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 1, 1984, the first day of the NTSB hearing into this midair collision, as reported by Milton Reporting, Inc.
[Return to "Reasonable Doubt" Home]
Gary W. Hobbs, a nine year FAA employee and the On-the-Job Instructor (OJTI) for Bill Simons, was ultimately responsible for the sector that day. He testified...
From page 125.. 19 Q Did you also look at the radar scope about that 20 point in time? 21 A Well, he gave the transponder code and I looked and 22 I saw the correct code change from a V to a 6721 code. Is 23 that what you mean, before we identified it? 24 Q Uh-huh. So then, do we understand that you were 25 dividing your attention between checking the strip and
From page 126... 1 looking at the radar scope? 2 A Sure. That's normal. 3 Q When Mr. Simons issued the discreet transponder 4 code 6721 to Flight 628, what did you see on the radar scope 5 at that point in time? 6 A I saw a code northwest of San Luis Obispo Airport. 7 I saw, I believe it was a Mode C of approximately 2,300 or 8 2,400. I saw a change to a 6721 code. 9 Q So in other words then, you did see a code 1,200 10 target initially and you saw this same target switch over to 11 a discreet code? 12 A Uh-huh. 13 Q Did you see any other VFR targets in proximity to 14 this particular target? 15 A I saw no one to the northwest of the target. 16 Q About how far? 17 A I said I saw no target. 18 Q Oh, no others in the northwest. 19 A To the northwest.
From page 131... 7 Q When you were checking for this traffic, did you 8 have to shift your position in your seat in any way, or were 9 you seated in such a way that you had an unobstructed view of 10 the scope? 11 A I was standing behind Mr. Simons. I had an 12 unobstructed view of the radar. 15 Q Based on your recollection during your experience 16 at the Los Angeles Center, about how often have you 17 experienced a situation where a pilot says he sees traffic 18 out there in proximity to his aircraft and this traffic does 19 not show up on your radar scope? Does that happen very 20 often? 21 A Well, it happens occasionally. I wouldn't describe 22 it as very often, maybe once or twice a week. Of course, it 23 depends on what sectors you end up working for that week. If 24 you worked low altitude sectors for a week you'd be more 25 inclined to observe that type of phenomenon, I'm sure.
Page 132 1 Q And have you ever experienced a situation where 2 this has occurred, the pilot said he had traffic and you 3 looked down and did not see it, and then later on this 4 traffic shows up, say on a code 1,2000 target? 5 A Yes.
Page 156 4 Q With respect to the Commander C-Mode transponder 5 targets for targets over 2,700 feet and within 15 miles of 6 the San Luis Obispo Airport, can you point to any 7 documentation that documents any history of transponder 8 targets not showing up on the scope in that area? 9 A Not documented. I can recall aircraft that were 10 transponder equipped not appearing in that area. 11 Q In the Mode-C not appearing in that area? Are you 12 suggesting then that there are blank spots in that area? 13 A I'm not. I'm just saying that I have had aircraft 14 that were transponder equipped not appear. For what reasons, 15 whether it's equipment or not, I can't say. And that's not 16 the only area, of course. There's other areas too that that 17 occurrs. 18 Q Mr. Hobbs, to be a little more specific, I said 19 transponder equipped. How about squawking a transponder code 20 in the Mode-C position, do you have any knowledge of any 21 documented history of such aircraft not appearing in the 22 vicinity of Dobra? 23 A You're referring to altitudes above -- 24 Q 2,700 feet. 25 A It's not to my knowledge of any documentation
Page 157... 1 regarding it. I'm sure everyone who works that sector 2 probably has had experiences where they've had aircraft that 3 were transponder equipped and didn't appear.
Page 168... 22 Q I think you said earlier that there have been some 23 times when you've worked at least Sector 15, that some 24 aircraft have called you and you've not been able to discern 25 their target on the radar scope, and maybe even some above
Page 169... 1 3,000 feet? 2 A Sure. 3 Q And more specifically, above 3,000 feet northwest 4 of San Luis Obispo? 5 A I don't have any specific recollection of that. I 6 have worked the entire sector and as far as -- it could 7 happen in just about any part of the sector. 8 Q When these aircraft with transponders didn't 9 appear, though you knew generally the area they were, at 10 least they were in the sector you were working, did it 11 concern you that it didn't appear on the radar at all, and 12 the capabilities of your equipment? 13 A I presumed that it's in the aircraft rather than 14 the equipment, because you'd be showing other targets. 15 Q Did you ever report any of this to any of the 16 appropriate personnel with the FAA? 17 A You mean not receiving targets? 18 Q Yes, the fact that targets didn't appear but yet 19 you were talking to them and they should have appeared? 20 A Well, normally you would just consider it to be an 21 equipment malfunction on the aircraft rather than the radar. 22 Q Is there any way for you to discern whether it's an 23 aircraft malfunction or the radar? 24 A Just based on the other traffic. It's possible 25 that you could lose part of the common digitizer and not have
Page 170... 1 any targets in an area, and naturally that would be drawn to 2 you attention rather rapidly. 3 Q Who was ultimately responsible for the separation 4 of traffic and the issuance of safety advisories in Sector 15 5 at the time of the accident? 6 A I was responsible for the sector and the operation 7 of the sector.
[Return to Reasonable Doubt Home]
The above text was obtained from microfiche as obtained from General Microfilm of Whiten, 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
© 2000 by Lusch's Midair Collision Investigations. All rights reserved.