28 December 1978 - United 173
United Airlines Flight 173, registration N8082U, was a Douglas DC-8-61 en route from Stapleton International Airport in Denver to Portland International Airport on December 28, 1978. When the landing gear was lowered, only two of the green landing gear indicator lights came on. The plane circled in the vicinity of Portland while the crew investigated the problem. After about one hour the plane ran out of fuel and crashed in a sparsely populated area near 158th and East Burnside Street, killing 10 and seriously injuring 24 of the 189 on board.
The NTSB investigation revealed that when the landing gear was lowered, a loud thump was heard. That unusual sound was accompanied by abnormal vibration and an abnormal yaw of the aircraft. The right main landing gear retract cylinder assembly had failed, due to corrosion, and that allowed the right gear to free fall. Although it was down and locked, the rapid and abnormal free fall damaged the microswitch, which completed the circuit to the cockpit green light, which tells the pilots that gear is down and locked. It was those unusual indicators (loud noise, vibration, yaw and no green light) which led the captain to abort the landing, so that they would have time to diagnose the problem and prepare the passengers for an emergency landing. While the decision to abort the landing was correct, the accident occurred because the flight crew became so absorbed with diagnosing the problem that they failed to calculate a time when they needed to land to avoid fuel starvation.
TRANSCRIPT OF A SUNDSTRAND V557 COCKPIT VOICE RECORDER SERIAL NO. 1427 REMOVED FROM THE UNITED AIRLINES DC-8 WHICH WAS INVOLVED IN AN ACCIDENT AT PORTLAND,
OREGON ON DECEMBER 23, 1978
THE TIME IS IN PACIFIC STANDARD TIME
LEGEND
CAM Cockpit area microphone voice or sound source
RDO Radio transmission from
-1 Voice identified as Captain
-2 Voice identified as First Officer
-3 Voice identified as Flight Engineer
-4 Voice identified as off duty Captain
-5 Voice identified as Flight Attendant
-? Voice unidentified
UNK Unknown
* Unintelligible word
# Nonpertinent word
X Nonpertinent text
% Break in continuity
() Questionable text
(()) Editorial insertion
--- Pause
PA Portland Approach Control
CO United Company
VHF VHF Radio
XXX Nonpertinent aircraft or facility call
PD Portland Departures
TWR Portland Tower
INTRA-COCKPIT AIR-GROUND COMMUNICATIONS
TIME & TIME &
SOURCE CONTENT SOURCE CONTENT
CAM-? *
CAM-1 How you doing (Dory)?
CAM-5 We’re ready for your announcement
CAM-5 (Do)you have the signal for not
evacuate also the signal XXX
for protective position.
1744:41
CAM-5 That’s the only things I need from
you right now
CAM-1 Okay ah, what would you do? Have
you got any suggestions about when
to brace? Want to do it on the PA?
1744:50
CAM-5 I---I’ll be honest with you, I’ve never
had one of these before --- My first
you know --- *
CAM-1 All right, what we’ll do is we’ll have 1745:00
Frostie oh about a couple of minutes PA United one seventy three
before touchdown signal for brace position heavy, turn left
heading two two zero
1745:04
RDO-2 Left two twenty one
seventy three heavy
CAM-5 Okay, he’ll come on the PA
CAM-1 and then ah--
CAM-5 And if you don’t want w to evacuate
what’s are you gonna say
1745:09
CAM-1 We’ll either use the PA or we’ll stand
in the door and hollar
CAM-5 Okay, one or the other, ah we’re reseating
passengers right now and all the cabin
lights are full up.
CAM-5 Will go take it from there
CAM-1 All right
1745:23
CAM-5 We’re ready for your announcement any time
1745:43
CAM-3 I can see the red indicators from here, ya know
But I can’t tell * if there’s anything lined up.
Cause I only got this thing to shine down there
CAM-3 *** all the way down
1746:21
CAM-3 Last guy to leave has gotta turn the battery XXX
external power switch off
CAM-? You’re right
CAM-? *
CAM-? *
1746:52
CAM-2 How much fuel we got Frostie?
CAM-3 Five thousand
CAM-2 Okay
1748:00
CAM-4 Gonna get us a spare flashlight
CAM-5 Sir?
CAM-4 Gonna get us a spare flashlight
1748:17
CAM-4 Less than three weeks, three weeks to retirement
you better get me outta here
CAM-1 Thing to remember is don’t worry
CAM-? What?
