Newby Sierra questions. Flying the Sierra.

[flyingvet]

I am a newby 1980 C24R Sierra owner, and have a few operational questions for Sierra owners. (I have had the ldg gear KLUXed) thanks.

1. My oil dipstick after 10 hours says 6 quarts. Am I right that this is enough, and if I put more in, say to 7 quarts, it will just blow out onto the belly. What do you keep as a standard amount? Do you add more before a long cross country flight?

2. Cruise flight, at 5000 ft alt say, is 25 squared about right with 10gph, and CHT 290, EGT 1380? What do you use, and still get good speed (I know you can throttle back etc, but this is for long cross country flying, and we need speed too). Do you ever use full throttle and 2700 rpm constantly?

3.On takeoff, is it OK for the RPM to reach 2900 rpm for 10-20 seconds, or is that too high (I thought 10 % more than redline 2700 rpm briefly was still safe). I quickly adjust it down to 2700 rpm anyhow.

4. After takeoff to say 1000 ft agl, do you ever reduce power to 25 square to continue climb, or do you stay full throttle and 2700 rpm to cruise alt?

5.During descent do you ever follow the reduce MP by 2 inches at a time to reduce shock cooling, or since we do not have cowl flaps, this is not an issue for Sierras?

6. I can not keep RPM out of the red-band 2100-2350rpm on final approach to landing, descending with reduced MP say at 15 inches, and props full forward. I am assuming since MP is low, and we are about to land, the RPM in red-band is OK. Is it? If not, what combo of MP and RPM do you manage to keep RPM out of red-band?

Thanks for your advice in advance.
Happy holidays!

Dinj

 

[drseti]

Re: Newby Sierra questions..

I am a newby 1980 C24R Sierra owner,

Welcome to the community!

and have a few operational questions for Sierra owners. (I have had the ldg gear KLuXed) thanks.

Good move, Dinj. You're asking all the right kinds of questions. I'll try to answer a few, based upon my 30 yrs of flying an A24R (your plane is a little different, so do please take that into consideration).

1. My oil dipstickafter 10 hours says 6 quarts. Am I right that this is enough, and if I put more in, say to 7 quarts, it will just blow out onto the belly. What do you keep as a standard amount? Do you add more before a long cross country flight?

At an oil change, I always put in 7 quarts (and a new filter). After the first flight, the filter would fill and the level would drop to about 6 1/2 quarts. This is a normal level. If you fill to 8 qts as the book recommends, you'll blow out the extra quart in the first flight. When the level drops to 6 qts or below, I add one more. This is a good idea before a long XC. But, never let the level indicate above 7 or below 5, and you should be in great shape.

. Cruise flight, at 5000 ft alt say, is 25 squared about right with 10gph, and CHT 290, EGT 1380? What do you use, and still get good speed (I know you can throttle back etc, but this is cfor long cross country flying, and we need speed too).

At altitude, I tend to use full throttle and between 2300 and 2400 rpm, and lean back for 8 GPH. It's quieter at the lower rpm, and probably puts less strain on the engine and prop. I would true 130 kts, which is fast enough for me.

Do you ever use full throttle and 2700 rpm constantly?

Only for takeoff. Never in cruise.

3.On takeoff, is it OK for the RPM to reach 2900 rpm for 10-20 seconds, or is that too high (I thought 10 % more than redline 2700 rpm briefly was still safe). I quickly adjust it down to 2700 rpm anyhow.

Your prop governor should limit you 2700 max. If it's going above that, then either your governor or your prop needs attention.

4. After takeoff to say 1000 ft agl, do you ever reduce power to 25 square to continue climb, or do you stay full throttle and 2700 rpm to cruise alt?

First off, on takeoff, don't touch ANYTHING (throttle, prop, mixture) until reaching safe turn-around altitude. (1000 ft is probably a bit low; I like to be at 1500 AGL before I'd feel safe doing a 180 back to the runway. Test this in your plane at normal climbout speed -- at altitude. The reason for this is that an engine failure is more likely to occur when you change something.

