You guys think my F is too slow.

[Hank]

I need to do the 4-way check. I've made the same 35 nm hop both ways yesterday and today (out and back twice). GS has been 132-136 knots, IAS has been as shown, 145-150 mph at 3000 msl, 23/2300, 50° ROP. Since getting my carb heat box reworked at annual last month, that's a 10-15 mph increase.

Found out all of my Instrument power settings changed, too; 16"/2300 used to be straight & level clean at 90 knots, now it's straight & level, Approach flaps, at 90 knots. Go ahead, call me a happy camper. This morning, throttled back to ~120 mph, a gentle 300 fpm descent pushed it to 145-150. Descending at 500 fpm is no longer near the top of the green at 170, it's now into the yellow pushing 180.

If your plane "seems slow," there are many not-so-obvious things to check. Granted, your F has no carb heat, but what else under the cowl could be disturbing the airflow? Check it all. Do you have Alt Air? Does Ram Air work right? Also check the nose gear doors for proper overlap, and all three doors for full retraction and closing against the wing.

[Marauder]

I don't want to be a party pooper on the awesome KIAS you guys are showing off, but you should really do a 3 or 4 leg speed check to validate them.

 

Last summer I used my IAS, temp, pressure alt, etc to compute my TAS.  Funny though, when i compared it to my ground speed, I was "always getting a headwind"... when I did the GPS 3 (or 4) way speed checks, I found a 6 knot error in the IAS at cruise speed - it was showing 6 knots fast!  My POH does show a ASI correction chart, but not 6 knots.  Anyway, I'd highly recommend doing the GS check to figure out what you really have... or leave well enough alone and just enjoy it?

 

If you do the speed check, you can figure out your real TAS and then work backward to IAS and see how far your IAS is off which might be nice to know.

 

So, Mr. Not A Party Pooper Got a question for you. Since I have 3 separate airspeed indicators but 1 common pitot tube, how much of the error could be caused by the pitot and associated tubing over an issue with the actual indicator itself? The reason I ask is that all 3 of my ASIs agree to the knot. Just curious from your experience where the majority of the error is introduced.

[Ragsf15e]

That's actually a really good question.  I only have one ASI, so I couldn't really determine (I didn't have it recalibrated after I found the error).  Since all your 3 (!?) ASIs agree, I guess you will know it's the pitot system that has the error if you do a groundspeed test, solve backward for IAS and find that it's not what's indicated.

 

Remember, there is an IAS correction in the POH that is supposed to be applied and the faster you go, the more you have subtract from the IAS to get CAS (Calibrated Aspd).  

[dmc]

I used this calculator today to check what my Debonair was getting. http://www.csgnetwork.com/tasgpscalc.html

My airspeed indicator was actually very close to the results I got from the calculator. I was showing 158 to 160 mph at 7500 which calculated out to be about 155knt true. The calculator came out with 156knts true for the three GPS readings.

[Marauder]

That's actually a really good question.  I only have one ASI, so I couldn't really determine (I didn't have it recalibrated after I found the error).  Since all your 3 (!?) ASIs agree, I guess you will know it's the pitot system that has the error if you do a groundspeed test, solve backward for IAS and find that it's not what's indicated.

 

Remember, there is an IAS correction in the POH that is supposed to be applied and the faster you go, the more you have subtract from the IAS to get CAS (Calibrated Aspd).  

 

 I will give the ground speed test a try. I did one years ago and was able to determine the TAS with one ASI. When I had the IFR cert done, they told me my pitot had some leaks in it. If anything, I should be faster! 

[Shadrach]

I recorded some video today, but I'm still sorting through the editing. It was about 2C today when we departed. We were light at 2350ish lbs. I do believe my ASI is a bit optimistic, but not by a huge margin.

We rotated at 65KIAS, gear up, flaps up and pitched for 105KIAS. 49sec later we were through a 1000ft. That's an average of 1224FPM, including clean-up and acceleration to Vy. 

The VSI was showing ~1500 FPM for the last 300ft of climb.

I was conservative in my timed climb. Field elevation is 703msl (TDZ for the runway I departed is 685.5msl). I initiated a left turn at 1720msl which is the 49sec mark. 

 

At 3000ft, WOTRAO, 30LOP and 2550RPM I was indicating 154KIAS

At 5500ft WOTRAO, 30LOP and 2550RPM I was indicating 151KIAS
From 5500, I pitched for 130KIAS which resulted in 1000fpm climb for about 500ft, settling to about 750fpm to 6500ft where we stopped and did a 3 way speed run. WOTRAO 10LOP, OAT-10C at 6500ft yielded a GPS derived airspeed of 152.9Kts. I was indicating about 147KIAS.

I believe the pressure was 30.07 but I don't recall. I thought it would be viewable in the video, but the Kollsman window is glared out.

[bonal]

Did the 3 and 4 with GPS at 8000ft the 3 heading netted 148 knots and the 4 heading netted 149 knots plus change.

[bonal]

So to all the naysayers my flight back from Palomar to home took 3 hours 22 min and was flown into a confirmed 10 knot head wind. My fore flight planning computed a time of 3 hours 20 min with a 5 knot head wind and my programed speed is set for 145knots. Aircraft settings were 2500 rpm 21 inches MP with a climb from sea level to 10500ft. my average speed would be 150 knots.  DA BOMB

[Ragsf15e]

That's one fast puppy!

[bonal]

That's one fast puppy!

Funny you should say that since he is named after a very famous flying beagle