In a message dated 2/22/2010 10:10:08 P.M. Central Standard Time,=20 mikeeasley@aol.com writes:

Gary,

Since the B&C regulators have an in= ternal=20 voltage warning light circuit that indicates low or high voltage, I gues= s you=20 could assume that a total failure of the regulator would mean you'd lose= the=20 warning light feature too. Maybe there's a failure mode that has= the=20 warning light working when the regulation circuitry fails. There= might=20 be an argument here for separate warning light boxes, B&C sells=20 them.

http://www.bandc.biz/overunder-voltagesensor.aspx

Mike Easley

Colorado Springs

In a message dated 02/20/10 20:47:43 Mountain Standard Time,=20 casey.gary@yahoo.com writes:

I assume that this most excellent report was also published on th= e=20 Aeroelectric List. If not, it should be. On that list the= =20 subject of over-voltage protection has been discussed at immense lengt= h.=20 The B&C regulator has been (correctly) lauded for its overvo= ltage=20 protection. However, a device cannot be expected to protect the= =20 aircraft against the result of a failure of itself. Therefore,= the=20 system should have a monitor that will warn the pilot of an over-volta= ge=20 condition. It is just a conjecture on my part, but in the case= =20 described below, there was probably plenty of time before any permanen= t=20 damage was done to shut down the secondary alternator - if there had= been a=20 warning that it was in trouble. If there exists two independent= =20 electrical systems(a battery connected to a functioning alternator) EA= CH=20 should have a voltage monitor to warn the pilot of over- or under-volt= age=20 conditions. I don't know if the accident pl ane had such a warni= ng=20 system, but I suspect not.

Gary Casey

ES, single battery/alternator/B&C regulator, all under the ho= od,=20 and an independent monitoring system.

Fw: B&C Regulators

B&= C Regulators

February 19, 2010 11:17= :50 AM=20 MST

From:

"Robert Pastusek" <rpastusek@htii.com>

To:

"" <lml@lancaironline.net>

=

LML Family,

Bill Harrelson and I had a cha= nce to review the=20 investigation and preliminary causes of an in-flight fire in a Lancair= IV-P=20 that occurred last spring (2009). The findings and conclusions are not= yet=20 established, but the investigator felt that some of the information=20 discovered was not in question, and would be useful to the experimenta= l=20 community. We agreed to help spread the word=E2=80=A6as follows:

The accident aircraft experien= ced an in-flight battery fire=20 of the secondary electrical system shortly after takeoff. The pilot wa= s able=20 to return to the airport and extinguish the fire in the tail section= of the=20 aircraft after landing. The battery, case, and nearby components were= =20 consumed/destroyed, and the aircraft fuselage sustained significant he= at=20 damage from the aft pressure bulkhead to the elevators/rudder. The cau= se of=20 the fire has not been absolutely determined, but the lead/acid battery= vents=20 had apparently been obstructed, resulting in a case rupture and ventin= g of=20 hydrogen gas into the tail section of the airplane. The exact cause of= this=20 apparent over pressurization and rupture awaits additional information= and=20 analysis. This finding and the final NTSB report are expected within= a month=20 and we will disseminate this report through the LML and LOBO newslette= r.

One initial result of the inve= stigation was that the B&C=20 regulator for the secondary electrical system was inoperative upon=20 post-flight analysis. The NTSB investigator conducted a detailed exami= nation=20 and analysis of the defective unit and determined that the electrical= design=20 was robust and appropriate to the task. The unit was mounted to the en= gine=20 side of the firewall with the spade terminal connectors projecting to= the=20 side of the aircraft. This unit is not sealed, and at some point liqui= d=20 (probably water) entered the metal box, most likely through the openin= g=20 around the spade terminals, and filled it to a depth of =C2=BC to =C2= =BD inch. The=20 liquid allowed arcing among internal components and to the case ground= ,=20 leaving carbon tracks on the circuit board and case, and destroying th= e=20 electrical functionality.

A review of installation instr= uctions provided with B&C=20 regulators recommends they be installed inside the cockpit or in a sim= ilar=20 environmentally-protected area. This regulator was mounted inside the= engine=20 compartment, as we believe are the vast majority of Lancair installati= ons.=20 When so installed, regulators are subject to additional heat and cooli= ng=20 stresses, as well as water/solvents from engine cleaning and other=20 maintenance when the cowling is removed. If mounted in any position ot= her=20 than with the spades down, liquid can enter in the area of the spade= =20 terminals and will then be trapped within the lower part of the enclos= ure,=20 immersing part of the main circuit board.

If you are still building and= have the option, review the=20 B&C recommendations on mounting location and consider locati= ng=20 your B&C regulator(s) inside the cockpit; preferably with the spad= es=20 down if there is any possibility of liquid exposure. No matter the loc= ation,=20 mount them in such a way that they cannot ingest and retain water.

If you are not able to locate= the regulator(s) as=20 recommended by B&C, consider shielding the terminal strip area fro= m=20 liquids. We expect to contact B&C about the feasibility of other= =20 improvements that could be made, but will refrain from making any=20 recommendations until we receive their comments.

Bob Pastusek & Bill Harrel= son

For the Lancair Owners &= Builders Organization=20 (LOBO)