BO 105 - Good, Bad or just Ugly?
 

BO 105's are as rare as rocking horse poo here in New Zealand, so can somebody tell me of any experiences of them, such as what's the direct operating costs really like (been quoted USD250 per hour), do they vibrate a lot through translation - are they as bad at this as BK117's or are they worse?? (ever tried to read the instruments on a BK when you drop out of translational lift!). Also what fails/drops off/etc..

I understand they are popular ships with the UK police force, I even saw one on TV the other day in an English series "Dangerfield" featured a very long police chase involving a Land Rover and the BO105.

Help me out with any info, there is a geniune reason. Thanks :)

When the canadian coastguard moved from 206's to 105 it is said that they experienced a decrease in doc's . I have no documentary evidence to support this but the 105 has very few limited life components , the reserve for parts on the L4 ( 111.7 /hr) is much more than the maint reserve for the extra engine ( 54.88 / hr) . The new blade as used on the super 5 and 105 LS super lifter reduces both vibration and noise.

First, I'm not a 'Kow driver. But you asked for "experiences" and I've ridden in'em. An hour and a half in the back seat is as exhausting as a 8 hour day flying a 355, 350 or a 206.
Second, 105 pliots seem to either love or hate flying them, no in-betweens.
Third, I have friend who had an in flight fire and tail boom seperation. He still flys 'Kows.

So I guess from the above that vibration is a problem? The ship I have an interest in is a BO105CB4, I take it this won't have the LS blades fitted, but can they be fitted if that reduces noise?

BO105's seem to be good buys for a twin engine jobby, and now two people have suggested the DOC could be reasonable.

A bog standard -4 without pendulum absorbers fitted will rattle your fillings out PDQ, especially going through translation on landing. Even if expertly tracked and balanced this machine is tiring to fly in for any length of time.
LS blades plus pen dabs decrease vibration a lot, also add 5-10 kts at cruise but are increadibly expensive and are prone to leading edge debonding, (at least the early ones were).
Over all it's built like a brick ****house, very manoeuverable and if well maintained reasonably reliable. Saying that though it's showing it's age now....and, yes it is ugly but so are some of my other best friends!

Probably not such a good buy then after all. But it's still attractive in that it costs the same as a 350D or B, and a twin would be advantageous. A 355 is just too far out of budget.

Are ex-millitary spares available/an option for a commercial use BO105, given how many the German army have? I'm thinking about the LS blades and pends.

First off let me declare that I am a 105 lover, I've got near 2000 hrs in the little suckers and am now very involved with the BK117..... they fly very much like the Hu500 series helo and the vibration is very much dependant on how you fly them....having said that the pendular weights are a must for really smooth flight as is a good track.... problems with vibration usually have a lot to do with M/R pitch link slop!...dont drag the a/c in on the approach fly a good constant angle varying airspeed approach...and you should have no problems at all...they are are very trustworthy a/c which you can take ANYWHERE with absolute confidence...try to talk to anybody from the "Peter Button" trust in WGTN. he (Peter) had one there when he unfortunately met his end(in a B206)alternatively try to track down "Bob Davidson" who I think lives in Tauranga...he has 4000+ hrs on them and has a lot of info and advice....Cheers and good luck! :) :(

Angry Palm Tree- No, my comments regarding fatigue weren't vibration induced. The only noticable vibes were on my first ride 17 years ago. Decel thru translational then was exciting.
Riding in the 105 is tiring because it IS built like a brick out house. The front pax, who has the "good" seat, is on the floor in the bubble. Think early 60's Sprite with a glass roof and no suspension.
The poor souls in back are nose down, pushing themselves back into the seats at cruise. I remember looking at the horizon thru the greenhouse over the pilots head the whole flight.
Also, the 105 doesn't ride "loose" and pendulous like a Long Ranger. But it never seemed to be in trim for more than a second or two, then it was wandering off in one axis or the other, requiring pilot intervention.

You get used to it, I must say!

Solid machine, whatever its faults.

It does seem to me that the BO105 might be that most elusive of helicopters - a cheap twin.

What do you think??

Just got this reply from the seller:-

"The blades are 105-15150, the absorbers are pendulum 105-81022".

So I guess it has pendulum absorbers at least, anybody any idea if these are 'S' or 'LS' blades?

105-15150 + 105-81022 = 105-15141 which are the blades on the 2.5 t CBS 4 and LS A3 . CBS Super 5 and LS super lifter blades are 105-15170.have a very noticeable tapering towards the tip.

BTW anyone wants any low time 105-15141 blades drop me a mail.

