X-Virus-Scanned: clean according to Sophos on Logan.com X-PolluStop-Diagnostic: \eX-PolluStop-Score: 0.00\eX-PolluStop: Scanned with Niversoft PolluStop 2.1 RC1, http://www.niversoft.com/pollustop Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c4) with ESMTP id 863348 for flyrotary@lancaironline.net; Sat, 09 Apr 2005 17:10:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.res.rr.com [24.74.185.127]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j39L9N0W018124; Sat, 9 Apr 2005 17:09:25 -0400 (EDT) Message-ID: <001301c53d48$6fb3ef50$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Cc: "Butch Diaz" Subject: No Joy on Sun & Fun{:<( Date: Sat, 9 Apr 2005 17:09:36 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C53D26.E84ED820" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C53D26.E84ED820 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Folks, for those of you who I hoped to meet at Sun & Fun this year, its = not going to happen. =20 Story follows: After the sun broke through the early AM clouds, I launched at 1000 and = found myself with a tail wind (unbelievable). I started a 500 fpm slow = climb to stay under Bravo airspace and reached 7000 MSL about 20 miles = or so on top of a overcast (clear on the other side), when the fun = started. The first indication was a difference in the engine sound, then I = noticed the EGT on the rear rotor dropping. #&%^@ spark Plug SAG was my = initial thought - but, I had just put in 4 new B9EQV spark plugs the = previous day. Then as things continued to develop (like EGT went to min = 1200F) I noticed that the EGT (which normally only drops 300F) was at = effectively zero (or bottom of meter at 1200F). Well, as Tracy has = mentioned pulling back on the power generally helps, so I did - no joy. = Tried switching off primary and secondary injectors (alternatively of = course) still no improvement. By this time I had begun a 180 deg turn = (into a now headwind). I tried varying the mixture control - switched fuel tanks in case I = picked up bad fuel in one tank (see I do learn) - fuel pressure was 43 = psi (nominal), oil pressure was 70 psi (nominal), Oil temp was down to = 160F, coolant was also down to 160F ( a bit low). Indicating that = perhaps less power was being produced. The aircraft was now vibrating = with the characteristic one-rotor-running vibration. Altitude was down = to 6500 MSL, but I was making no attempt to hold altitude. Finally can = see ground beneath, home base still 50 miles away. Situation is = continuing to deteriorate, I have increased fuel flow to 14 gph just to = maintain 5000 rpm. A fuel flow of below 12 gph and the engine starts = to unwind as if it is going to stop.=20 Now I noticed that EGT on rotor number one is coming down to around = 1500F. Clearly not Sparkplug SAG. Because of the high fuel flow I = though perhaps I had a fuel problem even though pressure was OK. I had = also switched fuel tanks, just in case on tank was bad. Engine is = clearly losing power progressively. I still had 6000 MSL and was = thinking about getting home, but then decided that going into the = headwind I would have very little glide (ground path) and there were no = airfield down wind of me anywhere within 40 miles. I decided to divert to Lancaster ,SC airport (cross wind) as it was the = closest and had a 6000 ft runway - plus I could see it off my left wing. = On the way, down I thought about turning off the engine to preserve any = remaining engine power in case I needed it to make the runway. THEN! I = remember saying so many time, that despite damage - so long as a rotary = is RUNNING, it will stay running - but, if you turned it off you would = probably never get it started again. I quickly switched the injectors = back on while the prop was still windmilling and the engine caught and = fired back up. Actually had 3000 ft when I arrived over the airfield, = so would probably have made it with the engine stopped. Landing was = uneventfully and I turned off on the taxi way with the engine still = running. I notice that it took almost full throttle just to make the = aircraft taxing up a the small incline to the terminal. Got parked, uncowled and could find no evidence of anything amiss - but, = clearly I was not going any further in the air this day. Then I grabbed the prop and pulled it through - no evidence of = compression on any of the six rotor faces! It will be a day or two before I can get the engine off and torn down to = determine the cause of the problem but here are my two candidates in no = particular order other than the sequence in which they occurred to me. THIS IS PRELIMINARY, so stand by for corrections after I open the engine = up. Candidate one (my initial thought) - the new style B9EQV spark plugs = electrodes stuck too far down into the combustion chamber and all six = apex seals got clipped. However, if this were the cause, you would have = though that my several full throttle runup the day before Or early in my = max power climb it would have happened. Why did it wait until 70-80 = miles down the road - took that long for heat expansion to elongate the = plug sufficiently to clip the apex seals? Hard to believe, but I guess = it possible. These are colder plugs so would stay cooler longer But, I = would have expected that if this were the cause, the effective would = have been immediate or very soon after take off.. Candidate two. I installed the plastic plenum several days ago and have = had a number or WOT runs on the ground, but this was the first flight. = Recall, thought, I have flown with plastic plenums for a number of = hours on previous iterations of intake systems (three intakes to be = precise). There is a 3/8" wall of plastic separating the primary and = secondary runners inside this plenum. This wall divides the two runners = from each other . When the TB is wide open the throttle plate edge is = at that divider and parallel to it. To improve airflow I had sanded = that divider at the throttle body to a thinner front edge (a 3/8" blunt = wall would hurt airflow). The thought occurs that perhaps this had = disintegrated and been ingested causing the damage (those powerful FAW = pulses). This would account for the problem not happening immediately = and after the climb to 7000 MSL. I examined the engine and the exterior = surface of the plenum and there was no evidence of cracks, etc. = However, it did not occur to me at the time, while waiting for the wife = to drive 50 minutes to get me, to take off the air flow tube to examine = the internal condition of the plenum, will do that tomorrow.=20 Candidate three??? Any other thoughts before I tear it down and end the = mystery?? Oh, to complete the picture with local color, the local airport manager = suggested that I remove my radios - I asked why? Well it turns out = they had theft of such a week before (just GREAT!). So pulled all the = electronic gear, even took my seat cushions home with me. While = removing the radios - guess who drives up - nope not the wife, yep!, the = county's local detective assigned to the theft case and asks me what I = am doing - well, removing radios, of course. But, all ends well and I = don't get hauled to jail on top of everything else {:>) So again, my disappointment in not getting to see many of you down = there. Fix it up and fly down Tuesday you say? Well, even if there = were no serious damage to housings or rotor (I should be so lucky), the = guy who sell the apex seal I would use - is down in Florida - at Sun & = Fun I do believe {:>). I have already talked with Tracy and told him of my sparkplug theory, = but I now have to give equal (if not more weight) to disintegrating = plenum. But, once again, I am amazed at the damage a rotary engine will = take and continue to produce power. Here both rotors were damaged -not = just one - and yet I could still manage, at its lowest 3000 rpm) - = probably enough power to keep my RV and me airborne in a long glide to = home (but why chance it when things could get worst). Besides the = prospect of having to make a go-a-round if I misjudged the approach to = our narrow 2200 ft runway was not appealing - 6000ft was better. Well, like I always say anything that wants to break on the ground if = just fine with me. Any thing that wants to break in the air - so long = as it gets me safely back to an airpatch (before dying completely) - is = also just fine with me. =20 My story for the day, now where did I put that bottle of Whiskey? Best Regards Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ------=_NextPart_000_0010_01C53D26.E84ED820 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Folks, for those of you who I hoped to = meet at Sun=20 & Fun this year, its not going to happen. 
 
