Vmc roll crash

[gotWXdagain]

If you are flying low altitude at high speed, you want to do the opposite and exchange airspeed for altitude. "Climb to cope".

So....not so much for the term 'never'.

You're right.

Insert [beyond the performance capabilities of your aircraft] ahead of my statement.

 

[SteveJeff]

What is the 5 degrees of bank into the operating engine giving you? Effectively it's giving you more rudder. It's using the HCL to your benefit, so you can ease up on the rudder a little bit. In your hypothetical situation, you mention that you're flying at Vmc, by definition this is the speed at which the rudder has lost it's effectiveness. The airplane is going to yaw and eventually roll in the direction of the dead engine, because the asymmetrical thrust is overpowering the effectiveness of the rudder, even with the aid of the HCL (5 degrees of bank into the good engine) giving you that "extra" rudder. If you're below Vmc, that means you've already lost control effectiveness... It WILL yaw and roll, only option is to reduce power and control the nose... unless you're in the region of the graph where it stalls before reaching Vmc. The latter usually occurs at higher density altitudes where your Vmc is so low, the wing stops flying before your rudder stops working.

Ok, but what about my doubts? What about banking toward the dead engine to turn? Does your Vmc change in a manner that you'll not be able to return to wings level since you started the turn? Or if you don't react fast enough when the engine fails and the ariplane assumes a banked attitude toward the dead engine, are you able to return wings level in this case?

This is what i don't understand. If Vmc changes when you bank towards the operative engine, I figure out it will increase when you bank toward dead engine. In this case, if reaching Vmc means loss of (roll) control without having the possibility to return wings level, I can figure out that if you banked towards dead engine (intentionally or not) you may lose control at a greater speed than expected Vmc.

 

[Hacker15e]

As a corollary, people make a big deal of getting below corner airspeed at low altitude. Granted (as you know) that is so that you have the airspeed to maneuver, and presumably climb to cope, but maybe airspeed is still life?

Oh, you are definitely correct -- multiengine military fighters still functionally have Vmc(se) like everything else, and they'll lose control and corkscrew/spin in just like any other twin if you're single engine and get below it under the right conditions.

In both the '38 and the Eagle, we had "safe single engine airspeeds" that as a rule of thumb we didn't want to be under while we were handling an engine failure (for those not familiar, there is no published 'blue line' in many of these jets, despite there actually being functional Vmc). Both of them were in the neighborhood of 250-300 knots, so if you were raging around at 500 feet and 450-480 KGS, there was still a lot of airspeed to convert into altitude in the event of an engine failure.

I was just commenting on the 'never sacrifice airspeed for altitude' statement, and that some things that apply to light GA twins don't apply to every multiengine aircraft out there.

Here's a Hornet doing a Vmc roll at low altitude, hehe:

 

[Vector4Food]

Hey that's Canadian, we have fighter jets?!?!?

 

[Pilotforhire587]

I seem to remember our very own Doug Taylor posting about having a student spin him in a light twin some time ago. I could be wrong though.

I didn't say light twin did I....