1. (U) On 3 July 1988, the USS Vincennes (CG 49), operating in the Southern Persian Gulf as a unit assigned to Commander, Joint Task Force Middle East, downed a civilian airliner, Iran Air Flight 655 on a routine scheduled flight from Bandar Abbas to Dubai, with two SM-2 missiles.
2. (C U) The material condition, combat systems, training and personnel readiness of the ship were satisfactory.
3. (U) The following narrative summarizes the events leading up to and including the downing of Iran Air Flight 655. It is in the form of a chronology because the situation leading up to, just prior to, and during the few critical minutes from Iran Air Flight 655 take-off to downing are considered important to a full understanding of the incident. All times in the report are “Z” time.
1. (SNF U) In the three day period prior to the incident, there was heightened air and naval activity in the Persian Gulf. Iraq conducted air strikes against Iranian oil facilities and shipping 30 June through 2 July 1988. Iranian response was to step up ship attacks. Additionally, Iran deployed two, possibly three, F-14’s from Bushehr to Bandar Abbas. U.S. Forces in the Persian Gulf were alerted to the probability of significant Iranian military activity resulting from Iranian retaliation for recent Iraqi military successes. That period covered the fourth of July holiday weekend.
2. (SNF U) During the afternoon and evening hours of 2 July 1988 {p.5-1988} and continuing into the morning of 3 July 1988, Iranian Revolutionary Guard (IRGC) armed small boats (Boghammers, and Boston Whalers) positioned themselves at the western approach to the Strait of Hormuz (SOH). From this position, they were challenging merchant vessels, which has been a precursor to merchant ship attacks. On 2 July 1988, USS Elmer Montgomery was located sufficiently close to a ship attack in progress as to respond to a request for distress assistance and to fire warning shots to ward off IRGC small boats attacking a merchant vessel.
1. (S U) On the morning of 3 July 1988, USS Elmer Montgomery was on patrol in the northern portion of Strait of Hormuz Western Patrol Area (SOHWPA). ¶
2. (S U) During the course of the gun engagement of the Iranian small boats, the USS Vincennes, at approximately 0654Z, had maneuvered into a position 1 mile west of the centerline of civilian airway Amber 59. The USS Sides, transiting from east to west through the SOH, was approximately 18 miles to the east and became involved in the evolving tactical situation. {p.6-1988}
1. (SNF U) On 3 July 1988, at approximately 0647Z, an Iran Air Airbus 300, Iran Air Flight 655, took off from the Bandar Abbas joint military/civilian airport destined for Dubai airport. The flight was a routine scheduled, international flight via commercial airway Amber 59.
3. (SNF U) An Iranian military C-130 took off approximately 7 minutes after Iran Air Flight 655, and a number of Iranian F-4’s {p.9} were observed to be operating in the area of Bandar Abbas approximately 30 minutes after the incident.
4. (SNF U) Iran Air Flight 655 took off on runway 21 (heading 210 degrees true), was directed by the Bandar Abbas Tower to squawk IFF mode III code 6760, and began a normal climb out to assigned altitude of 14,000 feet for the flight, which lasted a total of 7 minutes before the plane was hit by the missiles from USS Vincennes. The pilot remained within the Amber 59 air corridor (20 miles wide, 10 miles each side of centerline), made a routine position report to Bandar Abbas departure control at approximately 0654Z, and was ascending through 12,000 feet at a speed of approximately 380 kts at the time of making his report.
Senator Carl Levin: On page 6 of your report, paragraph 4, you indicate that Flight 655 was directed by the Bandar Abbas tower to begin a normal climb to an assigned altitude of 14,000 feet, to squawk Mode III code, et cetera.
How do we know that?
Admiral William M. Fogarty: Sir, I have to talk to that in closed session. I cannot discuss that at this level.
Senator Levin: We were not in touch with that tower?
Admiral Fogarty: No, sir.
Senate Hearing, p.25 (Sept. 8 1988).
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The intelligence sources, Mr. Fogarty here alludes to, were, presumably:
• Naval/NSA signals intelligence officers onboard the Vincennes itself with the Naval Security Group Command (NSGC) in charge of the Ship’s Signals Exploitation Space (SSES), recording all Iranian radio broadcasts.
• The NSA/DIA on-shore listening/radar station in Oman, on the Musandam Peninsula {photo: 257kb.html, map: 79 kb gif} (with antennas likely at 2,000 feet or better elevation {67 kb gif}, with line-of-sight to the broadcast antenna at Bandar Abbas airport, no more than 45 n.miles north), recording all Iranian radio broadcasts.
