BeechTalk - BT - Merlin IIIA purchase and prebuy questions

Username Protected · **Posted:** 08 Feb 2022, 23:33

Quote:

TPE331 can be hard to start in cold. I find the best way to start in cold is battery series. This is better than GPU, even, due to 48 volts on the starter. Really hard on the batteries, relays, wiring, and starter though.

We almost always used a series start on a 3B , and even then in real cold weather it would hang...

Username Protected · **Posted:** 09 Feb 2022, 00:08

Username Protected wrote:

...and even then in real cold weather it would hang...

Thanks, whats real cold for someone from California, Probably anything under 70F

Username Protected · **Posted:** 09 Feb 2022, 00:22

Username Protected wrote:

That would be contrary to the mfg recommended procedure as the engine and inlets are designed to run most efficiently at 96% per GarrettAlliedSignalHoneywell and the more RPM, the more blade creep and wear you get.

There is no prohibition against operating at 100% RPM, so it isn't "contrary" to do so.

Honeywell advises the engine wear is less at 96% and suggests you use.

Plenty of TPE331 engines run at 100% and make TBO just fine.

Quote:

Separately, there is zero percent chance it’s on MSP at $77/hour and transferable. Take that figure and double it and add 20%

If so, MSP is the worst deal ever.

Over a 5000 hour TBO cycle, you will spend about $300K in HSI and OH on a -10 engine. Works out to $60/hour. You math results in almost $1M in program fees per engine per TBO cycle.

Mike C.

Username Protected · **Posted:** 09 Feb 2022, 00:25

Username Protected wrote:

Separately, there is zero percent chance it’s on MSP at $77/hour and transferable. Take that figure and double it and add 20%

Bruce

I went and looked back through what they provided, I quoted wrong. It's actually around $87/hour for each engine.

I don't think they are lying.

Hilgard

Edited for the usual spelling and grammar mistakes.

Username Protected · **Posted:** 09 Feb 2022, 12:10

Username Protected wrote:

What the heck is the pilot doing with his fingers in this video?!

He is pushing the "enrich" button which introduces more fuel.

[...]

Starting a TPE331 is a dance of eyes watching a bunch of stuff and fingers pushing buttons.

Mike C.

Username Protected · **Posted:** 09 Feb 2022, 14:02

Username Protected wrote:

Fascinating. It looked like more work than starting a big radial, and that surprised me.

Starting TPE331 is a bit of an art. You got to watch so many things like temperature, RPM, voltage, etc, and manipulate start button fuel enrich and be ready to abort on the condition lever. There is a lot to know about parallel, series, and GPU starts.

There are also tricks. Foe example, in really cold weather, perform a start that you abort at 25-30%. Put in inlet and tail pipe plugs. Wait 15 minutes. Remove plugs and then start. Preheats the oil and makes it much easier to start in very cold weather.

It is a kind of security system. I didn't worry about people stealing my MU2 because few people know how to start it.

In comparison, the JT15D on my Citation is laughably easy. Push button, throttle to idle at 8%. You are verifying oil pressure, N1 turns, start light goes out, etc, but not too onerous. You don't even have to turn on the generators (for a battery start).

Mike C.

Username Protected · **Posted:** 09 Feb 2022, 22:43

Username Protected wrote:

Fascinating. It looked like more work than starting a big radial, and that surprised me.

Starting TPE331 is a bit of an art. You got to watch so many things like temperature, RPM, voltage, etc, and manipulate start button fuel enrich and be ready to abort on the condition lever. There is a lot to know about parallel, series, and GPU starts.

There are also tricks. Foe example, in really cold weather, perform a start that you abort at 25-30%. Put in inlet and tail pipe plugs. Wait 15 minutes. Remove plugs and then start. Preheats the oil and makes it much easier to start in very cold weather.

It is a kind of security system. I didn't worry about people stealing my MU2 because few people know how to start it.

In comparison, the JT15D on my Citation is laughably easy. Push button, throttle to idle at 8%. You are verifying oil pressure, N1 turns, start light goes out, etc, but not too onerous. You don't even have to turn on the generators (for a battery start).

Mike C.

Username Protected · **Posted:** 09 Feb 2022, 22:49

Username Protected wrote:

Starting most 331’s is a beautiful one touch operation. It’s all automatic with fewer steps than a PT6 or a JT15D. There is literally nothing to do after hitting the start switch other than monitoring the start. The manual fuel enrichment of certain models is easy and, on most properly rigged airplanes, requires one depress and release of the button.

