MD 600N
Helicopter is destroyed
Santé SLB
Is the MD600 dangerous like a Robbie in Low G conditions ?
Quote:
Originally Posted by VegasHeloPyl8 View Post
"Airframe 54, I do not read nor write French, ...http://www.aeroboek.nl/600/RN054_BEA_04062004.pdf
"Helicoptre est detruit"
Helicopter is destroyed
Santé SLB
Isn’t the MD meant to be one of the fastest, most maneuverable, precise and safest (as long as the donk is running) helicopters? Or is this privilege reserved to the 500. Despite the 500 and 600 looking so similar, are they possibly two very different kind of aircraft? And is the difference maybe beyond the obvious (NOTAR vs conventional TR) and has to do with their very different proportions?
Here we go on lambasting 2-bladed teetering head choppers as being inherently prone to catastrophic mast bumping if flown ham-fistedly, or in conditions of strong turbulence. On the other side, forum members credibly report having flown the 2-bladed JetRanger for thousands of hours in often extreme turbulence, without even the slightest on-set of mast bumping.
Only to find that the 6-bladed, fully articulated MD-600 carries a safety warning in its Rotorcraft Flight Manual similar to the one we have for Robisons (almost identical wording to R44 Safety Notice SN-10). Here is the wording from the MD flight manual:
Normal Procedures Section 4-9: “Rotor ‘blowback": …condition is exacerbated by … low rotor RPM, high collective angle pitch setting which causes blade stall over a large portion of the main rotor disk. If the resulting blowback is excessive, the main rotor may contact the tail boom.
2.1 Simulated engine failure at cruise speed
At the time of the accident, the helicopter was flying at a ground speed of close to 140 KTS. At least 4 of the 6 rotor blades deeply cut into the tail boom. This damage is indicative of rather abrupt control movements. It also appears that [at the time of the tail boom strike] the rotor blades were not subjected to high centrifugal forces, in other words, there is indication of reduced rotor RPM. While such loss of rotor RPM could have been caused by loss of engine power or failure of the override clutch, no pre-existing mechanical problem was found.
At the time of the accident, the helicopter was flying at a ground speed of close to 140 KTS. At least 4 of the 6 rotor blades deeply cut into the tail boom. This damage is indicative of rather abrupt control movements. It also appears that [at the time of the tail boom strike] the rotor blades were not subjected to high centrifugal forces, in other words, there is indication of reduced rotor RPM. While such loss of rotor RPM could have been caused by loss of engine power or failure of the override clutch, no pre-existing mechanical problem was found.
The owner-student had around 1,000 HRS TTRW on R44 and EC120. The mishap flight was part of his type-rating on the MD600. The report found that the instructor tried to challenge (well, the actual word in the BEA accident report is “entertain”) the student with a surprise simulated engine failure at fast cruise and 800’ AGL.
Turbulent conditions [which according to the BEA report may have prevailed at the time of the incident] and/or the surprise element have probably triggered the incorrect response by the student pilot. The need to at the same time turn into the wind [in preparation for an autorotation landing] would have further increased the student pilot’s workload.
3.2 Accident cause
In all probability, the inappropriate control inputs of the student-pilot have caused an in-flight break-up of the tail boom, caused by the main rotor striking the tail boom.
“1.18.1 Simulated engine failures
“Entering autorotation at cruise speed is complicated. The pilot has to make small but precise control inputs to reduce speed to Vy. Dumping the collective can cause a low G condition (between “low positive G”, up to “negative G”), which, together with large and abrupt cyclic AFT movement, can cause the rotor plane to come dangerously close to the tail boom.
1.12.5 Damage history
“The mishap aircraft had been involved in an incident [3 years before this accident]. [Another] pilot at the time lost yaw control close to the ground, and the main rotor cut through the composite structure of the tail boom in almost its entire width.
1.12.6 Other MD600N accidents linked to tail boom strike
“Between 1996 and 2004, thirteen accidents of the MD600N involving tail boom strikes were reported. 11 of those happened on the ground, of in the course of a hard landing. One tail boom strike happened in flight during the certification test flying program, and another in-flight tail boom strike occurred while flying outside the flight envelope.
3.2 Accident cause
In all probability, the inappropriate control inputs of the student-pilot have caused an in-flight break-up of the tail boom, caused by the main rotor striking the tail boom.
“1.18.1 Simulated engine failures
“Entering autorotation at cruise speed is complicated. The pilot has to make small but precise control inputs to reduce speed to Vy. Dumping the collective can cause a low G condition (between “low positive G”, up to “negative G”), which, together with large and abrupt cyclic AFT movement, can cause the rotor plane to come dangerously close to the tail boom.