1748:11
CAM-1 Thing to remember is don’t worry
1748:21
CAM-4 Yeah
CAM-4 If I might make a suggestion ---
You should put your coats on ---
Both for your protection and so
you’ll be noticed so they’ll
know who you are
1748:30
CAM-1 Oh that’s okay
CAM-4 But if it gets, if it gets hot it
sure is nice to not have bare arms
1748:40
PA United one seventy three heavy,
CAM-1 Yeah traffic eleven o’clock five miles
north bound VFR Code Unknown
1748:40
CAM-1 But if anything goes wrong you just charge
back there and get your ass off, Okay RDO-2 Yeah, we’ve got somebody out
there
PA ‘Kay.
CAM-4 Yeah
CAM-4 I told, I told the gal, put me where
she wants me, I think she wants me at
a wing exit
CAM-1 Okay fine, thank you
CAM-2 (We better turn around and head west)
1748:54
CAM-2 Ah, what’s the fuel show now, buddy?
1748:56
CAM-1 Five
CAM-2 Five
CAM-3 (The lights in the fuel pump ---)
1749:00
CAM-1 That’s about right, the feed pumps are starting to blink
XXX
CAM-? That lights too big to shine down there
CAM-? Yeah
CAM-? Maybe * *
CAM-? You can always get a *
XXX
PA United one seventy three
heavy turn left heading
one six zero
RDO-2 Okay, left one six zero
You got one seven three
heavy
1749:45
CAM-? Main gear back there
CAM-? Yeah both of them appear to be down
and locked * *
1749:50
RDO-2 That guy’s out there about
nine thirty, now is that right?
1749:53
PA Say again
1749:55
RD0-2 Ah, traffic’s out
there about nine thirty now?
CAM-? I see him 1749:57
PA Ah no, he’s about six o’clock now
the one that I called earlier, now
you got another about nine thirty,
about five miles circling
1750:17
RDO-2 Yeah, I see somebody out there
with a light on
1750:16
CAM-1 Okay
CAM-1 Hey, Frostie
CAM-3 Yes, sir
CAM-1 Give us a current card on weight figure about
another fifteen minutes
1750:30
CAM-3 Fifteen minutes? XXX
CAM-1 Yeah, give us three or four thousand pounds
on top of zero fuel weight
CAM-3 Not enough
1750:34
CAM-3 Fifteen minutes is gonna --- really
run is low on fuel here
1750:35
PA United one seventy
CAM-? Right three heavy continue your
left turn heading zero five zero
1750:39
RDO-2 Okay, left zero five zero
1750:47
CAM-3 * okay --- take three thousand pounds,
ah two hundred and four
XXX
1751:09
CAM-2 Maintenance have anything to say
1751:16
CAM-3 He says I think you guys have done
everything you can and I said we’re
reluctant to recycle the gear for
fear something is bent or broken,
we wont be able to get it down
1751:22
CAM-? I agree
1751:29
CAM-2 Think we ought to warn these people on
the ground
CAM-1 Yeah, will do that right now
1751:35
CAM-1 Ah call the ramp, give em our passenger
count including laps tell em we’ll land
with about four thousand pounds of fuel
and tell them to give that to the fire
department, I want United mechanics to
check the airplane after we stop, before
we taxi
1752:02
CAM-3 Yes, sir
1752:17
CAM-1 New numbers thirty four and thirty nine
RDO-3 Seattle er Portland ramp United one seventy
three
CO United one seven three Portland, go
RDO-3 United one seven three will be landing, ah in
ah little bit and the information I’d like for
you to pass on to the fire department for us.
We have souls on
PA United one seventy three heavy traffic at
twelve o’clock five miles opposite
direction two targets
RDO- 3
Cont'd board one seven two one hundred and
seventy two plus five ba; ah lap ah
children
RDO-2 Okay, thank you
RDO-3
Cont’d That would be five infants that’s one
seventy two plus five Infants and pass
It on to the fire department we’ll be landing
with about four thousand pounds
fuel and ah requesting as soon as we stop
United mechanics meet the airplane
for an inspection prior to taxiing further, go
Ahead
CO One seventy three copied it all and I’ll relay
that on ah we’re showing you at the field
about zero five does that sound close?
RDO-3 Ah, fuel correct currently about five
thousand pounds
CO Ah your ETA for the field about zero five
1753: 30
CAM-3 He wants to know if we’ll be landing
about five after
1753:30
PA One seventy three heavy traffic, two’clock
a mile unknown
CAM-1 Yes
1753:36
PA One seventy three heavy traffic ten to
nine o’clock one half mile altitude
unknown
1753:40
RDO-2 One seven three, thank you
1753:42
RDO-3 Affirmative about five after
CO Okay, Portland
XXX
CAM-? There’s one down there
CAM-? Yeah
1754:01
CAM-1 All done
CAM-3 Yes, sir
1754:08
CAM-3 Ready for the * final descent PA United one seventy three clear of the first
check final approach, final descent check traffic now there’s another one at eleven
o’clock, moving twelve o’clock a mile south
southwest bound
CAM-1 Okay
CAM-1 Do you want to run through the approach
descent, yourself?
