Enstrom Corner

[FSXPilot]

The aircraft is designed in such a way that failure of the boost pump will not impede fuel flow. The engine driven pump can deliver all the fuel you need. Is there any chance the stutter was caused by oiled plugs?

[lvflyer]

Well I'm not sure. I know when the boost pump was on I didn't have any hesitation. Also the mag check was fine. Next time I get a chance to fly I'll see if it runs on the engine driven pump only.

[CO280fx]

Question

Dirk,
Question: Have you had any instruction in your machine from a pilot with Enstrom experience?

Regarding the boost pump- What do you mean when you say you did the runup without boost pump "as directed"? The engine driven fuel pump does not supply sufficient pressure at idle to keep the engine running smoothly in hotter temps. The fuel injected turbocharged engine is prone to vapor locking. Run the boost pump.

[lvflyer]

The warmup checklist says to do so with the boost off to verify the engine driven pump is working correctly and then the pre departure checklist says to turn boost on. Just following directions. So I take it when it is warmed up the engine driven pump will not produce enough fuel for a turboed engine? I do notice on cool down if I turn the boost off it will backfire more than normal.

[flylow]

Originally Posted by CoO280fx

Question: Have you had any instruction in your machine from a pilot with Enstrom experience?

I've been wondering the same thing!

[lvflyer]

The answer to that has to be No since the former owner of 7 years did not follow proper procedures and was unaware anything wasn't right. There are no experienced Entrom pilots or mechanics around here. I can't even get an instructor to give me dual in my own Enstrom if I travel to them a distance because I don't have insurance and I can't get reasonable insurance without getting dual. I'm not interested in renting another Enstrom to satisfy that need since the flying characteristics of my Enstrom is what I want to learn and practice on. On another note I checked out the engine driven pump today. Just taxied over for fuel and I did so on the engine driven pump only without any problems. After fueling with engine warm I noticed a lot of backfiring and hesitation with just the engine pump on at low RPM, but when increased to over 2000 RPM it was smooth. In addition I checked the fuel flow indication with and without the boost pump and there was no change. So my conclusion is when warm the engine requires more fuel than the engine driven pump puts out at idle, but the pump produces plenty at higher RPMs. I was just concerned that I didn't have any redundancy and had to rely on the boost pump or the engine pump was failing, but that is not the case. Also in reading the start up checklist it says to leave the boost pump off when running up for the first cold start of the day. So after a fuel stop I guess it is normal for the engine driven pump to not be sufficient for runup.

[lvflyer]

Update on my previous thread concerning the rotors turning without being engaged. In the middle of my first annual of this Enstrom I discovered the belt drive system was not rigged properly. It was so bad that any mechanic doing a proper annual would have seen problems had they removed the seat as required. For 7 years this helicopter was out of rigging on the collective as well as the belt drive engagement. As it was the belt could not be disengaged all the way because the clevis was actually hitting and cracking the shield around the engagement lever and, if you know anything about the rigging the top bracket was not parallel with the pylon as it should have been. The clearance between the threaded rod and the spacer was almost an inch when it should have been 1/16 to an 1/8. Obvious issues. Now we have to clean it all and test run it to see that in fact took care of the rotor continuing to turn at 100RPM at idle while disengaged.

I need some advice of some corrosion. Below are some pics of my rotor head. Other than just use some scotchbrite on the corrosion is there anything else I should do?



More pictures are available at www.dahome.net/enstrom.htm

[Deheli]

problems

Sounds like you are having some problems. The Enstrom is a good machine. I will be in IL in august. I would be willing to stop by possibly if you would like. I have both mechanical and flight experience in the Enstrom. PM me if you would like to talk futher.

[Ascend Charlie]

I assume because the winds from the right were not allowing air flow from the engine fan through the oil cooler.

Errrrmmm.... If you are flying in balance, it doesn't matter a rat's patootie whether you have a crosswind, tailwind or headwind, the relative airflow will always be coming from dead ahead. Same with your door popping open, if you are in balance, that shouldn't happen - assuming the door is rigged correctly. Judging by your comments, the previous owner just didn't take proper care of it.