1.12.5 Damage history
“The mishap aircraft had been involved in an incident [3 years before this accident]. [Another] pilot at the time lost yaw control close to the ground, and the main rotor cut through the composite structure of the tail boom in almost its entire width.
1.12.6 Other MD600N accidents linked to tail boom strike
“Between 1996 and 2004, thirteen accidents of the MD600N involving tail boom strikes were reported. 11 of those happened on the ground, of in the course of a hard landing. One tail boom strike happened in flight during the certification test flying program, and another in-flight tail boom strike occurred while flying outside the flight envelope.
Despite the optical similarity, the MD600 is considerably heavier (40% higher empty weight compared to 500E). The rotor clearance between the rotor disc and the tail boom is maybe 10 cm less. I should think, equally importantly, both cabin and tail boom are much longer, resulting in the FWD and AFT masses of the airframe to be further away from the centre than in the MD500.
This in my books would result in a situation where the (already higher) mass of the MD600 acts upon a longer lever arm, generating larger inertia resisting the fuselage to follow the FWD/AFT movement of the rotor disk.
If you lower the lever in pretty much any helicopter, the disc will flap forward and the nose will drop - if you then haul back on the cyclic you are going to have the disc coming back while the tail is still going up. If your control margins are reduced (C of G) and your control power is low (type of rotor head) it is not a surprise that the rotors might meet the tail.
Perhaps the 600 is more susceptible than other helos, hence the RFM text but high speed cruise entry to auto does require more careful handling and those pilots used to 'standard' 90 knot entries may well be surprised at the aircraft response to their normal control inputs.
Perhaps the 600 is more susceptible than other helos, hence the RFM text but high speed cruise entry to auto does require more careful handling and those pilots used to 'standard' 90 knot entries may well be surprised at the aircraft response to their normal control inputs.
Cant speak for the 600 as I have only flown one once. The 500 in high speed flight auto rotates like a dream in fact you have to use a different technique than that you are normally taught.
Remember this is high speed flight ( above 100kts ) Say one is cruising at around 120 to 130 kts. If you close the throttle the first reaction should be to haul the cylic back leaving the collective lever where it is. The effect will be initially for the aircraft to climb at about 500 ft a min for about 5 to 10 seconds. You are aiming to get the speed back to 80 kts ( range speed) If you put lever down first the nose will drop severely causing one to yank the lever back up to protect Nr.
Once you are at 80 its then control the speed with the collective i.e. by lowering it slowly the nose will drop which means you can apply rear cyclic which increases Nr and gets the speed back to 60 kts which is best auto speed.
If you bottom lever at 130 its you will have ac on its nose with about 40 to 60 degrees pitch down. Effect is then to haul back cyclic which very very rapidly increases Nr so you have to rapidly bring lever back up.
Now if you have not been taught this technique then a 600 which I am sure flies in a similar manner ( but with higher ROD ) but faster then a 500 I can see why you would chop you boom off by bottoming lever with a rapid rear cyclic to stop massive nose drop !
Remember this is high speed flight ( above 100kts ) Say one is cruising at around 120 to 130 kts. If you close the throttle the first reaction should be to haul the cylic back leaving the collective lever where it is. The effect will be initially for the aircraft to climb at about 500 ft a min for about 5 to 10 seconds. You are aiming to get the speed back to 80 kts ( range speed) If you put lever down first the nose will drop severely causing one to yank the lever back up to protect Nr.
Once you are at 80 its then control the speed with the collective i.e. by lowering it slowly the nose will drop which means you can apply rear cyclic which increases Nr and gets the speed back to 60 kts which is best auto speed.
If you bottom lever at 130 its you will have ac on its nose with about 40 to 60 degrees pitch down. Effect is then to haul back cyclic which very very rapidly increases Nr so you have to rapidly bring lever back up.
Now if you have not been taught this technique then a 600 which I am sure flies in a similar manner ( but with higher ROD ) but faster then a 500 I can see why you would chop you boom off by bottoming lever with a rapid rear cyclic to stop massive nose drop !
Hughes 500 - your description of the high speed cruise technique for auto is OK for a practice one where you react immediately so the Nr has little time to decay - in the real case you will need to lower the lever a bit because you will be using the strong flare effect to recover the Nr rather than zoom climb.
We used to teach this type of technique on the Gazelle at low level (100') at 120 kts and you could show a climb of 2-300' if you reacted quickly but that was a false scenario with no delay between closing the throttle and applying aft cyclic.
Try doing it with a 1 - 2 sec delay between throttle chop and reaction - you won't be getting 500'/min RoC but you do recover Nr and delay the onset of the descent giving you the all important time to make a plan.