After reaching turn-around altitude, I always set 25 squared, verify gear up, accelerate, and raise takeoff flaps. I then lean for 12 gph indicated fuel flow. I climb to cruise altitude at 105 MPH indicated (that was best glide speed in my Sierra, a nice place to be trimmed for if you happen to lose an engine).

5.During descent do you ever follow the reduce MP by 2 inches at a time to reduce shock cooling,

Absolutely.

6. I can not keep RPM out of the red-band 2100-2350rpm on final approach to landing, descending with reduced MP say at 15 inches, and props full forward.

On my plane, with Macauley Black Mac 3-blade prop, the red zone was airspeed related as well as rpm restricted. If you slow the plane down enough, you can stay in a safe range. On midfield downwind (or at the FAF on an instrument approach), I always dropped gear (that's an effective speed brake), brought throttle back until the prop governor dropped off line, set 2000 rpm by throttle alone, trim for approach speed, and then put prop and mixture knobs all the way in. Then I didn't have to touch the throttle until the flare, managing altitude with airspeed and flaps.


Hope this is helplful to you. Fly that new Sierra safely!

 

[flyingvet]

Very useful and much appreciated first-hand advice. Thanks.

 

[wdnd5960]

I have been around these aircraft for a few days myself but have some different perspectives.

If you want to get the most out of your Sierra experience, start living every minute of your life with the awesome POH/AFM that Beech gave this great aircraft. Read it often, memorize it, live it & fly it.

I was hoping that Marty "Max V" Vanover, might chime in here.

I have flown with many great pilots, I have never seen any two that flew exactly the same way.

The engine should not exceed 2700 RPM, that is a rigging or indication issue, which needs to be resolved, especially for pilot work load. The last thing you need to be concern about when barreling down the runway or on initial climbout is trying to get the power set/reset to Max Continuous. You should be able to push the throttle full forward and know, that with Prop Control full forward, that 2700 (and not over) is where you will end up.

I do think most people fly, Max Con for T/O, trans to 25 square for a cruise climb setting, then maybe to 24 square for some econo cruising. I think most people do this for noise comfort and fuel economy, myself included.

I learned to fly Sierras at Beech. All climbs were done at full power (except cruise climbs). This is how one uses the T/O & Climb power range of the that awesome Fuel Flow Indicator, Beech gave this aircraft.

This aircraft will also perform at the POH/AFM, book numbers, which I think are pretty good. You can choose to run/cruise this aircraft, wide open 2700, 75% 2700, 75% 2500, 65% 2400 or 55% 2400, your choice, and you can use any of these settings all day long, without restriction. It is all in the book and also on that same great Fuel Flow Indicator. This is a very flexible aircraft. Mike R. has written another page to this book, making this awesome aircraft even more flexible.

I do not reduce power to descend, from altitude. I do not recommend anyone do this, except in the pattern (where power is alt & pitch is airspeed). High perf jets with FMSs, auto throttles and high tech autopilots do this to prevent mach overspeed, we do not have that problem. (The fixed pitch prop boys need to monitor the engine redline.) Be a better pilot. Wind, weather, ATC and terrain permitting start your descent from higher altitudes much sooner, 100nm or more from the destination. Add just a few degrees of nose down trim while the engine continues to pull cruise power. The POH/AFM recommends to descend using "Best Power Mixture" settings (that means "power on"), enriching as you descend. Let that airspeed needle wind up and watch the real estate roll under your wings as you hammer down into your destination. Nowhere in the POH/AFM does it suggest it is a good idea to pull power off for a descent. It says exactly the opposite, it is a bad thing. It says this will require advanced planning for you the pilot to incorporate this into your flight.

Sadly, a lot of CFIs teach students like they have never flown an aircraft outside of the traffic pattern.

If you are lucky enough to get your hands on a nice Sierra (Sundowner or Sport), jump off the deck, climb to altitude (8, 9, 10, 11, 12k), trim for cruise, trim the nose over with cruise power on for your power on descent 100+nm out, level off about 5 or 10nm out, you will be surprised what this aircraft can do!

