Navajos

[z987k]

http://www.risingup.com/planespecs/info/airplane372.shtml


I think in Denver things would be spooky - especially with an old plane, and with the Vg kit, I think SE Service Ceiling would be below ground in Denver (I'll check the STC next time I think about it) but theoretically, you should be able to climb out a little bit. Anecdotal evidence suggests that it is possible to survive a V1 cut in the thing, I met a guy in Nome a few years ago who told me that he lost one about a second after rotation in Fairbanks in the summer (read 80 degrees or so) and he said he was sinking rapidly with the gear and flaps out, with the gear and flaps up he was sinking at 50 fpm, and with the dead cowl closed and the good one open he was climbing at about 150fpm - yes he said the cowls made that much of a difference. So... I dunno, he also had the high gross weight kit on and was "loaded up" in his words.

My opinion? Takeoff with max power in all twins (and pistons for that matter) unless you have performance and the performance data available to take of with less - it lessons the steps you have to take after takeoff to get max power out of the engine. In the Navajo, if you lose an engine after you've already selected the gear up or are in the process of it, and catastrophically lose an engine there, let's say at the "barrier speed," then you're looking at having to go back over to the throttles and push the power the rest of the way up before going over to the flaps to retract them (if you use them) or starting the feathering process, because you're gonna need all the power you can get.

As for landing with the props back at 2300RPM, well, here they want us to have the props at 2400RPM for landing, I do, but I go a step further, once I get off of the governors (at about 90 - 85 KIAS) then I reach and push the props the rest of the way up to get max power if I need it in case a fourwheeler or a truck drives on the runway or whatever.

Ya, that's what I did. Once off the governor, props full. The reason they did it I think was noise abatement, and at that point we're still getting the same result, but being smart and safe about it. That 13k ceiling on one engine is BS, not even close in any I flew. On one of my checkrides we did the SE approaches into LMT, and it was everything it had to keep on the glideslope, we ended up circling at higher than MDA and sinking down to it on the circle in time to turn base and descend from MDA. This was empty.

 

[ppragman]

Ya, that's what I did. Once off the governor, props full. The reason they did it I think was noise abatement, and at that point we're still getting the same result, but being smart and safe about it. That 13k ceiling on one engine is BS, not even close in any I flew. On one of my checkrides we did the SE approaches into LMT, and it was everything it had to keep on the glideslope, we ended up circling at higher than MDA and sinking down to it on the circle in time to turn base and descend from MDA. This was empty.

Well K Falls is at what, about 4000' MSL? How warm was it outside, I mean the DENALT for any temp over 90 is over 7000', which realistically speaking, with an old ass airplane, could be a fatal trip if you lost one full of boxes. I dunno, don't have a POH handy.

 

[TallFlyer]

I think in Denver things would be spooky - especially with an old plane, and with the Vg kit, I think SE Service Ceiling would be below ground in Denver (I'll check the STC next time I think about it) but theoretically, you should be able to climb out a little bit.

The one "power loss" I've had (something in the exhaust failed, no exhaust to the turbo) I ended up feathering at 9,000 MSL at 6,500 lbs in one of our aircraft with no VG kit (I forget the temp, but it was an August early morning) and had no issue holding altitude.

As for landing with the props back at 2300RPM, well, here they want us to have the props at 2400RPM for landing, I do, but I go a step further, once I get off of the governors (at about 90 - 85 KIAS) then I reach and push the props the rest of the way up to get max power if I need it in case a fourwheeler or a truck drives on the runway or whatever.

Cruise prop setting for us is 2300 RPM, and we hold that to touchdown. On the few go arounds I've had at mins going Throttle, Prop, Mixture hasn't ever caused me any issues.

The most common reason I have to go around here is gear indication issues, that is, the light isn't seated correctly or burned out. I'm still above pattern altitude at that point, so back to 30", props stay at 2300, mixtures stay where there at, leave the cowl flaps closed, and figure out why the light isn't lighting up. It's never been the gear.

I get that it's a little weird, but like I said, all our guys are still breathing, we don't have many serious mx issues on our IO-540s, and the paychecks are on time. And if I need the power, I'll use it every time.

 

[Douglas]

We've had this discussion about prop-back landings, I just don't see the issue.

 

[scooter2525]

I love how there are two threads on the 'ho.

 

[z987k]

The one "power loss" I've had (something in the exhaust failed, no exhaust to the turbo) I ended up feathering at 9,000 MSL at 6,500 lbs in one of our aircraft with no VG kit (I forget the temp, but it was an August early morning) and had no issue holding altitude.


Cruise prop setting for us is 2300 RPM, and we hold that to touchdown. On the few go arounds I've had at mins going Throttle, Prop, Mixture hasn't ever caused me any issues.

Eeek! Backwards I hope?

 

[TallFlyer]

Eeek! Backwards I hope?

That's what I thought at first too, but the spool up time on the turbos makes it work out. I wouldn't want the excitement of going full rich on engines below 25" at 5,500 MSL in a go around.

 

[z987k]

That's what I thought at first too, but the spool up time on the turbos makes it work out. I wouldn't want the excitement of going full rich on engines below 25" at 5,500 MSL in a go around.

