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Calculating Aircraft Performance
Posted: Wed Mar 10, 2010 6:41 pm
by n2582d
PM me if you're interested in a copy of "Light Aircraft Operating Tips", a pamphlet put out by Transport Canada on calculating aircraft performance on unimproved airstrips.
Re: Calculating Aircraft Performance
Posted: Thu Mar 11, 2010 7:23 pm
by blueldr
One learns to hold ones breath. Exhalation only on completion of short field lift off, or obstacle clearance. This has been proven to considerably enhance the performance of almost any type of airplane.
Re: Calculating Aircraft Performance
Posted: Thu Mar 11, 2010 11:17 pm
by busav8or
Works especially well when said pilot is full of HOT AIR!

Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 2:40 am
by jrenwick
Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 2:46 am
by blueldr
Please be advised that common sense requires any active pilot to be as full of hot air as his or her body is capable of holding without excessive passing of gas.
My daughter, the FedEx pilot, informs me that this is primarily true among the male members of the brotherhood. She claims the distaff members are much more delicate.
P.S. Another amazing fact that I have seen with my own eyes is the levitation of a DC-7C, loaded to gross weight, lifted off of the Travis AFB runway by force of the upward pressure my late wife applied to the arm rests in row 21. This phenonenom was repeated in Hawaii and Wake Island and on all three cruise legs.
If I hadn't seen it with my own eyes, I never would have believed it. It's still a mystery to me how that airplane got off the ground leaving Guam and aparently continued on to the Phillippines.
Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 2:58 am
by johneeb
John, John, this ignores the time when passenger's did not have seat belts and the airplanes still flew. The truth of the matter is that as the airplane starts rolling down the runway all of the passengers simultaneously grip on their armrest until their knuckles turn white the airplane flies.

Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 3:25 am
by jrenwick
johneeb wrote:...John, John, this ignores the time when passenger's did not have seat belts and the airplanes still flew. The truth of the matter is that as the airplane starts rolling down the runway all of the passengers simultaneously grip on their armrest until their knuckles turn white the airplane flies.

Heh!
But wasn't there an AD requiring seat belts to replace the older, less reliable, arm rest implementation?
John
Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 11:35 am
by GAHorn
I have found it very helpful when, just prior to commencing take-off roll, just checking the magnetos ONE MORE TIME...and as you switch from Both to Left to Both to Right ....at each position stare intently at the tachometer and let out an audible "HMMMMmmmm...."
I have found this keeps the passenger's interest in the flight at a keen level.
(bluEldr.... contrary to the theory of lift.... I always thought that DC7's take off due to Curvature-of-the-Earth....Am I right?
Re: Calculating Aircraft Performance
Posted: Fri Mar 12, 2010 1:16 pm
by busav8or
How about ROTATION of the Earth? Does a westbound airplane get off quicker because the blue marble is turning against it, therefore producing groundspeed from the moment of brake release, or an eastbound as the rotation immediately adds (doing math here: 25000/24=?) over 1000 miles per hour to the airplane's forward velocity?

And what about either a north or south takeoff? Talk about some serious crosswinds!!!

Re: Calculating Aircraft Performance
Posted: Sat Mar 13, 2010 2:45 am
by jrenwick
busav8or wrote:How about ROTATION of the Earth? Does a westbound airplane get off quicker because the blue marble is turning against it, therefore producing groundspeed from the moment of brake release, or an eastbound as the rotation immediately adds (doing math here: 25000/24=?) over 1000 miles per hour to the airplane's forward velocity?

And what about either a north or south takeoff? Talk about some serious crosswinds!!!

It matters quite a bit if you're going for orbit....

Re: Calculating Aircraft Performance
Posted: Wed Mar 17, 2010 2:12 am
by Cooper
I would be interested in getting a copy of the document "Light Aircraft Operating Tips" that you mentioned in the forum.
Thanking you in advance.
Remel
Re: Calculating Aircraft Performance
Posted: Sun Mar 28, 2010 11:31 pm
by weedt
I would like a copy too. What kind of numbers do you guys find for short take-off and landings with you 145hp 170's? I have a 1954 that I think does pretty well.
Re: Calculating Aircraft Performance
Posted: Mon Mar 29, 2010 3:28 am
by hilltop170
weedt wrote:What kind of numbers do you guys find for short take-off and landings with your 145hp 170's? I have a 1954 that I think does pretty well.
I can count on 500' landings and 700' takeoffs at around 2000 pounds, level hard runway, no wind, and 1000' density altitude.
As far as "can I make it?", if you have 70% of takeoff speed at 50% of runway, you can take off ok. So to be conservative for the C-170, around 40mph indicated at the halfway point on the runway should allow you to leave the ground safely or stop safely if not up to speed.
Re: Calculating Aircraft Performance
Posted: Mon Mar 29, 2010 11:47 am
by W.J.Langholz
Richard
Does that work for the 195 also?
Another week we will be able to get back on the turf runway, I'll have to check it out. I'll have to make sure to get the nose wheel up right away..........
W.
Re: Calculating Aircraft Performance
Posted: Mon Mar 29, 2010 5:34 pm
by n2582d
hilltop170 wrote:As far as "can I make it?", if you have 70% of takeoff speed at 50% of runway, you can take off ok. So to be conservative for the C-170, around 40mph indicated at the halfway point on the runway should allow you to leave the ground safely.
Richard,
That works well for a level strip. With a sloped strip one's abort point may be just after releasing the brakes.