For shorter trips that require altitudes of only 4, 5, 6 or 7K start your power on descent 50 to 75nm out.

Fly high tight patterns. If you are in the pattern, you should have the runway made, should the engine fail.

Following this flight profile you should not have a reduced throttle for more than 1K of altitude and a couple of minutes of time. Your engine should still be hot on arrival.

On throttle movement, up or down, I would rather see a pilot move the throttle where it needs to be with a slow, steady, smooth transition, than 2", 2", 2".... There are some manufactures that will tell you each one of those tiny steps is a complete thermal cycle. The same as full throttle to idle or vise versa.

But this goes back to the way you fly, if you drive her down and all the way in under power. You are going to make one smooth power reduction entering the pattern, throw the gear out, flaps out, final and touchdown.

Just my perspective and there are not going to be two same,

Sciscoe

 

[paulwerbin]

I will echo what has been said by Bill and others. With a few additions.
Read the POH.
Try to find a CFI that knows Sierras. work the limits.
Get Lycoming's information from them.
Each Propeller has it's own limitations. Honor it.
Get your governor checked. Soon. MIght be a bad Tach too.
I plan my descents at yellow arc speeds, full throttle, mixture as needed, and I allow for proper slow engine cool down at pattern or as ATC requires. I paid to get up there, i use the speed on the way down.
I suggest an Engine monitor, I have a JPI, There are deals here on other good monitors. Well worth their cost in fuel and engine saving information.
I am almost always at full throttle in Cruise, per the POH, but rarely above 9 gal per in cruise. Lean like crazy when at altitude or in cruise. I set RPM 2400-2600 as noise bothers me some days more than others.
Search around the BAC site. There is great info on this as well as high performance takeoffs etc as you get used to your plane.
Welcome to the club, this place is great. Next time I am in NJ I will try again to catch up.
Paul W

 

[danielkirby]

Sierra

Dinj, welcome to the club, and thanks for asking these great questions. I learn more about flying my Sierra every time.

Dan

 

[AJCustom]

I haven't flown a Sierra, so take this for what it's worth, but I don't reduce power in the climb on any airplane unless it is a limitation set for in the POH. Such as an earlier 182 that has a 5 minute limit at 2600 rpm and must be reduced to 2450 rpm for continueous operation.

If there is such a prohibition in the Sierra's POH, I retract my statement.

 

[BobLewis]

I can't tell you anything about flying your Sierra. I can say that oil levels in engines vary. Yours will find the sweet spot, most likely in the 6 qt neighborhood. Most of our engines if filled to 8 qts will remove two of these quickly. You will end up lubing the rear tie down hook by filling to 8 qts.

 

[niechiro]

Sierra answers

Here are some observations from a B24R Sierra driver who has done it for about 25 years. My methods come from multiple instructors and my personal experience. I am not an expert on the Sierra. Just experienced.
1. My Sierra always wanted to stay around 6 qts. For long trips I would have it at the 7 qt. level so it did not fall much below 6 qts. 6qts. is plenty of oil to fly the Sierra on. (I have been told that this engine could run on 2 qts. if it had to. I sure would not want to have to try that. Might be an expensive lesson.) About 5 years ago I had an M20 air/oil separator put on my engine to try and keep the oil from going out the vent tubes and greasing up the belly. It has helped conserve the oil consumption and the belly is cleaner. After doing some of my own oil changes since the M20 installation, I found out that I can fill the crank case with 8 qts. However, when I do this it indicates 7 qts. on the dip stick. So you may have more than 6 qts. in the engine when the dip stick is indicating 6 qts. The 8 qts. will gradually decrease to an indicated 6 qts and the decrease will be slower from there. I have wondered if my M20 was installed properly. The fellow who invented the M20 told me that I could run my Lycoming on 8 qts. and it would stay there. The advantage of this would be, according to him is that the engine would run cooler and be lubed better. However, as I said, it doesn't stay at 8 qts. It may be that I am burning it and that there is very little going out the vent tube.
2. In agreement with what others have said, I run the throttle in the full position above about 3,600 ft. This is because I fly it at 25 square after departure and above 3,600 ft. the manifold pressure drops below 25 inches anyway.
3. Same as others have said. The rpm should not reach above 2,700. Check it out.
4. I reduce power to 25 square after retracting gear and flaps as my time and attention permit. Usually this is before 1,000 ft. agl, but not much. Why run the engine harder than 25 inches when it does not have to be.
5.I don't reduce manifold pressure until it reaches 25 and then I reduce it enough to keep it at 25 or below.
6.On final approach, I don't worry about the rpm. I have the prop lever full forward and don't pay attention to rpm once the gear and flaps are down and the manifold pressure is reduced to allow a 500 fpm descent. I only adjust the manifold pressure as needed for proper rate of descent.
I am indebted to you for raising the questions you have as I very much like to read how the other pilots and A&P's have to say. I am never too old to learn. Thanks very much!
Mike Nielsen
McCook, NE
B24R Sierra N9164S

