PRM1 climbs to FL270 unpressurized account bleed air not turned on. Hypoxia for all aboard is abated...

Attributes
ACN	779187
Time
Date	200803
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl single value : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	general aviation : corporate
Make Model Name	King Air C90 E90
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 120 flight time total : 24575 flight time type : 15
ASRS Report	779187
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 110 flight time total : 16100 flight time type : 1135
ASRS Report	778901
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : exited adverse environment flight crew : regained aircraft control
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Part of the 'taxi' checklist was missed due to the captain trying to help me with a route change in the FMS. There were several interruptions during the taxiing to the active runway. The flight was planned at a cruising altitude of FL270. The missed item on the checklist was the bleed air switch not placed in the 'both' or 'on' position; hence unpressurized. Cabin altitude climbed to a point that hypoxia began to set in. I was the PNF and sitting in the right seat since I had not been to training on the aircraft. Somewhere during the flight at FL270; I kept hearing center calling and asking if we could make our crossing restr that I had acknowledged. At this point (due to hypoxia) I was unable to reach the yoke microphone button to respond. Somehow I realized that we were not descending to our assigned altitude and my flying partner and all passenger were not responsive. I disconnected the autoplt and deployed the speed brakes and started an emergency descent. At about FL180; I got the captain on oxygen and continued descent to below 10000 ft. I made a safe landing at ZZZ. 1) crew distraction was the primary factor causing this event; 2) there was no cabin 'altitude high' master caution; and 3) the cabin oxygen mask did not present (drop). 4) the use of electronic checklist should be used since an item would not be missed as it was using a paper checklist. 5) the captain had flown several trips the 3 previous days -- all starting very early and ending very late at night. Fatigue was a huge factor. There is no status light on the annunciator panel indicating that the bleed air switch is in the 'off' position as there is on all pressurized aircraft that I have flown. Supplemental information from acn 778901: during preflight checks; attention was diverted from quick turn checklist to assist new crew member in programming route change into FMS. This took 3-4 mins to accomplish. Returning to checklist; bleed air switch was missed and not turned on. After takeoff and climb to assigned altitude of FL270; cabin altitude climbed to the point that hypoxia began to set in. New crew member recognized the problem and started descent while calling for crew to go on oxygen. 1) crew distraction and breaking the flow of preflight checklist was primary cause of this event. 2) cabin 'altitude high' warning light failed to illuminate when cabin altitude passed 10000 ft. 3) cabin oxygen masks failed to drop after cabin altitude climbed above 10000 ft even though the system was armed and sufficient oxygen pressure was present. 4) use of electronic checklist will help prevent this in the future. This feature does not forget where it left off. 5) suggest that a status light indicating that the bleed air switch is in the off position be added to the annunciator panel. Most pressurized aircraft have this feature. 6) no injuries occurred during this event. 7) this was the third leg of the day and is why quick turn checklist was used.

Original NASA ASRS Text

Title: PRM1 CLIMBS TO FL270 UNPRESSURIZED ACCOUNT BLEED AIR NOT TURNED ON. HYPOXIA FOR ALL ABOARD IS ABATED WHEN FO REALIZES THE SITUATION AND INITIATES AN EMERGENCY DESCENT.

