Help planning my first dual XC

[jconway2002]

Hello,

My instructor has tasked me with planning my first dual cross country. We are flying from KCRQ (Palomar) to L35 (Big Bear).

I initially drew a direct line from KCRQ to L35, but realized the mountains around L35 were quite high. I am wondering how I should handle flying into Big Bear?

As you can see in the attachment, which is a screen capture from skyvector.com, I have the direct route, and than I have a route I drew to avoid the highest mountain peaks, fly to a street pattern, and then go straight in for a landing. Am I doing this right? Anyone have better suggestions?

 

[poadeleted20]

If I were your instructor, and you had a question like this, I'd want you to ask me before going to a bunch of folks on an Internet discussion board. Have you tried that? Really -- it's OK to ask your instructor for instruction.

That said, if you were my trainee, I would teach you that avoiding a crossing of the highest terrain like that is a good plan. The only additional suggestion I'd make is to move the route even further southeast to that gap at the edge of the TRSA -- go due north up to the Banning Pass, east through the pass, then north up to the gap east of L35 and in from that direction. You could also go up by Redlands, and then follow the creek northeast through the passes to the west end of Big Bear Lake.

 

[jconway2002]

Thank you! Dont worry, I plan to talk to my instructor about this, but since I am stuck at work all day, and wont be able to talk to him until tomorrow, I figured and answer from the PoA community would get me through the day.

If I were your instructor, and you had a question like this, I'd want you to ask me before going to a bunch of folks on an Internet discussion board. Have you tried that? Really -- it's OK to ask your instructor for instruction.

That said, if you were my trainee, I would teach you that avoiding a crossing of the highest terrain like that is a good plan. The only additional suggestion I'd make is to move the route even further southeast to that gap at the edge of the TRSA.

 

[John221us]

What kind of plane are you flying? Big bear is 6,700 feet and this is summer.

 

[jconway2002]

What kind of plane are you flying? Big bear is 6,700 feet and this is summer.

A C152.

 

[poadeleted20]

A C152.

Solo? Or are you and your instructor both lightweights?

 

[Skip Miller]

Am I doing this right? Anyone have better suggestions?

Any route that gets you there is correct, but the bottom line is that there are safe routes, safer routes, and unsafe routes, such as the high rock route you mentioned.

Draw out several routes that are safe or better and then look carefully to determine which of those routes would be better under what circumstances; e.g. winds aloft may favor one route over another. Then when you discuss this with your instructor, you can have a two way conversation as he understands your logic and you his. This will provide a framework to select your actual route on the big day.

-Skip

 

[jconway2002]

Solo? Or are you and your instructor both lightweights?

Dual. We are both around 190 I would guess?

 

[John221us]

Better do the math for DA and check the climb chart. Two people in a 152 coming out of L35 especially in the summer doesn't sound like a great idea.

 

[jconway2002]

Better do the math for DA and check the climb chart. Two people in a 152 coming out of L35 especially in the summer doesn't sound like a great idea.

Thanks for the heads up. Maybe this is a trick question. Maybe he wants me to tell him its unsafe?


...maybe not though?

 

[poadeleted20]

Dual. We are both around 190 I would guess?

In addition to the performance issues, I'm guessing you'll have to short-fuel it to stay below max gross. How much fuel can you carry with the two of you plus whatever nav bags, extra oil, step ladders, chocks, etc you have in the back? Is that enough to make that trip with adequate reserves?

 

[jconway2002]

In addition to the performance issues, I'm guessing you'll have to short-fuel it to stay below max gross. How much fuel can you carry with the two of you plus whatever nav bags, extra oil, step ladders, chocks, etc you have in the back? Is that enough to make that trip with adequate reserves?

Not sure to be honest... haven't got that far into the planning.

 

[poadeleted20]

Thanks for the heads up. Maybe this is a trick question. Maybe he wants me to tell him its unsafe?

That is certainly possible.

...maybe not though?

If not, then I'd have some additional questions for that instructor, because unless it is a test, the idea of two 190-pounders making that flight this time of year in a C-152 gives me pause regarding that instructor's judgement.

Or is this one of those C-152's with an O-320 engine and the 100-lb max gross weight increase?

