Enstrom Corner
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There is no corraltor on the 280C so you have to work the throttle as you raise or lower the collective, try to lead with the throttle when pulling the lever up but watch the revs, you get used to it after a while.
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So I have had my first flight in my Enstrom since taking delivery. 1977 280C. I have lots of questions, but first I want to share my near disaster first flight. The seller wanted to be benevolent and give me his left over fuel in his truck mounted tank. So an 85 degree afternoon with 20 gallons fuel and me and my instructor about 400 lbs. As I begin to lift off I get an overboost light so I settle back down and try again after leaning mixture a bit. I did this a couple times, but it seemed it was getting more and more difficult to stay out of overboost. By the time I taxied away from the hangar I noticed really high CHT and oil temperature was approaching redline. I set down to allow it to cool off a bit before continuing. First off I am not familiar with this or any Enstrom so I didn't know what was normal. I did think to myself surely there is more performance than an R22. After cooling off a bit I began to lift off and about 2' off the ground I lost a lot of power and got lots of vibration and backfiring. Fortunately I was able to settle without too much speed, thanks to high inertia. We checked the sumps once again and found lots of black sand like particles in the tank where the benevolent fuel was pumped. Needless to say I took a complete tear down and now it seems to be OK as far as I know. Much less manifold pressure needed, but I still don't know what I should expect. So now the questions:
The book says to bring engine RPM to 2900, but it seems a lot smoother and a better performer at top redline. I notice my rotor RPM is at the bottom of the green when I am at 2900 so what is your technique and how critical is the redline on the engine speed? It seems I enter overboost and lose rotor RPM rapidly if I stay at 2900 in a hover.
Regarding the tires for the ground handling. The tires on mine have cracked sidewalls and the brackets that attach the deployment mechanism is slightly tilted so the wheels angle outward. Is the tilt normal? How can tires with 475 lb capacity each carry 2000 lbs? They are Kenda tires 4.10/3.50-4 made in Taiwan. Are those the correct tires and has anyone found any better tires? Desser has those tires for $33 each so should I just replace these? As it is now it is very difficult to move it on the ground and the tires flatten a lot. Is that because the sidewalls are cracked? Can I install tubes to stiffen them?
The book says to bring engine RPM to 2900, but it seems a lot smoother and a better performer at top redline. I notice my rotor RPM is at the bottom of the green when I am at 2900 so what is your technique and how critical is the redline on the engine speed? It seems I enter overboost and lose rotor RPM rapidly if I stay at 2900 in a hover.
Regarding the tires for the ground handling. The tires on mine have cracked sidewalls and the brackets that attach the deployment mechanism is slightly tilted so the wheels angle outward. Is the tilt normal? How can tires with 475 lb capacity each carry 2000 lbs? They are Kenda tires 4.10/3.50-4 made in Taiwan. Are those the correct tires and has anyone found any better tires? Desser has those tires for $33 each so should I just replace these? As it is now it is very difficult to move it on the ground and the tires flatten a lot. Is that because the sidewalls are cracked? Can I install tubes to stiffen them?
Last edited by lvflyer; 10th Oct 2013 at 05:22.
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irv
to be blunt you need to sack the instructor and get one with some experience on enstrom and one a bit lighter you didnt add your weight its more than possible you are grossly overloaded did you or your instuctor do a w and b calc
most accidents that i have heard of are because of overpitching so please take care
and regarding the tires you have answered your own question and yes the wheels do angle a bit
to be blunt you need to sack the instructor and get one with some experience on enstrom and one a bit lighter you didnt add your weight its more than possible you are grossly overloaded did you or your instuctor do a w and b calc
most accidents that i have heard of are because of overpitching so please take care
and regarding the tires you have answered your own question and yes the wheels do angle a bit
Last edited by md 600 driver; 10th Oct 2013 at 08:10.
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Ivy,
I owned a 280C for 16 years. If it was a hot day and heavy, I would wind the rpm up to full, lean off the mixture to 130 pounds at 36.5 inches of manifold pressure and cushion creep slowly out into the wind. Do not lean any more as your EGT would go too high and you would loose power. Very easy to over pitch, so listen to the engine revs as you go. Check your oil cooler is not caked up with old oil and there is no grass stuck in the vent.