But maybe I am biased, I detest every hour I flew in Enstroms.

[Gaseous]

Corrosion.

IV,

The degree of corrosion on your grips is not a cause for concern and is not unusual. Just clean it off. The grip spindles appear to have been cadmium plated from the factory but most older aircraft seem to have lost it. Cracking around the clutch lever stop is not unusual either. Keep an eye on it. Incorrect rigging of everything is common. I feel that is the reason lots of pilots like AC above have had bad experiences. Lots ARE horrid to fly.

Inaccurate rigging and incorrect main rotor blade chordwise centre of gravity appear to be the main culprits.

A well set up Enstrom is a joy to fly. Your attention to detail should get yours right eventually.

[lvflyer]

Regarding the cross wind. We were getting severe cross wind gusts in flight so the tail was swishing for sure. Every time we would get a big gust the wind came through the passenger door and applied pressure to the pilot door and pop wide open. Also the cross wind gusts were going right into the oil cooler outlet preventing the outward flow of air and the oil temp spiked. I had to crab out of the direction fo the gusts. It was a particularly lousy day.

I cleaned the rotor mast area and discovered the stain was actually cast off from the feathering nut and pin. I cleaned those up as much as I could and gave them a good coat of LPS2. I'll keep an eye on it from now on.

I think the rigging on the belt drive system is going to help a lot. The belt was not able to be disengaged fully, but there was still slack. Cleaning it up is going to help too now that I can get to it. I was told to spray it down with mineral spirits on everything in the engine compartment and drive belt area and let it dry. Any comments?

[Paul Cantrell]

Crosswinds...

Regarding the cross wind. We were getting severe cross wind gusts in flight so the tail was swishing for sure. Every time we would get a big gust the wind came through the passenger door and applied pressure to the pilot door and pop wide open. Also the cross wind gusts were going right into the oil cooler outlet preventing the outward flow of air and the oil temp spiked. I had to crab out of the direction fo the gusts. It was a particularly lousy day.

Like Ascend Charlie, I'm feeling a little puzzled about the whole gusty crosswind thing. If you were in cruise flight (even slow, like 60 MPH) a gusty crosswind isn't going to prevent the oil cooler from doing it's job. If the temperature was spiking, I think it's likely something else was going on. If you think about why the tail is twitching, it's because the natural weathercock stability the tail is providing (admittedly much less in an Enstrom than in other types) is trying to keep you in trim. When the wind gusts from the right, the tail is forcing the nose to the right to keep you in trim. When the gust subsides, the nose is being forced back in order to keep the aircraft in trim. In all of those cases, the airflow is still mostly from nose to tail and the oil cooler should be quite happy.

The door may be a different thing, but I suspect there's something else going on with the oil temperature. Especially given all the other things you've discovered rigged wrong with this aircraft...

I've been out in 45 knot gusts and never had an issue like you are describing... All my (Enstrom teaching) experience was in an F28A if it matters...

[lvflyer]

All I know is when I crabbed more into the wind the oil temp came down and the door didn't blow open. I have found the latches on the pilot door were not engaging properly. I don't know how, but the door latch on the frame was actually missing the whole about 1/8 inch to the top of it. I've adjusted the plate and filed the top a bit and now it latches if I pull up on the door as I pull it shut. I tried to let the heat in the hangar remold the doors so they close flush, but I have discovered there is no way for them to close flush due to the infrastructure on the inside of the door won't clear the door frame at the bottom. I've tried to adjust the hinge to get the door higher, but it still sticks out on the bottom. I'll just install some more weatherstrip in the areas where I can see light at the bottom. I'm curious if other's doors do not close flush at the bottom.

[Paul Cantrell]

High oil temps

All I know is when I crabbed more into the wind the oil temp came down

I don't doubt what you observed. I'm saying you don't need to fly an Enstrom out of trim in order to prevent high oil temperatures. I think you have a problem with the oil cooler that needs to be looked into.