 

[poadeleted20]

FWIW, back in the day, we used to put two adults in a C-150 with full fuel and nary a thought for what the actual takeoff weight was in relation to book max gross. In retrospect, that wasn't a good idea even if it was convenient. In addition, average adult weights were probably 20 lb less than they are today. You take that extra 40 lb along with the typically greater amount of optional and now-required gear (like more radios, ELT's, etc), and it's an even worse idea.

When I was running the flight program at the university, we had the FBO doing our flight training keep the 152's fueled only to 16 gallons (8 per side) to help with that, but it did mean stopping for gas more on XC's. Some of our larger students (like the shotputter from the track team) just had to do their training in the 172 even if it cost more. Think about that, and choose wisely.

 

[John221us]

Not sure to be honest... haven't got that far into the planning.

Ron might be trying to point out that perhaps your planning cycle is reversed. If you don't have enough fuel, you either have to plan for a fuel stop or not make the trip. Either way, you should probably know that before deciding your route.

 

[jdhowe75]

Better do the math for DA and check the climb chart. Two people in a 152 coming out of L35 especially in the summer doesn't sound like a great idea.

Ditto that. You're route is fine. Going through Redlands would be a good idea.
Plenty of room to climb if DA permits.

 

[kimberlyanne546]

Not sure to be honest... haven't got that far into the planning.

Silly question but don't you do WB like that every time you fly with him, on every flight (not just cross countries)?

 

[poadeleted20]

Silly question but don't you do WB like that every time you fly with him, on every flight (not just cross countries)?

If you're flying the same plane with the same load all the time, that's not really necessary after you've done it once and know it's OK.

...unless, of course, one of you has been eating too many meals at Pizza Hut and Mickey D's recently.

 

[kimberlyanne546]

If you're flying the same plane with the same load all the time, that's not really necessary after you've done it once and know it's OK.

...unless, of course, one of you has been eating too many meals at Pizza Hut and Mickey D's recently.

Right but you asked him how much fuel he could carry. I figured that every time they fly it may be roughly the same amount of fill up at the pumps.

 

[poadeleted20]

Right but you asked him how much fuel he could carry. I figured that every time they fly it may be roughly the same amount of fill up at the pumps.

Not following you, KA. The amount needed to fill up will depend primarily on how long they flew, and that will vary each time. OTOH, the maximum amount they can have in the tanks without going over max gross will probably be about the same every time. That's why we always had the line crew dip-stick the tanks of the 150's and 152's before refueling -- so they knew how much to pump in to get back to 8 each side, allowing the plane to be used for an instructional flight next. If a student was going solo, they'd only top it off just before flight so we wouldn't be left with a "solo only" plane or have to drain 8 gallons out of the tanks -- makes for expensive lawn mower fuel.

 

[kimberlyanne546]

Not following you, KA. The amount needed to fill up will depend primarily on how long they flew, and that will vary each time. OTOH, the maximum amount they can have in the tanks without going over max gross will probably be about the same every time. That's why we always had the line crew dip-stick the tanks of the 150's and 152's before refueling -- so they knew how much to pump in to get back to 8 each side, allowing the plane to be used for an instructional flight next. If a student was going solo, they'd only top it off just before flight so we wouldn't be left with a "solo only" plane or have to drain 8 gallons out of the tanks -- makes for expensive lawn mower fuel.

That's what I meant, the Max they can have in the tanks without going over max gross, thought that was what you were asking.

I agree about it being different if there are other factors, I just wondered why there was no reply with the "max amount of fuel" they can have.

Oh, and in the three 150's and 152's I've seen a range of useful loads - as much as 50 - 100 lbs difference so it definitely varies.

 

[poadeleted20]

That's what I meant, the Max they can have in the tanks without going over max gross, thought that was what you were asking.

I agree about it being different if there are other factors, I just wondered why there was no reply with the "max amount of fuel" they can have.

Oh, and in the three 150's and 152's I've seen a range of useful loads - as much as 50 - 100 lbs difference so it definitely varies.

OK, but after you've done a W&B on each of the three, the max fuel load with the same instructor isn't likely to change the next time you fly that airplane, so if you kept that number, you don't need to do all the math again. Of course, if you're changing planes and instructors all the time, then in a 150/152, you'd probably need to do one every flight.

 

[BayAreaFlyer]

Right but you asked him how much fuel he could carry. I figured that every time they fly it may be roughly the same amount of fill up at the pumps.

He could be flying somewhere where you don't have to fill up the plane yourself. I had never filled up a plane prior to my first dual XC.

