At Home - Oil and IFR Questions

[Nemesis]

 

So, I went to Minnesota this past Wednesday, to participate in the final repairs/changes to N231NF, and then to finally bring it home to Denver. Well, participate is maybe not the right word. Watch and learn is more like it.

Jason Doscher is formerly of Willmar and now (and for the last 8 years) has his own shop in Benson, MN about 30 miles to the west. It did not take long to discover that he is a fine mechanic with tons of Mooney experience, but he is also helpful and knowledgeable with any question that I had. Will I see Jason again? Absolutely.

It was Jason's responsibility to put everything right and back in order with my new to me machine. Everything from the fuel pump at the front of the engine, to the tail strobe at the back has been examined and either repaired or simply passed as airworthy. Also included was the installation of a JPI 830 to properly monitor everything that is happening to that all important producer at the front.

Thursday and part of Friday I "helped" everything go together. Well, maybe it would have gone faster had I not been there but then I would know much less than I do. Friday afternoon and it was time for a couple of more hours of review and flight training with Bruce Jaeger. All was well with the exception of one landing at Brainerd and of course the reason for going to Brainerd in the first place; a smoked radio, literally. Not a good smell a few thousand feet over central Minnesota. Welcome to aircraft ownership. There was also a bumping noise while the landing gear were going down. Could not find the problem on the ground.

Saturday morning, and with Bruce's signature, I am on my own. I left Willmar to go back to Benson at 7am to check on this bumping noise. I flew the 30 miles with the gear down just in case. Turns out there was a small piece on the right gear door that was worn a bit and with air loads was able to go edge to edge with part of the wheel well. Jason ground down the offending piece of metal and riveted an extension so that the door was once again it's original size. All is well and about 10:30am I am off to Denver.

Well, the 3 hour flight turned into a 4 hour flight thanks to the 20+ knot headwind at 8000'. All of the radios, GPS, autopilot, JPI, worked flawlessly. The air was like glass for the whole trip until I was in NE Colorado closer to the mountains. All CHTs were 333dF or less. I was at about 70% power or maybe a notch or two higher. Maybe it is the cooler OATs, but so far this engine is not difficult to manage. With a little more experience, I will push the power a bit more and migrate to LOP.

There was a steady drop in oil pressure during the trip. The lowest that I saw was about 45 psi - down from the 57 psi in early cruise, well above the redline for the Continental, but still concerning. Looking back, maybe I should have made a precautionary landing to be sure that I was not losing oil. In the end, I did not lose a drop. There are still 7 quarts in the engine when checked today. Concerning the oil, I saw a steady rise in temp from about 175dF to 187dF over the 4 hours. Also, there was a steady rise in OAT from -4dC to +10dC. Perhaps the change in temperature can account for the rise in oil temp as well as the drop in pressure. Perhaps I can get some comments on this one. The oil in question is Exxon 20W-50 in a standard TSIO-360LB in a 231 with a fixed wastegate. The only other thing with regards to the oil is that up in the frozen north, it is common to block part of the oil cooler in the winter months. The foam pad to block half of the cooler was still in place during this flight. When I landed in Denver it was 68dF. I took out the foam pad today.

Because I did not have any O2 with me, and because of the winds, I planned for 8000' for the entire trip. Also, the weather in Denver was showing the possibility of rain a couple of hours after my planned landing. Before I left, I sent in an IFR flight plan with fltplan.com. I departed VFR and wanted to get settled with the new machine and have a better understanding of it's equipment without an instructor on board. ie play with it a bit before I needed more precise navigation under IFR. I figured that once I got settled, I would ask for a clearance in case Denver had some weather and all of my info would be in the system for reference. However, I wanted flight following so I called Minneapolis Center as I was climbing. I never called for a clearance on the ground. Upon initial contact, the controller started to read back a clearance, complete with a limit to KFTG as filed and transponder code. I never even asked for anything. My call was simply "Minneapolis Center, Mooney 231NF off Benson." My only experience from an uncontrolled field has been to call on the phone for a clearance and then try to run up and complete checklists and get in the air before the void time rolls around. Is this a normal procedure or did I just get lucky with a cool controller that noticed my flight plan on her desk for that sector?

Anyway, I think all is well if I can get this oil pressure business explained. I am home, and for the first time, so is my airplane. Maybe one of these days I will write to ask/answer a question rather than write a book. Also, thanks for all of the well wishes under the other posts that I made.

[N9937c]

Seems like you dont have an oil pressure problem. All the 231's I have flown have operated at those indications or less.

In texas we normally see the very high temps and lower oil pressures and will normally drop one cowl flap 2 or three turns in the summer. I bought my first 231 in 1981 and have enjoyed several since.

Normally center/ area controllers are looking for you on your departure at about your time so it pays to be prudent for fast pickup.

larry

[Hank]

Dave--

I live at, and frequently fly to, uncontrolled fields. If I am clear to depart VFR, I'll go, and call up either the Class D across the river from home or whoever is listed as Departure to open up my IFR flight plan. So far, I've not needed to call and get a clearance do depart from an uncontrolled field, but I'm new at this game, too, and won't depart if I can't get back in VFR.

[FlyDave]

Congratulations! Sounds like you did everything right during the purchase process and it ended up in a successfull and fun first flight. I'll bet those 4 hours went by pretty quick as busy as your mind is on a first flight.

