X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 928367 for flyrotary@lancaironline.net; Mon, 16 Jan 2006 09:46:25 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id k0GEjZfW016991 for ; Mon, 16 Jan 2006 09:45:37 -0500 (EST) Message-ID: <001b01c61aab$842ba360$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Anatomy of an almost crash. Date: Mon, 16 Jan 2006 09:45:37 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0018_01C61A81.9AF18260" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0018_01C61A81.9AF18260 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Dave, Really hated to hear about your troubles, but naturally glad to hear you = handle a very difficult situation well (no surprise there). Good airman = decision not to continue on when you had a viable alternative landing = area. Starting to infringe on my Rv-6 glider time record though {:>) I can certainly relate to the old "haste makes waste". I committed the = same sin when I was in a hurry to get my aircraft off a derelict airport = ( when I lost the apex seal last April). When I found the engine = difficult to turn over after the rebuild, I should have taken it apart = in my shop to find out why - I didn't - so ended up rebuilding it a = second time down in Louisiana in June. But, my coolant leak was between = combustion chamber and coolant galleys - so was relatively slow. Loss of coolant would, of course, cause both water temps and oil temps = to elevate - but, most of the time when you loose sufficient coolant the = coolant gauge actually starts to show a decrease in temperature because = there is no water to bathe the sensor and transfer heat to it. But with = the NPG replacing normal coolant mixtures and its high boiling point - = the system may have still been full of liquid (which would not have = boiled off because of this which would account for the temp not = decreasing on the gauge due to a loss of fluid. =20 A lost belt could account for coolant temps increase and therefore = forcing the oil temps up as well. It would also account for your loss = of electrical power from your alternator. It could explain why the = temps increased so suddenly - I would have expected a coolant leak to = lead to a slower build up of temps. But, not certain why that would = have caused your oil pressure to go to zero unless a flailing belt = possible disconnected an oil line. Oil drops on the exhaust might = account for the smoke puff. High oil temps does cause the oil pressure = to go down - but 200F should not have that much effect on oil pressure = as I've been there many times. But, you will find out the cause in short order - and naturally we are = all very interested. I don't envy you taking the wings off - a real pain in the butt. Good = luck, hope you find some help to get it home. Best Regards Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ----- Original Message -----=20 From: David Leonard=20 To: Rotary motors in aircraft=20 Sent: Monday, January 16, 2006 1:54 AM Subject: [FlyRotary] Anatomy of an almost crash. I had to set my RV-6 down on highway 395 near Bishop Tuesday, and here = is the story. Mostly things I could have done better, some that I did = right or otherwise got lucky. It is an RV6 tip up with a turbocharged = Mazda rotary engine.=20 I took the RV up to Mammoth to ski for the weekend. When I returned to = the plane Sunday evening I discovered a small puddle of coolant under = the engine. I had some concerns about the cold as my antifreeze had been = recently diluted with water when I had to make a field repair of a = coolant leak but I neglected to replace the antifreeze (big mistake #1). = I estimated 25/75 antifreeze/water and the temperatures were supposed to = be in the low 20's overnight. This I thought would be enough but I was = not sure. The puddle of coolant seemed to prove that overnight the temp = got low enough to freeze some coolant and crack something.=20 A quick look under the cowl failed to reveal the souce of the leak = other than it was not coming from the previously fixed coolant line or = anywhere other than the radiator itself. I didn't have time to trouble = shoot as I had to get home to be at work the next day.=20 I was able to hitch a ride home in another aircraft, then drive back = up the following evening after work. When I arrived at the airport at = 10pm the temperature was 3 deg F. In order to prevent any further = damage, I added some anti freeze and ran the engine for a while to = circulate it. When I left the airport at 11:30 pm the temperature was -3 = deg. This is obviously colder than I had expected and was probably = responsible for the damage. The temperature in town was 20 deg despite = the fact that town is higher in elevation. The only explanation I have = for the extreme low temp at the airport is temperature loss from = sublimation of the vast deep snow fields around the airport in the very = dry air (just a guess).=20 I arrived at sun-up the next morning (temp again 4 deg at airport but = 19 in town) and got to work on fixing the leak. After several engine = runs I determined that the leak was indeed coming from somewhere in the = radiator. There did not seem to be any coolant in the oil, but I = identified and fixed an oil leak in the turbo oil return line. Also, the = engine breather tube (which vents down in the gear leg) had frozen and = was causing the turbo to burn oil. That issue was fixed as well.