• The Hawkeye crew aloft nearby at the time, above the Northern Gulf of Oman, recording all Iranian radio broadcasts.
• The AWACS crew aloft at the time, above the Northern Persian Gulf, recording all Iranian radio broadcasts.
• Possibly, British Intelligence (on its warships, or its likely GCHQ feed from the same listening station at Musandam), recording all Iranian radio broadcasts.
• And, finally, the NSA Head Office at Fort Meade Maryland, and the Defense Intelligence Agency at the Pentagon in Virginia, each recording in real time, via satellite relay from their listening station at Musandam, if that’s they wanted to do, all Iranian radio broadcasts.
Plainly, Mr. Fogarty had in his possession multiple tape recordings and transcripts of the broadcast conversations between Air Traffic Control and the IR655 pilot. And, between the IR655 pilot and his airport office.
And surely these were tone time-stamped, automatically in the recording (like Air Traffic Control tapes are), at the uniform U.S. Military time, synchronized to a zillionth of a second, worldwide, by the U.S. Military’s atomic clocks.
These time-stamped recordings are among the most material facts in this investigation. As we shall soon see. And, not being a nincompoop, William M. Fogarty knew that too.
And yet, Mr. Fogarty concealed these material tapes and transcripts from his report.
Concealed them from the classified exhibits to his report.
And concealed them from the classified enclosures to his report.
Why did Mr. Fogarty decide to omit this material information? And thereby commit a prima facie crime (lying by material omission).
He must have had a good reason.
Could this be the reason?:
Congressman Les Aspin (Chairman): Is there some reason to doubt that when you are asking a plane to identify itself or its purpose, it may be the plane doesn’t know that it is being addressed? ...
Rear Admiral Robert J. Kelly: What I said was basically that the international distress frequency on VHF, which is a frequency of 121.5, is what is commonly used for these warnings.
There is also an effort underway to install more VHF radios on our ships over there. The VHF radio on Vincennes was difficult to re-tune, so it couldn’t be done very quickly.
One of the recommendations and steps that we have taken is to install an additional VHF radio on those ships which is dialable. In other words, the guy can just dial in the new frequency like a telephone and it will change.
What we were hoping to be able to do was to establish through some network over there another method besides 121.5 to communicate if a coordination problem arises.
For example, if we knew what the frequencies the aircraft were assigned as they transited certain areas of the Gulf, our ships could then come up on those frequencies.
We are still working on that.
In the interim, we have already installed radios on the ships that are serving in the Middle East forces.
Robert J. Kelly (Rear Admiral, Vice Director for Operations, Joint Chiefs of Staff, U.S. Department of Defense), House Hearings, p.184 (Sept. 9 1988)
Senator John Glenn: I would be interested ... if you considered assigning any responsiblity for the Vincennes shoot down to the Commander of the Joint Task Force of CinCCent for failure to recognize and extablish adequate procedures to deal with commercial air traffic in the Gulf.
Admiral William M. Fogarty:... There was nothing that I found during the course of my investigation in this regard that would have made me consider assigning any responsibility for the Vincennes incident to Commander Joint Task Force Middle East of USCinCCent.
Senate Hearing (written questions/answers) p.55-56 (Sept. 8 1988)
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And, there are two other good reasons:
• See below, for a warning broadcast by the Vincennes IAD radio-talker, while the IR655 pilot was busy talking to Air Traffic Control — a carefully concealed material fact and prima facie crime.
• And see here, for carefully concealed evidence that the Vincennes and Montgomery IAD radio talkers were broadcasting and talking at the same time, simultaneously, a jumble of nothing any human being could understand — a carefully concealed material fact and prima facie crime.
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These carefully concealed recordings bear directly on the State Responsibility of the United States of America to the Islamic Republic of Iran.
Accordingly, to conceal this material evidence constitutes all those participating in the prima facie criminal conspiracy to lie (a “felony”), in this official report, and in testimony to Congress, equally complicit in the foreseeable consequences of their felony conspiracy, namely:
The felony-murder, or manslaughter, of the mostly American victims of Pan Am 103, bombed a few months later (December 21 1988, 270 victims), a promised, foreseeable, apparent, international countermeasure to the first criminal enterprise, the conspiracy of criminal liars, who decided to lie, and falsely deny responsibility, on behalf of the United States, thereupon legalizing an eye for an eye (a species of self-defense). –CJHjr
5. (S U) At approximately 0654Z, the missiles fired from USS Vincennes impacted the aircraft at an altitude of 13,500 feet, approximately 8 miles from USS Vincennes, with Iran Air Flight 655 still in its assigned air corridor. Debris from the aircraft and a significant number of bodies were found 6.5 miles east of Hengham Island at 26-37.75′N/56-01′E. While no passenger manifest nor list of deceased has been released by Iran, various sources have established that some 290 persons from six nations, were on board Iran Air Flight 655.
