X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 04 Nov 2009 10:26:56 -0500 Message-ID: X-Original-Return-Path: Received: from imr-mb02.mx.aol.com ([64.12.207.163] verified) by logan.com (CommuniGate Pro SMTP 5.2.17) with ESMTP id 3930115 for lml@lancaironline.net; Wed, 04 Nov 2009 02:18:43 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.207.163; envelope-from=Sky2high@aol.com Received: from imo-da02.mx.aol.com (imo-da02.mx.aol.com [205.188.169.200]) by imr-mb02.mx.aol.com (8.14.1/8.14.1) with ESMTP id nA47Htap027989 for ; Wed, 4 Nov 2009 02:17:55 -0500 Received: from Sky2high@aol.com by imo-da02.mx.aol.com (mail_out_v42.5.) id q.d69.5111df9f (41809) for ; Wed, 4 Nov 2009 02:17:50 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Wed, 4 Nov 2009 02:17:50 EST Subject: Re: [LML] 290 Gear-Up electrical short? X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1257319070" X-Mailer: AOL 9.1 sub 5006 X-Spam-Flag:NO X-AOL-SENDER: Sky2high@aol.com -------------------------------1257319070 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Richard, =20 Well, this doesn't help improve the insurance company's Lancair risk =20 calculations. You wrote: =20 "... did GUMPs last time on short final. This time, looked at lights,= =20 all OUT, gear switch down, no yellow. Hmmm something=E2=80=99s amiss her= e=E2=80=A6!? Gear=20 lever is down, why are lights out?! Circuit breaker is in, not popped. = =20 Concentrate on landing......" =20 =20 Did "Go around" ever enter the list of possible actions? How about the= =20 instructor's thoughts? You had the opportunity to practice a non-emergen= cy=20 power up and then to fly away from the pattern to resolve an issue clearl= y=20 indicated by the missing gear lights. Landing with an unknown status of= the=20 gear could have been fatal since the lack of green only means they are no= t=20 locked down - there is no other information about each wheel position. = =20 This was a perfect situation to initiate the emergency gear extension=20 checklist at a safe altitude and speed. Oh well..... =20 I am pregnant with expectation of your A&P's further analysis about the= =20 failure. It could be costly in time since it appears he is not familiar= with=20 Lancairs. If the system was wired per Lancair instructions: =20 Down ops: lo amperage power from the "relay breaker" goes thru the switc= h=20 in the down position, thru the pressure switch and thence to an =20 intermittent relay coil if the pressure is low enough. If the relay is= energized, hi=20 amperage power from the "pump breaker" passes thru the relay contacts and= =20 on to the down side of the pump motor. A tap off the relay contact=20 provides power to the "transition" light (from power going to the pump).= Once the=20 hydraulic pressure is high enough, the pressure switch opens and removes= =20 power from the relay coil - thus removing power from the motor and=20 transition light.=20 =20 Up ops: Change the word "down" to up" in the previous description except= =20 that there may be a "squat" switch before the pressure switch to prevent= =20 the gear from being retracted before flight. Most commonly this is an ai= r=20 switch that closes above 70 KIAS (plumbed to the pitot). Perhaps this=20 explains the reference to a "console bypass switch" and such a switch is= used to=20 allow retraction of the gear while the plane is on jacks (or in a sling). =20 So, If the master switch is on, how could the gear switch be in the down= =20 position with the gear retracted and both the relay and pump breakers =20 engaged? Could the power be removed from the down circuit and somehow ap= plied to=20 the up circuit without moving the gear switch? Could the pump power=20 bypass the relays? Could the down relay open on its own and the up relay= close=20 on its own? These conditions are not likely. Could hi pressure be prese= nt=20 at both pressure switches, thus preventing the motor to act (as sometimes= =20 reported here) - oh, that would have meant the gear never came down (no= =20 green lights, no transition light).