Story follows:
 
After the sun broke through the early = AM clouds, I=20 launched at 1000 and found myself with a tail wind (unbelievable).  = I=20 started a 500 fpm slow climb to stay under Bravo airspace and reached = 7000 MSL=20 about 20 miles or so on top of a overcast (clear on the other side), = when the=20 fun started.
 
The first indication was a difference = in the engine=20 sound, then I noticed the EGT on the rear rotor dropping.  = #&%^@ spark=20 Plug SAG was my initial thought - but, I had just put in 4 new B9EQV = spark plugs=20 the previous day.  Then as things continued to develop (like EGT = went to=20 min 1200F) I noticed that the EGT (which normally only drops 300F) was = at=20 effectively zero (or bottom of meter at 1200F).  Well, as Tracy has = mentioned pulling back on the power generally helps, so I did  - no = joy.  Tried switching off primary and secondary injectors = (alternatively of=20 course) still no improvement.  By this time I had begun a 180 deg = turn=20 (into a now headwind).
 
I tried varying the mixture = control  -=20 switched fuel tanks in case I picked up bad fuel in one tank (see I do = learn)=20  - fuel pressure was 43 psi (nominal), oil pressure was 70 psi = (nominal),=20 Oil temp was down to 160F, coolant was also down to 160F ( a bit=20 low). Indicating that perhaps less power was being produced. =  The=20 aircraft was now vibrating with the characteristic one-rotor-running=20 vibration.   Altitude was down to 6500 MSL, but I was making = no=20 attempt to hold altitude.  Finally can see ground beneath, home = base still=20 50 miles away.  Situation is continuing to deteriorate, I have = increased=20 fuel flow to 14 gph just to maintain 5000 rpm.  A fuel flow = of below=20 12 gph  and the engine starts to unwind as if it is going = to=20 stop. 
 
Now I noticed that EGT on rotor number = one is=20 coming down to around 1500F.  Clearly not Sparkplug SAG.  = Because of=20 the high fuel flow I though perhaps I had a fuel problem even though = pressure=20 was OK.  I had also switched fuel tanks, just in case on tank was=20 bad.  Engine is clearly losing power progressively.  I still = had 6000=20 MSL and was thinking about getting home, but then decided that going = into the=20 headwind I would have very little glide (ground path) and there were no = airfield=20 down wind of me anywhere within 40 miles.
 
