LEAR60 flight crew reports dual bleed air lights at FL430; lights go out as power is reduced for des...

Attributes
ACN	758602
Time
Date	200710
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 43000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : charter
Make Model Name	Learjet 60
Operating Under FAR Part	Part 135
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance
Independent Detector	other flight crewb
Resolutory Action	aircraft : equipment problem dissipated flight crew : returned to assigned altitude flight crew : diverted to another airport flight crew : landed as precaution
Consequence	other
Supplementary
Problem Areas	FAA Aircraft
Primary Problem	Aircraft

Narrative:

Cruising at FL430 I had both red bleed air lights illuminate. I then asked center for a lower altitude to 10000 ft due to a possible bleed air leak in the tail cone area; which could possibly cause a fire. I then ran the checklist for proper procedure. A combination of lower power setting and lower altitude lowered bleed air temperature in the tail cone ducts extinguishing the bleed air lights. Center gave us a descent from FL430 to FL410; followed by a descent to FL400 until clear of opposite direction traffic. I had a visual on traffic at FL390. The automatic altitude capture did not capture FL400. I then manually climbed the aircraft back to FL400. After a loss of approximately 300 ft; I did not declare an emergency. In retrospect I should have. Bleed air lights are a serious problem. Even though I was able to seemingly contain the problem; declaring an emergency would have given me more room to maneuver if needed. I will not hesitate to do so in the future. Callback conversation with reporter revealed the following information: the bleed lights did not come on again during the descent; but since a bleed air leak was suspected; the aircraft was diverted for maintenance. A pneumatic seal in the tail cone area was found to have failed and was repaired.

Original NASA ASRS Text

Title: LEAR60 FLT CREW REPORTS DUAL BLEED AIR LIGHTS AT FL430; LIGHTS GO OUT AS POWER IS REDUCED FOR DESCENT. ALT DEV OCCURS AT FL400 WHEN AUTOPILOT DOES NOT CAPTURE.

Narrative: CRUISING AT FL430 I HAD BOTH RED BLEED AIR LIGHTS ILLUMINATE. I THEN ASKED CTR FOR A LOWER ALT TO 10000 FT DUE TO A POSSIBLE BLEED AIR LEAK IN THE TAIL CONE AREA; WHICH COULD POSSIBLY CAUSE A FIRE. I THEN RAN THE CHKLIST FOR PROPER PROC. A COMBINATION OF LOWER PWR SETTING AND LOWER ALT LOWERED BLEED AIR TEMP IN THE TAIL CONE DUCTS EXTINGUISHING THE BLEED AIR LIGHTS. CTR GAVE US A DSCNT FROM FL430 TO FL410; FOLLOWED BY A DSCNT TO FL400 UNTIL CLR OF OPPOSITE DIRECTION TFC. I HAD A VISUAL ON TFC AT FL390. THE AUTO ALT CAPTURE DID NOT CAPTURE FL400. I THEN MANUALLY CLBED THE ACFT BACK TO FL400. AFTER A LOSS OF APPROX 300 FT; I DID NOT DECLARE AN EMER. IN RETROSPECT I SHOULD HAVE. BLEED AIR LIGHTS ARE A SERIOUS PROB. EVEN THOUGH I WAS ABLE TO SEEMINGLY CONTAIN THE PROB; DECLARING AN EMER WOULD HAVE GIVEN ME MORE ROOM TO MANEUVER IF NEEDED. I WILL NOT HESITATE TO DO SO IN THE FUTURE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE BLEED LIGHTS DID NOT COME ON AGAIN DURING THE DESCENT; BUT SINCE A BLEED AIR LEAK WAS SUSPECTED; THE ACFT WAS DIVERTED FOR MAINTENANCE. A PNEUMATIC SEAL IN THE TAIL CONE AREA WAS FOUND TO HAVE FAILED AND WAS REPAIRED.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

LEAR60 flight crew reports dual bleed air lights at FL430; lights go out as power is reduced for descent. Altitude deviation occurs at FL400 when autopilot does not capture.