Why is my mechanic so against a turbo?

[mandm]

So much truth

 

[Lance F]

Well I’ll play the contrarian here. I love my two turbos. One turbo failure in 7 years of flying my 414 I admit I wasn’t happy about, but OTOH I’ve seen every other make and model in shops with broken stuff too. I see the limited advantage in non-pressurized planes, e.g. Navaho, 310, etc. Use the turbo for pressurization though, and you’re above the weather, above the turbulence, way above mountain ranges not wearing an O2 mask at a nice low cabin altitude. Your SO, small kids, pets, whatever are happy. That’s worth a lot to me. And by the way don’t knock the turbo twin Comanche. My son’s does an honest 190 kts TAS at FL180 at 19gph (ROP) total and 170-175 kts TAS at 17,000’ at 14.5gph LOP.

 

[iamtheari]

Therein lies the rub. If you have pressurization, you will use the turbo on almost every flight, in the sense of doing something that couldn’t or wouldn’t in a NA plane. If your cabin altitude matches your ambient pressure altitude, you will avoid using the turbo but continue to pay for it.

I try hard to stay below 10,000 for passenger and dog comfort. My rare excursions into oxygen altitudes, when terrain and icing force me up there, are slower in my NA plane but not so much slower that I wish it had a turbo.

Then again, the early unpressurized airliners had forced induction. Did DC-3 pilots stay below 15,000 or did they offer oxygen masks to passengers on routine cross-country flights?

 

[Steamflyer]

If pressurized will use the turbos all the time for power. If the cabin is not pressurized, then no bleed off the compressor. You'll still need to compress the intake charge to some degree, varying on the altitude chosen. Sure, at low power settings down low the turbos won't be "working" that hard (waste gate more open).

Turbos let you climb above the haze, the clouds, the mess down low when you need to. They allow you to maintain the climb rate at a greater value much longer. Think 1000 fpm in a turbo single all the way to maybe 13,000' then a good 750 fpm.

Derating is a non-turbo means of getting a little more oomph to altitude - think of an IO550 in an originally O-470 powered 182. The other means is to have completely manual turbos like on a turbo twin Comanche - the pilot selects the degree of boost from none to max by turning knobs. With the waste gate fully open they become NA essentially.

DC-3s are non pressurized. Early jets like DC-8, 707 used bleed air driven compressors - DC-8 inlets are right at the front. Don't know what big pressurized airliners used - DC-6, DC-7, Connie, etc. They had turbo compound engines, so maybe some air was available, or maybe they had onboard compressor like the early jets.

 

[Grum.Man]

You didn't really state what your load carrying requirements are but I agree with some others in the fact you just need a higher performance airplane, not necessarily a turbo. RV10, Bellanca Viking, 520 Bonanza, Big engine mooney. Keep the arrow and get a 2 place experimental for the NY trip.

 

[Pinecone]

I fly into the teens for anything over a couple of hours. Depending on conditions, maybe even a shorter trip. Less traffic, less weather, smoother, less frequency changes.

I don't mind a cannula. And a boom cannula is even nicer.

Mountain High O2D2 and 115 cf built in bottle means few fills. And an oxygen concentrator means even fewer fills.

 

[Racerx]

There's a 310 in the weeds over at c81...

 

[Grum.Man]

I fly into the teens for anything over a couple of hours. Depending on conditions, maybe even a shorter trip. Less traffic, less weather, smoother, less frequency changes.

I don't mind a cannula. And a boom cannula is even nicer.

Mountain High O2D2 and 115 cf built in bottle means few fills. And an oxygen concentrator means even fewer fills.

Having a high performance plane I too flight plan the winds. Eastbound I'll climb as high as beneficial for the winds, westbound I rarely climb over 6-8k or what ever I need for terrain clearance. Usually the winds aloft from 15-25k don't increase enough to justify the climbing time or the switch from canula to mask. On nice days I usually stay below 18k so I can go direct as needed around busy areas like Chicago. For the casual nature of my flying if the weather is sketchy enough that I feel the need to climb into the 20's I will probably elect to stay put. Being able to climb above the ice is nice but eventually you have to be able to descend back through it or deal with it during an approach. I get the allure of it and the speed potential to be gained but depending on the plane the tank capacity might not be enough to capitalize on that speed.

I have a friend building a Venture that plans to turbo it. It want be done any time soon but I am anxious to see what kind of speeds he can reach at altitude.

 

[Ted]

Then again, the early unpressurized airliners had forced induction. Did DC-3 pilots stay below 15,000 or did they offer oxygen masks to passengers on routine cross-country flights?

Keep in mind that sometimes you have forced induction just for more horsepower over what you could get naturally aspirated. I think that's more what you found on those aircraft.

Things were also different back then regulation wise...

 

[iamtheari]

Keep in mind that sometimes you have forced induction just for more horsepower over what you could get naturally aspirated. I think that's more what you found on those aircraft.

Things were also different back then regulation wise...

I read somewhere that the altitudes for oxygen requirements (12,500, 14,000, and 15,000) were primarily based on enabling travel throughout the continental United States. I don't know how much truth there is to that or when the oxygen regulations were written. But I do know that the regulations applied differently in the cockpit than on the ground in many cases.

 

[Ted]

I read somewhere that the altitudes for oxygen requirements (12,500, 14,000, and 15,000) were primarily based on enabling travel throughout the continental United States. I don't know how much truth there is to that or when the oxygen regulations were written. But I do know that the regulations applied differently in the cockpit than on the ground in many cases.

They still do apply differentily for cockpit vs. passengers, and also for 91 vs. 135/121.

Point is, I wouldn't read the current FAR/AIM and try to apply that to a DC-3 when it was new.

 

[mandm]

You didn't really state what your load carrying requirements are but I agree with some others in the fact you just need a higher performance airplane, not necessarily a turbo. RV10, Bellanca Viking, 520 Bonanza, Big engine mooney. Keep the arrow and get a 2 place experimental for the NY trip.

Used to be 2 pax 400lbs, I lost a good 70lbs since getting my ticket (Covid weight) so that’s now 330lbs, cheaper to go on a diet instead of buying an airplane with higher UL. LOL

My pups too lost some Covid weight I have the number somewhere but they are 90-100lbs together.

So 330 lbs + 100lbs = 430lbs plus fuel and baggage I would say 100lbs is at the higher end. So 500-550lbs plus fuel. If a long trip I’ll add more to the baggage since we will bring a tent and extra stuff.

 

[iamtheari]

They still do apply differentily for cockpit vs. passengers, and also for 91 vs. 135/121.

Point is, I wouldn't read the current FAR/AIM and try to apply that to a DC-3 when it was new.

What I meant is that an airline pilot in the air in 1935 may have done things differently from whatever the 1935 rulebook back at the home office suggested.