C414 Speed Issue

[Beagle12 137]

Thanks for your input Yoda967 🙂

[Mace 1,896]

This is good stuff in this thread.  I watched a vid of a real-world 414 pilot the other day, and I kept some notes of what I saw, which I'll post here:

real world pilot started port engine first.
He did crack the throttle a little
and shot only about 2-3 seconds of primer
Also he immediately leaned the mixture after startup.

cowl flaps open for takeoff
aux pumps to low

runup
1500 rpm exercise props
then go to 1700 rpm and do mag check
he flicks each of the 4 mags one at a time, pretty quickly, only off for a second or so.

then check for "match" where fuel flows between the two engines match at least fairly closely,
and manifold pressure and temps match

did not richen mixture until right on runway powering up
did not use flaps for takeoff
went to full power rather slowly on the throttles but appeared to go to about 40" or 41"

yaw damper came on right away
looking for 130 KIAS
climb power 35" mp rpm 2500
kept aux pumps on in climb

[cchiozza 106]

I will take a closer look but I did have 10 know crosswind but I dont think that would have effected airspeed that much. Yes GTN indicated only 167 GS at 12000 feet.

[ryanbatc 12,770]

15 hours ago, Cpt_Piett said:

I've been running 31" MP and 2300 RPM at FL200. But I guess there's no reason why not to choose 34" for a higher cruise speed. I guess it also depends on how economical you have to be in terms of fuel burn. 

EDIT: At the moment I'm getting a TAS of 250 kts with the above settings at FL200. Must have a pretty decent tailwind 🙂

Just a small mention.  You're getting a ground speed of 250 kts if you're involving wind into the equation.  TAS or true airspeed is your speed through the air, and has nothing to do with your speed relative to the ground.  You probably had a 40 knot tailwind or so and were having a TAS of about 210 or so.

[Frag 27]

On 8/17/2022 at 2:57 AM, Sceadu said:

You have that the wrong way round, its ground speed that is affected by wind not airspeed

Actually this is what I meant. I think the OP could think that the airspeed showed is too low, while in fact his ground speed is fast.

From KNAviation

Wind speed vs ground speed

Wind’s Effect on Ground Speed

The relationship between airspeed and ground speed is fairly simple. Ground speed is simply the sum of airspeed and wind speed.

If the aircraft is flying in the same direction as the wind is blowing, the aircraft experiences tailwind, and its ground speed is higher than its airspeed. On the other hand, if the wind is blowing against the direction the aircraft is traveling in, the aircraft experiences headwind, and its ground speed is lower than its airspeed.

 

 

Edited August 18, 2022 by Frag

[Cpt_Piett 4,490]

9 hours ago, ryanbatc said:

Just a small mention.  You're getting a ground speed of 250 kts if you're involving wind into the equation.  TAS or true airspeed is your speed through the air, and has nothing to do with your speed relative to the ground.  You probably had a 40 knot tailwind or so and were having a TAS of about 210 or so.

Not sure if I understand completely Ryan. I was referring to the TAS from the TDS GTNXi. 

[Mace 1,896]

3 hours ago, Cpt_Piett said:

Not sure if I understand completely Ryan. I was referring to the TAS from the TDS GTNXi. 

My TDS unit is set up to show Ground Speed.  I wasn't aware that it could show TAS, but there are a lot of options, maybe I'm forgetting it.

[Cpt_Piett 4,490]

17 hours ago, Mace said:

My TDS unit is set up to show Ground Speed.  I wasn't aware that it could show TAS, but there are a lot of options, maybe I'm forgetting it.

No you're right. @ryanbatc also. The TDS display is showing GS, not TAS. Sorry about the confusion guys.