Date: 201301
Local time of day: 1201-1800
Location: DEN.Airport, CO
Flight conditions: IMC
Weather elements / visibility: Icing; Windshear; Turbulence; Snow; 4
Light: Daylight
Aircraft: DC-9 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DEN
ATC / advisory: TRACON D01
Aircraft component: Altimeter
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer
Human factors: Distraction; Human-Machine Interface; Situational Awareness
Anomaly: Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Contributing factors: Aircraft; Human Factors; Weather
Primary problem: Human Factors

Narrative: Day 3 of 3-day; leg 2 of 3; enroute to DEN we received the first of several ACARS messages from Dispatch. They were worried about our fuel since we had been dispatched w/ no alternate and the weather 'caught them by surprise; big-time' (Dispatchers words not mine). Weather had been rapidly changing from CAT II (we had an MEL for no autoland) to MVFR. ATIS also had reports of moderate icing below 10;000 FT and there was a previous PIREP of severe turbulence from 15K-18K in the descent. Armed with this info; we elected to seat everyone including the FA's prior to TOD and hurry down. We had all anti-ice systems on (extra power required) and were issued the 'descend via the KOHOE 1.' This arrival has all altitude ranges except for a final hard altitude of 11;000 FT I believe at [DOGGG]. At KOHOE we checked in with approach as being 'a little high; hurrying down' (about 11;500 FT on our altimeters) and were given 9;000 FT followed by a 7;500 FT; base turn; and 7;500 FT until FRONZ; cleared ILS 35R. Due to the airfoil ice protection being on and the power being up; we struggled to get down the entire arrival in VNAV (take away for me: next time I will come OUT of VNAV....it was not working well). The ILS was armed and the next thing we received was a low altitude alert from approach instructing us to climb immediately to 7;500 FT. This was confusing momentarily as our altimeters said 7;500 FT. As we received this call we also got a 'landing gear; landing gear'. I looked at the Radar altimeter and it said 1;600 FT. I climbed immediately by clicking off the autopilot and autothrottles and proceeded to hand fly the ILS. As I was doing this; I yelled out something to the effect of 'verify the altimeter' and believe I heard the Captain say 'Oh [expletive]' but am not sure as I was very busy. Rest of approach was uneventful and we heard nothing further from ATC. Preventive measure as I write this; I can not believe that it happened. In fact; it was a grim reminder to me walking through the airport afterwards of the seriousness of our business and the inability to EVER let your guard down. This incident has gotten my attention. The Captain and I even talked about altimetry before TOD because I asked the Captain if we need to apply cold weather corrections. I could not remember 'how cold was cold' for altimetry purposes (ATIS had -08/-04). I had also asked the Captain if he wanted me to activate the ATIS AUTO/UPDATE function on the ACARS and he said no. He had been texting w/ Dispatch and we had pulled up several ATIS messages due to rapidly changing conditions at DEN. Despite being well aware of the weather; apparently the Captain put the incorrect altimeter in the STBY altimeter rolling it the wrong way from 29.92 to 30.38. Later; when it came time to set altimeters and run checklists; he set his (incorrectly) to what he had previously set in the STBY and as the busy pilot flying; I did the same when queried. The correct altimeter was a very low one and should have been 29.38. In the future; I will swap aircraft control if needed to check the ATIS myself rather than looking across to see what the pilot not flying set in his windows. Perhaps on the descent and approach checklist we should pull up a hard copy of the ATIS to 'verify' as we do with the PDC now. This would help to actually 'verify' since a 'crosscheck' of an incorrect number results in nothing more than another incorrect number. This might sound like overkill but it would have prevented what happened to us from happening again. Lastly; from now on I will have more of a 'verify' mentality and much less of a 'trust' mentality regardless of who I am flying with (this particular Captain is an Line Check Airman).




Synopsis: DC-9 series First Officer reports an altimeter setting error descending into DEN that results in the aircraft being 1;000 FT low prior to the FAF. ATC issues a low altitude alert and EGPWS annunciates 'landing gear; landing gear.'