Post your 300 CBi Pre-Flight Tips Here

[merlin3]

Hi All,

 

Just curious if anyone would care to share any special emphasis items during pre-flight of the 300 CBi. I do have a commercial rating and a couple hundred hours in helicopters, but most has been spent in Enstroms and Hillers.

 

Just looking for a little more knowledge from people that are experienced with this machine.

 

Thanks!

[John90290]

Hi All,

 

Just curious if anyone would care to share any special emphasis items during pre-flight of the 300 CBi. I do have a commercial rating and a couple hundred hours in helicopters, but most has been spent in Enstroms and Hillers.

 

Just looking for a little more knowledge from people that are experienced with this machine.

 

Thanks!

 

 

This should cover the basics...

 

 

http://heli.com/helicopter-resources/pre-flight-video.php

[zemogman]

I'm a student with about 35 hours dual in the 300 C...

 

Couple things we've run into...

 

- Bugs or wasps living or actually nesting...in the pitot tube (twice)--- use a cover over night it'll save you the headache.

 

- Water in the static port tube (rear under tail-boom) --- also use cover

 

- Excessive forward and aft movement in the CCW shaft --- happened once --- didn't fly.

 

- Collective can get caught / hindered slightly by the seat cushion on the way down while the seat cushion is compressed by the person sitting in it. It makes for a quick momentary drop in blade pitch during auto's and set-sowns --- very seldom but can happen. You will catch this during your freedom of movement check.

 

- periodically seem to have a problem with the fuel pressue guage reading correctly (yes it's been repaired/replaced) maybe they are cheap guages.

 

- The drain tube on the battery is usually "tie-wrapped" to the aft crossbeam. Ensure that the tie wrap is secure and far enough from the bottom of the tube so that the tube cannot become loose at the bottom end and possibly cause interference witht the scroll fan. It helps if the tube is a few inches beyond the tie-wrap.

 

- There will always be water in the fuel check after a rainy night...this is because the pan underneath the fuel tanks drain to the same tube where the fuel sample is taken from on both sides. I know this is obvious but don't put that fuel sample back in the tank. The only fuel that you will find not contaminated by water that day is the sample from the gasculator (hope I spelled that right) underneath the aircraft.

 

- I always check the cable running from the TR to the pedals very carefully underneath the aircraft under the right seat (looking up). It seems to me that that cable runs too close to the edge of the metal hole in the cabin frame...I always make sure that it is not rubbing or frayed all the way up and down the cable but especially there. (I think you'll see what I mean...just follow the cable all the way under the aircraft). A rubber "bushing" of sorts would have helped. IMHO...

 

- I also check the clamp at the front and rear of the air intake hose (about 4"-5" in diameter). Follow the air intake from the front to underneath the aircraft. I have notice that clamp to be loose twice...a quick tightening with a flathead and you are good to go.

 

If I think of any others I'll post again...hope this helps!

 

No offense to any aircraft maintenance personnel...these are just the things I've found...We are all part of the safety process!!

[HelliBoy]

Just remember that the 'Pilots Preflight Checklist' from the POH is very thin and only hits major points. Have an experienced instructor go over a preflight of the entire machine with you a few times until you get it.

 

Question from student: How many points are there on the preflight??

Answer from Instructor: How high can you count??

 

I aways thought the best way to preflight an aircraft was to clean it really well with some rags and a bottle of cleaner.

[joker]

OK, most of the main ones said..

 

Don't fall off, when climbing down from the main rotor. Look at where you place your feet.

 

I didn't once and managed to skin my shin the side! Very ouch!

 

Joker

[RotorRunner]

Always check the tiny little screw that holds the clutch cable idler pulley!

 

This should be at least a 1/2" Grade 8 Galvanized bolt. Oh well, they are still a blast to fly, just don't think about that little #10 machine screw.

 

RR

Edited September 20, 2007 by RotorRunner

[jet trash]

- Excessive forward and aft movement in the CCW shaft --- happened once --- didn't fly.

 

What's a "CCW" shaft?

[zemogman]

What's a "CCW" shaft?

 

Thanks for clarifying...

 

I should have written the..."lower coupling drive shaft"...the inspection of which is to turn it "CW" and "CCW" and listen for metal to metal sound which would indicate lack of lubrication...what I'm trying to point out is that that same shaft should not have fore and aft movement either, this should be inspected also.

 

Sorry about that mis-nomer...It is abbreviated on my pre-flight checklist as "CW-CCW/Shaft"

[jet trash]

I should have written the..."lower coupling drive shaft"...the inspection of which is to turn it "CW" and "CCW" and listen for metal to metal sound which would indicate lack of lubrication...what I'm trying to point out is that that same shaft should not have fore and aft movement either, this should be inspected also.