In the cruise I would reduce rpm to bottom line and lean off to 85 pounds per hour fuel flow at 29 inches, watching EGT. with this I would get an endurance of 2.6 hours.
You can fit tubes in the tyres, they should be hard, 50 ppsi at least. If you buy some locally and keep them for spare in case you over inflate the old cracked up ones.
The Enstrom is a lovely bird and I have never felt safer in any other machine.
Have fun.
I owned a 280C for 16 years. If it was a hot day and heavy, I would wind the rpm up to full, lean off the mixture to 130 pounds at 36.5 inches of manifold pressure and cushion creep slowly out into the wind. Do not lean any more as your EGT would go too high and you would loose power. Very easy to over pitch, so listen to the engine revs as you go. Check your oil cooler is not caked up with old oil and there is no grass stuck in the vent.
In the cruise I would reduce rpm to bottom line and lean off to 85 pounds per hour fuel flow at 29 inches, watching EGT. with this I would get an endurance of 2.6 hours.
You can fit tubes in the tyres, they should be hard, 50 ppsi at least. If you buy some locally and keep them for spare in case you over inflate the old cracked up ones.
The Enstrom is a lovely bird and I have never felt safer in any other machine.
Have fun.
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I guess I didn't make myself clear on weight. Total between myself and instructor was 400lbs and 120lbs fuel. 200lbs less than gross. Power issue was because fuel system was getting plugged up and eventually cut off fuel flow to one or more cylinders. Do you guys rest your arm on a knee pad so your hand in on the cyclic grip or do you just adjust as needed to operate the trim? My grip when resting my arm on my leg is about 3 inches below the trim and I'm not a tiny person.
By the way I would have to fly 4 hours to get to an instructor I trust that has Enstrom experience. Obviously the seller didn't fly it right. He never leaned the mixture. The mechanic/instructor he had didn't even clean the spark plugs and fuel injectors on last annual 20 hours ago and even had the wrong pin on the fuel screen cup which allowed the debris to bypass it.
By the way I would have to fly 4 hours to get to an instructor I trust that has Enstrom experience. Obviously the seller didn't fly it right. He never leaned the mixture. The mechanic/instructor he had didn't even clean the spark plugs and fuel injectors on last annual 20 hours ago and even had the wrong pin on the fuel screen cup which allowed the debris to bypass it.
Last edited by lvflyer; 10th Oct 2013 at 14:18.
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Now I'm probably going to show the extent of my ignorance. Please be patient with me.
I went to wax my main rotors as suggested by Sharkeys and saw some pretty heavy nicks on the leading edge like a layer of aluminum was peeling. I have posted some photos here www.dahome.net/enstrom.htm
Is this normal wear and tear and should these spots be repaired? Is there any approved tape for these like the big boys?
Also is there any greasing that pilots need to do regularly on these or any other maintenance that you guys do?
I went to wax my main rotors as suggested by Sharkeys and saw some pretty heavy nicks on the leading edge like a layer of aluminum was peeling. I have posted some photos here www.dahome.net/enstrom.htm
Is this normal wear and tear and should these spots be repaired? Is there any approved tape for these like the big boys?
Also is there any greasing that pilots need to do regularly on these or any other maintenance that you guys do?
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email Enstrom and ask them for the procedure for attaching the latest blade tape. It is far superior to earlier tapes. Have a look at SIL 172.
http://www.enstromhelicopter.com/wp-...03/SIL0172.pdf
http://www.enstromhelicopter.com/wp-...03/SIL0172.pdf
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I read that, but I also read some horror stories of tape coming loose or tearing. I don't think I am in an environment that would require tape, but I am wondering if the wear on mine is normal and all that is needed is some sanding and polishing. I tried some emery cloth and it smoothed out the edges then I tried a polishing stone on some of it. I've never seen aluminum flake or peal in layers like this. Is the leading edge made up of laminated layers of aluminum? Roger did say the trailing edge is more important than the leading edge. He said to make sure the trailing edge is waxed and they have found a gain of over 2 inches less manifold pressure to hover.
