Gunnars Driver

In this chart the throttle was in flight( called 'flight idle' in some systems, dont know for the UH-1). Im pretty sure the throttle was'nt touched during this event. First thing is to lower collective, and not close the throttle. In this case it might be possible to regain normal flight by increasing the collective again. As soon as the collective was lovered the surge disappeared. The small needle split is due to the overspeed governor is keeping the N2 at the beeped N2 speed, when this is reached after the compressor stall, the N2 stays on spot as it should. The needle split difference will depend on the collective( = rotor speed) and the governor commanded rpm by beeping the gov increase or decrease. At idle( not flight idle) the governor is not active. The idle on all turbine engines I know is by regulating the N1/ gas generator. The N2/NR isnt governored and can vary a bit depending on transmission temp and air pressure/temperature. In most cases, it would be around the 60-70% mark or somewhere around 200rpm. The reason not to regulate the rotor or N2 rpm is that it is very important to keep the N1 above the minimum limit where it can self sustain. If N1 comes under a limit, the engine cannot continue to run without the starter engine. The idle is therefore set by N1 speed. In a training full down autorotation the throttle would be put to idle and in this case the N2 meter would fall back to the 200rpm mark or something like that, maybe a bit higher because the idle is regulated on N1 and the rotor is not driven by the engine, causing the free turbine to get a bit higher speed because no drag from transmission and rotor system. I havent tried to reduce the throttle in the DCS Huey(yet) , all autos was performed by shutting the fuel valve of, killing the engine.

Light aeros ? Can you Back flip the F18? :-) Can you do a piroflip( complete yaw turn during forward 180 flip) with any other aircraft ? :-) So, what all other A/C is doing, is light aeros. The BO does the real aeros !

It seems to produce the power, so if everything else is ok in model, it should feel like it should. But, EGT is to high compared to IRL.

The EGT model actually seems a bit of. I havent fried any engines, except when checking what people say, and ”pulling a lot of EGT” But the EGT rises to quick according to some sheets of 5he manual posted in EGT Limits in UH-1H” under news and updates. I made some checks and posted this: https://forums.eagle.ru/showpost.php?p=3319049&postcount=72

To be extra clear: You can absolutely lower the collective all the way down without unloading the rotor if you do this slowly.. If you do it quick when entering an auto, the rotor will be unloaded( unloaded rotor= low G and you feel like falling). When in an established auto, you can lower the collective all the way down. Depending on helicopter type, weight, speed and density altitude the rotor rpm might increase and overspeed. Low density altitude( cold and high pressure) will make the rotor rpm in an auto lower. Low helicopter weight will make the rotor rpm lower. When performing test flights after maintenance it is checked that the rigging of the rotor is sufficent to keep enough rotor rpm in winter days with a light helicopter. From memory( many years now), in artic cold and Bell 206 you mostly had the collective all the way down during an auto to keep rotor rpm in green.

I think there is a missunderstanding here. What you shouldnt do, is to unload the rotor. Unloading the rotor will never overspeed it in an autorotation. It is the weight of the helicopter (through G-force) that pull through the rotor mast that gives the rotor its possybility to autorotate. Unloading the rotor will take the autorotating force away, thus making the rotor rpm decrease.( this is a dangerous situation if you are flying a gyroplane) When entering the auto, in stragith and level flight, I dont think it is too dangerous to quickly dropp the collective. This because the Earth's gravity there still is a force down on the helicopter body and if you dont do any ecxessive movements with the cyclic, you will be fine. For the Huey or a bell 206, the rotor inertia is very high and there is absolutely no need to push the collective down that quick. (Other helos with very low inertia rotors, is another story...). Unloading the rotor by pushing the cyclic to much forward during flight in forward speed, is dangerous with a teetering rotor. Dont know for the Huey, but the Bell 206 is limited to minimum +0.5G to keep the rotor loaded(it should be the same rule...). The ”rotor loaded part” is not that the rotor get dangerous when not loaded but the helicopter hull/empenange is only kept hanging straight by its weight and need positive G to continue to do this. ”Unloading the rotor” is to take the lifting force put that keeps the helicopter hanging straight. Other issues is center of gravity off. The more the CG is away from the rotor mast the more forces is present trying to pitch the helicopter body if in a low G situation. Also, quick cyclic commands, for example trying to correct for turbulence is a risk to get into mast bumping. When flying the Huey, keep the rotor loaded by using collective stick and power. If you need to start a quick descend: lower the collective and do not push the cyclic forward.

