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What decreases VMC

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higher altitude........less air pressure up there means less horsepower output of the working engine means less yaw tendency.
 
Ok Thanks for the reply. It has been a very long time since I had to get into the books for an interview.
 
Decreasing Vmc

Couple of things. Using zero sideslip lowers Vmc; in other words, raising the wing on the dead engine. Think "raise the dead." Slipping raises Vmc.

Gear extended. Sort of like the keel on a boat. Increases stability.

Feathered prop on the "bad" (inop) engine. Windmilling prop increases drag and Vmc.

Go back to your factors of Vmc and they should suggest the answer to your question.

Hope that helped a little. Just like the above, I haven't taught multi in nine years. Miss it, too. :(
 
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1. Gear extended
2. Flaps down
3. Higher density altitude
4. More bank into operative engine
5. Lower power on operative engine
6. Being in ground effect
7. Higher weight
8. Forward CG
9. Lateral CG toward operative engine
10. Inop prop feathered

Remember to never associate Vmc factors with performance. Vmc is only about rudder effectiveness and thus heading control. As you can see...if the airplane is in the above configuration, you will be able to maintain heading but will be falling to the ground like a rock! When learning the factors you will want to know how the airplane is configured for certification, rather than what makes Vmc the lowest.

Oh...just read your profile...you probably already know the basics. Hope the list helps.
 
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Depends what it does to the CG, I would guess. If you have ice on the vertical/horizontal stabilizer...baaad. Nose...goood. Wings=more rearward CG...baaad. Although if you've lost an engine in icing you better keep your speed up anyway.
 
If you take out bank, VMC actually increases. Try doing a VMC demo without putting your 5 degrees of bank and it will prove this true. You'll VMC 15 knots faster. Also, remember that the 5 degrees of bank is just part of the FAA regulation, you can put more than that and lower VMC even more.
 

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