Take-off / Landing distance required to clear a 50 foot or existing obstacle

[anthonyp]

Hello everyone. I will be using a 1956 Tripacer to complete my PPL, however I'm hung up on one part.




Circled in red are two Ground requirements that are needed to be determine prior to flying. The POH and AFM with the aircraft only contain the following details:



however the figures here are not enough to calculate a take-off / landing distance required to clear a 50 foot or existing obstacle in other conditions.

Can anyone assist?

 

[dgapilot]

Use a Koch chart. What you have is what was required for certification and the examiner cant ask any more than what the manufacturer provided, or what the certification requirements for the aircraft required.


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[anthonyp]

Use a Koch chart. What you have is what was required for certification and the examiner cant ask any more than what the manufacturer provided, or what the certification requirements for the aircraft required.


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Thanks for your response. This may be the only course of action I can take. Hopefully the examiner will accept this.

 

[dgapilot]

Thanks for your response. This may be the only course of action I can take. Hopefully the examiner will accept this.

Best to talk to him about it ahead of time. You don’t want a denial after you get there. If he won’t accept it, find a different examiner!


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[59pacer]

If you're interested---
up until about 40 years ago, our then Department of Civil Aviation (who knew that they knew everything that was possible to know about aviation) required that any new type coming into the country had to be flight tested to establish it's takeoff and landing performance. They would not accept that the FAA approved figures for the PA22 (for example) were at all reliable.
The flight test data was then crunched and P charts were produced for takeoff and landing.
The attached ones are for a PA22-160 Tripacer. Basically they were for a level, short dry grass strip. Allowance could be made for pressure altitude, temperature, weight, and head/tailwind.
Takeoff was from a standing start, flaps 0, climb at Takeoff Safety Speed to 50ft.
The landing was based on the stated minimum speed in a power off glide from 50 ft. and maximum braking.
The distances obtained were then increased by 15% (ever conservative, our DCA).
Of course, these had to be carried in an approved Flight Manual in the aircraft. That type of Flight Manual was purely an Australian thing and bore no relationship to anything else around the world. Talk about creating an empire to protect jobs!
If you can't blow these up enough, I can post larger ones.

 

[dgapilot]

If you're interested---
up until about 40 years ago, our then Department of Civil Aviation (who knew that they knew everything that was possible to know about aviation) required that any new type coming into the country had to be flight tested to establish it's takeoff and landing performance. They would not accept that the FAA approved figures for the PA22 (for example) were at all reliable.
The flight test data was then crunched and P charts were produced for takeoff and landing.
The attached ones are for a PA22-160 Tripacer. Basically they were for a level, short dry grass strip. Allowance could be made for pressure altitude, temperature, weight, and head/tailwind.
Takeoff was from a standing start, flaps 0, climb at Takeoff Safety Speed to 50ft.
The landing was based on the stated minimum speed in a power off glide from 50 ft. and maximum braking.
The distances obtained were then increased by 15% (ever conservative, our DCA).
Of course, these had to be carried in an approved Flight Manual in the aircraft. That type of Flight Manual was purely an Australian thing and bore no relationship to anything else around the world. Talk about creating an empire to protect jobs!
If you can't blow these up enough, I can post larger ones.

View attachment 21142View attachment 21142

So how close were those charts to the Piper owners manual? Granted they only list a single condition, sea level standard day.


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[59pacer]

So how close were those charts to the Piper owners manual? Granted they only list a single condition, sea level standard day.

In the years between light aircraft flying and flying airlines (ie building house/family etc etc), it appears that our Department of Civil Aviation was forced to acknowledge that the FAA had learnt an awful lot in the meantime, and so we could accept the FAA data and scrap the P Charts! Needless to say, I have never bothered to do a comparison between the systems, but I'd guess that ours would have been about 15% more due to the 1.15 factor alone.
Our current regulations still do warn us that other authorities (eg FAA) have no factoring and so we should take a conservative approach to using their figures. Covering their a===s or not wanting to admit that they were wrong for 40 years??
In the same vein (digressing again)---
About the time that the B767 was introduced here, it was finally acknowledged that stall speed here was defined differently to the USA, and that had an effect on circling minima and circling area dimensions under PANS-OPS (IIRC the USA doesn't use that). V2 and Vref had to be fiddled with to get 'corrected' numbers. I was glad I was on the 747 and wasn't affected.

 

[davidk77]

I passed a PPL checkride in November 2022 in 1955 PA-22/150 using the Department of Civil Aviation weight chart similar to the one posted above (I had the 150 chart). If you want to cover your bases then practice calculations with that chart and with the Koch chart. It doesn't have to be the perfect answer so long as you can demonstrate an understanding of the principals and get close to the right answer. I never heard of the Koch chart until a couple of days ago when I was reviewing the FAA Density Altitude circular. It says to use a Koch chart if the POH doesn't specify the takeoff/landing performance graphs

https://www.faasafety.gov/files/events/nm/nm09/2013/nm0951144/density_altitude.pdf

See bottom of page 2

 

[tloes]

It says to use a Koch chart if the POH doesn't specify the takeoff/landing performance graphs

And if you are really lazy yet have access to the internet, you can use this site on the web to make a "current condition" Koch chart quickly. https://www.takeofflanding.com/

Just enter the code for a nearby field that reports METARs and it'll draw the line for you.