=20 In order to temporize the radiator leak I decided to use a can of = radiator stop-leak and switch coolant to Evan's NPG. NPG is a pure = propylene glycol coolant that has a very high boiling temp and can = therefore be run with little or no coolant system pressure. I switched = out the coolant, added the stop-leak, and changed to a 7 psi radiator = cap. The stop-leak appeared to do it's job as there was no visible = continued leak after an hour of running the engine on the ground at fast = idle with some brief runs at higher RPM.=20 At about 2pm I was cold (temp at the airport now in the mid 20's) and = tired (had slept in the car overnight) but decided it was safe to make = the flight to Bishop - 27 miles away and 3000 feet lower. There I would = remove the cowl and give everything a good look. Since the coolant leak = had only lost about a quart in 3 days, was now sealed and would be flown = with low pressure I assumed the most I could loose in the 15 min flight = would be about a cup of coolant (Big mistake #2?)=20 The first 8 minutes of flight all systems were green. Then over the = course of a minute the coolant temp went up to over 280, oil temp up to = over 200 (the highest it has ever been). Being about half-way I decided = to continue to the lower Bishop airport. Then the alternator quit (buss = voltage dropped to 11.7 and battery showed a discharge). Then oil = pressure dropped to zero, followed shortly after by the engine stopping = to make power and a puff of smoke coming in into the cockpit thought the = heater vent (cowl air - not a heat muff).=20 It appeared as though I would be able to glide to the Bishop airport. = I was at 9000 feet. Bishop was 13 miles away at 4000 feet with no = significant winds. This distance is solidly within the typical glide = ratio of the RV6 so I calmly assumed there would be an easy dead-stick = onto the airport.=20 I tried to get the prop to stop windmilling by slowing. In my initial = flight testing I had been able to stop the prop from windmilling at = about 80 kts. However, even by slowing to 65kts IAS I was unable to stop = the windmilling. It turns out that overheating the engine had caused the = loss of compression on all rotor faces and this prevented me from = stopping the windmilling. I was seeing descent rates of 800-1000 fpm at = 90 KIAS and it soon became apparent that making the airport would be = sketchy at best, so I opted for a quality highway rather than try to = overfly the town to make the airfield.=20 I was able to spot a section of Hwy 395 that was 4-lane divided (no = opposing traffic) that also seemed to be free of turns, power lines and = intersections. I relayed my situation to the Bishop unicom and got a = prompt response. I turned off my fuel pump and in accordance with my = training turned off the master power on short final... Doh! I have all = electric flight instruments and now had no time to re-boot either of my = 2 air speed indicators.=20 My plan for traffic avoidance was to come in faster than typical = traffic speed, then bleed off that speed at 20 feet over the highway. = That way any traffic has plenty of time to see me and slow down while I = am bleeding off speed. Touchdown was uneventful and quite a relief. No = injury or damage.=20 The Bishop police were there within minutes, and 2 hours later the = plane was tied down at the Bishop airport. I had no time or desire to = remove the cowl so the cause is still very unclear. A loss of the = accessory belt would explain both the inability to cool and the loss of = the alternator, but my bet is still on something to do with the extreme = cold and radiator leak. I have to shamefully admit that time pressures = were a contributing factor. Feeling the need to return home, I probably = rushed the testing process after making repairs. I should have circled = Mammoth airport in order to test the repairs at high power before = attempting continued flight, especially in mountainous terrain (though = there is no freeway in SoCal that would be as forgiving as that section = of 395).=20 I plan to rent some kind of truck next weekend and drive up, remove = the wings, and bring the plane home. It will remain in our garage for = the next 8 months while I deploy to Iraq. (Suggestions or offers for use = of an adequate truck or trailer would be much appreciated). This will = also give me a chance to paint the plane and do a lot of the finishing = touches that will be easier to do at home than at the airport. Obviously = I will need to rebuild the engine as well, but that is a relatively = minor issue.=20 This was quite a learning experience I obviously hope I never have to = repeat. All things considered, I feel quite lucky that things turned out = so well. Lastly, I want to thank the Bishop Unicom, Police Dept, Highway = Patrol, Cal Trans, and Fire Department who were all very professional = and helpful. Also, thank you to the fellow RV6 owner was passing by and = took an hour and a half out of his day to drive back up to Mammoth and = get my car for me.=20 --=20 Dave Leonard Turbo Rotary RV-6 N4VY http://members.aol.com/_ht_a/rotaryroster/index.html http://members.aol.com/_ht_a/vp4skydoc/index.html ------=_NextPart_000_0018_01C61A81.9AF18260 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Dave,
 