 

[kimberlyanne546]

He could be flying somewhere where you don't have to fill up the plane yourself. I had never filled up a plane prior to my first dual XC.

I always got stuck filling up my plane alone. My instructor wouldn't even join me, he would just meet me later or make me taxi the plane back.

 

[MAKG1]

Silly question but don't you do WB like that every time you fly with him, on every flight (not just cross countries)?

W&B at altitude is different.

The issue is takeoff performance. Density altitude at L35 can get up to almost 10,000 feet. You need to get light enough so you can climb out of ground effect at that density altitude, or you go swimming in the lake. Fortunately, there are no obstructions between the runway and the lake.

Having said that, the lowest-altitude route is over Lake Arrowhead, and then follow Hwy 18 over the dam on the west end. But I'd take a lightly loaded 172 if I were you, and cancel the flight if it's a hot day up there. There is a LONG history of people going for a swim off the end of that really long runway, because they can't climb.

And Vy will be significantly slower than you are used to.

When I did my Piper checkout up there, I did it in the Spring, and density altitude was only 8000 feet. Vy for that Piper (PA28-161) at that density altitude was about 65 KIAS. The POH says 79 at sea level.

This sounds like a bad choice for a cross-country. L35 is a really nice airport, but it's so different from the normal flying you'll be doing that it really should wait until after your checkride.

 

[Henning]

Come in over the dam and turn right, same way out, you can make it even with 2 in a 152, you'll have fun. Remember, you lose weight as you get nearer the mountains, and from Palomar you have a ways to go. We did it out of LGB as well but I do admit it was easier in my turbo'd Travelair.

 

[denverpilot]

The issue is takeoff performance. Density altitude at L35 can get up to almost 10,000 feet.

Oh, I bet it can get higher than that.

Here's my DA calculation climbing through 8500' MSL south of Denver today with a temperature inversion.

Yes it was 40C. 29.97 in Hg.

DA at the surface was little better. 37C at 5885' MSL and the same 29.97. Y'all can do the math.

 

[MAKG1]

Field elevation for L35 is only 6700 feet, and that 10,000 foot DA is at the surface. Of course, you do have to climb over the mountains, with some terrain clearance, to get out. But you aren't trying to climb out of ground effect, then.

 

[Henning]

Field elevation for L35 is only 6700 feet, and that 10,000 foot DA is at the surface. Of course, you do have to climb over the mountains, with some terrain clearance, to get out. But you aren't trying to climb out of ground effect, then.

Big Bear doesn't require much of a climb to get out, just enough to clear the dam which IIRC is lower than the runway anyway.

 

[poadeleted20]

Henning's advice reflects his exceptionally high tolerance for risk. I strongly advise the OP against taking it.

 

[MAKG1]

Big Bear doesn't require much of a climb to get out, just enough to clear the dam which IIRC is lower than the runway anyway.

If you can't get out of ground effect because you're too heavy for conditions, you'll be flying within a wingspan of the lake surface, not the runway. I guarantee that dam is higher than the lake surface. It could be much higher if the lake is low.

And it's not hard to imagine sinking (probably turbulent) air coming over the hills there.

I wouldn't go there in any aircraft loaded near max on a warmer than standard day (which covers most of the year). A 152 with two people in it is much closer to max than I'd be comfy in, even if the two people are very small.

 

[denverpilot]

I wouldn't go there in any aircraft loaded near max on a warmer than standard day (which covers most of the year). A 152 with two people in it is much closer to max than I'd be comfy in, even if the two people are very small.

Any aircraft? I can think of a few I'd happily take.

 

[MAKG1]

Any aircraft? I can think of a few I'd happily take.

Any aircraft loaded to max gross. Max gross is determined at sea level.

I would need to be convinced it doesn't make a difference, sufficiently to bet my life on it, for me to say otherwise.

I suppose you'd be fine with a Citation, but I'd really want confirmation from the AFM (and a type rating....).

 

[denverpilot]

Any aircraft loaded to max gross. Max gross is determined at sea level.

Max gross is the same at all altitudes. Perhaps you are thinking of maximum takeoff weight limited by calculated performance?

The POH contains performance data for max gross takeoffs and landings and adjustments for headwind, density altitude, and aircraft configuration.

Flying an aircraft at max gross isn't the issue at hand.

Flying it beyond its performance capabilities is.

Plenty of airplanes that can climb like a bat out of hell at max gross. They typically have lots of excess thrust.