Angry,
I have been flying the 105 type for eight years now with the police in the UK, and have several thousand hours on the clock with them. Can only agree with Spinwing - they WILL get you anywhere at all, and are built like the outside loo!! BUT -
Make sure you check on the following points - depending on the role you have in mind the Stretched version (105 CBS 4) has more room, greater WAT-2500kg and is more comfortable for pax. Make sure the Tie-Bar mod has been done (most should be). The Anti-tank tail rotor is the most efficient and has assymetric blades. You would be advised to have Fuzz Burners on the engine mag plugs (will save landing out) Facet oil filters will DOUBLE the oil life and save on mag plug warnings. Make sure that the MGB has had a recent o/h (can be expensive) and the Hyd pack should be o/h too. Pend Abbs are essential for a good track and bal (we flew all the time with these and found that the CBS-5 blades were too expensive) It will drink 180 L per hour max and if you don't fly with the lever up under your armpit it will give better consumption than that. The DOC the police used was in the region of £600 to 1000 sterling per hour. If you need any other titbits of info mail me

FLIR. :cool:

Thanks Widgeon!

FLIR, thanks too! I take it the figure of 600 to 1000 sterling is the 'cost to ratepayer', because that's a little on the high side for a DOC. For that sort of money I can hire a BK117 for about an hour and a half!

I do miss England, but not the prices... :D

Angry,
Yes, you are correct the costs quoted are to the ratepayer so-to-speak. Have had some good and bad times in the 105 - but she never let me down, when a donk ate something mettalic and ******ed the compressor!! Mr Alison/RR with the C20B does not have the best of histories, but when used in a police role they are hardly up to temp when needed to work - they can leak a bit too, but the oil loss needs to be around one liter per hour before the limit is reached - messy to clean up if you leave it too long.

regards FLIR. :cool:

BO-105 Questions
 

Hi all,
I'm on the hunt for information on the BO-105.Could any pilots/Techs give me a good run down on what kind of ship it is re DOC's,downtime,reliability,what its like to fly etc.I know its built like a brick S**THOUSE but is it's low purchase price at the moment(Twin wise)for a real reason,or becuase they are getting a bit long in the tooth, or because it's got a face only a mother could love.Thanks in advance for the help,

Skiv:D :D

Kiwi Skiv

On the NewsGroup 'rec.aviation.rotorcraft', the thread 'Angles during different modes of flight' was started three days ago. A number of knowledgeable people commented on this subject and used the Bo-105 as an example of rigid rotors. Their comments on the Bo-105, pros and cons, might be of interest to you.

Helidrvr is right. Since several years, i am on the way with such ships. It`s my favourite under a lot of helos. Why? Best of all, compact, a direct control and a really good view for the pilot. To fly like a sportscar. Proven a/c, no surprises. The question is, for what kind of operations, do you want to use it. Isn´t the long liner, no single pilot ifr, forget hot ´n high. Good small ambulance ship, good for observations (2-3 crew,FLIR+aux. fuel tanks) and night trips (incl. NVG). I also recommend the CB"s" stretched variant. The CBS-5 (Super Five) are recommended for elevated helipad (CAT A) or offshore ops. (improved OEI limits due to other blades & improved m/r gearbox). The BO 105 "LS" with Allison 250 C28 for hot`n high (only 10-20 ships are built).
A lot of additionally stuff is available for really all kind of ops. Underpowered- yes, with MTOW (2,5 tons). Good to fly below 2,3 tons. Empty weight aprox. 1300-1400 kg. In europe a lot of ships + spare parts for sale. Very cheap to get (below some singles). Maintenance isn`t so cheap. The frame needs some special tools + hyd. ground unit. The engines (CB variant) also used on AS355F, A 109, BH 206, MD 500...

Thanks for the info so far guys,The airframe will be used for survey work with a few bits of equipment strung from it.3 crew plus the occasonal strap hanger.Should not be required to operate at MAUW very often if at all.

Kiwi Skiv I flew BO105's for two years on & off doing Police Flying, Load Lifting & general flying about type stuff! :)

I never had any power problems with the machine even at MAUW in the Welsh Valleys. The tail rotor authority is second to none! The machine will just swallow huge amounts of gear aswell! Handling is excellent & you can throw one about no probs!

The down side is the accomodation! Rear seats are very cramped...front seats better(ish). I'm six foot four & hit my head alot!!

If you want a cheap to buy machine that'll carry lot's of gear it's a good bet! However, I understand that they are relatively expensive to run & if you're not required to have twin engines the 'B' Squirrels will do as good a job for less running costs!

