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Extra 400

Yes I have indeed ! Now close to 48%, which is still low, but a lot depends on probe placement I think. The effect in the climb is very pronounced, I can bring fuel flow back from 35usg to 32usg up to FL160 and still be very comfortably below 360deg CHT and 1450deg TIT. In the cruise I have 1usg less for the same temps.

What was done: right intercooler was rectified/cleaned, left intercooler was replaced, and the baffling was replaced.

I’ve been chasing temp issues ever since my top overhaul two years ago, and I now think everything’s back where it should be.

EGTF, LFTF

@flyingfish great videos, thanks for sharing your overflight of Dennis.

Question: when you encountered turbulence in the descent, was lowering the gear an option? It would be standard practice in the PA46. In your case, with your higher Vno, it’s more a question of comfort; in my plane sometimes it’s the only way to punch down icing layers in ascending air masses.

EGTF, LFTF

denopa wrote:

Yes I have indeed ! Now close to 48%, which is still low, but a lot depends on probe placement I think. The effect in the climb is very pronounced, I can bring fuel flow back from 35usg to 32usg up to FL160 and still be very comfortably below 360deg CHT and 1450deg TIT. In the cruise I have 1usg less for the same temps.

What was done: right intercooler was rectified/cleaned, left intercooler was replaced, and the baffling was replaced.

I’ve been chasing temp issues ever since my top overhaul two years ago, and I now think everything’s back where it should be.

Awesome! Congratulations. this is a massive improvement and it is encouraging to me.
In my aircraft FF is 33 to 34 GPH in the climb and TIT is comparable to yours.
What are your cruise settings and temps ? Also I noticed that my intercooler is more efficient in cruise (50%) than in the climb (43%). You?
Wonder how that other PA46 got 55% efficiency…

denopa wrote:

Question: when you encountered turbulence in the descent, was lowering the gear an option? It would be standard practice in the PA46. In your case, with your higher Vno, it’s more a question of comfort; in my plane sometimes it’s the only way to punch down icing layers in ascending air masses.

Ahem… I got so little training on the E400 that I never encountered this situation during training so take my answer with a grain of salt…
The E400’s Vle and Vlo are low: 140 KIAS, so we’d need to slow down considerably before doing the gear down trick. Plus my guts tell me that the E400’s gear should probably not be used as an air brake because… it is too much of it. I don’t feel comfortable with the way the plane stops flying – I am acutely aware of the phenomenon now and I suppose this is perceptible in the video – Before and after switching to gear down, you can see my hands almost stuck on engine controls…

The E400 really can take a lot of turbulence and it remains comfortable, but I had been greedy and set it up for minus 1500 fpm to get through the icing layer as quickly as possible. I knew that this would take us to around 195 KIAS which is just the beginning of the yellow arc.
When the turbulence happened, I though “hmm, let’s play it safe” stopped the descent, pulled up to reduce speed a bit and then reinstated 1000 FPM which worked fine.

As I briefly hinted in the video, we lost this race and the cause was that we should have declined the coffee kindly offered by the airport manager at our fuel stop airport (LFRI).
Had we been on schedule, the weather would have been much less of a challenge. It really was rough and the only benefit was that it rinsed all of the salt water that the same Dennis had blown on Galatea when it hit our island!

But back to the topic: I am very happy for you and it inspires me in my quest for improvement. Safe flying

LSGG, LFEY, Switzerland

Flyingfish wrote:

I noticed that my intercooler is more efficient in cruise (50%) than in the climb (43%)

Not really, what I see is that efficiency increases with altitude. If anything it’s slightly more efficient just before levelling off (by less than half a percent

What are your cruise settings and temps

At FL190 last week, ISA+2, at 29.5"/2400RPM/21USG, TITs were 1582/1613, highest CHT 362 (cylinder 5), highest EGT 1531 (cylinder 4), IAT 90, CDT 183 (that’s actually 49% efficiency if my math is correct)

The E400’s Vle and Vlo are low: 140 KIAS

Indeed that’s low compared to your Vno. In the PA46, Vle is just 3kias below Vno. The only way I get 1500fpm in the green arc is with the gear down. This means keeping sufficient power to sustain level flight comfortably above stall speed, gear down, when levelling off – there have been accidents where people forgot to add back power, so it’s good practice.