Really hated to hear about your = troubles, but=20 naturally glad to hear you handle a very difficult situation well (no = surprise=20 there).  Good airman decision not to continue on when you had a = viable=20 alternative landing area.  Starting to infringe on my Rv-6 glider = time=20 record though {:>)
 
I can certainly relate to the old "haste makes=20 waste".  I  committed the same sin when I was in a hurry to = get my=20 aircraft off a derelict airport ( when I lost the apex seal last=20 April).  When I found the engine difficult to turn over after the = rebuild,=20 I should have taken it apart in my shop to find out why - I didn't = - so=20 ended up rebuilding it a second time down in Louisiana in June.  = But, my=20 coolant leak was between combustion chamber and coolant galleys - so was = relatively slow.
 
Loss of coolant would, of course, cause both = water temps=20 and oil temps to elevate - but, most of the time when you loose = sufficient=20 coolant the coolant gauge  actually starts to show a decrease = in=20 temperature because there is no water to bathe the sensor and = transfer heat=20 to it.  But with the NPG replacing normal coolant mixtures and its = high=20 boiling point - the system may have still been full of liquid (which = would not=20 have boiled off because of this which would account for the temp = not=20 decreasing on the gauge due to a loss of fluid. 
 
A lost belt could account for coolant temps = increase and=20 therefore forcing the oil temps up as well.  It would also account = for your=20 loss of electrical power from your alternator.  It could explain = why the=20 temps increased so suddenly - I would have expected a coolant leak = to lead=20 to a slower build up of temps.  But, not certain why that would = have caused=20 your oil pressure to go to zero unless a flailing belt possible = disconnected an=20 oil line. Oil drops on the exhaust might account for the smoke = puff.   High oil temps does cause the oil pressure to go down = - but=20 200F should not have that much effect on oil pressure as I've been there = many=20 times.
 
But, you will find out the cause in short order = - and=20 naturally we are all very interested.
I don't envy you taking the wings off - a real = pain in the=20 butt.  Good luck, hope you find some help to get it = home.
 
Best Regards
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.com
----- Original Message -----
From:=20 David=20 Leonard
Sent: Monday, January 16, 2006 = 1:54=20 AM
Subject: [FlyRotary] Anatomy of = an almost=20 crash.

I had to set my RV-6 down on highway 395 near Bishop Tuesday, and = here is=20 the story. Mostly things I could have done better, some that I did = right or=20 otherwise got lucky. It is an RV6 tip up with a turbocharged Mazda = rotary=20 engine.

I took the RV up to Mammoth to ski for the weekend. When I returned = to the=20 plane Sunday evening I discovered a small puddle of coolant under the = engine.=20 I had some concerns about the cold as my antifreeze had been recently = diluted=20 with water when I had to make a field repair of a coolant leak but I = neglected=20 to replace the antifreeze (big mistake #1). I estimated 25/75 = antifreeze/water=20 and the temperatures were supposed to be in the low 20's overnight. = This I=20 thought would be enough but I was not sure. The puddle of coolant = seemed to=20 prove that overnight the temp got low enough to freeze some coolant = and crack=20 something.

A quick look under the cowl failed to reveal the souce of the leak = other=20 than it was not coming from the previously fixed coolant line or = anywhere=20 other than the radiator itself. I didn't have time to trouble shoot as = I had=20 to get home to be at work the next day.

I was able to hitch a ride home in another aircraft, then drive = back up the=20 following evening after work. When I arrived at the airport at 10pm = the=20 temperature was 3 deg F. In order to prevent any further damage, I = added some=20 anti freeze and ran the engine for a while to circulate it. When I = left the=20 airport at 11:30 pm the temperature was -3 deg. This is obviously = colder than=20 I had expected and was probably responsible for the damage. The = temperature in=20 town was 20 deg despite the fact that town is higher in elevation. The = only=20 explanation I have for the extreme low temp at the airport is = temperature loss=20 from sublimation of the vast deep snow fields around the airport in = the very=20 dry air (just a guess).

I arrived at sun-up the next morning (temp again 4 deg at airport = but 19 in=20 town) and got to work on fixing the leak. After several engine runs I=20 determined that the leak was indeed coming from somewhere in the = radiator.=20 There did not seem to be any coolant in the oil, but I identified and = fixed an=20 oil leak in the turbo oil return line. Also, the engine breather tube = (which=20 vents down in the gear leg) had frozen and was causing the turbo to = burn oil.=20 That issue was fixed as well.