I'm betting if there's enough runway, an F-18 in full afterburner would do just fine at max gross.

 

[John221us]

There is a huge history of fatal accidents at L35 from low performance aircraft failing to climb out. There are many aircraft that are high enough performance to not have a problem, but a C152 is not among them. Load it up to near gross with high temps, you'll just be another statistic. This either a troll or the instructor wants him to check high DA performance. I had such a question on my Checkride (my Cherokee climbing out of Reno on a hot day).

 

[denverpilot]

No argument there. It's not what MAK said. He said ANY aircraft loaded to max gross.

 

[MAKG1]

Max gross is the same at all altitudes. Perhaps you are thinking of maximum takeoff weight limited by calculated performance?

OK, I guess you need to explain the difference to me.

I suppose you could have weight limited by something other than takeoff performance, but that's all I've seen, even for the 747 I work on.

A severely overloaded aircraft may not be able to climb 50 feet off an infinitely long runway. There are, of course, takeoff performance tables in every compliant AFM specifically for this, and that's the table to use, rather than the published max weight.

There is a published max gross weight, determined for assumed conditions, but it does not guarantee you can actually fly safely.

 

[denverpilot]

I think we are just talking last each other. You said you wouldn't fly ANY aircraft loaded to max gross out of that airport.

I said I'd fly anything loaded to max gross that would still perform adequately for the takeoffs and landings.

Max gross isn't the limiting factor. Performance is.

Max gross limits exactly that only... How much "stuff" you can put on board. People, fuel, cargo... It AFFECTS performance, but the purpose of max gross is structural.

In your world, your operating limitations may change your MGTOW by looking at performance. In light aircraft, we have no such tables or lookups. We can load right to max gross but if we then don't do the performance calculations and crash, we screwed up.

Most of our performance tables in our books are based on max gross. If the book says it'll fly, it'll fly full. (Smart pilots leave a little extra margin in the figures, too. Most of these birds are 30+ years old and never hit book numbers when brand new except with a high-time test pilot behind the yoke.)

Is that making sense now? I was arguing your point that you would not fly ANY aircraft at max gross.

All that said...SOME light aircraft do have a difference between MGTOW and landing weight. The new Cessna 182 comes to mind. I probably would NOT depart out of a hot high airport at MGTOW knowing that it was just a paperwork ploy by Cessna to make their new overloaded 182s look like they have some useful load. The charts in those aircraft's books are corrected to the MGTOW but I know (from experience) that a 182 loaded to 3100 lbs is a struggling beast.

A turbo 182 is better. But it'll chew up a lot of runway at hot/high DA. The limiting factor may become runway length and climb rate after liftoff.

As mentioned in the thread, a 150/152 is ALWAYS struggling, even in the best conditions. It's not a good hot/high aircraft.

A 172 without 180HP conversion is a very "lost in the middle, make a judgement call" aircraft. With 180HP it's slightly better.

I think we're saying the same thing. I'm just pointing out that "Max Gross" is a structural/weight limitation and there are aircraft that can (and do) make hot/high takeoffs at "Max Gross" all the time. It's whether or not the aircraft can still climb at max gross (performance charts) that one is really concerned about.

In your aircraft, performance and weight are mixed on your charts. You can also have temperature limits on engines which are factored into the chart and affect your MGTOW.

 

[MAKG1]

OK, thanks.

I think we are talking about the same thing.

FWIW, my connection to N747NA is rather distantly related to performance planning (though I have read the AFM).

My light aircraft experience is limited to c172/c152 and PA28, where the limiting factor for gross weight still seems to be takeoff performance. Witness, for instance, what one has to do to a 180 HP C172 conversion to get the max gross weight raised. You have to limit flap travel to 30 deg if it originally came with 40. Otherwise, you can't climb adequately in a go-around with the higher weight, at full flap.

I took a PA28-161 out of L35 in the Spring, with an instructor and partial fuel. It was adequate then -- and it climbed at nearly 500 FPM over the southwest ridge (as long as I got Vy right for the altitude) -- but I'm not so sure I'd want to do that on a really hot day.

L35 has a nice long runway for a light aircraft -- 5800 feet. I think the issue isn't so much runway length, but rather if the aircraft will climb at all out of ground effect. I'd hate to imagine trying a very-lightly-banked 180 30 feet off the lake, while trying to avoid a stall or altitude loss -- this seems impossible.