6. Vincennes—Critical Decision Window
Query: “900 feet”? “1500 feet”?
Are these the same altitude?
They indeed could be.
The explanation, for why these two altitudes could be the same, senior U.S. Military Officers omitted from their report.
This explanation would reveal some things they were very eager to conceal. (To be explained below).
A fine piece of obfuscation. One of the many elements in this report, and omitted from it, contributing to the richly deserved recognition it later received: The annual Doublespeak Award for 1988.
We’ve had the warship clock.
Here, now, is another missing piece of this doublespeak jigsaw puzzle:
The 900-feet altitude value, perceived by the Vincennes, was the altitude broadcast by the aircraft’s transponder (mode-C).
An SSR/IFF transponder broadcasts “pressure altitude” (rounded to an even 100 feet), not actual altitude. This is the altitude value used to denominate Air Traffic Control “Flight Levels”. And, because all transponders broadcast this altitude value, Air Traffic Controllers can know with certainty the vertical separation between aircraft aloft.
To accomplish this certainty, the altimeter connected to the transponder, supplies to the transponder an altitude value based on the “standard” barometric pressure of 1013.25 millibars (hPa: hecto-Pascals) (29.92 inches of mercury) (QNE). And this, the pilot cannot alter.
This “standard pressure” was 15 millibars higher than the actual airport air pressure when Iran Air Flight 655 took-off, namely: 998 millibars (hPa) (29.47 inches of mercury) (QNH: adjusted down to mean sea level pressure, by ISA standard formula).
Thus, when the aircraft was sitting on the runway, its transponder (if interrogated) would broadcast an altitude of roughly 400 feet below sea level (about 28 feet per millibar).
This amounts to about 550 feet lower than what the warship radar perceived to be the aircraft’s actual altitude.
See ¶¶ (aa)-(bb), p.56/39, and add 50 feet to the transponder’s altitude broadcast, to reflect the aircraft’s climbing rate of 25 feet per second (1500 feet/minute) during the 2 seconds prior to the warship’s radar altitude value. But see ¶ (g), p.40/28, asserting a 3 second difference, indicating a 525 foot difference instead.
The 150 foot difference (from a runway broadcast) was due to: The 22-foot runway elevation. The height of the warship radar antenna above the sea. The transponder rounding up or down by as much as 50 feet, to an even 100 feet. The DoD report-writers possibly rounding the precise radar altitude value. A slightly different precise air pressure. The state of the tide (on which the warship radar floats up and down, from “mean sea level”): Low tide at 0615. An airport surface air temperature (35°C ) 20°C higher than the ISA standard atmosphere model (15°C), to which altimeters are calibrated. An air temperature at 10,000 feet (18°C) 22.6°C higher than the ISA model, and 2.3°C higher than specified by the ISA “lapse rate” (1.98°C per 1000 feet) from the actual airport temperature. And such. (Meteorological data: ICAO Report, ¶ 1.7, pp.4-5).
The transponder does not broadcast continuously, only in response to an interrogation pulse-train. When interrogated, it broadcasts a pulse-train, encoding either it’s 4-digit identification code number (mode A) or its pressure altitude (mode C) rounded to an even 100 feet. Depending on which pulse-train it received from the interrogator. (The interrogator broadcasts both queries, one after the other).
A transponder broadcasts its reply (on 1090 mHz), 2-microseconds after it receives the last of an interrogation pulse-train (on 1030 mHz). It can reply to 2000 interrogations per second.
The report asserts, that the Vincennes SPY-1 radar interrogated automatically “at one minute intervals”.
Is this a mistake? Perhaps referring to interrogations to an empty sky? Which is not what this report is about. Concealing more frequent automatic interrogations? Once the computer detects a moving target?
I would expect once per second, or thereabouts. An aircraft can cover a lot of altitude in one minute. And though the radar is pulsing fast to watch it, why not pulse the transponder too?
