170B out of 1700' grass strip

A place to relax and discuss flying topics.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

170B out of 1700' grass strip

Postby airtractorflyer » Thu Sep 05, 2019 12:26 am

Hi guys. Have a 1700' grass strip at my house departure end is wide up. Will stock 170B haul me 210lbs, wife 115lbs, and my 7 year old that is 50lbs with few bags full of fuel? About 250' msl. Most of time is left quartering headwind. Had a 1957 182 would do it no problem. Sold it I prefer taildraggers, and always wanted a 170. Thanks!
airtractorflyer
 
Posts: 11
Joined: Mon Nov 16, 2009 9:11 pm

Re: 170B out of 1700' grass strip

Postby ghostflyer » Thu Sep 05, 2019 1:25 am

I would be doing a few circuits and bumps before loading the family into the aircraft. I would be getting to know the aircraft first . Have a experienced instructor with you or a very experienced 170 driver with you . Fly with 1/2 tanks for a while . I know of someone was in a similar position and he fitted 50lb water bladders in each of the seat positions . He roped them in and seat belts secured to the bladders but couldn’t undo his knots. So he used a knife to cut the rope on one of the bladder and punctured the bladder. 50 lbs of water goes a long way when split.
User avatar
ghostflyer
 
Posts: 1198
Joined: Mon Apr 21, 2008 3:06 am
Location: queensland ,australia

Re: 170B out of 1700' grass strip

Postby Vertical » Thu Sep 05, 2019 2:13 am

You're pretty close to the line. There will be days/conditions you shouldn't do it. I'd get a climb prop...or make sure you are really good at knowing where the line is...or both.
Vertical
 
Posts: 88
Joined: Mon Oct 08, 2018 12:41 am

Re: 170B out of 1700' grass strip

Postby lowNslow » Thu Sep 05, 2019 2:40 am

It should be doable if you don't have any takeoff obstructions in the way. Notice ground run is 40% of number shown.
Attachments
Screen Shot 2019-09-04 at 6.35.10 PM.png
Karl
'53 170B N3158B SN:25400
ASW-20BL
User avatar
lowNslow
 
Posts: 1492
Joined: Mon Apr 22, 2002 4:20 pm
Location: Carmel, CA (KMRY)

Re: 170B out of 1700' grass strip

Postby n2582d » Thu Sep 05, 2019 5:48 am

airtractorflyer wrote:Hi guys. Have a 1700' grass strip at my house departure end is wide up. Will stock 170B haul me 210lbs, wife 115lbs, and my 7 year old that is 50lbs with few bags full of fuel? About 250' msl.

Seven years ago you were 10 lbs. lighter (I can relate! :oops:), your boy was about 40 lbs. lighter and your strip was 400 feet shorter.
airtractorflyer wrote:... I built a 1300 ft grass strip at my house. Live at about 250msl. Will a 170a haul me my wife and baby boy out of there? I weigh around 200lbs, wife around 110lbs and just had a baby boy.
Karl's performance chart was a bit garbled -- looks like our copy in the Library for the '56 is a bit messed up on this page. Here's another try from the 1952 manual:
Screen Shot 2019-09-04 at 8.54.26 PM.png
Click to enlarge
Using rules of thumb from Light Aircraft Operating Tips you should be able to plant a 50' tall tree at the end of your 1700' strip and just clear it. This is assuming you're 10% under max. gross weight, the density altitude is 250', the strip is level with short grass and no wind. Your ground run under these conditions should be 630'. The variables pretty much cancel each other out. The above chart is based on using a McCauley prop but it doesn't specify the pitch. After flying an Air Tractor for a living you'll be wanting a few more horses up front.
Gary
User avatar
n2582d
 
Posts: 2388
Joined: Mon Apr 29, 2002 4:58 am
Location: Mariposa, CA

Re: 170B out of 1700' grass strip

Postby Bruce Fenstermacher » Thu Sep 05, 2019 9:41 am

Until recently I operated my 170A with standard prop, out of at 1800 ft grass strip. The difference being it was 3% down hill starting 2/3 down the runway and we had a very hard 50ft obstacle at the end with a tree line on the left and wires on the right of the runway. We had to be able to clear 50ft or abort before we would skid off the runway. In other words, we didn't get light on the wheels at the right spot we had to shut down and get on the brakes. Once we broke ground we had to clear the obstacles or go through them. We would never consider the load you are. 1 person 200 lb, half tanks or maybe 2 people with less fuel if the wind and conditions were right.