I loved flying it! Lovely to fly a machine that'll hover in any direction in most winds! (But then I've got a thing about tail rotors! :rolleyes: )

I dont have the conklin figures for DMC but have been told that they are actually close to a 206L. Main reason is there are very few life limited parts .Transmission overhauls and Hydraulic repairs can be expensive especially if you are in a corrosive environment . In the US there are many choices for engine overhaul and quite a few approved PMA parts for them the help keep down the engine overhaul costs. There have been 56 105 LS delivered in total. The German wermacht were selling a load of 105's with military certification for bargain prices some time ago.

Thanks guys for all the info,I appreciate the input,

Safe Flying,

Kiwi Skiv

BK-117, BO- 105 Rotor blades
 

What do the weight things on the BK and BO blades do. They look like a small weight on each side of the blade which is free to rotate, but Im stuffed if I can figure out what its for.
Help needed. THanx

Centrifugal or, is it centripetal
 

These weights are thrown outward by centrifugal force. As the blades rotational velocity builds up the centrifugal force builds up increasing the apparent mass of the pendulum weights. The helicopter blades as they rotate will form a traveling wave from the tip to the root. An example of this would be if you tied a rope to a fixed point and then raised and lowered the free end very rapidly. The rope would have a traveling waveform running from the free end to the fixed end. As this traveling wave on the rotorblade moves inward the increased mass of the pendulum weights must be displaced in order for the waveform to be reacted by the rotorhead. The energy of the traveling wave is cancelled out in the attempt to displace the pendulum weights. In plain English they are vibration dampers.

Some Bell blades accomplish this by having a weight imbedded at the nodal point on the blade while other helicopters have dual pendulum weights that react to different frequencies.

:ok:

Lu,

Congratulations, that's the best description I've read!

Spaced,

They are also there to severely bruise your fingers when you let the weight fall on your hand during a pre flight ;)

Slightly off topic, how many operators are currently suffering due to the KSB on blade cuff inspections? 3 weeks downtime and $A50k to establish that the blades are serviceable is a real PITA :(

Lu, thanx for the amazingly simple and concise explination. Is this due to the nature of the rigid rotor system? Or do all rotor blades have a dampner of some sort?
John, Thanx for the heads up. Hopefully oneday Ill get to fly one and be able to put the advice to good use.:D

Vibration dampers
 

To: Spaced

Not all helicopters incorporate vibration dampers and those that do utilize as many designs as there are helicopters that employ them.

The bell 412s use pendulum dampers while some two blade Bell rotors incorporate a tuned weight inside the blade at the nodal point. Remembering the example of the moving rope and the traveling wave this included weight keeps the vibration from passing to the root of the blade by absorbing the energy of the wave.

The Bristol Sycamore has three weights suspended on flexible shafts, which are attached to the transmission. These weights vibrate on the flexible shafts in tune with the vibration generated by the blades. The vibrating weights absorb the energy of the vibration keeping it from passing into the fuselage.

The MIL Mi-17 uses a Bifiler system similar to that used on Sikorsky helicopters. I am not too clear on how the weights move in relation to the attaching arms in that they move to absorb loads generated by lead and lag or if they move up and down to absorb the traveling wave or, if they do both.

Many Eurocopter helicopters have a weight mounted on a coil spring which is mounted under the coollie hat on the rotorhead. The incoming vibrations excite the weight and in doing so the vibrations are cancelled out.

Bell helicopter devised an electronic system on the Huey that sensed the incoming vibration and the device generated a signal (vibration) that canceled out the incoming vibration. The unit was installed in the nose compartment.

Boeing has a mechanical system that mounts under the pilots’ seats on the CH-47 and this device absorbs vibrations. If it ever goes unserviceable the vibrations would be so great that the helicopter could not be flown. The poor guys in the back don’t have this convenience.

The most unique way of absorbing vibration induced by rotor movement is the NodaMatic system designed by Bell. This system allowed the transmission to move up and down in relation to the fuselage. The suspension system had a tunable weight that would be displaced by the linkage on the suspension. The displacement of the weight absorbed the incoming vibration that caused the transmission to move up and down keeping any vibration from passing through the fuselage. The system worked great but it caused a lot of problems.

The Hiller UH-12 had flexible arms attached to the flight controls below the rotor. Attached to the flexible arms were metal weights. Any vibration that would feed-back from the flight controls would cause the weight to deflect thus absorbing the feed-back forces.

:ok:

You want to see some complex vibration dampers? Look at a Sikorsky S76 rotor head. Stay away from whatever drugs that design engineer was on!

Regarding the BK 117, the best comment I heard about the dampers was from a woman who looked at the two pendulous ball-shaped items hanging from each blade root, and said, with a grin:
"I suppose this is a BOY helicopter?":uhoh:

Mr Selfish

The EC120B appears to have 'Chinese weights' in its tail rotor. When used in a main rotor, they are perpendicular to 'in-plane', and are used to counter the centrifugal flattening moment of the blade. (Tennis Racket Effect).

