[Milsurplus] Interesting findings on post-WWII aircraft VHF (Long)

[Todd Bigelow - PS]

I've been doing a little research today, including reading some crash
investigation reports. One of the reoccurring themes seems to be
unfamiliarity with VHF and/or the inability of the crew to use it
properly. Of particular note are the following excerpts from a crash
involving a C-47 into Pike's Peak in October of 1947:


13. NARRATION OF EVENTS:   On 14 October 1947 C-47A  No. 42-23503,
piloted by Maj. Robert R. Oliver, took
off from Hill Field, Utah at 1431 M for a flight to Lowry Field, Co.  At
approximately 1659 the copilot contacted Denver
approach control on VHF for letdown instructions, estimating his
position as 25 miles north of Denver on the north leg of the
Denver radio range. At 1608 the C-47 crashed on Pikes Peak. The pilot,
copilot and two passengers received major injuries.
Three passengers were killed and/or died from injuries and exposure.

........

F. No malfunctions nor discrepancies of the C-47 had been noted on the
flight from Des Moines to Hill other than the
needle-ball being inop.

G. At 1607 MST, the pilot contacted Sinclair radio and changed his
flight plan from VFR to IFR. Denver ATC cleared
the C-47 at 15,000ft to the Henderson fan marker at Denver.

H. The pilot violated AAF Reg. 60-16, Para. 55, Subsect (2), HQ AAF 28
Aug 1947 by requesting change of flight plan to IFR and encountering IFR
conditions with the T/B indicator inop.  This regulation states: "A
pilot will not fly an aircraft on an instrument or night flight unless
it meets the following requirements : The pilot's instrument panel
contains the following in
operating conditions: (c) Turn and Bank Indicator"

.......

M. The pilot, due to the great amount of precipitation static and
oscillation of the compass needle, was attempting to
track into Denver range by use of a nose null on the loop position of
radio compass.

N. A moment prior to the crash the copilot noticed trees a few hundred
feet below them. The copilot placed the props in
high rpm and pushed the throttles full forward. The pilot in an attempt
to climb, maneuvered the aircraft into an extremely nose
high attitude. The airspeed dropped to 50 mph and the aircraft mushed or
stalled into the north-east slope of Pikes Peak.

.......

T. Denver has a VHF radio range, but no attempt was made to use it.

.......

Under contributing factors, two are radio related:

15. CONTRIBUTING CAUSE FACTORS:

         A. Weather.

         B. Inability of the pilot to accurately report his actual
position to Denver Approach Control.

         C. Poor radio orientation in that the pilot failed to recognize
passing Denver while tracking on aural null.

         D. Failure of the pilot to to use all radio equipment available

Under 'Comments' is where the interesting stuff seems to be with respect
to VHF and radio compass:

 b. Using loop position on radio compass due to the precipitation
static, the pilot did not realize that the null would and
did pass to the tail of the aircraft as it passed over the Denver range.
Not realizing that he had passed the cone, it was quite
natural for the pilot to assume that the station was still ahead of him.
Had the pilot switched to a wing tip null as he approached
Denver, he could have definitely identified the station.

 c. It is believed that the marker beacon was inop. as the pilot could
not remember it operating on the flight from Des Moines that morning.
Radio compass had been used from Des Moines to Hill Field and it is
likely that he would have noticed it operating as there are several fan
markers and marker beacons along the airway.

 d. How the pilot could receive the Denver range on loop position as far
south as Colo. Springs cannot be explained as the investigating officers
flew over the crash area on a clear day when radio reception was
excellent. Denver radio range was
turned on, the radio compass and reception was excellent on "antenna"
position, fair on "compass" position, but there was no
reception on "loop" position. The scene of the crash on Pikes Peak is
appx 65 miles south of Denver. The pilot should have
known that the volume would build as he approached the range station.
Actually he would have had to increase the volume
several times going away from Denver radio if he were receiving Denver
radio at the time of the crash.

f. Denver is equipped with a VHF radio range. The C-47 carried ILS
(ARN-5) equipment. The radio facility chart lists
all VHF ranges and diagrams of range legs, aural and visual, yet no
attempt was made to utilize this equipment even though the
low frequency radio equipment was practically useless because of static.
It is believed that the pilot was not familiar with the
operation and procedure for VHF ranges.

g. A spot check of several pilots revealed that very few are familiar
with VHF radio ranges and several did not know
such equipment existed. Since the majority of Air Force aircraft are
equipped with ARN-5 equipment, VHF ranges could be
used during adverse weather conditions.

Finally under 'Recommendations" is listed this suggestion:

 b. That the "Operation and Procedures" for VHF ranges be published as a
special subject by Flying Safety Division, this
HQ.


....wow! Of course, it doesn't state what this 'spot check' consisted
of, what kind of sampling or how widespread, but it would seem that
pilots weren't as familiar with VHF as we'd perhaps think? This was late
1947, too.


de Todd/'Boomer'  KA1KAQ