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Here's another ignorant set of questions.
Regarding the fuel/oleo measuring stick. I'm a bit confused. Since the tanks are connected is the reading on the stick total fuel or just the fuel in that tank. Are we suppose to top both tanks to the neck for the 40 gallons?
On the oleo measurement: Mine has the extensions installed and a boot so I can't see the red line spoken of in the pilot manual. What is a fairing bump as written on the stick? How do you use the stick to measure the oleos? I assume center of attachment bolts. What should I be seeing?
I also didn't get a response to the daily maintenance. The manual says to keep the machine greased, but it doesn't go into details. Do you grease the main and tail rotors regularly and if so how much and what grease?
I worked on my door latches a little bit so they couldn't come open in flight. Why in the world did they angle the latch so all it takes is a good tug to slip past and open the door. Locking the doors is useless when left on the ramp for any reason.
Regarding the fuel/oleo measuring stick. I'm a bit confused. Since the tanks are connected is the reading on the stick total fuel or just the fuel in that tank. Are we suppose to top both tanks to the neck for the 40 gallons?
On the oleo measurement: Mine has the extensions installed and a boot so I can't see the red line spoken of in the pilot manual. What is a fairing bump as written on the stick? How do you use the stick to measure the oleos? I assume center of attachment bolts. What should I be seeing?
I also didn't get a response to the daily maintenance. The manual says to keep the machine greased, but it doesn't go into details. Do you grease the main and tail rotors regularly and if so how much and what grease?
I worked on my door latches a little bit so they couldn't come open in flight. Why in the world did they angle the latch so all it takes is a good tug to slip past and open the door. Locking the doors is useless when left on the ramp for any reason.
Enstrom 280FX registration SP-GMB crashed Saturday in Poland with the tragic loss of both aboard.
W Wielkopolsce rozbi? si? Enstrom 280FX - Altair Agencja Lotnicza
W Wielkopolsce rozbi? si? Enstrom 280FX - Altair Agencja Lotnicza
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Enstrom quirks and advice
For new Enstrom owners and prospective owners.
As a 6000 hour Enstrom type experienced pilot with ownership going back to the mid 1970s, I thought I might be able to help with some of the various vagaries of Enstrom type ownership threaded above.
Rotor Blades: Yes, many of the earlier MR blades suffered various problems. The leading edge 'flaking' mentioned above is called 'exfoliation' being a form of inter-granular corrosion. The factory stainless steel leading edge tape is a good preventative as is the earlier 3Ms polyeurothene (spelling!) tape. Best applied in short lengths so that the offending portion can be removed easily. IF the tape comes adrift in flight, yes it can cause a fierce vibration and the fix is simply to land and remove the tape. Only happened to me twice in 40 years and both times following continued flight in heavy rain. The factory service letter does allow leading edge re-profiling iaw the factory approved figures. Currently there is no fix for long (over 3 inches) leading edge voiding ... Neither is trailing edge bond separation repairable although I have seen rivet repairs which are not approved in CAA land. If in doubt ask your local AME about the 'tap test' for rotor blade serviceability.
Overheating: The Lycoming 360 is nicely cowled but in older engines with poor mixture set up will often overheat in prolonged, high power hovers at highish ambient temperatures. I think there is a fix by having two oil coolers. Due to cowling the problem is self perpetuating so as the temps get higher, they tend to progress in that direction. In fact in prolonged hover training, it is often necessary to move into a short period of forward flight to bring the CHT and oil temps down.
Mixture: The numbers provided above are OK, but special mention has to be made of the best EGT indications. The Lycoming E series turbo engine (280/28C models) produce the best power at 1550 degrees with 1650 allowing the best economy setting and thus range. Mixtures should only be leaned at MAP less than 29 hg. OR to 130 lbs per hour if indicating above that fuel flow. I teach leaning using the mixture vernier control at 28 MAP to give 85-90 lbs per hour. Normal when full rich can be anything up to 130 lbs per hour so a 40 lbs per hour fuel save is possible. (a little over 5 UK gallons!) and at the UK price of £2 per litre we are talking about a saving of £40-45 an hour!!!