If this assertion be true, and not a mistake, then this detail might have affected events on the day. Because of the sudden jump in altitude displayed to the warship crew, before the radar altitude starts to work (at 6000 feet, in this case). And, thereafter, the jumping disparity between the two altitude values (over a one minute lag). And especially so when, as here, the two altitude values are already more than 500 feet apart to start with.
This sudden jump, in transponder altitude, might be confusing, and suspicious, in a suspicious mind, in a stressed mind. This AirBus was climbing 1500 feet per minute. As it approached.
However, the separate Vincennes rotating air search radar antenna (AN/SPS-49(V)) also interrogates target transponders, as it sweeps, selectable, at either 6 or 12 sweeps per minute (every 10 or 5 seconds). Like an Air Traffic Control radar does. The report does not state whether its radar returns, and transponder responses, are integrated by the SPY-1 computer, automatically updating its database, for all its CRO computer displays. If not, they are anyway certainly shown on the computer console of that rotating radar’s operator (49 ADT).
But I imagine they do update the database, every 5 or 10 seconds. In which event, there is no sudden jump in transponder altitude, and this detail has no bearing on the events of the day.
We’re also supposed to believe this: All warship crew members, in the CIC, having responsibility for aerial threats, can position their computer mouse cursor (“range gate”), on a radar target, displayed on their computer consoles. And thereby manually interrogate a target’s transponder. As often as they wish. And many of them did this, many times, during the flight. Sometimes referred to as a “challenge” (p.48/32, ¶¶ 0650(f); p.49/33, 0651(i)) or an “interrogation” (¶ 7, p.65/47; Crowe endorsement, ¶¶ 5(b)).
This is apparently possible with the UPX-29 transponder-interrogator system:
“The AN/UPX-29 can be controlled from up to 22 manually operated display positions, one semi-automatic operating position, and one shipboard computer controlled interface. These positions can function simultaneously, and AIMS functions are available at each position independent of the functions selected at other positions.”
because its OE-120/UPX antenna is separate from the interrogator antennas connected to the warship’s two radars (phased array and rotating, though the phased array radar may share this interrogator antenna):
“The AIMS antenna consists of 64 radiating elements arrayed in a circle around the ship’s mast. Unlike conventional IFF systems which employ mechanically rotated antennas, the AIMS antenna elements remain stationary while the beam is steered electronically to scan a full 360 degrees around the ship. The beam can also be positioned selectively in any direction within microseconds and has a continuous scan rate of up to 90 revolutions per minute.”
According to this DoD report, the transponder response appears on a separate display from the normal CRO computer screen (which also displays transponder responses, from interrogations by the two radars.) We’ll hear more about this later, in connection with a certain C-130, ducting, and an F-14.
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The Sides was 15 n.miles closer to the airport than the Vincennes. But not in the middle of the airway (as the Vincennes was), due to the geography of the area.
The Sides was, however, likely in Iran’s territorial waters (as the Vincennes was too). I haven’t yet tried to determine the precise territorial boundary at the bend in the Strait of Hormuz, but it looks like the shipping lane boundary is also the territorial boundary. This, because the strait is too narrow to enable ships to be 12 n.miles from all surrounding land. And so, a shipping lane has been agreed by the neighboring countries, to enable the “innocent passage” international law requires.
The Sides was not inside that shipping lane, as I plot its position, but, instead, a mile or two towards the airport from the shipping lane boundary.
This may indicate that the report writers decided to conceal the Sides precise location. And to obfuscate which altitude value they reported. (The lower the altitude, the closer to the airport). And why they use their favorite word, “approximately” (“approximately 355 degrees,” “approximately 32 miles”).
They omitted it too from their classified secret exhibits. They list the position log of the Vincennes, and the Montgomery, but not the Sides. (Position Log: The continuous time-stamped position of the ship, from the inertial navigation system).
Did they have a good reason? To purposely conceal position information on the Sides? Or is this merely their unintentional oversight? Or did they honestly consider that information was not material to their task?
It’s almost like the Sides was standing picket, on the airport, while the Vincennes set out to attack and destroy Iran’s coast guard boats. Part of Operation Praying Mantis.
Being much closer to the airport than the Vincennes, the Sides 1500-foot altitude value, reported by the DoD report-writers, could be the aircraft’s radar altitude, not its mode-C transponder broadcast.
The aircraft was well above the Sides’s horizon, at its 32 n.mile range, and well in view by the Sides radars.