I promise that won't snuff em out. Good god man, you guys operate that thing against basically every common safety practice. I have 600 hours in a pa31-350 and I really like that airplane.

 

[scooter2525]

Same thing was taught in the be-58. Mix, props, throttles. Although the hand movement was Mix right, props left, throttles center.

 

[ppragman]

That's what I thought at first too, but the spool up time on the turbos makes it work out. I wouldn't want the excitement of going full rich on engines below 25" at 5,500 MSL in a go around.

Yeah, the spool up time on the turbos is negligible. You oughta (or maybe your management oughta) read the lycoming guide to engine operations. They specifically mention full power for takeoff, and if I remember correctly, they make mention of "the order" you advance the power. Invision this scenario: driving along on the approach and you get to mins and you don't see anything, and after the necessary freight dawg hesitation (wait, I thought I just saw the lights, was that the strobe?!) you decide to go missed (nope it wasn't, let's get the hell out of here).

You first advance the throttles to maximum - with the prop back, the engine begins to lightly detonate (you wouldn't be able to hear it over the engine noise, and 23" may be enough where it wouldn't happen at all at max power - that begs another question, do you go to full power on the missed or 40x2400?), the fact that the engine is leaned out so much doesn't help the situation much, the EGTs and CHTs rapidly climb into dangerous territory.

Next you push the props forward. Any detonation has stopped, though the mixture is very lean still.

Finally you get to the mixtures, and finally start to cool off those fuel guzzling TIO-540s which are closing in on the 1650 EGT mark. I guarantee those EGTs climb faster than you'd think when you push power in.

I dunno, I feel like operating exactly the opposite of the POH and the Engine manufacturer's guide is probably not a good idea - but it's they're airplane, so they can tell you how to fly it.

 

[spbrian]

That's what I thought at first too, but the spool up time on the turbos makes it work out. I wouldn't want the excitement of going full rich on engines below 25" at 5,500 MSL in a go around.

TSIO-540... Correct me if i'm wrong since its been 8 years since i've even seen one but the I stands for injected???

Injected doesn't have the same density altitude issues that a non fuel injected engine would... Aka, fuel is metered to the cylinder on a density altitude schedule (AKA, how much M.P. the engine is taking in) and full forward is a maximum setting for that M.P..... It will not cause the engines any issues to go full forward with a low power setting other than burning a bit more fuel unless maintenance has effed up the rigging.... This is a silly operating technique, and could lead people issues when they leave KLA...

 

[TallFlyer]

Guys, bottom line, I fly it like they tell me. The engines don't break, I'm still breathing, and the paychecks are on time. If I end up flying a Navajo somewhere else ill fly it like they tell me.

Feel free to add all my info to the ever growing pile of bad KLA karma, but I'm done.

 

[ppragman]

TSIO-540... Correct me if i'm wrong since its been 8 years since i've even seen one but the I stands for injected???

Injected doesn't have the same density altitude issues that a non fuel injected engine would... Aka, fuel is metered to the cylinder on a density altitude schedule (AKA, how much M.P. the engine is taking in) and full forward is a maximum setting for that M.P..... It will not cause the engines any issues to go full forward with a low power setting other than burning a bit more fuel unless maintenance has effed up the rigging.... This is a silly operating technique, and could lead people issues when they leave KLA...

Fuel Injected doesn't really matter, as long as the engine is "normally aspirated" - i.e. no turbocharger, some leaning will be required to compensate for the altitude. With a turbocharger (the T in TSIO) the turbo compresses the air before it goes into the cylinders to be combusted, the flow of fuel is metered in relation to the compressed air, not in relation to the outside air. So yeah, basically, there's nothing to worry about "leaning on takeoff" because the mixture entering the cylinders is compressed. This is why you see something like 40 GPH on takeoff, because of the massive amount of fuel required to be able to keep the engine cool.

 

[z987k]

TSIO-540... Correct me if i'm wrong since its been 8 years since i've even seen one but the I stands for injected???

Injected doesn't have the same density altitude issues that a non fuel injected engine would... Aka, fuel is metered to the cylinder on a density altitude schedule (AKA, how much M.P. the engine is taking in) and full forward is a maximum setting for that M.P..... It will not cause the engines any issues to go full forward with a low power setting other than burning a bit more fuel unless maintenance has effed up the rigging.... This is a silly operating technique, and could lead people issues when they leave KLA...

You're thinking of a car's fuel injection system where it takes care of that for you. The injection on these dinosaurs does not. Climb above the altitude where you're not getting full power anymore and you'll still need to lean.

 

[z987k]

Guys, bottom line, I fly it like they tell me. The engines don't break, I'm still breathing, and the paychecks are on time. If I end up flying a Navajo somewhere else ill fly it like they tell me.

Feel free to add all my info to the ever growing pile of bad KLA karma, but I'm done.

Honestly I don't want to see you become a smoking hole because you had the mixture back (maybe LOP?), and go throttle full.. or even 40" and put holes in half a dozen pistons. I really don't care what they've been getting away with for how long. Eventually physics will happen.

 

[spbrian]

Hmmmmm, I am no longer safe in pistons... What loss!