I think the main helicopter and weapons system of the swedish Bo is english. Only military ad ons, checklists and frequency list in swedish

This was during a demonstration firing internally in Swedish armed forces. Was supposed to take the shot in front of the audience. Minimum allowed altitude( ie height above ground) was 4 meters ( technical safety reason). In this case nothing was ahead obsuring the target, so it was possible to fire from minimum height. I flying and of course it would look better this way. For tactical reasons the best/safest was to hover behind trees with only the sight above the trees( actually not above but high enough to position it between some tree tops). When about to fire ascent was made to get the missile launch assembly over the trees, then immediately fire and then descend back behind the trees, with the sight unit back between the tree tops, allowing to track the missile until it hit the target. Optimally it should have been possible to descend further after the shot to be 100% invisible to the target area, and fly nap of the earth without being detected. In the war arena you don't always get the ideal firing position, so this way of taking shots wasnt that unusual. Most important was to have some kind of nature behind the helo to mask it. Hovering with the sky as the background was a big nono, making you clearly visible for the enemy. My memory isnt 100% clear about maximum speed when firing, but I think it was 60 or 80 knots IAS forward.

I flew the Hkp9/BO105 in the anti tank role, and I'm with Deadnine: Nope, no spare TOWs in storage compartment. First of all, equipped with 2 pilots and their gear, 4TOWs it wasnt possible to take full fuel. Standard refueling was 325kg to keep within limits( and also to be able to hover behind the trees). As Deadnine says, the FARP(TOLO in swedish) rearmed and refueled as Deadnine says. These where placed rather short flight from battlefield, and in all cases fuel got low before the TOWs. If you can remember Deadnine, we also got 'fika' from the guys at FARP. Mostly *Renklämma* and small pakets of juice :thumbup: Always appreciated during extended wargames... Secondly, as Deadnine says, compartment was full of electronics and the pilots gears. Actually Im not that sure that you even had the space to load extra TOWs in there without the pilots gear. The TOW, if loaded, should have been in the protective casing, and its a lot bigger than the TOW missile itself. I know the pilot in that clip :) (actually, the clip seems "borrowed" from my youtube)

No, the blades will only flex as much down if idoing -1G as they do up when flying with the normal +1G. The centrifugal force is the thing thats keeping them relatively straight out. Depending of helo type there will be a very little margin, so it is not recommended to try if not allowed for minus G's. Translational lift wont help, you need negative pitch to do sustained* inverted flight. But there are a lot of buts. All full scale helos have the blades twisted, with less blade angle at the tip then at the root. This is to give a good distribution of lift over the length of the blade. Doing negative pitch with a blade twisted like that will give very bad distribution of lift, close to the blade tip will make most lift, and this will bend the blade an cause a lot of vibrations and so on. The fuel system of helis, in general, doesnt allow for negative g( it wount pick up fuel att minus G's, the same counts for the oil system.) No full skale heli does sustained minus G or inverted flight. *) you can fly at minus G for a short whiel with some helos. Pushing the cyclic stick forward when having good airspeed will produce negative G's. For example the Bo105 was allowed down to -1G where I flew it, and if flying fast forward and pushing the stick did produce minus G's for a short while, until the airspeed bled of. You could also roll it on to inverted and after that push the stick a little forward and then you got the feeling of inverted flight forma short while(airspeed dropped quickly...). For the huey and all two bladed (teetered rotors) negative G is very dangerous because cause the helo is actually hanging free under the rotor and minus G will cause the rotor to hit the helicopter body. Then you die. So do the bo105 vibrate when flying minus G's? Yes it does, and it also loose the oil pressure in engines.

Taken out of kontext, and put in this thread, it could be taken wrong. AFK, learning to fly a new aircraft or helo, isn't about learning it all again. For aircrafts, mostly to learn about special caracteristics, for example stalling, and to learn how to operate it in the safest way. For multi engine aircrafts, the handling and procedures if one engine quits. Helicopters, most part is about emergency procedures. Autorotation, stuck pedals or single engine failure if you have at least a couple differs a lot between types. Other emergency procedures, för example hydraulic system failure has to be known exactly and trained, otherwise youre dead if it happens. Thats said, it it a tremendeous difference in handling between helicopters (and arcrafts). Some are quite alike, but not all. Of course, the laws of natures applies to all flying things.