 

[18903]

Hi and welcome to BAC!

Just to add to the great post's already put in. I fly my C24R pretty much by the book, which gives the results punlished by Beech. On a long trip and at or above 6K I usually fly at 2550RPM and about 22inMP that gives almost 158MPH at 10GPH, I also was taught by a CFII that to quote him said "you paid for all that fuel to get up here, why not use it to get to the destinitation more quickly" so I too come down (and teach my students) under power and if the air is smooth I may see 180 to 185 (MPH) which makes up for the losses in climb! There is no absolute correct answer! and as long as you are in the numbers from Beech you will find the "sweet" spot that your particular aircraft likes the best! I have the "Air Wolf" air/oil seporator and will do a artical on this later...I do NOT reccomend the Air Wolf as will be shown when I can get the pictures up and all the details written. I am looking foward to using the M-20 and have heard good results from it.

All the best flying!

Steve Nelson, CFI, CFII
N18903, Sierra

 

[wdnd5960]

Paul W. & Steve N, That is the kind of flying that I am talking about!

I am glad aviation has great CFIs/CFIIs like you guys, that know how to fly. Your students are blessed. I had a great instructor that loved these aircraft and taught me how to fly them. Pilots that think these aircraft can not really perform need to check their stick actuator.

Many students do not get great instruction from guys that really know how to fly. My instructor had 10K hours of B747 time. He knew all about flight profiling. And how to get the most out of these aircraft.

Power on descents are how block times & ETAs are made. Not to mention, that it is lots of fun, to wind up that old mach meter. Most pilots do not learn power on descents until they get their hands on more high perf aircraft, (geared engines, truboprops & jets). Pull the power off of geared engines for descent and you will fly them from overhaul to overhaul.

This is not for just the Sierras, the fixed pitched props require more planning and finer execution but this is where pilots are made. I know that Bob Lewis flys this way because we discussed it at BACFest.

Sciscoe

 

[drseti]

I will echo what has been said by Bill and others. With a few additions.
Read the POH.

Unfortunately, the earliest Sierras (the A24Rs from 1970 and 1971) predate the GAMA standard POH format. Thus, those of us who fly older planes have rather sketchy POHs, which lack a lot of the detail of the newer ones. As a consequence, many of us had to make up our own procedures, and figure out for ourselves what works and what doesn't! If you're blessed with more than a cursory POH, then by all means use it.

 

[BobLewis]

I am pleased to see these instructional posts becoming more frequent. The maintenance posts are great but, I would like to know how to get as much performance out of the plane as I can when I fly. Keep these posts going. I am paying attention.-Bob

 

[mvanover]