 

According to the POH, it only says : Lower Coupling Shaft- Fore and Aft Movement--Check.

 

It does not specify there should be no movement. With the design of this, it has to move some, it's not a rigid shaft. Since the H-Frame is rigid and the engine is on flexable mounts, the shaft has to take into consideration some movement.

[zemogman]

It only says that if you stop reading there...If you read further down (page 4-5) from where it says "fore and aft movement---check" you will find:

 

"-- Audibly inspect lower coupling drive shaft for adequate lubrication as follows:

--- Grasp lower pulley AFT spacer and rotate coupling shaft back and forth to take up backlash in both directions (CW and CCW). Listen for hard metal to metal contact noise between gear teeth. If any metal to metal contact noise is heard, lower coupling drive shaft and engine adapter must be removed and inspected in accordance with Basic HMI, Section 10 prior to further flight."

 

In reference to fore and aft movement...it should be minimal...I'm sure there is a measurement for "minimal"...all I know is that we did not fly one of my cross-country's due to excessive fore and aft movement in the lower coupling drive shaft.

 

Bottom-line...check for excessive fore and aft movement AND metal to metal sound when rotating the shaft to detect lack of lubricant...if either of these conditions are evident DON'T FLY until it is checked out...

[Fastlane]

Most of the "quirks" have already been posted, but here's one I've run across. The sunshield on the OAT gauge sender makes a perfect "bug home." Make sure it's clean and clear.

[apiaguy]

I'm going to jump in now to try and clarify the lower coupling drive shaft ordeal before it gets out of hand......

 

The lower coupling drive shaft is the shaft that sits inside the engine mounted drive coupling and inserts into the lower pulley "shaft".

 

People are talking about two different items on this thread and confusing the two.

 

The lower coupling drive shaft does "float" and move fore and aft in the drive coupling and lower pulley.... movement will be as much as an inch or so. It will move fairly easy when lubricated properly but should not "thud" into either end (engine crankshaft plug or lower pulley aft spacer plug) This is a easy item to overservice and then the thing slings grease everywhere... the maintence manual talks alot about not overlubricating it.

 

 

The POH is talking about grasping the lower pulley aft spacer... that's the thing that sticks out behind the lower pulley.... and twisting it to make sure there is grease and not a dry metal to metal sound between the lower pulley and the lower coupling drive shaft.

 

Now we go a little deeper...... it is a major NO-GO if the lower pulley shaft has ANY movement between it and the lower pulley. This is a HEAVY press fit item. Also there should be witness marks on the inner races of the lower pulley bearings to the lower pulley shaft to see if there is any bearing movement.

 

Hope that helps with this check item.

Edited September 21, 2007 by apiaguy

[jet trash]

I'm going to jump in now to try and clarify the lower coupling drive shaft ordeal before it gets out of hand......

 

The lower coupling drive shaft is the shaft that sits inside the engine mounted drive coupling and inserts into the lower pulley "shaft".

 

People are talking about two different items on this thread and confusing the two.

 

The lower coupling drive shaft does "float" and move fore and aft in the drive coupling and lower pulley.... movement will be as much as an inch or so. It will move fairly easy when lubricated properly but should not "thud" into either end (engine crankshaft plug or lower pulley aft spacer plug) This is a easy item to overservice and then the thing slings grease everywhere... the maintence manual talks alot about not overlubricating it.

The POH is talking about grasping the lower pulley aft spacer... that's the thing that sticks out behind the lower pulley.... and twisting it to make sure there is grease and not a dry metal to metal sound between the lower pulley and the lower coupling drive shaft.

 

Now we go a little deeper...... it is a major NO-GO if the lower pulley shaft has ANY movement between it and the lower pulley. This is a HEAVY press fit item. Also there should be witness marks on the inner races of the lower pulley bearings to the lower pulley shaft to see if there is any bearing movement.

 

Hope that helps with this check item.

Gee.....Ya Think????

[apiaguy]

Jet trash... are you mocking me for trying to explain or clarify something that would seem so plain?

 

I'm deeply hurt, in a pissy mood and now am going to kill myself and never check that lower pulley shaft again. Damn you.

[merlin3]

Thanks for the replies everyone. Some good tips.

 

The videos were ....uhhh...pretty good.

[zemogman]

Jet trash... are you mocking me for trying to explain or clarify something that would seem so plain?

 

I'm deeply hurt, in a pissy mood and now am going to kill myself and never check that lower pulley shaft again. Damn you.

 

Don't do it apiaguy...I value you for your explanation <_ ...clarity is a good thing>

 

Seriously though...this thread could help everyone, not only in the details, but in the attitude towards the details...the more we know (especially about safety issues) the better pilots we can be. This is a good example of how something that would "seem so plain" can land you in an emergency situation".

 

So seriously...thanks for the explanation.