1754:19
CAM-1 So you (don’t forget something) PA United one seventy three heavy traffic
at twelve o’clock a half a mile
CAM-3 Yes, sir 1754:23
RDO-2 Yeah we got it down below
1754:27
CAM-2 He’s going to have the company call out
the equipment?
1754:31
CAM-1 We’ll (call) dispatch in San Francisco and
maintenance down there will handle it that XXX
way so we don’t get it all over local radio
The ramp here is going to back it up by
getting the crash equipment. How many
people and all that?
CAM-1 When we get done back there then I’ll tell
them what we’re going to do, so we don’t
end up with about a million rubber neckers
out there.
1755:04
CAM-3 Okay, approach descent check is complete
1755:13
CAM-1 Okay, check the new ATIS is delta
CAM-1 What I need is the wind, really
VHF Portland International Information delta
Portland weather four thousand five hundred
scattered visibility three zero temperature
three zero, dew point one three winds three
four zero degrees at eight altimeter three
zero one six
1755:51
CAM-1 Wind is three forty at eight
1755:55
CAM-1 Okay
CAM-1 You want to be sure the flight bags
and all that # are stowed ***
fastened, why don’t you put all your
books in your bag over there, Rod.
1756:53 XXX
CAM-2 How much fuel you got now?
1757:02
CAM-3 Four, four --- thousand --- in PA One seventy three heavy turn left two eight
each --- pounds five
1757:06
CAM-2 Okay * RDO-2 Two eight five one seventy three heavy
1757:21
CAM-1 You might --- you might just take
a walk back through the cabin and
kinda see how things are going Okay?
1757:30
CAM-1 I don’t want to, I don’t want to hurry,
em but I’d like to do it in another oh,
ten minutes (or so)
CAM-3 Yeah, I’ll see if its, --- get us ready
1758:18
CAM-2 If we do indeed --- have to evacuate
assuming that none of us are
incapacitated. You’re going to take
care of the shutdown, right.
1758:28
CAM-2 Parking brakes, spoilers and flaps,
fuel shut off levels, fire handles,
battery switch and all that * *
1758:38
CAM-1 You just haul ass back there and do
whatever needs doing
CAM-1 I think that Jones is a pretty level
headed gal, and
1758:45
CAM-2 Pardon?
CAM-1 I think that "A" Stew is a pretty
level headed gal, and sounds like
she knows what she’s doing and
CAM-1 * * been around for a while, I’m
sure Duke will help out
1800:15
CAM-2 We’re not gonna have any antiskid
protection, either
XXX
1800:24
CAM-1 Well, I think the antiskid is working,
it’s just the lights that ain’t working
1800:33
CAM-2 That light go off when you push the
circuit breaker In?
CAM-1 Yeah
CAM-2 Oh, it did
CAM-1 Yeah XXX
CAM-2 Oh
1800:42
CAM-1 I won’t we much breaking we’ll
just let it roll out easy * *
1800:50
CAM-2 You plan to land as slow as you
can with the power on?
CAM-1 Ah, I think about ref or thereabouts
try and hold the nose wheel off, I’m,
I’m tempted to turn off the automatic
spoilers to keep it from pitching down, but
lets try and catch it
1801:12
PA United one seventy three heavy turn left
Heading one niner five
1801:15
RDO-2 Left one niner five one seven three heavy
1801:34
CAM-3 (You’ve got) another two or three
minutes
CAM-1 Okay --- How are the people
1501:39
CAM-3 Well, they’re pretty calm and cool
ah --- some of em are obviously
nervous, ah --- but for the most
part they’re taking it in stride ---
they ---
CAM-3 I ah stopped and reassured a couple
of them, they seemed a little bit more
--- more anxious than some of the
others
1802:08
CAM-1 Okay, well about two minutes before
landing that will be about four miles
out, just pick up the mike --- the
PA and say assume the brace position
CAM-3 Okay
1802:22
CAM-3 We got about three on the fuel (and
that’s it)
1802:28
CAM-1 Okay, on the touch down if the gear
folds or something really jumps the
track, get those boost pump off so
that --- you might even get the
valves open.
1802:44
PA United one seventy three heavy did you
figure anything out yet about how much
longer?