Indeed, at 1500 feet radar altitude, the aircraft would have line-of-sight to the Sides at 45 n.miles. And so, at the airport’s apparent actual range (32-33 n.miles), the Sides could theoretically detect the aircraft at 350 feet transponder pressure altitude (900 feet radar altitude):— Long before it reached 1500 feet transponder pressure altitude (2050 feet radar altitude).
And all this without enhanced detection range, from the ducting they claimed existed on the day.
The Sides AN/SPS-49(V) rotating air search radar is a two dimension radar (2D: range, bearing). It cannot determine the height of a target. (The Vincennes SPY-1A phased array radar can).
Therefore, the Sides could determine the target’s altitude in only two ways: From the target’s transponder broadcast and by locking-on with its fire-control radar, which is a three dimenson radar (3D: range, bearing, altitude) and does determine altitude.
And that’s exactly what the Sides commander did, within a minute or so after take-off.
Hence, the 1500 feet, the DoD report-writers asserted, could be the Sides fire-control radar altitude value, not the aircraft’s transponder broadcast.
And, query, does the Sides fire-control radar have a tape recorder attached? And is there a written log in real-time showing these values (time, range, bearing, altitude)? Is switching on a targeting radar, merely to determine altitude, or to warn a pilot, a big enough deal that the Navy requires a written or tape-recorded record of the event? And a justification for it? Or is it routine, and not logged?
The report asserts, that the Vincennes computer system switched, from the aircraft’s transponder mode-C altitude broadcasts, to the warship’s own SPY-1 phased array radar altitude value, at a range of 34 n.miles, when the aircraft was at about 6000 feet radar altitude, and broadcasting about 5400 feet pressure altitude. This fact they concealed from the public report. One of their many obfuscations.
The Vincennes’s initial altitude value of 900 feet pressure altitude (the transponder broadcast) was detected at 0647:37Z. The DoD report writers concealed from their public report both the time and the altitude. And they concealed the time from their classified report. They disclosed the altitude later, in Congressional hearings. (Senate Hearing, p.10 (Sept. 8 1988); House Hearings, p.88 (Sept. 9 1988)). And the secret ICAO Report later disclosed the exact time (ICAO Report, p. A-3 (Nov. 7 1988)). “At approximately 0647Z,” as the DoD report-writers generalized the time in their report (both classified and public) and in their Congressional testimony.
The Sides, 15 n.miles closer to the airport, was able to detect the aircraft before the Vincennes did. Allowing for a few seconds difference between the two observations, the Sides’s value of 1500 feet, “at approximately 0648Z,” could be identical, if it was a radar altitude value.
But, this cannot be the case.
Unless the report writers misposition on the timeline when the Sides first locked on.
The DoD report writers willfully misposition other events and recollections on the timeline, detailed elsewhere herein, in order to portray a false reality. Did they also do that here?
The report writers positioned directly together on the timeline both the Sides lock-on and the Sides “weapons on target” message to the Vincennes (concealed from the 1988 public report). The lock-on and the message are separated in the DoD report only by supposed recollections of the event.
If the “message” they refer to were a verbal radio conversation, then this is unlikely the case. Because the Sides officer first had to lock-on, and wait, before he could evaluate the pilot’s response, if any.
Did the report writers conceal, that the lock-on was that many seconds sooner than the “message,” that the Sides 1500 feet altitude observation was a radar altitude value, not a transponder value?
The Sides did not report altitude to the Vincennes (at least, the DoD report writers don’t say so). Altitude isn’t what the Sides officer was mainly interested in. And that’s not why he locked-on.
He locked-on because that’s what his Rules of Engagement required him to do. To warn the pilot. To attempt to learn if the aircraft was military or civilian.
And so, that purpose required him to wait some seconds to see if the pilot would react, to the cockpit alarm, from his cockpit radar homing and warning receiver (RHAW), which airliners don’t have.
If the DoD report writers buried the Sides earlier radar altitude observation, in this lock-on “message,” then the Sides was yet another mile or two closer still to the airport, and that much deeper still into Iran’s territorial waters, than if the 1500 feet was a transponder value.
An excellent motive. To obfuscate this altitude observation. And to conceal the position of the Sides.
The DoD report writers had two tape recordings of the conversations between the Sides and the Vincennes, and so had no difficulty in knowing precisely who said what, to whom, and when. Any delay, however, between the initial lock-on, and the “message” to the Vincennes would not appear on those tapes. While the Sides officer was evaluating the target’s reaction to being locked-on.