=20 =20 Your description is puzzling. Remember that you said that the gear was= =20 up and tightly stowed - thus, they were held up only by hydraulic pressur= e. =20 While in the sling, if the master switch was turned on and the switch was= =20 in the down position, the gear should have powered down unless the down= =20 pressure was also high or the relay breaker (fuse) was open. Moving the= =20 switch to the up position didn't matter because the pressure was holding= the=20 gear up or the squat switch (if present) would not allow any power to rea= ch=20 the up relay. You had an opportunity to further test things if, after=20 opening the dump valve, you would have re-engaged the pump breaker to see= if the=20 motor would start. Oh well.... =20 This is going to be interesting. Keep us posted. =20 Scott Krueger =20 =20 In a message dated 11/3/2009 3:57:26 P.M. Central Standard Time, =20 Richard.Neal@pega.com writes: =20 Here=E2=80=99s the email I did not want to ever write but if someone know= s or has=20 insight, I need your thoughts. This morning with my instructor in my=20 Lancair 290 we took off to do a trip around the pattern at our local airp= ort. =20 It was clear sky, unlimited visibility. He and I performed a normal run-= up,=20 by the book with no issues. Radio check, no issues, took off and=20 gear-switch up at point of no landing, no issues.=20 As we were going to just do a simple landing, on downwind I did my normal= =20 before landing checklist, slowed to gear down speed 120 kts and did my=20 GUMPs. Gas on correct side, fuel pump on, Undercarriage, gear down and= three=20 green, check. (Instructor right seat audibly verified. They are very=20 bright green lights! And a bright yellow in-motion light illuminates) Mi= xture=20 full rich, Prop max RPM (MT electric prop). Airspeed with gear down very= =20 quickly drops from 120 to 100 so twisted in 16=E2=80=9D on throttle from= 13=E2=80=9D. =20 Announced base turn, put in more flaps, did GUMPs again. Fuel correct.= =20 Again, same verification three green! Mixture full rich, throttle twisted= =20 tight (high rpm). Airspeed 95 kts. Right on glideslope. (VASI lights= good).=20 =20 Announced final turn, put in all flaps, did GUMPs last time on short=20 final. This time, looked at lights, all OUT, gear switch down, no yellow= . Hmmm=20 something=E2=80=99s amiss here=E2=80=A6!? Gear lever is down, why are li= ghts out?!=20 Circuit breaker is in, not popped. Concentrate on landing, PING PING PI= NG of=20 blades and shooosh of composite on asphalt. Slide to a stop and look at= =20 instructor who is looking at me. What happened??? We had THREE GREENS= on=20 downwind and base, and gear down switch is STILL DOWN!=20 Ok, if I was reading this I=E2=80=99d say sure, you imagined three greens= didn=E2=80=99t=20 you? But before you say so, we climbed out of the plane, and after a cra= ne=20 arrived picked up the plane the gear was cleanly stowed. Moved it off th= e=20 ramp and had an A&P the first person to check it while still lifted up by= =20 the crane. Everything turned on, electronics, radios, etc. No circuit= =20 breakers popped. But the Gear Down switch (which was still in the down= =20 position) did NOT move the gear down or up, nor start the hydraulic motor= . No=20 smell of any burnt wiring, etc. A&P moved the gear switch up and down wi= th=20 no effect. Pulled and reset the dedicated hydraulic pump breaker, no=20 effect. Checked the locking center console bypass switch, correct positi= on, and =20 finally A&P asked me if there was a bypass. I pulled the hydraulic pump= =20 breaker and flipped the hydraulic lever bypass and the gear dropped. We= =20 pushed the nearly completely extended gears to full lock position, and go= t=20 THREE GREEN. =20 We were about 50 feet above the ground on very short final when on the 3r= d=20 GUMPs I noticed the lights out, but with the gear down, and having seen= =20 three green 2x and verified by the instructor, I=E2=80=99m at a loss as= to what=20 happened. All points to the gear retracting which makes me think there= must be=20 short somewhere=E2=80=A6 =20 So now off to meet the FAA guy, call the MT Prop guy, getting ready to=20 call the insurance guys=E2=80=A6 =20 Lovely day to fly indeed!=20 Regards, and remember it=E2=80=99s not if, but when=E2=80=A6=20 Richard Neal =20 =20 ____________________________________ PegaWORLD 2010 Join us at the world's largest BPM Thought Leadership Event April 25-27, 2010 | Philadelphia, PA USA | www.PegaWORLD2010.com -------------------------------1257319070 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
Richard,
 
