Gear Retraction on Take Off

[Ernie Martin]

Two thoughts.

1. I don't think any of us should assume the POH climb rates to be realistic for our aircraft. Those numbers, squeezed to the max by Cessna, are for brand new aircraft, with perfectly smooth (and waxed) skin, perfectly tuned engines, perfect-pitch props, etc. Ours don't fly that good. I assume 100 - 200 fpm penalty for age, plus the adjustments for temperature, pressure density, etc., and I try to fly below max load, so if an engine fails I can get close to the POH numbers.

2. Of the added drag introduced by the gear in transit, I don't know the proportion of the big doors (the ones removed by the STC), but if you've seen a gear retraction test up close, you know it's big. My guess 2/3 of the in-transit added drag is due to the big doors.

Ernie

[aldoradave]

OK guys, it seems I'll have to do it myself! Tomorrow I will give it the big test and report back as soon as I safely land. I'll go up to 10,000 msl with gear down, retard the rear engine to zero thrust, pop the front to full boogie then record my rate of climb. At 10,500 I'll cycle the gear up and note what happens.

Given that there are so many differences in our birds, this is the only rational way to do it anyway. I'll post my results as soon as I can.

[JeffAxel]

Ernie,
No argument from me on either of your points. Don't make assumptions is a good point. In my case, I also don't fly at gross wt. too often, and so also hope for book numbers. But out of curiosity, when I bought the plane, I took it up with an instructor to see what it would do. I was pleasantly surprised, but we were pretty close to gross wt., and the plane did climb at 100-150fpm with the gear down on the rear engine. Later, when I lost the rear engine on a go around in instrument conditions, it climbed out at 350fpm on the front engine, probably 250lbs under gross on a cool day. Turns out the fuel was set up way rich on the rear engine and it choked when I gave it power, came back when I leaned the mixture, thankfully. Made me a Skymaster believer though! Fuel set up is better now too. I am still not sure what the best course of action is with the gear though. I usually leave it alone until all set for cruise climb, then retract it. When I asked about this at Recurrent Training Center, they made the argument that getting the gear up resulted in better climb, and altitude is your friend, and so had no problem with positive rate gear up. They weren't unhappy if you waited either. I guess to each his own. I can wait to pull up the gear myself....

[billsheila]

What are the settings for zero thrust on a NA Skymaster. My instructor dug these up a few years back and I recall keeping a copy, but now can't find it. In my 1965 Owner's Manual, there is no data given.

Thanks to anyone who can help.

[Ernie Martin]

Dave, when you do the test, please note weight (how close to max load) and weather conditions (temperature). Also check carefully the specs for zero thrust, because temperature enters into the mix. Anxious to see what you get.

Ernie

[hharney]

Originally Posted by billsheila

What are the settings for zero thrust on a NA Skymaster. My instructor dug these up a few years back and I recall keeping a copy, but now can't find it. In my 1965 Owner's Manual, there is no data given.

Thanks to anyone who can help.

Here are the numbers from my 1968 model. Should be close to yours.

[billsheila]

This page is not in my manual, so must be something they added between '65 and '68

Really appreciate you sending it along.

Bill