And did the Sides “weapons on target” message to the Vincennes (omitted from the report) specify a radar altitude?
If the 1500 feet was a transponder value, then the two reported observations are that many seconds apart that the aircraft climbed in the meantime.
And this I believe to be the fact of this particular altitude report.
The Sides certainly observed the aircraft much sooner. And I suppose the DoD report writers simply concealed that fact. Though, it may be, that nobody on the Sides was asked about, or mentioned, a lower altitude observation.
The “message” the DoD report writers refer to (which they concealed from the 1988 version of their report) was not a verbal conversation on the radio. It was computer-talk: An automatic, computer-generated, Link-11, computer message. This fact the DoD report writers concealed, from both the public and the classified versions of their report, presumably to conceal three separate items of negligence discussed below.
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To determine the position of the Sides (which the report writers omit from their report), you have to know, where was the aircraft at 1500 feet altitude? Be that actual or transponder.
How far from the end of the runway?
And to know that, you have to know the weight of the aircraft, and its flight profile, on takeoff.
IR655 may have been at 1500 feet actual altitude directly over the coastline, which lies about 1.5 n.miles off the end of the runway, doing about 150 knots. And, conceivably, he may have been higher. (Admiralty Chart 2888, widths: 620px,
780px,
1000px,
1263px,
1580px).
This, based on its take-off weight of 288,026 pounds (130,921 kg). (ICAO Report, pp. A-4, D-10). And, based on the manual for an AirBus A300B4. (IR655 was a B2, and maybe I can eventually find a B2 manual). And, based on two flight profile sheets from AirBus, in the ICAO Report (pp. D-21, D-22). And, assuming he took off about half way down the runway (2.0 n.miles long).
According to this information, at a take-off weight (TOW) of 290,000 pounds, IR655 rotated (V1), on its take-off roll, at 137 knots, took-off (V2) and climbed under full power at about 150 knots (V2+10 knots), at a pitch of 15-18 degrees nose-up. At 800 feet AGL (above ground level), the pilot reduced thrust to his “climb” power setting, and compensated, by reducing pitch to 10 degrees nose-up, thereby maintaining his speed at about 150 knots, and reducing his rate of climb (but maybe not, as he had also retracted his landing gear by then, and eliminated that drag). By 2000 feet, he may have retracted his flaps (V3: 153 knots), thereby beginning his acceleration. Following slat retraction (V4: 192 knots), he was due to reduce pitch again, to 7.5 degrees nose up, continuing to accelerate to his “final take off” speed (Vfto: 222 knots).
If he took off half way down the runway, then the coastline was 2.5 n.miles away.
Could he get to 1500 feet, in two and a half miles? Or 2000 feet?
At 150 knots? (IAS: Indicated Air Speed, not ground speed).
I guess I need an AirBus pilot with a stop watch, or an Air Traffic Controller, to tell me. But I haven’t given up searching for the answer to this. And I’m even thinking about getting out my graph paper, and see if I can plot this profile. And vector his speed (part up), and determine his altitude, from pitch (assuming little additional lift).
If the aircraft was directly over the coastline, at 1500 feet — be that actual (radar) altitude, or be that transponder altitude (about 2050 feet actual) — then the position of the Sides, at that moment, was about 56-24 E, 26-39.5 N. To the right of the “Z” in “HORMUZ,” on the chart, above the bend in the Strait. (Admiralty Chart 2888, widths: 620px,
780px,
1000px,
1263px,
1580px). This, based on the observation the report writers attribute to the Sides: “bearing approximately 355 degrees, range approximately 32 miles at 1500 feet altitude”. (I’ll plot it exact, later).
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Transponder details: “Aircraft information — Equipment,” ICAO Report, ¶ 1.6(c), p.4 (two Collins 621A-6 transponders, Serial Numbers: 3800, 2881). Specification sheet: Rockwell International, Series 500, Collins ATC Transponder, 621A-6A (specification standard ARINC 572), Rockwell document number 074-3874-000, 7M-SP-3-85 (March 1985). What is a Transponder? (Rockwell International, Collins Air Transport Division, Avionics Group, Cedar Rapids Iowa 52498, Instruction Guide, Rockwell document number 523-0773764-10111R, 10-1-88, 8+56 pages, October 1 1988). (A current model Collins transponder: TPR-901). Basic Flight Instruments, Chapter 4 of Instrument Flying Handbook (U.S. Federal Aviation Administration, Advisory Circular 61-27C, Jan. 1 1980).
–CJHjr