Here's a thing to try. Set the Enstrom at 28 MAP, and accurately trimmed to straight & level, mixture full rich. Now lean as above. Observe the fuel flow reduction, the rotor rpm INCREASE and ditto the ASI by around 5 mph. A graphic indication of the mixture leaning requirement. BUT to new pilots NO LEANING until properly briefed by a qualified and experienced instructor.
Remember the boost light is there as an ' attention getter' to remind the pilot he is approaching the max 36.5 MAP boost figure.
Lamiflexs: When flying is done ... Never just dump the lever and go off for the weekend. This places a pitch 'set' on the M/R lamiflex bearing which hastens their demise and they come in at circa $1800 a copy. (three required!) Have the collective lever raised and locked in an approximate flying position to relieve the bearing load. Caution, new pilots might attempt to start on the next sortie with the lever half up. (pre start checks!)
I like the type. Good looking, spacious cabin - over 5 feet wide, relatively fast (100 mph cruise at 11 gph) quiet, stable and can be trimmed to fly 'hands & feet off' ... three seats, a 60- to 100lb, 7 cu ft dedicated luggage locker ... autorotates almost as good as the old Jetbanger, and especially safe. There has never been a fatality in the UK on the type in over 45 years of operation. Due to the large keel surface area, I've landed the Shark safely on two occasions following T/R failure where the left hand control cable was snipped by the up going T/R blade. And once when the T/R drive shaft sheared. BUT I've never had a mechanical engine failure in some 6000 type hours. (14,650 in total rotary) One might be forgiven for asking why any one buys anything else! (only half-joking) And some of you will know, the type is near aerobatic!
I'm happy to answer any specific questions by PM, but the real answer is to make a good type experienced engineer and ditto a FI your new best friends.
Happy and safe flying to all Enstrom pilots on here. Sincerely. Dennis Kenyon.
As a 6000 hour Enstrom type experienced pilot with ownership going back to the mid 1970s, I thought I might be able to help with some of the various vagaries of Enstrom type ownership threaded above.
Rotor Blades: Yes, many of the earlier MR blades suffered various problems. The leading edge 'flaking' mentioned above is called 'exfoliation' being a form of inter-granular corrosion. The factory stainless steel leading edge tape is a good preventative as is the earlier 3Ms polyeurothene (spelling!) tape. Best applied in short lengths so that the offending portion can be removed easily. IF the tape comes adrift in flight, yes it can cause a fierce vibration and the fix is simply to land and remove the tape. Only happened to me twice in 40 years and both times following continued flight in heavy rain. The factory service letter does allow leading edge re-profiling iaw the factory approved figures. Currently there is no fix for long (over 3 inches) leading edge voiding ... Neither is trailing edge bond separation repairable although I have seen rivet repairs which are not approved in CAA land. If in doubt ask your local AME about the 'tap test' for rotor blade serviceability.
Overheating: The Lycoming 360 is nicely cowled but in older engines with poor mixture set up will often overheat in prolonged, high power hovers at highish ambient temperatures. I think there is a fix by having two oil coolers. Due to cowling the problem is self perpetuating so as the temps get higher, they tend to progress in that direction. In fact in prolonged hover training, it is often necessary to move into a short period of forward flight to bring the CHT and oil temps down.
Mixture: The numbers provided above are OK, but special mention has to be made of the best EGT indications. The Lycoming E series turbo engine (280/28C models) produce the best power at 1550 degrees with 1650 allowing the best economy setting and thus range. Mixtures should only be leaned at MAP less than 29 hg. OR to 130 lbs per hour if indicating above that fuel flow. I teach leaning using the mixture vernier control at 28 MAP to give 85-90 lbs per hour. Normal when full rich can be anything up to 130 lbs per hour so a 40 lbs per hour fuel save is possible. (a little over 5 UK gallons!) and at the UK price of £2 per litre we are talking about a saving of £40-45 an hour!!!