The other area you have to be careful is when the flare effect is waning and you have a nose-high attitude; you need to select a speed stable attitude for your best auto speed but you must push the nose forward gently - any rapid pitch nose down will decay the Nr you have worked so hard to recover.
We used to teach this type of technique on the Gazelle at low level (100') at 120 kts and you could show a climb of 2-300' if you reacted quickly but that was a false scenario with no delay between closing the throttle and applying aft cyclic.
Try doing it with a 1 - 2 sec delay between throttle chop and reaction - you won't be getting 500'/min RoC but you do recover Nr and delay the onset of the descent giving you the all important time to make a plan.
The other area you have to be careful is when the flare effect is waning and you have a nose-high attitude; you need to select a speed stable attitude for your best auto speed but you must push the nose forward gently - any rapid pitch nose down will decay the Nr you have worked so hard to recover.
Crab
Unlike a 341 the NR in a 500 is very very lively. You can use the technique I describe even counting to 2 before rear cyclic !
The 500 when you drop the lever seems to drop its nose way way more than any of the other types I fly. So you are able to use the lever as speed decays i.e. slowly putting it down drops the nose alarmingly which means you flare back to maintain attitude and speed which also obviously helps the rrpm stay in the green. I hear what you are saying but the 500 seems to autorotate like nothing else ( well having done an EOL in a Scout with 3200 fpm ROD Ii might take that back )
Not sure on the 600 but auto Vne in a 500 is 130 kts, a 600 will easily get to 135 / 140 kts. So if they were doing an auto from this speed I can see why they hit the tailboom especially with an inexperienced instructor !
Unlike a 341 the NR in a 500 is very very lively. You can use the technique I describe even counting to 2 before rear cyclic !
The 500 when you drop the lever seems to drop its nose way way more than any of the other types I fly. So you are able to use the lever as speed decays i.e. slowly putting it down drops the nose alarmingly which means you flare back to maintain attitude and speed which also obviously helps the rrpm stay in the green. I hear what you are saying but the 500 seems to autorotate like nothing else ( well having done an EOL in a Scout with 3200 fpm ROD Ii might take that back )
Not sure on the 600 but auto Vne in a 500 is 130 kts, a 600 will easily get to 135 / 140 kts. So if they were doing an auto from this speed I can see why they hit the tailboom especially with an inexperienced instructor !
Hughes 500 - roger that 
NASA and MDHC did a quiet rotorcraft test programme in the late 1980's in a 500E. Part of the test programme required that they fly at 75 per cent rotor RPM. To release the aircraft for that test, the test pilot had to do a few autos starting at 75%. Not sure they held the collective for 2 seconds before lowering it! Maybe that was dependent on the entry speed. I hope the test pilot got a bonus payment for that job!
500 Fan.
BITD!
The then Hughes demo party trick was ~120 knots at about 6 ft. Roll the throttle, zoom climb as described here previously, roll left when down to about 60 knots, haul it around in a descending turn and flare to touch down back where you started!!
Remembering that it all started from here -
And the basic blade hasn't changed much over the years.
All they have done is make it a bit longer and add a few more so there are limits as to what can be achieved.
Chan Morse at Prescott AZ ( I think) ~ 5000'.
As the retreating blade stalls at low Nr and conveniently drops into the tailboom.
FYI I was pilot/mechanic on the second MD600N in service, the first went to South Africa, and before anyone in the U.S. operated them. Talk about being a guinea pig!!
We did all the delightful things and went through all the initial teething problems like rebuild the instrument panel because the original engine instrumentation guys went out of business, FADEC EMI testing, replaced the undercarriage with upgraded items, overrunning clutch mods, fan shroud replacement, FADEC sockets the wrong size, tailboom attach fitting mods, removal of the thruster cap to improve flight characteristics, MGB oil pressure switch mods, swashplate offset mod, cyclic stick mod, cyclic electrical connector mods, fuel system mods and its pitfalls, and on and on.......................
The thing is still flying in Venezuela somewhere I think.
Although it was nearly 20 year ago I can't think of anything it did really well.
Just goes to prove that unfortunately you still can't polish a turd.
For perspective I can compare it to about 12 other types I have flown.
The then Hughes demo party trick was ~120 knots at about 6 ft. Roll the throttle, zoom climb as described here previously, roll left when down to about 60 knots, haul it around in a descending turn and flare to touch down back where you started!!
Remembering that it all started from here -
And the basic blade hasn't changed much over the years.
All they have done is make it a bit longer and add a few more so there are limits as to what can be achieved.
Chan Morse at Prescott AZ ( I think) ~ 5000'.
As the retreating blade stalls at low Nr and conveniently drops into the tailboom.