Well, this doesn't help improve the insurance company's Lancair= risk=20 calculations.  You wrote:
 
 "... did GUMPs last time on short final.  This time, looke= d at=20 lights, all OUT, gear switch down, no yellow.  Hmmm something=E2=80= =99s amiss=20 here=E2=80=A6!?  Gear lever is down, why are lights out?! Circuit bre= aker is in,=20 not popped.  Concentrate on landing......" 
 
Did "Go around" ever enter the list of possible actions?  How ab= out=20 the instructor's thoughts?  You had the opportunity to practice a=20 non-emergency power up and then to fly away from the pattern to= =20 resolve an issue clearly indicated by the missing gear lights. = =20 Landing with an unknown status of the gear could have been fatal since the= lack=20 of green only means they are not locked down - there is no other= =20 information about each wheel position.  This was=20 a perfect situation to initiate the emergency gear extension che= cklist=20 at a safe altitude and speed.  Oh well.....
 
I am pregnant with expectation of your A&P's further=20 analysis about the failure.  It could be costly in time since it= =20 appears he is not familiar with Lancairs.  If the system was wired pe= r=20 Lancair instructions:
 
Down ops:  lo amperage power from the "relay breaker" goes thru= the=20 switch in the down position, thru the pressure switch and thence to an=20 intermittent relay coil if the pressure is low enough.  If= the=20 relay is energized, hi amperage power from the "pump breaker" passes thru= the=20 relay contacts and on to the down side of the pump motor.  A tap off= the=20 relay contact provides power to the "transition" light (from pow= er=20 going to the pump).  Once the hydraulic pressure is high enough,= the=20 pressure switch opens and removes power from the relay coil - thus re= moving=20 power from the motor and transition light. 
 
Up ops:  Change the word "down" to up" in the previous descripti= on=20 except that there may be a "squat" switch before the pressure switch = to=20 prevent the gear from being retracted before flight.  Most=20 commonly this is an air switch that closes above 70 KIAS (plumbed to= the=20 pitot).  Perhaps this explains the reference to a "console bypas= s=20 switch" and such a switch is used to allow retraction of th= e gear=20 while the plane is on jacks (or in a sling).
 
So, If the master switch is on, how could the gear switch be in the= down=20 position with the gear retracted and both the relay and pump breakers=20 engaged?  Could the power be removed from the down circuit and someho= w=20 applied to the up circuit without moving the gear switch?  Could the= pump=20 power bypass the relays?  Could the down relay open on its own and th= e up=20 relay close on its own?  These conditions are not likely.&n= bsp;=20 Could hi pressure be present at both pressure switches, thus preventing th= e=20 motor to act (as sometimes reported here) - oh, that would have meant= the=20 gear never came down (no green lights, no transition light). 
 
Your description is puzzling.   Remember that you said that= the=20 gear was up and tightly stowed - thus, they were held up only by= =20 hydraulic pressure.  While in the sling, if the master switch wa= s=20 turned on and the switch was in the down position, the gear should ha= ve=20 powered down unless the down pressure was also high or the relay br= eaker=20 (fuse) was open.  Moving the switch to the up position didn't ma= tter=20 because the pressure was holding the gear up or the squat switch (if prese= nt)=20 would not allow any power to reach the up relay.  You had an=20 opportunity to further test things if, after opening the dump valve, you= would=20 have re-engaged the pump breaker to see if the motor would start.  Oh= =20 well....
 
This is going to be interesting.  Keep us posted.
 