Here's a thing to try. Set the Enstrom at 28 MAP, and accurately trimmed to straight & level, mixture full rich. Now lean as above. Observe the fuel flow reduction, the rotor rpm INCREASE and ditto the ASI by around 5 mph. A graphic indication of the mixture leaning requirement. BUT to new pilots NO LEANING until properly briefed by a qualified and experienced instructor.
Remember the boost light is there as an ' attention getter' to remind the pilot he is approaching the max 36.5 MAP boost figure.
Lamiflexs: When flying is done ... Never just dump the lever and go off for the weekend. This places a pitch 'set' on the M/R lamiflex bearing which hastens their demise and they come in at circa $1800 a copy. (three required!) Have the collective lever raised and locked in an approximate flying position to relieve the bearing load. Caution, new pilots might attempt to start on the next sortie with the lever half up. (pre start checks!)
I like the type. Good looking, spacious cabin - over 5 feet wide, relatively fast (100 mph cruise at 11 gph) quiet, stable and can be trimmed to fly 'hands & feet off' ... three seats, a 60- to 100lb, 7 cu ft dedicated luggage locker ... autorotates almost as good as the old Jetbanger, and especially safe. There has never been a fatality in the UK on the type in over 45 years of operation. Due to the large keel surface area, I've landed the Shark safely on two occasions following T/R failure where the left hand control cable was snipped by the up going T/R blade. And once when the T/R drive shaft sheared. BUT I've never had a mechanical engine failure in some 6000 type hours. (14,650 in total rotary) One might be forgiven for asking why any one buys anything else! (only half-joking) And some of you will know, the type is near aerobatic!
I'm happy to answer any specific questions by PM, but the real answer is to make a good type experienced engineer and ditto a FI your new best friends.
Happy and safe flying to all Enstrom pilots on here. Sincerely. Dennis Kenyon.
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Thank you Dennis for your input. It is very valuable to new inexperienced Enstrom owners like myself.
I've been told I can sand the exfoliated areas on the main rotors and then primer them. With these heavy blades how much material removal will effect the balance and tracking? In my research of exfoliation I assume that if I can peel the flakes of aluminum with my fingernail the corrosion is already done and I should sand to where no more can be flaked off by my fingernail. So far it appears like only a small layer is affected. I was told by Pablo at Heliblade to not try to remove the corrosion just sand it smooth. What do I do with the divets left by the exfoliation? I think I have this right, please advise. I plan on sanding smooth and using LPS3 for now to stop the corrosion then later on Alumi-prep it then apply epoxy polyamide primer then possible sandable primer then urethane. I'm sure that much painting may effect the balance, but it will be done on all 3. I don't have anyone near that can balance and track so I'm kind of stuck. Any experience with the Dynavibe? I can't afford $8k plus for a Chadwick.
I've been told I can sand the exfoliated areas on the main rotors and then primer them. With these heavy blades how much material removal will effect the balance and tracking? In my research of exfoliation I assume that if I can peel the flakes of aluminum with my fingernail the corrosion is already done and I should sand to where no more can be flaked off by my fingernail. So far it appears like only a small layer is affected. I was told by Pablo at Heliblade to not try to remove the corrosion just sand it smooth. What do I do with the divets left by the exfoliation? I think I have this right, please advise. I plan on sanding smooth and using LPS3 for now to stop the corrosion then later on Alumi-prep it then apply epoxy polyamide primer then possible sandable primer then urethane. I'm sure that much painting may effect the balance, but it will be done on all 3. I don't have anyone near that can balance and track so I'm kind of stuck. Any experience with the Dynavibe? I can't afford $8k plus for a Chadwick.