Dont know or remember the history of that picture. That most certainly is one of three pre series helicopters, rented or leased from MBB before the actual Hkp9A arrived. This helo do not have the wire strike kit and doesn't seem to have the "ears" made for mounting EWS(Sweden didnt have radar warning system, but the "ears" above/front of each crew door was present). The 'pylon hinge' for mounting the MLA/missiles doesn't look the same way the final one did, and the MLA doesn't look the same either. The modification of the roof to fit the sight unit doesnt look like the final one either. The color scheme is not as the final ones had.

No, only 4 TOW's on the Hkp9 system. That pic was from before I entered service and most certainly from development and testing. The MLA (Missile Launch Assembly) was the same use by AH64 and could be mounted underneith each other. That way it was possible to actually mount more than two on each side. On this picture the MLA doesn't seem to be the same one that actually entered service. The Hkp9 was never used with more than 4 missiles and from memory the weapons system was not built for more than 4 TOW's, at lest not for Hkp9. From operating it, fully equipped with 4 TOW, pilot and gunner it wasn't possible to carry full fuel. MTOW(2500kg) was reached with around 75-80% fuel. Theoretically if fitted with 4 MLA /8 TOW the onboard fuel amount would not be enough to use 8 missiles in a tactical scenario, probably not even 4 TOWs. I would be quite surprised if the SAAB Helitow system wasn't customizable to more TOW's, for example for export to other helicopter types. I don't know anything about that though. [Edit]Forgot to say, that photo was used as a poster. Seen it lot of times on walls around :-)

Its not really the size, but the weight and MTOW. B206 around 1500kgs, and BO 105 around 2500kg. Hufhes/Schweizer 300 can be used for slingload. Or....it can carry the cargo hook but not that much in it :)

It has slingload capacity. Swedish version had 900kg limit in hook( value from memory, might be wrong), but due to much more built equipment it wasnt possible to lift 6-700 kg as maximum with little fuel onboard. The hook was not permanent installed.

Today BO105 celebrates 50 years in air :-)

It wasn't the Swedish version.

No. There was no RWR on the swedish Hkp9. There was mounting pads, above the windshield an most aft of the tail boom delivered when the bo105 was bought but no RWR-system was ever installed. All Hkp 9 got a modification during early 2000's for NVG-capability and then there was formation lights mounted on the forward RWR-mounting pads. Perhaps these you have seen? I have to make one possible exception for the Viktor 90(later Kalle 90) aiframe, used for tests by FMV. It was equipped with the Helitow2 FLIR day/night system. It is not completely impossible that that airframe had RWR, but as I recall it, it had not.

The Swedish version, Hkp9, had nothing but brave pilots :-)

About 2K on the BO. Yes, I was active then. At the time belonged to 33.Sqn and all four was very close colleagues and friends. :-( Flying at another unit today I'm still carrying that squadrons patch every day. It was designed mainly by two of the perished pilots.

We still have a BO at work, and I have access to it. Also, it said to be a complete weapons system stored so good chance to get it right.

Thats good to have nice pictures. Perhaps these pictures and my knowledge is the key to the help they need ? I have some pic's, but only the Bo in flight - never cared to take photos of the inside equipment. Ehhhh, about one flight on the Huey so far :) Installed DCS a few weeeks ago, have flown the Mirage2K a handfull of flights. At least, now I have a real joystick/throttle instead of o broken one from the millenium before :thumbup:

SAAB was the manufacturer. The system was called Helitow by SAAB and RBS55H by the Swedish armed forces. The missiles was the same, and if I recall it correct Helitow could use all types( at least RBS55B,C,D...maybe/maybe not E). Helitow used a optical daytime only sight with 3x and 12x magnification. Gyrostabilized with very good accuracy/stability. Weather needed (visibility) was the same as the shootong distance. In bad wx you hade to shorteb the distance by selecting a position close enough. SAAB also made the Helitow2, wich was a IR sight system, making it a day/night system. Swedish armed forces did not aquire Helitow2 except on one demo/test helo for demo use. It was quite good though...

Actually more like a 'Gocart' compared to other helos :) There's a lot of secondary rudder effect on the controls, don't know if you would like to impose that to the module ? These are the same for all models( not only the Swedish one). You also have weak response in cyclic stick when making left input at low speeds worst between 30-60 knots IAS. If you perform a steep right turn, you will hit the left cyclic limit if you need a quick left roll response.

I probably have all the info needed. I flew the HKP9A with Helitow, both as Pilot and Gunner. I might be able to help. What's the plan? ...to make it precisely as the HKP9 or just livery ?