I decided to divert to Lancaster ,SC = airport (cross=20 wind) as it was the closest and had a 6000 ft runway - plus I could see = it off=20 my left wing.  On the way, down I thought about turning off the = engine to=20 preserve any remaining engine power in case I needed it to make the=20 runway.  THEN! I remember saying so many time,  that despite = damage -=20 so long as a rotary is RUNNING, it will stay running - but, if you = turned it off=20 you would probably never get it started again.  I quickly switched = the=20 injectors back on while the prop was still windmilling and the engine = caught and=20 fired back up.   Actually had 3000 ft when I arrived over the=20 airfield, so would probably have made it with the engine stopped.  = Landing=20 was uneventfully and I turned off on the taxi way with the engine still=20 running.  I notice that it took almost full throttle just to make = the=20 aircraft taxing up a the small incline to the terminal.
 
Got parked, uncowled and could find no = evidence of=20 anything amiss - but, clearly I was not going any further in the air = this=20 day.
Then I grabbed the prop and pulled it = through - no=20 evidence of compression on any of the six rotor faces!
 
It will be a day or two before I can = get the engine=20 off and torn down to determine the cause of the problem but here are my = two=20 candidates in no particular order other than the sequence in which they = occurred=20 to me.
 
THIS IS PRELIMINARY, so stand by for = corrections=20 after I open the engine up.
 
Candidate one (my initial thought) =  - the new=20 style B9EQV spark plugs electrodes stuck too far down into the = combustion=20 chamber and all six apex seals got clipped.  However, if this were = the=20 cause, you would have though that my several full throttle runup = the day=20 before Or early in my max power climb it would have happened.  Why = did it=20 wait until 70-80 miles down the road - took that long for heat expansion = to=20 elongate the plug sufficiently to clip the apex seals?  Hard to = believe,=20 but I guess it possible. These are colder plugs so would stay cooler=20 longer  But, I would have expected that if this were the cause, the = effective would have been immediate or very soon after take = off..
 
Candidate two.  I installed the = plastic plenum=20 several days ago and have had a number or WOT runs on the ground, but = this was=20 the first flight.  Recall, thought,  I have flown with plastic = plenums=20 for a number of hours on previous iterations of intake systems (three=20 intakes to be precise).  There is a 3/8" wall of plastic = separating=20 the primary and secondary runners inside this plenum.  This wall = divides=20 the two runners from each other .  When the TB is wide open the = throttle=20 plate edge is at that divider and parallel to it.  To=20 improve airflow I had sanded that divider at the throttle body to a = thinner=20 front edge (a 3/8" blunt wall would hurt airflow).   =  The=20 thought occurs that perhaps this had disintegrated and been ingested = causing the=20 damage (those powerful FAW pulses).  This would account for the = problem not=20 happening immediately and after the climb to 7000 MSL.  I examined = the=20 engine and the exterior surface of the plenum and there was no evidence = of=20 cracks, etc.  However, it did not occur to me at the time, while = waiting=20 for the wife to drive 50 minutes to get me, to take off the air flow = tube to=20 examine the internal condition of the plenum, will do that=20 tomorrow. 
 
Candidate three???  Any other = thoughts before=20 I tear it down and end the mystery??
 
 
Oh, to complete the picture with local = color,=20  the local airport manager suggested that I remove my radios - I = asked=20 why?  Well it turns out  they had  theft of such a week = before=20 (just GREAT!).  So pulled all the electronic gear, even took my = seat=20 cushions home with me.  While removing the radios - guess who = drives up -=20 nope not the wife, yep!, the county's local detective assigned to the = theft case=20 and asks me what I am doing - well, removing radios, of course.  = But, all=20 ends well and I don't get hauled to jail on top of everything else=20 {:>)
 
So again, my disappointment in not = getting to see=20 many of you down there.  Fix it up and fly down Tuesday you = say? =20 Well, even if there were no serious damage to housings or rotor (I = should be so=20 lucky), the guy who sell the apex seal I would use - is down in = Florida -=20 at Sun & Fun I do believe {:>).
 
  I have already talked with Tracy = and told=20 him of my sparkplug theory, but I now have to give equal (if not more = weight) to=20 disintegrating plenum. But, once again, I am amazed at the damage a = rotary=20 engine will take and continue to produce power.  Here both rotors = were=20 damaged -not just one - and yet I could still manage, at its lowest = 3000=20 rpm) - probably enough power to keep my RV and  me airborne in = a long=20 glide to home (but why chance it when things could get worst).  = Besides the=20 prospect of having to make a go-a-round if I misjudged the approach to = our=20 narrow 2200 ft runway was not appealing - 6000ft was = better.
 
Well, like I always say anything that = wants to=20 break on the ground if just fine with me.  Any thing that wants to = break in=20 the air - so long as it gets me safely back to an airpatch (before dying = completely) -  is also just fine with me. 
 
My story for the day, now where did I = put that=20 bottle of Whiskey?
 
Best Regards
 
Ed
 
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com
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