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Oleo question
I understand if the oleo pressures on the skids aren't correct it is a good reason for the severe ground rock. When I ran up to check the new Tempest plugs I almost rocked off the platform and moved the platform about a foot. I can't see the oleos because there are what are suppose to be clear dust boots added on, but they turned semi-opaque yellow. The measuring stick doesn't make sense to me because extenders are also installed. So I'm not sure if my oleos are correct. When I pull down on the tail the rear oleos collapse, but don't spring back up and when I get into the cabin none of the oleos move. Should they? What is your advise for pressures with just me mostly, 220 lbs, full fuel, and occasional passenger? When I pull on the tail should the front oleos move?
Last edited by lvflyer; 16th Mar 2015 at 22:49.
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Email Enstrom for the pressures to set them to. Also if it is rocking on the ground your main rotor head dampers may well need bleeding as this can cause the aircraft to rock on the ground as well.
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I emailed Bayard at Enstrom a couple days ago and no response so far. He posted on M1 that he had written up a guidline. I'll have to learn how to bleed the dampers, but I would think the "qualified expert mechanic" that was working on this would have done this when he replaced the lamiflex bearings less than an hour flight time ago. But it wouldn't surprise me if he didn't. They claim that they got .01ips after replacing the bearings though. Should the oleos be springly like a shock absorber or just take a set and stay there? Like I said I can collapse the rear ones by pulling down on the tail and then return them by pushing up, but they don't take a set by themselves and the front ones don't move in or out when doing that?
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Most piston Enstrom's do rock on the ground, it when its stop's most worry.
The Enstrom does not normally suffer from ground resonance, the main problem as previously stated is unequal spacing of the blades due to the dampers, which when the shock absorbers are not equal as well just gets the old girl all excited, run it up as its says in the flight manual and just try if you can to hover her.
90% of Enstrom's if the track etc ok go smooth once the aerodynaimc force's take over, just don't loiter at flight idle on the ground.
Plus get someone to look after her, who has looked after Enstrom's before, a bit of TLC goes along way on them, but they need regular pampering to get the best out of them.
Its no good putting them in the corner and bringing them out once a month.
The Enstrom does not normally suffer from ground resonance, the main problem as previously stated is unequal spacing of the blades due to the dampers, which when the shock absorbers are not equal as well just gets the old girl all excited, run it up as its says in the flight manual and just try if you can to hover her.
90% of Enstrom's if the track etc ok go smooth once the aerodynaimc force's take over, just don't loiter at flight idle on the ground.
Plus get someone to look after her, who has looked after Enstrom's before, a bit of TLC goes along way on them, but they need regular pampering to get the best out of them.
Its no good putting them in the corner and bringing them out once a month.
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So do you pilots check the oleo pressures yourself and adjust if needed? With what equipment. I notice they have nitrogen tire fill kits at auto parts stores now. Is that something we can use with one of the oleo pumps? I tried a heavy duty truck inflation gauge to see if there was any pressure in the oleos and it seemed to either not engage the stem or it didn't register any pressure. Is there a special gauge?
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Yeh don't have one around here with the tools. I flew it today and it is most definitely the oleos. You tell me. Shook hard right before hover off of landing pad. Moved to pavement and it shook a little less on set down and pick up. Moved to grass and shook very little. I also tried a nose high pick up and it settled down as soon as I pulled the cyclic back when light on the skids. I'm pretty sure that is indicative of the oleos not at the correct pressures. I did go ahead, at the advice of a blade shop, take 120 grit on an orbital and got rid of most of the exfoliation. Enstrom manual said exfoliation is common and it does not effect anything structural as long as it isn't severe. That is why they advise installing the stainless tape. I don't think I want to do that in the middle of the states. This was minor to moderate and only effected a thin layer. As I worked it more and more flaked off so I'm assuming those bonds were already shot. I don't feel any more unbalance then when I began so I surmise the amount of material that needed to come off was no more than flying through a sworm of insects. I put a coat of LPS3 on it for the time being so I can watch and see if the corrosion has stopped. If it has I'll go ahead and etch, prime, and paint. The mechanic and last owner should never have allowed it to get this far. I also installed Tempest plugs and it runs a lot smoother. I don't know what to expect for power, but with full tanks and 10 knot wind I was able to hover with me by myself, 220lbs, at 28" to 29". Is that about right?