Oversquare

[jetsam]

Is it true that Goose drivers never set more than 25 MP with RPM less than 2100 because engine life? What about Beaver 29/1900 , 28/1800 . Engines are the same.

[angry inch]

No this is not normal. (for a commercially operated G-21A) At those power settings in a Loaded Goose, you will most likely be descending, or watching your airspeed decay while maintaining level flight. The T/O, climb, & cruise power settings are pretty much the same for the Goose's 985's as in the Beaver, with the exception (don't ask me why) that in the Goose manual, T/O power(36.5"/2300) is allowed up to 5 min, whereas in the Beaver, I believe the manual says 1 min... Max Continuous is also slightly different. In the Goose manual they say 34.5"/2200rpm up to 5500' & 33.5"/2200 above 5500'. Beaver is 33.5"/2200rpm. Normal cruise power for Goose is 28/18.

Here's a good thread discussing "over square"..viewtopic.php?f=3&t=65665

[xsbank]

Maybe they allow you to thrash the Goose a bit harder coz there's 2?

[sarg]

I believe that there is more than 1 model of 985 approved for the Beaver one that had the lower ratings and one the higher, -AN1 & -14B, I think my manual is in a box in the basement and it's been 10+ years. The goose might only be approved for the one model.

[Rowdy]

Doesnt the goose have better airflow around the engine, being as theres no cabin/cockpit behind it? I'm just pulling this out of my ass, but I figured it would be based on temps.

[The Old Fogducker]

It has been forever since I flew a Beaver, so I join Rowdy in pulling things out of my beeehind, ...... I'm pretty sure the FAA engine certification standards call for the engine to run at 5 minutes at max power settings before reduction to max continuous power.

Where a one minute restriction would come from? .... beats me.

The Old Fogducker

[angry inch]

I wonder what the t/o power time limit is on the Beech-18, Staggerwing, & various other airplanes that use the 985 are compared to the 1 minute on the Beaver? The Goose has better cooling than the Beaver from the extra 20kts in the climb...

[snoopy]

D18S wheels or floats:
450 hp - 36.5" Hg @ 2300 RPM
limit 1 minute...

Cheers,
Kirsten B.

[Northern Skies]

One minute limit for the ASz-62 also: 41.3 in MAP, 2200 rpm, 986hp.

[1000 HP]

True, but it only takes 8 to 12 seconds to get airborne, depending how fast you move the throttle

[beaverbob]

While heat effects time limits at full power, I would be more concerned with vibrations and that is probably the reason for the 1 minute.
Bob