Last Edited by denopa at 23 Feb 20:35
EGTF, LFTF

denopa wrote:

At FL190 last week, ISA+2, at 29.5"/2400RPM/21USG, TITs were 1582/1613, highest CHT 362 (cylinder 5), highest EGT 1531 (cylinder 4), IAT 90, CDT 183 (that’s actually 49% efficiency if my math is correct)

Oh great I found comparable data in my spreadsheet:
FL190 – ISA+ 5. 29.5 inches and 2250 RPM . FF 19 GPH. TIT 1650, IAT 88 CDT 167. Efficiency 47%.

Only difference is you had higher RPM – and power? – this is my 65% setting,
I suppose this explains the higher CDT as your turbos had more work to do feeding the higher RPM.

Apart from that it looks like we have very similar thermal challenges. FWIW indicated airspeed was 140. I did not make a note of TAS but probably 188.

LSGG, LFEY, Switzerland

IAS 142kts, TAS 191kts so I wasn’t getting my money’s worth for those two extra USG of fuel flow.

EGTF, LFTF

I think your 2 extra GPH reflect higher power and a slightly more conservative TIT limit.
My self-imposed limit is/was 1650, but POH says 1750 and I am now allowing 1675 occasionally thanks to the Inconel exhaust.

These are really interesting comparisons… the more we exchange, the more it becomes apparent that these two birds are very very similar… despite the radical differences in airframe and engine.

LSGG, LFEY, Switzerland

@Flyingfish, a really interesting ‘through-Dennis’ flight!

That is however not a flight I would gladly do in our P210 and one that, if shared with the family would cost me what I love most: flying with them!

My wife would never come back on board…Galatea or Maria Centurion (our 210) it does not matter, she’s not coming back after such a flight! Something I cannot afford.

Most non-flying pax hate anything more than short-duration, light turbulence.

Thanks for posting! I really enjoyed your analysis and watching your execution. Next time, however, I would suggest you get your timing priorities right on departure, most likely 30-45 mins would have made the difference in your descent.

Antonio
LESB, Spain

Antonio wrote:

Thanks for posting! I really enjoyed your analysis and watching your execution. Next time, however, I would suggest you get your timing priorities right on departure, most likely 30-45 mins would have made the difference in your descent.

Hi @Antonio

Feedback much appreciated. I can only agree… The purpose of the video was to share the whole analysis and execution as you noted and I have indeed admitted my mistake and “defeat”. Hopefully other people will have observed the mistake as you did and learnt something from it.
The last 15 minutes were rough and I was certainly not implying that I was proud of having taken my brave girlfriend (and soon student pilot) through that.

The go / no go decision is always a difficult one, even with such a capable aircraft.
I am learning by doing and certainly in this case, I learnt to pay more respect to the timing parameter under such circumstances.
It was not dangerous, but not pleasant and completely unnecessary…
Safe flying!

LSGG, LFEY, Switzerland

Antonio wrote:

My wife would never come back on board…Galatea or Maria Centurion (our 210) it does not matter, she’s not coming back after such a flight! Something I cannot afford.

Most non-flying pax hate anything more than short-duration, light turbulence.

Having experienced quite often moderate to occasional severe turbulence in passenger jets, my wife took the only time we did get some turbulence in the Mooney quite well. Obviously, this is a factor of life when flying ANY airplane, yet the difference is that in larger airplanes they can be quite dangerous with all sorts of stuff and people flying through the cabin, whereas normally in our light planes at least the pax are usually buckled in.

Yet the experience is very different and depends largely on the individual. Your problem however is probably one which most people fear more than the actual turbulence and rightly so.

LSZH, Switzerland
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