FYI I was pilot/mechanic on the second MD600N in service, the first went to South Africa, and before anyone in the U.S. operated them. Talk about being a guinea pig!!
We did all the delightful things and went through all the initial teething problems like rebuild the instrument panel because the original engine instrumentation guys went out of business, FADEC EMI testing, replaced the undercarriage with upgraded items, overrunning clutch mods, fan shroud replacement, FADEC sockets the wrong size, tailboom attach fitting mods, removal of the thruster cap to improve flight characteristics, MGB oil pressure switch mods, swashplate offset mod, cyclic stick mod, cyclic electrical connector mods, fuel system mods and its pitfalls, and on and on.......................
The thing is still flying in Venezuela somewhere I think.
Although it was nearly 20 year ago I can't think of anything it did really well.
Just goes to prove that unfortunately you still can't polish a turd.
For perspective I can compare it to about 12 other types I have flown.
Cracking video RVDT - it looks like the pilot might have tried a bit of aerodynamic braking on the slippery runway to get the blade to hit!
There really isn't much clearance on those things is there?
There really isn't much clearance on those things is there?
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The then Hughes demo party trick was ~120 knots at about 6 ft. Roll the throttle, zoom climb as described here previously, roll left when down to about 60 knots, haul it around in a descending turn and flare to touch down back where you started!!
Wow, 6' huh. I believe it.
I have done these form 120knots about 200' (180 touchdown autos back to the spot where the throttle was chopped, liked others said, you can get a 500' climb for almost 10 seconds, climb up to 350 or so' while doing a 180' turn. As Hughes 500 said, you leave the collective where its at until you get to the desired airspeed. A good 5-7 seconds If I remember correctly.
Wow, 6' huh. I believe it.
I have done these form 120knots about 200' (180 touchdown autos back to the spot where the throttle was chopped, liked others said, you can get a 500' climb for almost 10 seconds, climb up to 350 or so' while doing a 180' turn. As Hughes 500 said, you leave the collective where its at until you get to the desired airspeed. A good 5-7 seconds If I remember correctly.
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My father, a private pilot owned about eight 600N's they were great AC. Sportiness of the 500/520 range with the capability to carry more passengers. You should speak to Simon Oliphant at Eastern Atlantic, if he can't help you know one can!!
Just following this thread and note that a couple of 600's have entered Australia recently, SO, I am thinking would a 600 be a viable machine to own OR my financial ruin. Having owned 6 Eurocopters all with turbomecas I have a number of orifices that have yet to heal correctly. So the thought of no 12 yrs no 15 yr engine oh and not having to deal with turbomeca appeals. So does 130 kts, plenty of room FADEC and a neat looking aircraft, make sense. With a new one at 1.9m usd I can see why they have struggled to sell but a (relatively) low time example can now be found with a few yrs on it for 700k, + or -. Doesn't this change the equation? I could put one of these in the hangar and do 100 hrs a year for the next 10 yrs till they box me up. I can't see it biting nearly as hard. Not really worried about the auto capability as I haven't had an auto in anger in the last 35 yrs flying and if I did and it went bad so what; better than dying of cancer. Considering I also have had a half dozen R44's I don't see the risk comparison.
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350 nut,
the only criticism of the previous resident 600 was the stability issue. This was acknowledged by the guy operating it and the agent at that time. Worked with it on fires around SYD
I thought it would be a good run for the money against the squirrels other than b3 for fires etc Prob not good for tourist stuff when compared with squirrel.
for picture search vh-ath on google.
the only criticism of the previous resident 600 was the stability issue. This was acknowledged by the guy operating it and the agent at that time. Worked with it on fires around SYD
I thought it would be a good run for the money against the squirrels other than b3 for fires etc Prob not good for tourist stuff when compared with squirrel.
for picture search vh-ath on google.
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350 nut,
don't know of it in BNE but was operating with National helicopters whilst owned by Rene Rivikin. Was working fires around SYD with a bucket. It was a while ago but think this is correct.
The FX conversion is worth a look if wanting to avoid troublemecca.
don't know of it in BNE but was operating with National helicopters whilst owned by Rene Rivikin. Was working fires around SYD with a bucket. It was a while ago but think this is correct.
The FX conversion is worth a look if wanting to avoid troublemecca.
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Engine ignitor MD600
Good day , I am having a problem . My ignitors are going off every time we switch on the battery , we hear them go off ..
Also as we are flying we are hearing the auto ignition going off..
Does anyone have any idea where to look to resolve this problem .. we have no warning lights
Also as we are flying we are hearing the auto ignition going off..
Does anyone have any idea where to look to resolve this problem .. we have no warning lights