In the "for what it's worth" department. I am ready do depart KBTR (Home of Bill Manhiem) after flying non-stop from KCHD (Home of me) to KOPL (Opaloussa, La.) That was 1015.4 nm as the crow flies. I could have made it to KBTR, but I'm not used to landing with booth fuel gauges in the yellow. Turned out I still had 9 gallons of in the airplane. I could have made the KBTR with 1/2 hours fuel in reserve at economy cruise. Good winds and very low fuel flow at 13,500 (this time I had supplemental O2) with no turbulence enroute made for a very long and boring flight. Start up to shutdown was 6:36. I found it interesting that initially the engine would only run smoothly with fuel flow at 8 gph. Later I was able to lean to 7 1/2 gals with no problems. OATs were in the 20s F at 13.5K. I have seen as low as 4 gph up high. Adjusted true air speed was 133 kts most of the way. Ground speed varied from 170 to 188 kts at 13.5K. Yes, the wind gods finally smiled upon me for once. I didn't see a need to climb higher.

Marty Vanover
Phoenix, Az

 

[drseti]

after flying non-stop from KCHD (Home of me) to KOPL (Opaloussa, La.) That was 1015.4 nm as the crow flies.

Well, you sure beat my record all to hell, Marty! My all-time best leg in the Sierra was Dyersburg TN (KDYR) to Albuquerque NM (KABQ) back in 1982. That was a measly 841 nm. Pretty much no wind, so it took me a good 6 hours (and yes, I landed with legal reserves - barely!) I feel like such a wimp...

 

[wdnd5960]

We all live and learn, I hope. I learn every day how much I do not know. And it is very scary. :shock:

This post had me reading the Sierra POH/AFM Performance Section again. I found an interesting note on page 5-22. This is the Full Throttle 2700 RPM (mostly full rich mixture, see how much gas you can throw at this little engine page). Note 3), says the engine will be operating at 5% above the "rated power", based on a manifold pressure increase of 1 in. Hg due to ram rise. Hummmmm. That is a very interesting note! :shock:

The "rated power" of this engine is 200 hp at 2700 rpm. 5% of 200 hp, is 10 hp, for a total of 210 hp. So, when this engine is installed in the Sierra C24R (A24 & B24 I don't know about), it has the ability to produce 210 hp. :shock:

This was a surprise, to me. It comes at a heavy fuel flow, but you could buy a lot of gas for what Lycoming wants for a IO390, that you can not install in your airframe anyway. It looks to me, like the 10 extra hp you were looking for, was already built into your aircraft, decades ago by Beech. :roll:

I guess you Sierra drivers can hold your heads a little higher and change your cowling decals to "Sierra 210". :lol:

Sciscoe

This is the way that I have read and interpreted the POH/AFM, please correct me if I am wrong. :?

 

[AJCustom]

I would guess that fuel flow would be around 17.5 gph at those power settings... am I close to the POH?

WWWEEEEEEE....

 

[wdnd5960]

Aaron, You are one sharp cat!

The highest fuel flow on the chart shows 16.9, sea level ISA Minus 20C. But as you climb in altitude the fuel flows are not a great deal over what the other perf charts show, at about 10K they equal out.

The book TAS, chart speeds are very good on this aircraft 144kts/166mph to 146kts/168mph at sea level, with not a lot of speed loss at altitude, maybe 7 or 8 kts at 10K.

You are really dumping some gas in the engine but at sea level the charts show as much as 20kts/23mph gain in speed, over the 2700 rpm 75% chart settings. As stated above at about 10K everything starts to level out with the other charts.

Sciscoe

 

[drseti]

You are really dumping some gas in the engine but at sea level the charts show as much as 20kts/23mph gain in speed,

I guess the way you fly 'em depends on your objective. Some folks want to get there quick. I just wanted to build hours. :wink:

 

[18903]

I just got back from the KPMH BAC trip and showed 164Kts ground speed the whole trip back......I was running 2550RPM, 25MP 10.1 GPH........and almost 30kts of tail wind :lol: But the TAS was almost 158MPH not bad, as it has been said "these aircraft will fly the way you want them to.....It just depends on weather you want to spend the time or the money.

By the way since it is in the POH for the 210HP at 2700, does that mean I can sign off a student for "High Proformance"? :wink:

Run that one by the FSDO!

Steve Nelson
N18903, Sierra.......Now seeing snow in N.E. Ohio