I fly a 201 and have no experience with the 231 engine characterstics. So I'm not the right person to coment on the oil pressure issue - but I'd certainly pursue it.

I've had controllers just start reading a clearance to me on the ground at busy airports but haven't departed VFR to pick up a clearance. I guess since you filed IFR, they had your clearance ready and, being expeditious, assumed you were ready to enter the IFR system.

Again, congratulations on your successful purchase - you're going to enjoy the heck out of that airplane!

[Parker_Woodruff]

Congrats on the plane.  I doubt you have an oil pressure problem as well.

[flight2000]

Quote: Nemesis

However, I wanted flight following so I called Minneapolis Center as I was climbing. I never called for a clearance on the ground. Upon initial contact, the controller started to read back a clearance, complete with a limit to KFTG as filed and transponder code. I never even asked for anything. My call was simply "Minneapolis Center, Mooney 231NF off Benson." My only experience from an uncontrolled field has been to call on the phone for a clearance and then try to run up and complete checklists and get in the air before the void time rolls around. Is this a normal procedure or did I just get lucky with a cool controller that noticed my flight plan on her desk for that sector?

[carusoam]

From my limited experience...

If possible, call for your clearance in advance to avoid the writing while flying.  fltplan.com will text you the most updated clearance and is a good place to start prior to calling.

Depart VFR, contact ATC (local frequency is on approach chart of your departing airport).

If you are fortunate, they work you right in, if not continue on VFR until they can work you in...

When you make contact, let them know that you have picked up your clearnace already, they may want to give it to you again....

Otherwise, trying to get clearance on the ground at an uncontrolled field can be quick, a cell phone is required.  Know how long it takes to get through run-up and be ready to go....  Usually you can get a void time of 10 - 15 minutes.  It is hard for ATC to reserve more time than that.

Best regards,

-a-

[jlunseth]

I have a 231 and fly in Minnesota.  It is cold here right now ( and when you picked up your plane).  The oil tends to start a little thick and then as it warms it thins out.  The pressures you saw are pretty much exactly what I see every time I fly this time of year.  Not unusual to see a starting pressure at around 60, and then when the engine gets to full operating temp the OP is in the 40-47 range.  I would say a starting pressure of 57 and a cruising pressure of 45 is spot on. 

You will also see the quantity (qts.) look like it took a dive on the first trip after you pick the plane up.  You might see 7 qts. on the dipstick before starting the engine and about 5 when you get home.  The oil is still in the engine, the other quart or two are now in the filter and distributed around in the channels in the block, crankshaft, etc. 

I have found that the best way to climb to cruising altitude in the 231 (high teens or the Flight Levels) is WOT and prop at 2700 all the way up, adjusting the MP as you climb to stay at WOT.  If you have the intercooler equipped 231, that should be around 36, and if you don't it should be around 40.  The engine will stay cooler at WOT, because WOT causes the fuel system to provide full fuel flow at 22 - 24.5 gph.  I have also found that if I level off somewhere before starting the climb to altitude and just leave the settings at WOT, let the airplane pick up speed, then start the climb, that the climb will be at a higher sustained speed, somewhere between 110 and 120 depending on OAT's.  The climb rate will be around 700 fpm.  If I go right into a Vy climb or cruise climb, without giving the plane a chance to pick up this "head of steam," the same 700 fpm climb will invariably be around 96, which is Vy in the 231. 

You will probably notice that when you do a sustained WOT climb, you will lose some oil.  This is fairly common in turbos.  So I normally fill to 8 qts. at the start of a long trip, where I am going to do a WOT climb, and then I may be down a qt. at the end of the trip.  I put the full 8 in just in case something is not right with the oil, and I have a leak somewhere.  Probably that means I am blowing some oil out just because I started at 8.  If I am just flying locally I let it stay between 5 - 7 qts.  It seems pretty happy at 6 qts. and will not lose much oil, whereas if I fill it to 8, a quart or two will depart the engine pretty quickly and it will then settle down.  You will find this is pretty typical of most piston airplane engines, that is, that they have an oil level at less than full capacity that the just "like" and once there, not much oil blows out.

PS I heard a story from a CFI awhile back, about the oil cooler block.  He had one in and was flying up around 7k and saw what he thought was an alarming rise in Oil Temp.  Was being held up there by ATC.  Was glad to get to the ground.  Discovered he had been in a temp inversion layer where the temps were significantly higher than what he usually flew in during the winter, and that caused the engine temps, particularly the OT, to rise.  We need the block here in Minnesota in the dead of winter.  You may or may not need it out in Denver.

[Nemesis]

Quote: jlunseth

You will also see the quantity (qts.) look like it took a dive on the first trip after you pick the plane up.  You might see 7 qts. on the dipstick before starting the engine and about 5 when you get home.  The oil is still in the engine, the other quart or two are now in the filter and distributed around in the channels in the block, crankshaft, etc. 

Leaving Saturday morning from Willmar and before start, there were 6 quarts in the sump. While Jason was working on the gear door, 1 more quart was added. When I checked the oil on Sunday there were 7 quarts. So, I did not loose any oil during the trip. Perhaps 7 quarts will be what this engine likes.

The concensus from email and mechanics all appear to be that all is normal with what I saw during those 4 hours. I will see how the oil temps react wthout the block for the oil cooler.

Thanks to all for the responses and experience.