Could you do what you are proposing. Yes. If your departure is truly wide open. Until you know your plane, it may not be that comfortable.

How close is the next longer airport? In our case when we departed our runway, we where practically on base leg for landing at a 3000ft paved runway. Most days we meet our passengers there.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email:
N7A '49 170A -More original than most making folks GREEN with envy
N42532 '45 J-3 Clipped Wing Cub
User avatar
Bruce Fenstermacher
 
Posts: 9904
Joined: Tue Apr 23, 2002 11:24 am
Location: Telford, PA Based at UKT

Re: 170B out of 1700' grass strip

Postby GAHorn » Thu Sep 05, 2019 10:14 am

I’ll bet Bruce meant to write...”. IF...we didn't get light on the wheels at the right spot we had to shut down and get on the brakes. ....”

When I administer flight reviews I like to wait until line-up to ask the pilot “Where is your abort-decision-point?”
I let them think about that a moment and if they don’t have a ready-answer (because they’ve not thought about that for awhile) then we pull off the runway and have a bit more ground school.

If you don’t ask yourself this question on EVERY takeoff ... You will waste 300’ of indecision and if the tail is already up off the grass you’ll need another 1,000’ to get it stopped. You will then feel slightly sick and your passengers trust in you will be shaken.
(I’m thinking now of a time a flight review was underway in a friend’s C175 and a magneto began mis-firing during takeoff-run around 50 mph. We almost ended up “in the rough” with that abort. This is the event which prompted me to add the question to my reviews.)

I’ve stopped finding enjoyment in passing close to obstacles on takeoff.
When I was a much younger pilot... I would go searching for short strips purely for the fun of it... and make takeoffs that would scrape the green off the leaves with the bottom of the wing.

Nowadays I don’t find any pleasure in passing less than a couple hundred feet above obstacles. I have a 3,500’ grass runway with 30’ p-line on the east end and 15’ trees on the west end. On standard days things are relaxed. But on most hot Texas days... when near gross weight ...(which is anytime there is more than one pax and full fuel in a 170)...there is a nice paved runway 4 miles to the east.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight.
An originality nut (mostly) for the right reasons. ;)
User avatar
GAHorn
 
Posts: 19654
Joined: Fri Apr 12, 2002 8:45 pm
Location: Spicewood (Austin), Texas

Re: 170B out of 1700' grass strip

Postby airtractorflyer » Thu Sep 05, 2019 10:33 am

n2582d wrote:
airtractorflyer wrote:Hi guys. Have a 1700' grass strip at my house departure end is wide up. Will stock 170B haul me 210lbs, wife 115lbs, and my 7 year old that is 50lbs with few bags full of fuel? About 250' msl.

Seven years ago you were 10 lbs. lighter (I can relate! :oops:), your boy was about 40 lbs. lighter and your strip was 400 feet shorter.
airtractorflyer wrote:... I built a 1300 ft grass strip at my house. Live at about 250msl. Will a 170a haul me my wife and baby boy out of there? I weigh around 200lbs, wife around 110lbs and just had a baby boy.
Karl's performance chart was a bit garbled -- looks like our copy in the Library for the '56 is a bit messed up on this page. Here's another try from the 1952 manual:
Screen Shot 2019-09-04 at 8.54.26 PM.png
Using rules of thumb from Light Aircraft Operating Tips you should be able to plant a 50' tall tree at the end of your 1700' strip and just clear it. This is assuming you're 10% under max. gross weight, the density altitude is 250', the strip is level with short grass and no wind. Your ground run under these conditions should be 630'. The variables pretty much cancel each other out. The above chart is based on using a McCauley prop but it doesn't specify the pitch. After flying an Air Tractor for a living you'll be wanting a few more horses up front.


And I still haven't got a 170 yet! Had a straight tail 182. Got rid of it have a little champ to piddle on. Looking for something we all can go in.
airtractorflyer
 
Posts: 11
Joined: Mon Nov 16, 2009 9:11 pm


Return to The Pilot Lounge

Who is online

Users browsing this forum: No registered users and 9 guests