These weights have been call "Chinese balls". Does this make the EC 120 a BOY helicopter, also. :D


Cannot respond to 'Meaning of Life', since it is off-topic. ;)

Advancements in aerodynamics
 

It is my personal opinion that the incorporation of these various devices that counter rotor induced vibrations were incorporated after the development of cambered airfoils on rotor blades. This added a degree of instability that resulted in vibrations that either were not there on NACA 0012 blades or they were not as prominent.

Fire away engineers.

:ooh:

Lu,

Can you please expand on your comment that the Nodamatic system devised by Bell "worked well but caused problems".

Are you referring to any particular Bell model that incorporated this system or just generally?

Thanks in advance

NodaMatic
 

To: Aladdinsane

My only experience with the NodaMatic suspension was on the Bell 214. Other Bell models had this system installed but I can’t say that the problems if any were the same.

As indicated in my post the transmission moves up and down in relation to the fuselage and by definition the engine. Connecting the engine to the transmission is a short shaft with couplings at either end. These couplings were filled with a viscous grease and the movement of the transmission relative to the engine caused the couplings to extend and retract turning them into grease pumps. The grease that was extruded from the couplings would be injected into the airflow going into the engine.

This grease would plate out on the engine inlet bell and it would attract sand and small debris. The engine was very sensitive to airflow distortion and would result in compressor stalls. The compressor stalls would generate a shock load into the drive line and rotor system resulting in frequent major inspections and resultant change out of dynamics and drive line components. More serious compressor stalls would result in airframe damage.

The problem was solved locally by frequent detergent washes of the engine, which ran up the maintenance rate, which was already over 70 MMH/FH

:sad:

Thanks Lu, only played with the smaller "nodal beam" Bells without problem so was wondering about your comment.

Question for BO105 pilots
 

Hi everyone...

I am flying a HEMS BO105 since June on a 35-40ºC/no winds/high altitude enviroment.

SOPs on my company said I have to shut off the engines before get the injured in the helicopter.

Sometimes I need to start the engines on less than 15 minutes and the TOTs are over 270ºC.
FM say "engine start is not permitted if TOT is higher than 150ºC."

On this situation, fellow pilots use starter gen for cooling the engines.

Is the use of the starter gen the right way?
What is your procedure?


Thanks in advance. (...and sorry for my english)

You are permitted to vent the engines useing the starter/gen before commencing the start.

Most of the time this is not required as the TOT limit of 150 is for the moment you chuck the fuel in, not when you press the starter.

So it is normally below this after the engine has run up to 12-15 % anyway!

Best method is to Vent run the engine (Dry motor) it to 15% N1. Wait for the N1 to drop back to 0% N1 then start it.. In my experience, if the Temp is below 200 deg on fuel input, she will not hot start..
However, do NOT attempt to modulate the start (using fuel flow lever) at all. This messes with the fuel bellows and will constantly give you hot starts. The fuel flow must be moved into the idle gate for start.
PM me if more info is needed.
C4

Hi Talvin, no problem with your english, as Bosher has stated as long as your TOT is around 150 at light off there should be no problem. I do not agree with C4 and the start/stop /start method. If you have a weak battery you are then trying to do two starts when one is enough. If you have a problem at over 12%N1, 150 c and the temp is looking like a hot start it is time to talk to the other side (engineer's) and have them readjust the start (mixture.)It can be done, I mean taiking to an engineer, just take's time and free beer.

what you could try is shut down one engine and vent it while the other one is still running, thereby using its generator instead of the battery. Then shut the other one down as normal.

This should give you a cold and a hot engine for the start. Start the cold engine first, then vent the hot engine if required using the generator from the running engine.

It is probably not a practice recommended by the manufacturer, but it should work on twins.

brgds, S76Heavy

It is probably not a practice recommended by the manufacturer
 

Dead right there, RR/Allison are quite specific in mandating against "venting" their engines after shut down, citing thermal shock damage as a likely consequence. Conversely, the LT101 is required to be motored for 10 seconds after shut down, to move the oil around and prevent coking in the oil galleries :rolleyes:

Also, the practice of cross starting is allowed by some manufacturers, and not by others. It can put a strain on the starter/gen quill shaft, leading to failure, when the extra load is applied during cross start. Watch the ammeter load go off the clock, and consider the effect it might be having!

C4's reply is as good as you'll get.

Thank you very much for your responses.

I've sent a mail to Rolls Royce asking about this topic.

As soon as I receive an anwser, I'll post it here.


Talvin.

:ok: