CAT File No. C-1075-33
MoT File No. RAP-6504-P077468-026276



Minister of Transport, Applicant

- and -

Robert Garth Muddle, Respondent

Aeronautics Act, R.S.C., 1985, c. A-2, s. 7.7
Air Regulations, C.R.C. 1978, c. 2, s. 555(1)(a)

Take-off in visibility conditions below the required minimum

Review Determination
Robert L. Mortimer

Decision: April 11, 1996

The Minister's allegation is confirmed but, in consideration of the circumstances prevailing at the time of the incident, the monetary penalty is reduced from $200.00 to $50.00. That amount, payable to the Receiver General for Canada, must be received by the Civil Aviation Tribunal within fifteen days of service of this determination.

A Review Hearing on the above matter was held Thursday, March 21, 1996, at 9:00 hours at in the Council Chambers of the Town Hall in Rankin Inlet, Northwest Territories.


A Notice of Assessment of Monetary Penalty dated June 7, 1995 was forwarded to Mr. Robert Garth Muddle from Mr. D.J. Peever, Regional Director, Central Region, Transport Canada. The Notice reads in part:

Pursuant to section 7.7 of the Aeronautics Act, the Minister of Transport has decided to assess a monetary penalty on the grounds that you have contravened the following provision(s):

Air Regulation 555(1)(a) in that, at approximately 1908 UTS, on or about February 3, 1995, at or near Rankin Inlet, NWT, being the Pilot-in-Command of a Boeing 737 aircraft 663 you did unlawfully permit the said aircraft to take off from a runway where the take off visibility for the runway was below the minimum specified in Canadian Airlines International Operations Specification.

Payment of the penalty was not received by the prescribed date of July 17, 1995; therefore, arrangements were made to hold a hearing as provided for in section 7.9 of the Aeronautics Act.


As advised of his intention in a letter dated February 5, 1996, Mr. Hiscock, the Case Presenting Officer for the Minister of Transport, applied to amend the Notice of Assessment of Monetary Penalty by changing the aircraft number specified from 663 to 782.

Mr. Muddle contested the motion arguing that the amendment should not be permitted because it would alter the entire allegation, and that no proceedings could be instituted more than twelve months after the alleged contravention. He suggested that an amended allegation would amount to a new allegation, and because Mr. Hiscock's advisory letter about the amendment was written more than a year after the incident, such an amended allegation would not be valid.

In support of his motion, Mr. Hiscock stated that as his intent to seek an amendment was advised some six weeks before the hearing, adequate time was available to the Respondent to prepare his defence, and that the amendment would not prejudice Mr. Muddle from a fair hearing. Mr. Hiscock cited the Appeal of the Minister of Transport v. Gerald Fosberg (CAT File No. C-0067-33) in which it was stated that in considering a proposed amendment, the test should be whether the Respondent has been reasonably informed of the allegation against him and has had the opportunity to fully prepare a defence for presentation at the hearing.

I find that the proposed amendment is technical rather than substantive, and does not constitute a new allegation. Allowance of the motion will not preclude a just and fair hearing. Mr. Muddle was not misled about the alleged contravention by what T.C. admits was a mistake in specifying the correct number of the aircraft involved. The amendment therefore is allowed.


Ms. Terry Kirkhaus, Transport Canada's first witness, is the Flight Service Station (FSS) Manager at Rankin Inlet. She is an accredited weather observer qualified for Rankin Inlet.

Exhibit M-1 , the weather observation chart for Rankin Inlet, depicts the markers used for ground visibility observations. The 1/8 mile markers are the boxes in the Met compound which house and shelter the weather instruments. The ¼ mile markers are the anemometer mast to the west and the wind sock to the south.

A compressed audio tape of radio and telephone conversations between Rankin FSS, Canadian Flight 448, Territorial Flight 951 and Edmonton ACC was introduced and played (Exhibit M-2). A transcript of that tape was also entered (Exhibit M-3).

