Landing distance measured in time?

[runon]

I was reading one of my books by Sparky Imeson and I got to thinking about a possible alternative way to figure out my landing distance using a timer.
Could I use a "time" to figure out how long I land?
Say I come over the trees, and land, stop, and I see taxiway Sierra to my right... OK, take note of that.
Take-off again, come around and...
Then go overfly the landing start the timer at the trees and stop the timer at Sierra?
Does that make sense and do you think it would be a useable way to figure out a landing distance?
....
So say it takes 10 seconds flying 60 from the time I pass right over the trees to the time I pass right over the intersection at taxiway "S".
Could I theoretically now overfly the same runway types @ 60 and know I should land whatever 10 seconds will give me more or less?

[N-43121]

Re: Landing distance measured in time?

That is a common way to estimate off-airport landing area distances. Use 70 mph ... Which equals 100- ft per second.

[astjp2]

Re: Landing distance measured in time?

That's ground speed...not airspeed. Tim

That is a common way to estimate off-airport landing area distances. Use 70 mph ... Which equals 100- ft per second.

[jstall]

Re: Landing distance measured in time?

You have to be kidding right??

[astjp2]

Re: Landing distance measured in time?

My airspeed indicator is in knots, so I just use 60 kts and fly low and slo over the runway/gravel bar/field and use that to estimate if I am able to make a safe landing. 8 seconds is easy unless there is a big obstacle to clear. I have done 400' but its a challenge that requires a long approach without an obstacle. Tim

VG's help with the slow flight.

[Jim Hartley]

Re: Landing distance measured in time?

I have never used the timed method of determining landing distance. I have determined landing and take off distance by walking it...one stride is three feet.

I operate at 300-500 landing areas and the shorter distance requires agressive braking. I would like to have a pair of bush wheels to play with and do the measurements again.

[runon]

Re: Landing distance measured in time?

Thought being that if you have a headwind and there is no gradient (I know this almost never the case) 5 seconds is ...5 seconds.
Let's use 70 mph (100' per second no-wind)(ps thank you for that - I didn't know that).
In zero wind, you know your landings take 5 seconds (500') at your favorite ranch strip.
On a steady wind afternoon you fly over your ranch strip and there's a big mud puddle taking up about 100' on one end... but when you flew the low (recon/cropduster) pass, (70 mph) at 5 seconds you're 25' short of the mud puddle.
Is it reasonable to think that you could land without getting into the mud because... 5 seconds is.... 5 seconds?

[astjp2]

Re: Landing distance measured in time?

I have landed on mountain sides and the slopes were pretty steep. Saddles are real fun to go over, get your speed up and then bank to clear the other side. I measured the distance because I use a standard of 800' as a good rule of thumb. Dont make it too complicated by trying to interpolate in your head, 70 mph ground speed 1 second=100" 60 kts ground speed = 100' find what you can handle and take it from there. tim

Thought being that if you have a headwind and there is no gradient (I know this almost never the case) 5 seconds is ...5 seconds.
Let's use 70 mph (100' per second no-wind)(ps thank you for that - I didn't know that).
In zero wind, you know your landings take 5 seconds (500') at your favorite ranch strip.
On a steady wind afternoon you fly over your ranch strip and there's a big mud puddle taking up about 100' on one end... but when you flew the low (recon/cropduster) pass, (70 mph) at 5 seconds you're 25' short of the mud puddle.
Is it reasonable to think that you could land without getting into the mud because... 5 seconds is.... 5 seconds?

[runon]

Re: Landing distance measured in time?

I have never used the timed method of determining landing distance. I have determined landing and take off distance by walking it...one stride is three feet.

-Good point you bring up-
EVERYONE should learn to pace off distance to a reasonable accuracy and check it regularly. It is EXTREMELY useful.
(the technique I use is 5' every right step - my "regular" stride is about 2.5' I'd have to stretch a little to get 3')

[astjp2]

Re: Landing distance measured in time?

How do you know runway/strip length from the air on a strip you have never been to? And dont say that you dont fly into somewhere you have not walked off, we all have flown into new airports before. TIm

[Jim Hartley]

Re: Landing distance measured in time?

How do you know runway/strip length from the air on a strip you have never been to? And dont say that you dont fly into somewhere you have not walked off, we all have flown into new airports before. TIm

You have a general idea when you gain enough experience right?

I look over a potential landing area from different approaches an try to get every reference I can. If the landing area appears doable I may touch down two or three times with enough speed to become airborne and come back for another pass before I decide to brake to a stop or go away.

I think there are two many variables involved to allow the use of a timer.

[astjp2]

Re: Landing distance measured in time?

Thats really not an option for the one at the end of the Matnauska Glacier (steep cliff at the end) or some of the gold camp strips. I know I can stop in 800' or less depending on the wind. Timing it at 60 Kts Ground speed will tell you how many hundreds of feet you do have, its not a WAG, its fairly accurate. TIm

[Jim Hartley]

Re: Landing distance measured in time?

What is a WAG?

[Pearson]

Re: Landing distance measured in time?

Wild Ass Guess

[Mark Julicher]

Re: Landing distance measured in time?

So maybe a SWAG?
Scientific Wild Ass Guess