How Fast

[murphy]

How fast is a Taylorcraft? I have a 1983 F21A that seems to be alittle slow but I'm not sure just what one should cruse at. The book says 118-122 @ 6000-8000' 2450-2500 rpm but that is the book and they never seem to do that. Mine is happy at 100 mph @ 2500 with a 118 hp Lyc. but alot of the more seasoned pilots around our airport claim 65 BC 12's would cruse 100-105 so what do you think is my airplane slow (out of rig) or is it about normal.
I will say it gets off quick and has a cruse prop of 72/53 and is alittle dirty with no pants and a fairing missing under the belly covering up the shock cords. Anyone know where I can find that fairing?
Great site thanks for any input,
Mike

[MAC]

Re: How Fast

MIKE or others: I have the same question on my BCD85. It easily cruises 85 and up to max 90 and wonder if I have the right prop for an 85. It is an Senwisch 74-46 which has been shortened up over the years to 72 inches and was on the 65 before it was converted about 200 hrs ago. Any thoughts appreciated.
NC39973

[flylo]

Re: How Fast

I had a '46 with a 85HP Cont. that would cruise 100MPH @ 2200-2300 RPM.It had a "seaplane" prop that was between a climb & criuse prop. I now have a '38 BL that will cruise 88-90MPH with the little Lycoming. Hope this helps,Eric

[Frank DeBartolo]

Re: How Fast

My BC12-D with a wind alternator and climb prop trues out at appx 90 MPH.

FD
N43684

[Yellow Duck]

Re: How Fast

My two cents: I have a 74/41 on the Duck and cruise at low altitudes between 90-100 depending on RPM. Mostly 90 @2100 and about 100 @2300 Static 2100-2150

When I changed my oil yesterday(Friday) I also changed my prop to another I have, a 74/45. Haven't flown it yet, but statics between 1850 and 1900.

Plan on going up today. Will see how much longer it takes to get off with one on board and new cruise speed. Last winter it would cruise about 110 with this prop. Don't remember what RPM I was using.

But each aircraft will fly at slightly different speed, because of weight and rigging. Also we mustn't forget AS indicators. Most are not that accurate. A GPS measuring two ways at 90 degs to the wind and averaging is a good is a pretty good ck.

[mhorowit]

Re: How Fast

O boy, a chance for me to be a smart-ass

Air speed or ground speed?

Air speed has already been discussed, but IMHO, ground speed is what you need to determine how long it will take to go from A to B.

To determine Ground Speed, take the number of stops, and multiply that figure by :45 and add that amount to the total.

Why? because at each stop, two old-timers will make their way to where you've tied her down and will spend :45 telling you their Tcraft experiences . Not an altogether unpleasant experience, but it cuts down on your GS. - Mike

[paulp]

Re: How Fast

Mike,

That is exactly why I use a calander rather than a clock!

[Vasey fan]

Re: How Fast

Mike,

That is exactly why I use a calander rather than a clock!

That's what I used in my Aeronca!

[Chet Peek]

Re: How Fast

Here is what I believe to be the TRUTH about Taylorcraft airspeeds. I have
owned and flown all of them many hours.

Model A, 80 MPH with one person, 75 with two.

Early BC models, 105 with one person 100 with two

Later BC-12-D's, 90, 95 depending on weight.

F-19, 115 MPH loaded.

I have not flown an F-21, but it should be as fast as the F-19.

My DC-65 will cruise 90, sometimes.

Chet Peek

[Brady]

Re: How Fast

My F-19 is a great airplane...but slow. The prop was re-pitched by the last owner to 71-41. At about 2500 rpm, I might get 100 mph out of it on a good day. I usually plan on about 90 mph at 2300-2400 rpm on trips.

My F-21 is a lot faster. I think mine has the 72-53 prop also, as described by Murphy. I can normally coax 110+ mph at 24-2500 rpm cruise if I'm not too heavy. It climbs much better than my F-19 also. I can count on about 1000 fpm for the first couple thousand feet, as opposed to 6-700 fpm in the F-19. I recently flew the F-21 from Shreveport, to Fort Collins, CO, to Tucson, back to Shreveport. Even taking a fairly conservative route, I was thankful for the extra performance on the Ft. Collins to Tucson portion.

I had a '41 BC-12-65 for many years. It would consistently do 95 mph in cruise and about 105+ flat out. It was so much lighter and flew a lot nicer at slow speed. I want to say is was only 700 lbs empty. Great plane!

[murphy]

Re: How Fast

All great information my F21a indicates 110 but ground speed with no wind (GPS) is 100 @ 2500 RPM so I maybe alittle slow and my airspeed indicator needs overhauling. May check wing rigging but I hate to mess with the climb much as she does really well 800-1000 fpm and that is what really counts to me anyway. Just fishing for information so thanks to all.
Mike Murphy

[Acroeric]

Re: How Fast

A useful formula that I use when trying to determine how to pitch a prop is :
Pitch*Rpm*60 / 4 = airspeed .

This will assume 100% efficiency. The best most props on a Tcraft will do is 95% so if you are running a 74-46 at 2300 rpm
46*2300*60=63360

Now divide that by 4 and you get 100 mph at 100% efficiency. Multiply this by .95 and you get 95 mph which is probably what most guys get with that prop.

The 53 pitch prop at 2500 should do alot more than 100 mph- the formula says 125 mph

[Frank DeBartolo]

Re: How Fast

There is another way to compute average air speed, but you must have a chronograph watch or timer. You also need an accurate course to fly. It is easy where I live in Iowa because our section lines are exactly one statute mile. I just fly cross wind each way and average. A hand held GPS helps to verify this method.

FD
N43684

[Dusty]

Re: How Fast

46*2300*60=6348000/4=1587000

According to http://www.pgam.ca/airspeed.htm, the formula should read:

RPM * Pitch / 1056 = miles per hour

I get 85-90 at 2250 with a 74/41.

[VictorBravo]

Re: How Fast

A Taylorcraft will remove money from your pocket at a speed of approximately 500 miles per hour. It will routinely cause an argument during which your wife's words will flow at approximately Mach 1.3. It will make an insurance agent run the opposite direction at a velocity at least equal to the speed of light. During restoration it will slow down time to 1/10 the normal speed. It will make time stand still for one glorious moment just before touching down at sunset on a nice summer day.