BeechTalk - BT - 240 Kts in 421C

Username Protected · **Posted:** 25 Nov 2019, 23:57

I have an old book for the C 421C. It says it goes 236 KTAS at 25k ft. True or false? Some guy in a FBO told me the other day that his did 240 kts also. I don’t believe any of this. Please share...

Username Protected · **Posted:** 26 Nov 2019, 00:07

I don’t believe it either.

Username Protected · **Posted:** 26 Nov 2019, 00:10

I have pictures of the GPS TAS calculator in the one that I managed at FL230, ISA +16, 219 KTAS, 65% LOP. I'm pretty sure it would make close to the book numbers at 75% ROP...

Username Protected · **Posted:** 26 Nov 2019, 01:00

I tuned mine and it was painted with high build removing all rivet drag etc.

It did 232+ktas on a G600. I might believe an old steam gauge could indicate a number that produced 240, but thats not a real number.

Lots of performance stuff and videos in this thread...

viewtopic.php?p=1124908#p1124908

Username Protected · **Posted:** 26 Nov 2019, 01:12

I will find a link to it, but there is an old pbaron ad that claims it could do 242kts.

Username Protected · **Posted:** 26 Nov 2019, 18:03

I went to 70-71% power in cruise the other day and got 231 True. I was at FL230. It picked up about 8 knots from 65% to 70% power. So I would imagine it could do 240 at 75% power. at 70% power it was burning about 24gph a side. at 65% its just under 20gph.

But I am not sure how you get to 75% power as at 1900 rpm and 32.5 I was only at 70% on the JPI. It says to not cruise over 32.5MP in the flight levels in my power setting table so I don't know how you get to 75% power in the flight levels.

I cruise at 65% power and get over 220knots true in the flight levels.

Mike

Username Protected · **Posted:** 26 Nov 2019, 19:19

So 8 knots costs $40 per hour.

Username Protected · **Posted:** 26 Nov 2019, 19:23

Username Protected wrote:

So 8 knots costs $40 per hour.

Yes, LOL I didn't stay at that speed for more than 5 min. Its already painful enough at 40gph.

Thats really the only drawback of the 421, It's an AV gas guzzler. I am fortunate that I get a good price on 100LL at my home field. Most of my trips are 500-600nm so I can tanker some fuel to help on the return trip.

Mike

Username Protected · **Posted:** 27 Nov 2019, 08:53

calling Todd Amstein.....Todd has one of the fastest 421 around.....Todd what say you?

Username Protected · **Posted:** 27 Nov 2019, 10:42

Username Protected wrote:

So 8 knots costs $40 per hour.

Yes, LOL I didn't stay at that speed for more than 5 min. Its already painful enough at 40gph.

Thats really the only drawback of the 421, It's an AV gas guzzler.

Mike

Username Protected · **Posted:** 27 Nov 2019, 11:03

Username Protected wrote:

If a 421 were an Irishman it would miss the cut at Dublin drinking contest

Now me Aerostar

.97 GP...MINUTE

Would make any Irish drinking team proud

An Irish drinking team of midgets perhaps.

In the 421 you can take an Irish rugby team and their kegs.

Robert

P.S. Is the Dublin drinking contest about who can drink the least?! Weird Europeans...

Username Protected · **Posted:** 27 Nov 2019, 20:06

If you ever want to make a 421 go fast just leave it at climb power after level off. It goes plenty fast but burns 70GPH.

Username Protected · **Posted:** 27 Nov 2019, 22:46

Username Protected wrote:

I have an old book for the C 421C. It says it goes 236 KTAS at 25k ft. True or false? Some guy in a FBO told me the other day that his did 240 kts also. I don’t believe any of this. Please share...

I haven't tried 32.5/1900 at 25k, but comparing our records to the POH at various altitudes...236+ @ 25k and those power settings doesn't seem unreasonable.

Username Protected · **Posted:** 30 Nov 2019, 23:41

Username Protected wrote:

I have an old book for the C 421C. It says it goes 236 KTAS at 25k ft. True or false? Some guy in a FBO told me the other day that his did 240 kts also. I don’t believe any of this. Please share...

Not a chance in hell.

I've met people who had 170kt Skylanes and 125kt Warriors too.