BTW, Ascend Charlie: I loved flying the F28A. I think easier to touch-down than even the B206 (because of high inertia AND the oleos). Just not a very happy helicopter when sliding, but with that much inertia there's really not much reason to ever have to slide, even on a calm wind day.

The F28A was really underpowered (no hover on a hot summer calm day @ higher gross weights) but basically the best pickup truck I've ever hovered. (i.e. built like a tank, and weighs like one too!).

[CO280fx]

Doors

lvlflyer,
The 280 door design is not very good, the 28's latching mechanism is much better. You are dealing with 37 year old fiberglass and plastic which has warped over the years and no longer seats properly in the doorframe. The fiberglass holding the latching plates on the door has probably also weakened and is not firmly holding the latches in place. This is a common problem with the older 280s. I have flown two older 280s (1978 and 1980) whose doors never closed properly and would sometime pop open at high speeds, especially on hot days. Pops open like a gunshot and with the turbo exhaust screaming right behind you, it really drops your heart. No fun at all and the expectation is very stressful when it happens intermittently! You will probably have to rebuild the door and strengthen the inner frame and latching mechanism to eliminate the problem. A bandaid fix we've used is to rivet some strong fabric velcro to the doorframe and adhere the sticky hard piece to the inner side panel of the cabin. It is a crude but effective solution. Quirky machines they are but a real pleasure to fly when dialed in.

*edit* Also agree with others that crosswinds should have no effect on your oil temp. Keep digging...

[lvflyer]

Maybe I'm really anal about my aircraft maintenance, but I think this shows 7 years of neglect more than 7 years of care by "the best helicopter mechanic around here". What do you think? Found the transmission bolts loose and lots of RTV to cover it all up instead of just torque to SIL 0166 recommendations. Under cockpit floor and in engine bay and all skins show major neglect. Took hours to clean and will have to reapply zinc chromate to most panels and to many support tubes. Collective and belt drive not rigged properly. Main rotors never maintained and had bare aluminum exposure for the entire time, thus exfoliation. This is a mess, but won't be when I'm done. Here is link to what I discovered so far. www.dahome.net/enstrom.htm

[lvflyer]

500e I can't respond to your email. Answer no JL

[500e]

Thanks IVF answers question Thanks

[Dennis Kenyon]

Enstrom odds & Ends

As a few PPs will know, I'm an avid supporter of the Enstrom and even after 40 years associated with the type I still enjoy her handling.

The infamous 'fishtailing' really came about when the new sleeker shape was introduced in 1975. Greg Focella was the industrial designer who produced the sleeker 'nose job' which enhanced the types good looks. Greg was also responsible for the new nose on the MD500E. I expect you know a few years back the USA 'Fortune' magazine voted her the best designed product of the year.

I believe the longer nose when associated with the Dorsal & Ventral 'Shark' fin results in the airframe being over directionally stable about the normal axis. It is possible to fly out the random yawing, but over the years, I've just accepted the feature unless I'm flying passengers.

It says something for the type that the Shark is coming up for forty years and the one I'm flying now is still handling well and rotor vibration less than point one ips on the Vibrex.

And as a side note, and in 6,000 type hours I'd not experienced a power failure although my log book indicates around 5000 practice full stop autos. That was until a few weeks back when one cylinder let go on an airfield approach. The passenger wasn't even aware we'd made a 'no-engine' landing. That just one of the reasons I like the old girl. Regards to all. DRK

[lvflyer]

Dennis I think I speak for us all, thanks for all your contributions. I started writing prolifically about my experience so others can benefit. I'm not trying to voice opinions, just the facts. When I am done with this annual I hope to have it in better shape then when I started. I am still finding it real difficult to find zinc chromate to touch up the support tubes and inside panels. I'm tempted to just go with the Dupli-color self etching primer I can get at local Advance auto parts, which is zinc phosphate. I would like your input and others as well.