Non SRL aircraft (Metro II for example) required multiple presses of the start button for manual enrichment. Even then it wasn't that difficult. You are right though, if they had SRL system, push the button and just wait... nothing easier...

Username Protected · **Posted:** 09 Feb 2022, 23:24

Username Protected wrote:

Starting most 331’s is a beautiful one touch operation. It’s all automatic with fewer steps than a PT6 or a JT15D. There is literally nothing to do after hitting the start switch other than monitoring the start. The manual fuel enrichment of certain models is easy and, on most properly rigged airplanes, requires one depress and release of the button.

Non SRL aircraft (Metro II for example) required multiple presses of the start button for manual enrichment. Even then it wasn't that difficult. You are right though, if they had SRL system, push the button and just wait... nothing easier...

Username Protected · **Posted:** 09 Feb 2022, 23:38

Quote:

Thanks, whats real cold for someone from California, Probably anything under 70F

Actually..., it was Findley Ohio, 1981... 14 degrees or so...
We had to ask Marathon Oil to let us use a GPU to get started...
(I've only been in CA for 4.5 years)

Username Protected · **Posted:** 10 Feb 2022, 00:27

Username Protected wrote:

Reality: Starting most 331’s is a beautiful one touch operation. It’s all automatic with fewer steps than a PT6 or a JT15D. There is literally nothing to do after hitting the start switch other than monitoring the start.

It would be an amusing video to see you start my former MU2.

If the system is rigged so you don't need fuel enrich during the start, then you run the risk of an overly aggressive and hot start when conditions change (like higher elevations, denser fuel, tailwind, etc). The pilot can add fuel with enrich, but he can't take it away, so the safe thing is to program the start fuel schedule some amount under what the engine actually needs and let the pilot adjust with enrich to keep temperatures positively on the safe side.

There is no way it is less steps than a JT15D. Don't forget, you also have to do the NTS check at the same time, too!

Mike C.

Username Protected · **Posted:** 10 Feb 2022, 03:16

Username Protected wrote:

Reality: Starting most 331’s is a beautiful one touch operation. It’s all automatic with fewer steps than a PT6 or a JT15D. There is literally nothing to do after hitting the start switch other than monitoring the start.

It would be an amusing video to see you start my former MU2.

If the system is rigged so you don't need fuel enrich during the start, then you run the risk of an overly aggressive and hot start when conditions change (like higher elevations, denser fuel, tailwind, etc). The pilot can add fuel with enrich, but he can't take it away, so the safe thing is to program the start fuel schedule some amount under what the engine actually needs and let the pilot adjust with enrich to keep temperatures positively on the safe side.

There is no way it is less steps than a JT15D. Don't forget, you also have to do the NTS check at the same time, too!

Mike C.

Username Protected · **Posted:** 10 Feb 2022, 06:58

Flew in a 441 yesterday. I swear start seemed simpler than -10 mu2 srl - probably bc you could cross gen start and not sit there waiting for batteries to charge!

To Bruce’s point though, on my Solitaire you could just hit the button and it would do everything. All the ‘complexity’ was bc you were testing the NTS system and monitoring other systems while also having the engine spool up.

On the ramp in Durango there was an MU2, a commander and 441. It was a TPE 331 party! We just needed a Merlin to round things out.

Username Protected · **Posted:** 10 Feb 2022, 10:07

Username Protected wrote:

On the ramp in Durango there was an MU2, a commander and 441. It was a TPE 331 party! We just needed a Merlin to round things out.

I haven't been to Durango in years, but it was always in a Metro! I imagine one will come along before long for the day or weekend...

I loved the layovers there..

Username Protected · **Posted:** 10 Feb 2022, 10:11

Username Protected wrote:

Hi Jason,

I see some of that approach too, and the ticking approach may be required depending on FCU and setup, but generally if you depress the enrich button before light off/10% as is recommended and as the SRL planes effectively do for you, and hold it to 600 or whatever the engine likes, then release it, you may just find you only need to push the button once instead of a million times. There are so many bad habits that seemed trained into the system on 331’s. Add up the years of bad maintenance, poor operational techniques, and misleading advice and, well, here we are.

At that time, the airplanes were new to the company. We had 13 226's (non-SRL) and 5-6 227's (SRL). The non-SRL birds definitely needed enrichment to keep 690 degrees EGT during the start. The 227, like the 441 were push the button and wait.. They were much easier to teach new pilots until they were comfortable with the start, then we would have them simulate a deferred SRL system....