM's not including the 737NG FCTM, published a sink rate of 150fpm target on touchdown. I suspect this was removed, or was never present in the NG/CL FCTM, because of the problems associated with main wheel shimmy. And so, the 150fpm sink rate on touchdown isn't applicable.

 

So, in the NGx, follow Dan's advice. On a good day, you can shoot for a "greaser" if you wish; don't land long, short or bounce. In all other conditions, "firm" landings are your target...

 

For me (in FSX), this translates to a sink rate on touchdown of 300fpm plus/minus 100fpm. Sink rate of >600fpm is what I personally call a "hard" landing.

 

Final point - I think FSX ngx pilots should be more concerned with transition to final pitch and IAS during the flare more than the sink rate on touchdown... I know I certainly am, as I'm more worried about tail strike than a firm landing with the remote possibility of a hard landing.

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I don't look or plan to look at the VSI while flaring but since i have no butt  sensation while landing on flight sim at home I was hoping to get an idea by using the numbers

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I don't look or plan to look at the VSI while flaring but since i have no butt  sensation while landing on flight sim at home I was hoping to get an idea by using the numbers

Sure.... move your attention to the far end of the runway when you start your flare and watch your arrival to earth from that angle. You'll get a real good sense of the quality of your landing when you combine that (which provides a good indication of closure rate with terra firma) with where your touchdown occurs.

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Stabilized approach on Vref and down the chute dictates your rate of descent and nose up attitude, so it is a product of following your airspeed, but at those speeds 140 ish it is usually between 600-800 fpm. It is a most unstable instrument and I rarely use it in the last phases of the approach.

While coming in at flaps 30 and Vref, your nose up is about 3 degrees. At the 30 foot callout, pull power to idle and at the same time bring the nose up so you don't balloon and the airplane goes into ground effect. Like Dan says, look down the road. A good landing with precise speed will automatically give you an acceptable touchdown point and reasonable soft landing. Priority number one is to touch the pavement solidly on the spot--from 1,000 feet after the threshold and 1500 feet. Forget about the acceptable 3,000 feet figure, but if your runway is long you can take it and not go around. As long as you don't make it a habit my instructor used to say.

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