On February 3, 1995, the weather report from Rankin Inlet (Exhibit M-4) at 1600 gave a ground visibility of zero; in a special report at 1643 it had increased to ¼ mile in blowing snow; at 1700 it remained at ¼ mile in blowing snow; at 1800 it had decreased to _ mile in blowing snow; it remained at 1/8 mile in blowing snow in both the 1900 and 2000 reports.

Ms. Kirkhaus stated that during the time (63 minutes) that Canadian aircraft 782 was on the ground the visibility did not change from 1/8 mile. She further stated that, had the visibility increased from 1/8 to ¼ mile during that time, there was no obligation to make a special report because a special report was required only when the visibility reached ½ mile, in accordance with para 10.3.5 of the Manual of Surface Weather Observations (MANOBS) (Exhibit M-5). She acknowledged, nevertheless, that an observer could take the initiative to issue a special report when the visibility increased to ¼ mile.

Ms. Kirkhaus explained that to make visibility observations in winter it was necessary to go out onto the ramp to have a clear sight line to the markers, avoiding the snow banks. She concluded her direct testimony by confirming that at the time of the take-off in question, 1908, the ground visibility was 1/8 mile.

During cross-examination by Mr. Muddle, Ms. Kirkhaus stated that to her knowledge the distance to the ¼ mile visibility markers had never been measured precisely by survey methods, and that the distances were determined by using the Canada Air Pilot chart of the aerodrome. She further stated that weather observers were bound to use the markers depicted on the Visibility Markers chart, which dates back to about 1986. In response to questions about the dimensions and characteristics of the markers, Ms. Kirkhaus gave answers that were less than precise. In answer to a question of from where on the ramp visibility observations were made, she replied anywhere on the ramp, but claimed that observations reported were accurate because two equidistant markers were used as a cross-check.

Ms. Kirkhaus testified she directed Mr. Snyder, who was on duty at the time, to write up Aircraft Occurrence Reports on both Canadian Flight 448 and Territorial Flight 951 when they took off with the ground visibility reported as 1/8 mile.

The second witness for Transport Canada, Mr. Snyder, was a FSS operator and qualified weather observer working at Rankin Inlet in February 1995. Mr. Snyder testified that, when he came back on duty from lunch on February 3, 1995, he took an observation from the ramp in front of a parked 737 and determined the visibility to be 1/8 mile in blowing snow. He further stated that the visibility never improved beyond 1/8 mile between the times he took the observation and Canadian Flight 448 took off.

In cross-examination, Mr. Snyder could not recall detailed characteristics about the visibility markers at Rankin Inlet at the time in question, and he was not aware of any actual measurements being made of their distances.

Transport Canada's third witness, Mr. Hanson, explained that an air carrier company's operations manual is one that is developed by the company and approved by Transport Canada. Company pilots are expected to comply with the limits in the manual. The approved manual acts as a contract between the company and Transport Canada, which ensures a safe manner of operations and provides a basis for the issue of an operating certificate as an airline.

Mr. Hanson stated that the take-off visibility limits for Rankin Inlet are ½ mile, but that limit could be reduced to ¼ mile if the airline had an approved operations specification for take-off minima and provided the conditions specified in it were met.

A generic example of a take-off minima operations specifications (OpSpec) was entered as Exhibit M-6. Canadian Airlines International has this OpSpec and, in accordance with it, may use ¼ mile visibility as take-off limits for Rankin Inlet.

Mr. Hanson further testified that Canadian Airlines International Operations Manual specified that take-off weather limitations concerned visibility only as detailed in the OpSpec or Canada Air Pilot (CAP) (Exhibit M-8). The Manual directs that take-off visibility observations from different sources are to be used in the priority order of runway visual range (RVR), reported ground visibility, and pilot's runway visibility observation – the same criteria as in section 555 of the Air Regulations. The definition of Ground Visibility is the same as in the Air Regulations. An extract from the Canadian Flight Operations Manual related to take-off minima was entered as Exhibit M-7.

