Frontier DC3 hits mountain - 1957

FRONTIER AIRLINES, INC.
STAPLETON AIRFIELD
DENVER 7, COLORADO

DATE April 26, 1957
NO: 57-6

FLIGHT INFORMATION LETTER


To: All Pilots

Subject: Quick Decision


Report of Flight Irregularity - Captain Dale R. Welling - Flight 8, 4-21-57

On April 21, 1957, trip 8 and 7 departed Phoenix. I was in command of the
Phoenix, Arizona-Farmington, New Mexico—Phoenix segments. This is our
Denver trip, however, the crews connect at Farmington and return to their
respective origins. The trip was planned as VFR to Farmington and back to
Winslow, then IFR to Phoenix. We were anticipating a frontal passage by
late morning or early afternoon. The trip was flown as planned in every
respect to connection point (FMN) and back to Winslow, Arizona. At that
point it was evident that the frontal area had not approached as rapidly as
expected and I elected to continue VFR through Flagstaff and Prescott,
Arizona. Upon arriving at Prescott, I could see down the valley enroute to
Phoenix. I requested deletion of Prescott refuel from Denver Control and
would proceed VFR.

The trip departed Prescott at 1321 hours - eleven minutes behind schedule.
We were grossed out at 24,368 lbs. and had 22 revenue and 1 non-revenue
passengers on board. The flight continued in mild turbulence, similar to
what we had been experiencing all day. At approximately 1335 about 45 miles
south of Prescott, I requested and received latest Phoenix weather via VHF
as I could see build-up and converging layers ahead. I was told latest
weather available was 3 thousand broken, 10 thousand overcast. Changing
frequency to 118.1 to request approach control clearance, and being unable
I returned to Company frequency and requested and received clearance from
El Paso ATC. This clearance in part "cleared from Knob intersection to
Phoenix Omni, maintain 7 thousand”. Being at 65 hundred at the time, I
started to climb to assigned altitude before contacting cloud bank ahead.
The time now is about 1340. As climbing power was applied, still in VFR
conditions, the airplane seemed to settle slightly. No particular notice
was taken of this - it had been happening all day in light turbulence.
Settling continued so 25 hundred RPM and 35 inches was applied. Aircraft
still settled down. Maximum emergercy power applied at 41-42 inches and
2700 RPM. Aircraft still settled. Aircraft speed at this tine was 90 knots
indicated. We settled into a light snow squall below. It was light, fine,
dry, snow restricting visibility. The mountain peak below was hazily visible
through storm. Prior to this, it crossed my mind to make 180° out, but hesi-
tated to lose the lift I had because of low airspeed and sluggishness of
control. Aircraft still settled uncontrollably, contacting west slope of
mountain peak on my left wing. Measurements showed that 12 feet of wing was

Flight Information Letter 57-6 Page 2

sheared on this contact, as no pieces were blown off later. The aircraft
skipped and tumbled on its left side. Slightly decreased right engine power
and full right rudder was immediately applied. Plane staggered and slowly
returned to level flight. Left aileron (the piece that was still with me)
was frozen and immobile. Right aileron later disclosed as having 7 degrees
up-travel and restricted to 2 degrees down travel. Air speed at this time
started to increase and nose was lifted and maximum power continued.

At 1345 I declared emergency conditions through Company then contacted
Phoenix tower for emergency information, clear weather area, etc. I was on
solid instruments by now, but able to climb gradually under full power. Air-
craft returned to assigned altitude at 7 thousand where power was reduced as
best trim and controllability speed was found to be 130 knots. Vibration and
trembling encountered above 130 knots, sluggishness or wallowing below 130
knots. Flight was continued to Phoenix. Enroute emergency measures were
taken for arrival at field. Approach was made at 130 knots as reduced speed
felt inadvisable. Copilot and myself discussed briefly as to whether a chance
should be taken on lowering gear or ‘belly’ it in. We elected to try a fast
landing with gear down at last moment. We were over the fence at 125 to 130
knots. Touchdown after power reduction at estimated 115 to 120 knots. The
plane was taxied to the loading ramp and shut down.

Copy of Frontier's Statement sent to Civil Aeronautics Board

Frontier Airlines, Flight 7, encountered a sustained down draft 7.½ miles ESE
of Rock Springs, Arizona and made contact with a peak in the New River
Mountains at approximately 34° 00 ‘00" Lat.; 112° 0l' 30" Long., with full avail-
able power on both engines. The impact severed 12’ of the. left wing tip and
aileron from the aircraft.

PRC forecast for that period was ceiling 3000 broken, wind SSE 18 with showers.
vicinity by 1200M 1500 scattered, ceiling 2500 overcast with light rain
showers.

PHX forecast for that period was 8000 scattered, ceiling 10000 overcast,
occasionally 8000 broken with light rain showers by 1300M ceiling 8000 broken
light rain showers and possible light thunderstorms.

ABQ issued a flash advisory at 0555M advising of a cold front in the western
portion of Northwestern Arizona moving eastward at 15 knots. Front accompanied
by ceiling 1500 to 2500 overcast with light rain showers. Locally severe
turbulence in front and strong down drafts lee slopes of mountains and ridges
Northern Arizona.

A study of the sequence weather reveals that the front passed Phoenix at
approximately 1030M with weather better at 1130M than forecast. Testimony
of the Captain revealed weather conditions better than forecast prior to the
accident. Neither the turbulence nor weather encountered at that time would
be cause for alarm. He requested instrument clearance in the vicinity of
Rock Springs because the Phoenix 1330M weather was reported as estimated 3000
broken, 10000 overcast with a very light rain shower. This could be analyzed
as a local rain shower not associated with the front itself.

Flight Information Letter 57-6 Page 3

Considering the facts stated above the crew anticipated a routine flight to
Phoenix. The action taken by the crew at the time of the accident was all
that could be done considering the low airspeed given in testimony by the
crew. The action by the crew after the accident was commendable and the
contributing factor which eleminated the possibility of fatality.

Flexible Procedures

We should be grateful that there were no fatalities. Give the Crew a pat on
the back for a job well done. C.A.B. by telephone agrees with my report of
investigation. There is no pilot error involved in this accident.


E. L. Aden
Director of Flight Operations
and Chief Pilot
bw

<img src="www.stpaulairlines.com/albums/jerrysexhaust/FL_DC3HitMtn.jpg">

This is one heck of a story. I think I would have fainted even before the left wing hit the mountain peak.

Thanks for sharing the story Jerry.

Naresh

I would just have pressed "Esc"...very interesting story Jerry!!