Center of Gravity?

[pilot#476398]

So, you can't trust anyone, not even your own CFI, especially when he says, "I already took care of it!"

 

I wonder what would have happened to that 400hr pilot, "he_monkey" mentioned on that other thread, who sat there and watched as his Chief Pilot overloaded his 44, if he had gotten out of that chopper and said, "I'm not flying overloaded like this!"?

 

Me thinks he'd be working at McDonalds now?

[Hand_Grenade_Pilot]

As others have said, flying out of CG creates control problems. Under normal flight conditions, the pilot may not see this as a problem.

 

Lets use lateral CG as an example.

 

If out of lateral limits, one skid will be hanging much lower than the other. The ability to execucte a normal take-off, cruise, and a normal landing aren't dramatically impaired. Pick-up/set-down would certainly 'feel' awkward as you are compensating for the off-set CG w/ excessive lateral cyclic.

 

Why is this a problem?

 

Imagine trying to do a run-on landing now. There is now a much higher probability of someone botching the landing. The low skid contacts first, the high skid comes down a bit hard and ground resonance follows (in a fully articulated system).

 

Slope operations are particularly hazardous out of CG. Forget about trying to land with the high skid down-slope. Even w/ the high skid upslope, the CG is displaced in such a way that there is a greater rolling tendency downslope.

 

Finally, there will always be a situation you've never experienced or thought about. Flying in the envelope guarantees that your aircraft will perform as it was designed (assuming no mechanical problem occurs) and keep you legal.

 

Flying is all about stacking the odds in your favor.

[Hand_Grenade_Pilot]

And as a follow-up to the original question; yes, I do check CG and Gross Weight before every flight. I keep a W&B form in every one of my student's training folders showing max fuel and CG placement for each aircraft. I created an Excel spreadsheet for each aircraft to quickly calculate W&B when I'm flying w/ a new student, photographer, etc.

 

Tours are not exempt from this. A legitimate tour operation should weigh each passenger prior to flight and dispatch should make the appropriate calculations. For nearly every other flying operation, the PIC should compute W&B. I realize that with a line of walk-ins being loaded as hot-swaps, the pilot will not be able to whip out a spreadsheet and calculate W&B.

 

Since not all operators do things the right way, a smart pilot (especially a tour pilot) should at least know what their useful load is and make an estimate to determine if you're over max gross (800 pounds useful remaining after fuel, and a hefty family of 4 just hopped in. That's a problem).

 

To cross-check CG, make sure all basic loading rules are followed (heavy cargo/passengers are closest to the rotor mast, and keep right vs. left loading as proportional as possible). Crunching theoretical numbers in a spreadsheet on the ground is a great way to get a feel for what loading scenarios are acceptable and which ones aren't.

 

Ultimately, you will know if there is a CG problem once you start to pick-up into a hover. You know what the normal cyclic travel is for a balanced helicopter; any excessive cyclic travel should be seen as a red flag.

 

Crunching numbers and using a scale is ridiculously easy. Unfortunately, because some operators don't think that way, it will be up to you, the pilot, to put your foot down and say NO when you suspect limitations are being exceeded.

 

But it can be a very hard thing to do (saying NO under pressure)

 

(Last passenger thrown in, the line guy walks away, next helicopter is inbound for the pad in 30 seconds, the bitchy woman in the backseat is complaining that everything is running 2hrs late. You're boss has made it clear that $$$ is the priority. You're sitting there, thinking. 20 seconds. Just do it, it shouldn't be too far out...)

 

The best defense against these external pressures is understanding and accepting the fact that flying out of limits is a problem and dangerous. With that in mind, it becomes a lot easier to say no. And to make a call over the unicom telling the line guy to pull one passenger out, and that you'l talk to the boss-man after the flight.

 

 

[aeroscout]

So, you can't trust anyone, not even your own CFI, especially when he says, "I already took care of it!"

 

I wonder what would have happened to that 400hr pilot, "he_monkey" mentioned on that other thread, who sat there and watched as his Chief Pilot overloaded his 44, if he had gotten out of that chopper and said, "I'm not flying overloaded like this!"?

 

Me thinks he'd be working at McDonalds now?

"Trust but verify". -Ronald Reagan- (When he was a CFI)

[Mikemv]

And as a follow-up to the original question; yes, I do check CG and Gross Weight before every flight. I keep a W&B form in every one of my student's training folders showing max fuel and CG placement for each aircraft. I created an Excel spreadsheet for each aircraft to quickly calculate W&B when I'm flying w/ a new student, photographer, etc.

 

Tours are not exempt from this. A legitimate tour operation should weigh each passenger prior to flight and dispatch should make the appropriate calculations. For nearly every other flying operation, the PIC should compute W&B. I realize that with a line of walk-ins being loaded as hot-swaps, the pilot will not be able to whip out a spreadsheet and calculate W&B.

 

Since not all operators do things the right way, a smart pilot (especially a tour pilot) should at least know what their useful load is and make an estimate to determine if you're over max gross (800 pounds useful remaining after fuel, and a hefty family of 4 just hopped in. That's a problem).

 

To cross-check CG, make sure all basic loading rules are followed (heavy cargo/passengers are closest to the rotor mast, and keep right vs. left loading as proportional as possible). Crunching theoretical numbers in a spreadsheet on the ground is a great way to get a feel for what loading scenarios are acceptable and which ones aren't.

 

Ultimately, you will know if there is a CG problem once you start to pick-up into a hover. You know what the normal cyclic travel is for a balanced helicopter; any excessive cyclic travel should be seen as a red flag.

 

Crunching numbers and using a scale is ridiculously easy. Unfortunately, because some operators don't think that way, it will be up to you, the pilot, to put your foot down and say NO when you suspect limitations are being exceeded.

 

But it can be a very hard thing to do (saying NO under pressure)

 

(Last passenger thrown in, the line guy walks away, next helicopter is inbound for the pad in 30 seconds, the bitchy woman in the backseat is complaining that everything is running 2hrs late. You're boss has made it clear that $$$ is the priority. You're sitting there, thinking. 20 seconds. Just do it, it shouldn't be too far out...)

 

The best defense against these external pressures is understanding and accepting the fact that flying out of limits is a problem and dangerous. With that in mind, it becomes a lot easier to say no. And to make a call over the unicom telling the line guy to pull one passenger out, and that you'l talk to the boss-man after the flight.

 

 

 

HGP,

 

I applaud your mentality, it parallels mine about safe operations!!!!!!!!!!!!!!!!!!!!!!!!

 

Mike