A copy of the aircraft journey log for Canadian Boeing 737 No.782 was entered as Exhibit M-9. It gives the landing and take-off times of interest at Rankin Inlet as 1805 and 1908 respectively.

In cross-examination by Mr. Muddle, Mr. Hanson stated that the Air Regulations take precedence over company operating manuals. He also stated that as a pilot he had experienced variances in visibility between what was reported by an observer and what he could see, but regardless of the visibility he observed, the official governing value still prevailed.

Testifying as his own witness, Mr. Muddle informed the Tribunal of his background and experience as a pilot. At the time of the incident, Mr. Muddle had over 11,000 hours total flying time (Exhibit D-2), held a Class 1 Instrument Rating, and was certified in accordance with the Canadian Airlines OpSpec for RVR 1200 feet and ¼ mile visibility take-offs. He had extensive arctic flying experience and an unblemished flying record.

On February 3, 1995, Mr. Muddle was the pilot-in-command on Canadian Flight 448 in aircraft No. 782. Inbound to Rankin Inlet, he received the 1700 weather report from Rankin Inlet Radio which indicated a then obscured sky condition with ¼ mile visibility in blowing snow, but with the added verbal remark of "check visibility right now is _th". He flew over Rankin at 5,000 feet from where he could see the airfield and the entire community; he then flew a full VOR/DME approach and landed at 1805. His landing minima were a minimum decent altitude (MDA) of 440' and a visibility of 1 mile. With the correction for temperature, the MDA was 520'. He used a three degree descent profile chart with temperature corrections calculated. He stated that when he had descended to 520' he did not have the required visibility to continue, so he levelled at 520' until the runway was in sight, at which time he was able to complete a normal approach and landing. Visibility for the landing was such that it was necessary to make only minor adjustments from the normal approach flight path, and with a small reduction in power he touched down on the normal spot.

At 1840 he observed Territorial Flight 951 make an approach and carry out a missed approach. At 1850 he saw Territorial Flight 951 make its second approach and land. Territorial then gave a pilot report on the visibility as "... just about ½ a mile there we had it (runway) in sight ... Actually its bad right on the ground here but up there it was real good and the other end of the runway is actually almost I'd say ¾ of a mile."

Mr. Muddle stated that when he had taxied out for take-off to the button of runway 31 he could see up to eight runway lights and the terminal building, and that there was blue sky overhead. He asserted that the runway was bare and dry, the high intensity lights were on, the centre line markings were good and the runway environment was in vivid contrast to its surroundings. Mr. Muddle contended that visibility variability is different in conditions of blowing snow than it is in conditions of fog, stratus and rain. He stressed that both his first officer and he were completely satisfied that they had ¼ mile visibility for take-off as required by their manual, and that their departure was a safe operation.

In reference to Exhibit M-6, the generic OpSpec authorizing commencement of flights when visibility is ¼ mile or more, Mr. Muddle drew attention to paragraph 2(d), one of the conditions that must be met, which states "the pilot-in-command is satisfied that the required RVR 1,200' (¼ mile) visibility exists for the runway to be used before commencing take-off". He stated the criteria was the same in the Canadian Flight Operations Manual (Exhibit M-7) and the preamble to Take-Off Minima/Departure Procedures in the Canada Air Pilot (Exhibit M-8) which states in part "minimum visibility for take-off shall be determined by the pilot-in-command ...."

Mr. Muddle entered a page from Chapter 2 of MANOBS (Exhibit D-1) which states that "Visibility is the greatest distance at which objects of suitable dimensions can be seen and identified." He claimed that "suitable dimensions" are not defined anywhere, and he questioned whether the visibility markers at Rankin Inlet were of "suitable dimensions". He pointed out that in addition there is no information on whether the distances to the markers have ever been accurately measured.

