Testimony of Gerald Walton

The following is in the Matter of...

Investigation of Accident Involving
Wings West Airlines, Inc., Beech
C99, N6399U, and Aesthetec, Inc.,
Rockwell Commander 112TC, N112SM, near
San Luis Obispo, California, on
August 24, 1984

This following dialog was recorded on November 2, 1984, the second day of the NTSB hearing into this midair collision, as reported by Milton Reporting, Inc.

[Return to "Reasonable Doubt" Home]

Gerald Walton was the Air Traffic Manager of Los Angeles Center...

Page 356...

11      Q    The NTAP, Mr. Walton, clearly shows that the Aero 

12 Commander had an operating transponder and was being processed 

13 by the computer.  Now, the controllers claim that the beacon 

14 data did not show up on the radar scope.  Do you have any know-

15 ledge of why it shouldn't have been seen?

16      A    I have no knowledge of why it should not have been 

17 seen, no.

18      Q    Since the accident have you asked your data system 

19 staff to investigate this discrepancy?

20      A    They have investigated extensively.

21           MS. GOLDMAN:  And they will be testifying later.

22           MR. WALTON:  Yes, they will.

23 BY MR. MORRO:

24      Q    Did they indicate to you what they found?

25      A    They have no answer either.  I can only, I believe,

Page 357...

 1 I believed then, and I believe now that the target was not 

 2 on the radar scope.  Mr. Simmons issued a clearance to Wings 

 3 West 628.  I know that in issuing that clearance he would have 

 4 physically looked at the target when he identified Wings West 

 5 628, and I know that if he looked at that target and there was 

 6 a 1200 target as traffic in the immediate vicinity of that 
 
 7 target, he certainly would have seen it, and he certainly 

 8 would have issued the traffic because he was issuing traffic 

 9 to other aircraft.  The fact that he did not issue that 

10 traffic tells me that he did not see that traffic, and the 

11 fact that he didn't see it tells me that it wasn't there.  Why 

12 it wasn't there I don't know.

13      Q    But you would have to agree, Mr. Walton, that the 

14 raw data indicates that the target should have been on the 

15 radar scope.

16      A    It tells me that the raw data came into the facility,
 
17 it was processed, and it was printed out on the NTAP.  Why 

18 it did not get displayed on the radar scope I can't answer, and 

19 perhaps no one can answer.  Maybe someday someone will be able to 

20 answer.  But, in my judgement based upon all the facts that 

21 I know now and all the facts that I knew then, in my judgement, 

22 the target was not on the radar scope.

23      Q    Would you say that radar is in fact a safety tool

24 for the controllers in which to flow the flow of aircraft

25 through our airways?

Page 358

 1      A    Absolutely.

 2      Q    So, if we have a discrepancy now with the fact that

 3 the data was in fact at the Palmdale Center in the NTAP  and

 4 we have four controller that did not see it on the screen,

 5 did you pursue an investigation to find out why?

 6           MS. GOLDMAN:  He just said, he already said yes.  He

 7 just answered that.

 8 BY MR. MORRO:

 9      Q    Am I to understand they gave you no indication and

10 no results of that investigation?

11      A    They gave me results of that investigation, and the

12 results were that they don't know why it was not displayed.

13           MS. GOLDMAN:  And the person who did that investiga-

14 tion is one of our next witnesses.

From Page 371...

 6           MR. WALTON:  My testimony was that in my judgement

 7 it was not there because the controllers didn't see it.  As to

 8 why it was not there I don't know --

 9           MS. GOLDMAN:  Why or whether, okay.  Sorry, I

10 wanted to clarify --

11           MR. WALTON:  I'm expressing my opinion of the fact

12 that it was not there.

13 BY CAPTAIN McCLURE:

14      Q    And, your opinion is based upon what your data

15 systems personnel have reported to you is that correct?

16      A    No, my opinion is based on the fact that four

17 excellent air traffic controllers were observing the sector.

18 They issued a clearance to Wings West 628.  As a former con-

19 troller myself, I know that any time a controller issues a 

20 clearance to an aircraft, he would physically look at that

21 target on his radar scope.  And, if he looked at the target on

22 his radar scope, if there were traffic in the proximity of

23 that target, he would surely see that traffic.  Inasmuch as

24 Mr. Simmons was very being very conscientious about issuing

25 traffic, then he certainly would have issued that traffic had

From Page 372...

 1 he seen it.  Therefore, my conclusion is that he did not see

 2 it, the other three people did not see it, therefore, I can

 3 only conclude that it was not there.  Why it was not there

 4 I have no idea, and no one has been able to tell me why it

 5 was not there.

 6      Q    Do you think there is a possibility that other tar-

 7 gets might not be there?

 8      A    Certainly, I would say that there probably is that

 9 possibility.  I would think that if an aircraft perhaps had

10 a weak transponder, and there may be something in the mysteries

11 of computers which allows that to happen.  I don't know.

12      Q    Well, if, let me put it this way in speculation

13 only, and what concerns me the most is if in fact there is a

14 problem with the computer system that would allow a target not

15 to be displayed on a radar scope, and quite frankly, a lot of

16 people spend a good portion of their time n the air using

17 your service which we greatly appreciate, this could great a

18 bit of havoc, could it not?

19      A    Oh it certainly good, and I spend a great deal of

20 time in the air too and I share your concern.  But, I have no

21 indication that this is a problem area.  Only in this instant

22 case am I expressing my opinion based on the conclusion which

23 I just described.

[Return to Reasonable Doubt Home]

The above text was obtained from microfiche as obtained from General Microfilm of Wheaton, MD.

This text was converted from microfiche, to paper, then scanned for Optical Character Recognition (OCR) processing, followed by a great deal of manual editing by Tom Lusch for correct presentation on "Lusch's Midair Collision Investigations" web site <http://home.columbus.rr.com/lusch>. Any errors or omissions resulting from this microfiche to web page process are solely the responsibility of Tom Lusch. Every effort was made to make this an accurate representation of this deposition transcript, right down to mis-spelled and/or incorrect words.

This page created Feb 25, 2000