1802:49
RDO-2 Yeah, we, ah, have indication our gear is
abnormal it’ll be our intention in about five
minutes to land on two eight left, we would
like the equipment standing by, our
indication are the gear is down and locked,
we’ve got our people prepared for an
evacuation in the event that should become
necessary
1803:l4
PA Seventy three heavy, okay advise when
you’d like to begin your approach
1803:17
RDO-1 Very well, they’ve about finished in the
cabin --- I’d guess about another three, four,
five minutes
1803:23 United one seven three heavy, if you could,
ah, give me souls on board and amount of
fuel
1803:28
CAM-3 One seventy two plus, ah
1803:30
RDO-1 One seven two an about four thousand well,
make it three thousand pounds of fuel
CAM-3 Plus six laps PA Thank you
1803:38
RDO-1 Okay, and you can add to that one seventy
two plus six laps, infants
CAM-2 I think he wants souls on board, he
wants crew members and everything
CAM-3 Ah, that right, he does, doesn’t he?
1803:58
CAM-3 Ah, five, three, eight, nine
CAM-3 Eight, isn’t it?
CAM-1 Well, okay
1804:04
CAM-2 One eighty five
CAM-1 There’s one check that we missed
CAM-? What XXX
CAM-1 Checking the gear warning horn
CAM-? * right
CAM-? right
CAM-1 right
CAM-1 right
1804:44
CAM-1 How do we do that?
CAM-2 What we gotta do is get us past flaps
thirty five *
CAM-1 Thirty five what happens when you close
the throttles (any idea)?
CAM-2 You can do that too, it’ll be one or
three
1804:59
CAM-1 Yeah
1805:08
CAM-2 But we can’t tell with that breaker out
I guess
CAM-3 Yeah
CAM-1 Push the breaker momentarily
CAM-1 Ready?
CAM-3 Yeah
1805:26
CAM-3 Okay, pull the breaker?
CAM-1 Yeah
1803:35
CAM-3 Okay, now we won’t have the spoiler
pump automatic spoilers
1805:39
CAM-1 Yes we will
CAM-3 The antiskid?
CAM-1 Well, wait a minute, I think the
systems totally normal. Indications
are what they are because the circuit
breakers popped
CAM-3 Yeah
CAM-2 Right
CAM-3 Right
1805:54
CAM-1 Should have antiskid automatic spoilers
and all that, we may not get ground
shift because of mechanical ground
shift problems
1806:04
CAM-1 Well, ah (let’s have me) standby the
boilers, spoilers anyway if we don’t
get em, why I can ---
1806:10
CAM-1 I think if we get the antiskid fail light is
off we’ll-get the automatic spoilers
1806:13
PA United one seven three heavy turn left
heading zero five zero
CAM ((Sound of cabin door))
1806:19
CAM-1 How you doing?
1806:21
CAM-5 Well, I think we’re ready RDO-2 Left to zero five zero, United one seventy
three heavy
1806:23
PA Roger
CAM-1 Okay
CAM-1 We’ve reseated, they’ve assigned
helpers and showed people how to
open exits and ah,
CAM-1 Okay
CAM-5 We have they’ve told me they’ve
got able bodied men by the
windows
CAM-1 The captain’s in the very first row
of coach after the galley
CAM-? Any invalids (* * pull out windows *)
1806:34
CAM-5 He’s going to take that that middle
galley door its not that tar from the
window
CAM-? Yeah * *
CAM-? *
CAM-? *
CAM-1 Okay we’re going to go in now, we
should be landing in about five minutes
CAM-(3/2) I think you just lost number four
buddy, you
CAM-5 Okay, I’ll make the five minute
announce, announcement, I’ll go
I’m sitting down now
CAM-2 Better get some cross feeds open
there or something
CAM-3 Okay
CAM-5 All righty
1806:46
CAM-2 We’re goin to lose an engine buddy
CAM-1 Why?
1806:49
CAM-2 We’re losing an engine
CAM-5 * * * ((Voice fading out))
CAM-1 Why
1806:52
CAM-2 Fuel
CAM-2 Open the crossfeeds, man
CAM-1 Open the crossfeeds there or
something ((simultaneous with above))
1806:55
CAM-3 Showing fumes
CAM-2 (Think, maybe we)
CAM-1 Showing a thousand or better
1807:00
CAM-2 I don’t think its in there
CAM-3 Showing three thousand isn’t it
CAM-1 Okay, it, its a
1807:06
CAM-2 Its flamed out
1807:12
RDO-1 United one seven three would like clearance
for an approach into two eight left, now
1807:17
PA United one seventy three heavy, ok, roil out
heading zero one zero --- be a vector to the
visual runway two eight left and ah, you can
report when you have the airport in sight
suitable for a visual approach.