Narrative: PART OF THE 'TAXI' CHKLIST WAS MISSED DUE TO THE CAPT TRYING TO HELP ME WITH A RTE CHANGE IN THE FMS. THERE WERE SEVERAL INTERRUPTIONS DURING THE TAXIING TO THE ACTIVE RWY. THE FLT WAS PLANNED AT A CRUISING ALT OF FL270. THE MISSED ITEM ON THE CHKLIST WAS THE BLEED AIR SWITCH NOT PLACED IN THE 'BOTH' OR 'ON' POS; HENCE UNPRESSURIZED. CABIN ALT CLBED TO A POINT THAT HYPOXIA BEGAN TO SET IN. I WAS THE PNF AND SITTING IN THE R SEAT SINCE I HAD NOT BEEN TO TRAINING ON THE ACFT. SOMEWHERE DURING THE FLT AT FL270; I KEPT HEARING CTR CALLING AND ASKING IF WE COULD MAKE OUR XING RESTR THAT I HAD ACKNOWLEDGED. AT THIS POINT (DUE TO HYPOXIA) I WAS UNABLE TO REACH THE YOKE MIKE BUTTON TO RESPOND. SOMEHOW I REALIZED THAT WE WERE NOT DSNDING TO OUR ASSIGNED ALT AND MY FLYING PARTNER AND ALL PAX WERE NOT RESPONSIVE. I DISCONNECTED THE AUTOPLT AND DEPLOYED THE SPD BRAKES AND STARTED AN EMER DSCNT. AT ABOUT FL180; I GOT THE CAPT ON OXYGEN AND CONTINUED DSCNT TO BELOW 10000 FT. I MADE A SAFE LNDG AT ZZZ. 1) CREW DISTR WAS THE PRIMARY FACTOR CAUSING THIS EVENT; 2) THERE WAS NO CABIN 'ALT HIGH' MASTER CAUTION; AND 3) THE CABIN OXYGEN MASK DID NOT PRESENT (DROP). 4) THE USE OF ELECTRONIC CHKLIST SHOULD BE USED SINCE AN ITEM WOULD NOT BE MISSED AS IT WAS USING A PAPER CHKLIST. 5) THE CAPT HAD FLOWN SEVERAL TRIPS THE 3 PREVIOUS DAYS -- ALL STARTING VERY EARLY AND ENDING VERY LATE AT NIGHT. FATIGUE WAS A HUGE FACTOR. THERE IS NO STATUS LIGHT ON THE ANNUNCIATOR PANEL INDICATING THAT THE BLEED AIR SWITCH IS IN THE 'OFF' POS AS THERE IS ON ALL PRESSURIZED ACFT THAT I HAVE FLOWN. SUPPLEMENTAL INFO FROM ACN 778901: DURING PREFLT CHKS; ATTN WAS DIVERTED FROM QUICK TURN CHKLIST TO ASSIST NEW CREW MEMBER IN PROGRAMMING RTE CHANGE INTO FMS. THIS TOOK 3-4 MINS TO ACCOMPLISH. RETURNING TO CHKLIST; BLEED AIR SWITCH WAS MISSED AND NOT TURNED ON. AFTER TKOF AND CLB TO ASSIGNED ALT OF FL270; CABIN ALT CLBED TO THE POINT THAT HYPOXIA BEGAN TO SET IN. NEW CREW MEMBER RECOGNIZED THE PROB AND STARTED DSCNT WHILE CALLING FOR CREW TO GO ON OXYGEN. 1) CREW DISTR AND BREAKING THE FLOW OF PREFLT CHKLIST WAS PRIMARY CAUSE OF THIS EVENT. 2) CABIN 'ALT HIGH' WARNING LIGHT FAILED TO ILLUMINATE WHEN CABIN ALT PASSED 10000 FT. 3) CABIN OXYGEN MASKS FAILED TO DROP AFTER CABIN ALT CLBED ABOVE 10000 FT EVEN THOUGH THE SYS WAS ARMED AND SUFFICIENT OXYGEN PRESSURE WAS PRESENT. 4) USE OF ELECTRONIC CHKLIST WILL HELP PREVENT THIS IN THE FUTURE. THIS FEATURE DOES NOT FORGET WHERE IT LEFT OFF. 5) SUGGEST THAT A STATUS LIGHT INDICATING THAT THE BLEED AIR SWITCH IS IN THE OFF POS BE ADDED TO THE ANNUNCIATOR PANEL. MOST PRESSURIZED ACFT HAVE THIS FEATURE. 6) NO INJURIES OCCURRED DURING THIS EVENT. 7) THIS WAS THE THIRD LEG OF THE DAY AND IS WHY QUICK TURN CHKLIST WAS USED.

Data retrieved from NASA's ASRS site as of May 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.

PRM1 climbs to FL270 unpressurized account bleed air not turned on. Hypoxia for all aboard is abated when first officer realizes the situation and initiates an emergency descent.