Scott Krueger
 
In a message dated 11/3/2009 3:57:26 P.M. Central Standard Time,=20 Richard.Neal@pega.com writes:

Here=E2=80=99s the email I did not want to ever wri= te but if=20 someone knows or has insight, I need your thoughts.  This morning= with my=20 instructor in my Lancair 290 we took off to do a trip around the pattern= at=20 our local airport.  It was clear sky, unlimited visibility. = He and=20 I performed a normal run-up, by the book with no issues.  Radio che= ck, no=20 issues, took off and gear-switch up at point of no landing, no=20 issues.

 As we were going to just do a simp= le=20 landing, on downwind I did my normal before landing checklist, slowed to= gear=20 down speed 120 kts and did my GUMPs.  Gas on correct side, fuel pum= p on,=20 Undercarriage, gear down and three green, check.  (Instructor right= seat=20 audibly verified.  They are very bright green lights! And a bright= yellow=20 in-motion light illuminates)  Mixture full rich, Prop max RPM (MT= =20 electric prop).  Airspeed with gear down very quickly drops from 12= 0 to=20 100 so twisted in 16=E2=80=9D on throttle from 13=E2=80=9D.  <= /o:p>

 Announced base turn, put in more= flaps,=20 did GUMPs again.  Fuel correct. Again, same verification three gree= n!=20 Mixture full rich, throttle twisted tight (high rpm).  Airspeed 95= =20 kts.  Right on glideslope.  (VASI lights good). =20

 Announced final turn, put in all= flaps,=20 did GUMPs last time on short final.  This time, looked at lights,= all=20 OUT, gear switch down, no yellow.  Hmmm something=E2=80=99s amiss= here=E2=80=A6!? =20 Gear lever is down, why are lights out?! Circuit breaker is in, not=20 popped.  Concentrate on landing, PING PING  PING of blades and= =20 shooosh of composite on asphalt.   Slide to a stop and look at= =20 instructor who is looking at me.  What happened???  We had THR= EE=20 GREENS on downwind and base, and gear down switch is STILL=20 DOWN!

 Ok, if I was reading this I=E2=80= =99d say sure,=20 you imagined three greens didn=E2=80=99t you?  But before you say= so, we climbed=20 out of the plane, and after a crane arrived picked up the plane the gear= was=20 cleanly stowed.  Moved it off the ramp and had an A&P the first= =20 person to check it while still lifted up by the crane.  Everything= turned=20 on, electronics, radios, etc.  No circuit breakers popped.  Bu= t the=20 Gear Down switch (which was still in the down position) did NOT move the= gear=20 down or up, nor start the hydraulic motor.  No smell of any burnt= wiring,=20 etc.  A&P moved the gear switch up and down with no effect.&nbs= p;=20 Pulled and reset the dedicated hydraulic pump breaker, no effect. = =20 Checked the locking center console bypass switch, correct position, and= =20 finally A&P asked me if there was a bypass.  I pulled the hydra= ulic=20 pump breaker and flipped the hydraulic lever bypass and the gear=20 dropped.  We pushed the nearly completely extended gears to full lo= ck=20 position, and got THREE GREEN. 

 We were about 50 feet above the gr= ound on=20 very short final when on the 3rd GUMPs I noticed the lights= out,=20 but with the gear down, and having seen three green 2x and verified by= the=20 instructor, I=E2=80=99m at a loss as to what happened.  All points= to the gear=20 retracting which makes me think there must be short somewhere=E2=80=A6=

 So now off to meet the FAA guy, ca= ll the=20 MT Prop guy, getting ready to call the insurance guys=E2=80=A6

 Lovely day to fly indeed!

Regards, and remember it=E2=80=99s not if, but when= =E2=80=A6

Richard=20 Neal <= /o:p>

 


PegaWORLD 2010
Join us at th= e world's=20 largest BPM Thought Leadership Event
April 25-27, 2010 | Philadelphia= , PA=20 USA |=20 www.PegaWORLD2010.com
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