1807:25
RDO-1 Very well
1807:27
CAM- 3 We’re going to lose number three in a
minute too
CAM-1 Well
1807:31
CAM-3 It’s showing zero
CAM-1 You got a thousand pounds, you got to
CAM-3 Five thousand in there, buddy, but we lost it
CAM-1 All right
1807:38
CAM-3 Are you getting it back
1807:40
CAM-2 No, number four, you got that crossfeed
open?
1807:41
CAM-3 No, I haven’t got it open, which one
1807:42
CAM-1 Open em both, # get some fuel in there
CAM-1 Got some fuel pressure?
CAM-3 Yes, sir
1307:48
CAM-1 Rotation now she’s coming
1807:32
CAM-1 Okay, watch one and two
CAM-1 We’re showing down to zero or a thousand
CAM-3 Yeah
1808:08
CAM-2 Still not getting it
1808:11
CAM-1 Well, open all four crossfeeds
CAM-3 All four?
CAM-1 Yeah
1808:14
CAM:2 All right now, its coming
1808:19
CAM-2 It’s going to be # on approach though
CAM-? Yeah
1806:42
CAM-1 You gotta keep em running, Frostie
CAM-3 Yes, sir
1808:45
CAM-2 Get this # on the ground
CAM-3 Yeah
1808:50
RDO-1 United one seven three has got the field in
CAM-3 It’s showing not very much more fuel sight now and we’d like an ASR to ten left
er two eight left
1808:58
PA Okay, United one seventy three heavy,
maintain five thousand
1809:03
RDO-1 Maintain five
1809:16
CAM-3 We’re down to one on the totalizer
1809:17
CAM-3 Number two is empty
1809:21
RDO-1 United ah, one seven three is going to turn
Toward the airport and come on in
1809:27
PA Okay now you want to do it on a visual is
that what you want?
CAM-2 Yeah
1809:32
RDO-1 Yeah
1809:33
PA Okay United one seventy three heavy ah
turn left heading three six zero and verify
you do have the airport in sight
1809:39
RDO-2 We do have the airport in sight, one six three
heavy er, one seven three heavy
1809:42
PA One seven three heavy is cleared visual
approach runway two eight left
1809:45
RDO-2 Cleared visual two eight left
CAM-1 Yeah
((Sound of spool down))
1809:51
CAM-2 You want the ILS on there Buddy
CAM-1 Well XXX
CAM-2 It’s not going to do you any good now
CAM-1 No, we’ll get that # warning thing
if we do
1810:17
CAM-1 Ah, reset that circuit breaker
momentarily, see if we get gear lights
1810:24
CAM-1 Yeah, the nose gears down
CAM-3 Off
CAM-1 Yeah
1810:33
CAM-1 About the time you give that brace
position
CAM-3 You say now
CAM-1 No, no but when you do push that
circuit breaker in
1510:43
CAM-3 Yes, sir
1810:47
RDO-l How far you show us from the field?
1810:51
PA Ah, Pd call it eighteen flyIng miles
1810:34
RDO-1 All right
1810:59
CAM-3 Boy, that fuel sure went to hell all of
a sudden, I told you we had four
1811:14
CAM-1 There’s ah, kind of an interstate high ---
way type thing along that bank on the
river in case we’re short
XXX
1812:03
CAM-? Okay
1812:04
CAM-1 That’s Troutdale over there about six
of one half a dozen of the other
1812:22
CAM-2 Let’s take the shortest route to the
airport
1812:42
RDO-l What's our distance now?
1312:43
PA Twelve flying miles
1812:48
CAM-? Well, * *
1812:50
RDO-1 Okay
1812:52
CAM-1 About three minutes
CAM-1 Four
CAM-? (Yeah) XXX
1813:21
CAM-3 We’ve lost two engines guys
CAM-2 Sir?
1813:25
CAM-3 We just lost two engines, one and two
1813:28
CAM-2 You got all the pumps on and everything
1813:29
PA United one seventy three heavy contact
Portland tower one one eight point seven,
you’re about eight or nlner flying miles from
the airport
CAM-3 Yep
1813:35
RDO-2 Okay, eighteen seven
PA Have a good one
1813:38
CAM-1 They’re all going
1813:41
CAM-1 We can’t make Troutdale
1813:43
CAM-2 We can’t make anything
1813:46
CAM-1 Okay, declare a mayday
1813:50
RDO-2 Portland tower United one seventy three
heavy Mayday we’re the engines are
flaming out, we’re going down, we’re not
going to be able to make the airport
1313:58
TWR United one
1814:35 ((impact with transmission lines as
derived from tower tape.))
1313:59
TWR ((end of tape))
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