In order to temporize the radiator leak I decided to use a can of = radiator=20 stop-leak and switch coolant to Evan's NPG. NPG is a pure propylene = glycol=20 coolant that has a very high boiling temp and can therefore be run = with little=20 or no coolant system pressure. I switched out the coolant, added the=20 stop-leak, and changed to a 7 psi radiator cap. The stop-leak appeared = to do=20 it's job as there was no visible continued leak after an hour of = running the=20 engine on the ground at fast idle with some brief runs at higher RPM. =

At about 2pm I was cold (temp at the airport now in the mid 20's) = and tired=20 (had slept in the car overnight) but decided it was safe to make the = flight to=20 Bishop - 27 miles away and 3000 feet lower. There I would remove the = cowl and=20 give everything a good look. Since the coolant leak had only lost = about a=20 quart in 3 days, was now sealed and would be flown with low pressure I = assumed=20 the most I could loose in the 15 min flight would be about a cup of = coolant=20 (Big mistake #2?)

The first 8 minutes of flight all systems were green. Then over the = course=20 of a minute the coolant temp went up to over 280, oil temp up to over = 200 (the=20 highest it has ever been). Being about half-way I decided to continue = to the=20 lower Bishop airport. Then the alternator quit (buss voltage dropped = to 11.7=20 and battery showed a discharge). Then oil pressure dropped to zero, = followed=20 shortly after by the engine stopping to make power and a puff of smoke = coming=20 in into the cockpit thought the heater vent (cowl air - not a heat = muff).

It appeared as though I would be able to glide to the Bishop = airport. I was=20 at 9000 feet. Bishop was 13 miles away at 4000 feet with no = significant winds.=20 This distance is solidly within the typical glide ratio of the RV6 so = I calmly=20 assumed there would be an easy dead-stick onto the airport.

I tried to get the prop to stop windmilling by slowing. In my = initial=20 flight testing I had been able to stop the prop from windmilling at = about 80=20 kts. However, even by slowing to 65kts IAS I was unable to stop the=20 windmilling. It turns out that overheating the engine had caused the = loss of=20 compression on all rotor faces and this prevented me from stopping the = windmilling. I was seeing descent rates of 800-1000 fpm at 90 KIAS and = it soon=20 became apparent that making the airport would be sketchy at best, so I = opted=20 for a quality highway rather than try to overfly the town to make the=20 airfield.

I was able to spot a section of Hwy 395 that was 4-lane divided (no = opposing traffic) that also seemed to be free of turns, power lines = and=20 intersections. I relayed my situation to the Bishop unicom and got a = prompt=20 response. I turned off my fuel pump and in accordance with my training = turned=20 off the master power on short final... Doh! I have all electric flight = instruments and now had no time to re-boot either of my 2 air speed=20 indicators.

My plan for traffic avoidance was to come in faster than typical = traffic=20 speed, then bleed off that speed at 20 feet over the highway. That way = any=20 traffic has plenty of time to see me and slow down while I am bleeding = off=20 speed. Touchdown was uneventful and quite a relief. No injury or = damage.

The Bishop police were there within minutes, and 2 hours later the = plane=20 was tied down at the Bishop airport. I had no time or desire to remove = the=20 cowl so the cause is still very unclear. A loss of the accessory belt = would=20 explain both the inability to cool and the loss of the alternator, but = my bet=20 is still on something to do with the extreme cold and radiator leak. I = have to=20 shamefully admit that time pressures were a contributing factor. = Feeling the=20 need to return home, I probably rushed the testing process after = making=20 repairs. I should have circled Mammoth airport in order to test the = repairs at=20 high power before attempting continued flight, especially in = mountainous=20 terrain (though there is no freeway in SoCal that would be as = forgiving as=20 that section of 395).

I plan to rent some kind of truck next weekend and drive up, remove = the=20 wings, and bring the plane home. It will remain in our garage for the = next 8=20 months while I deploy to Iraq. (Suggestions or offers for use of an = adequate=20 truck or trailer would be much appreciated). This will also give me a = chance=20 to paint the plane and do a lot of the finishing touches that will be = easier=20 to do at home than at the airport. Obviously I will need to rebuild = the engine=20 as well, but that is a relatively minor issue.

This was quite a learning experience I obviously hope I never have = to=20 repeat. All things considered, I feel quite lucky that things turned = out so=20 well.

Lastly, I want to thank the Bishop Unicom, Police Dept, Highway = Patrol, Cal=20 Trans, and Fire Department who were all very professional and helpful. = Also,=20 thank you to the fellow RV6 owner was passing by and took an hour and = a half=20 out of his day to drive back up to Mammoth and get my car for me. =


--
Dave Leonard
Turbo Rotary RV-6 N4VY
http://memb= ers.aol.com/_ht_a/rotaryroster/index.html
http://members= .aol.com/_ht_a/vp4skydoc/index.html=20 ------=_NextPart_000_0018_01C61A81.9AF18260--