In completing his testimony, Mr. Muddle suggested the fact that he had landed at 1805 indicates that the visibility at that time was likely better than 1/8 mile in the runway environment; they had hand flown the aircraft and landed easily. When they were on the button of the runway for departure, they could see the terminal building. He suggested further that the weather observers were in a poor position to judge what the visibility was from the pilot's cockpit on the runway. He observed that the pilot-in-command was responsible for safe flight operations, but the authority to decide when the visibility met the minimum requirement was taken away from him. He maintained that authority should go hand-in-hand with the responsibility. He concluded by stating that he had done everything in absolute safety and within the limits of the law.

In response to cross-examination questions from Mr. Hiscock on whether he was aware that the visibility reported by the observer was binding on him regardless of what he saw, Mr. Muddle stated that he did not agree with the situation where he had the responsibility but not the authority, and he did not agree with the tools the observers had to work with. In response to a question on whether he thought he had the right to call his own visibility if he did not agree with what was reported, Mr. Muddle stated that he realized it was an extremely delicate matter and the exact letter of the law did not allow that.

In his final argument, Mr. Hiscock reiterated that section 555 of the Air Regulations states no pilot-in-command shall permit a take-off if the visibility is below that specified for the runway. The regulation further states that in the absence of a RVR reading, the visibility for the runway is the reported ground visibility for the aerodrome. The pilot-in-command may use his own observed visibility as the criteria against the specified minimum only if neither a RVR reading nor a reported ground visibility report are available. While the Canada Air Pilot specifies ½ mile as the minimum visibility for take-off at Rankin Inlet, the airfield is suitable for the ¼ mile visibility limits in the OpSpec. Mr. Hiscock stated again that the ground visibility was reported as 1/8 mile at 1908 hours on February 3, 1995 and therefore less than required when Canadian aircraft No. 782 took off.

Mr. Muddle stated that he was not questioning the FSS observers, but he questioned the tools they had to work with. The visibility markers were not of suitable dimensions, and their distances had not been precisely measured; moreover, the position from which the visibility observations were taken was not appropriate. He pointed out that many regulations in this matter referred to visibility for the runway, and only paragraph 555(2)(b) referred to ground visibility. What the pilot sees is not treated as relevant by the regulations, but it is recognized that it can be different, as noted in the transcript (Exhibit M-3) when the FSS observer in discussing the visibility with Territorial Flight 951 radioed, "... we can't really go out on the runway and do it ah I appreciate that you have better than what we are reporting."

Mr. Muddle concluded by stating that, in the circumstances that prevailed, the law treats what the pilot sees as not relevant, but he considers that what the pilot sees is very relevant and very, very important. He cited section 8.5 of the Aeronautics Act and said that he took every step to ensure that he could safely take off and do so within the essentials of the Air Regulations, and had therefore exercised all due diligence.


Section 555 of the Air Regulations states:

555. (1) No pilot-in-command of an aircraft shall permit the aircraft to take off from a runway if the take-off visibility for the runway, as determined in accordance with subsection (2), is below the minimum visibility for the runway specified in

(a) the operations specifications for the operator of the aircraft where the operator is an air carrier;

(b) the operations manual of the operator of the aircraft where the manual is required under the Private Aeroplanes Passenger Transportation Order;

(c) the operations manual, or equivalent document, issued by the state of the operator of the aircraft and accepted by the Minister; or

(d) the Canada Air Pilot, in any case other than a case described in paragraph (a), (b), or (c).

(2) For the purposes of subsection (1), the take-off visibility for a runway is

(a) the RVR of the runway, unless the RVR is

(i) fluctuating rapidly above and below the minimum visibility for the runway as specified in a manual or other document under paragraphs (1)(a) to (d),

(ii) less than the minimum visibility referred to in subparagraph (i) because of a localized phenomenon, or

(iii) not reported by an air traffic control unit or a flight service station;

(b) the ground visibility of the aerodrome for the runway, if

(i) the RVR is as described in subparagraph (a)(i), (ii) or (iii), and

(ii) the ground visibility of the aerodrome is reported as set out in the definition "ground visibility"; or

(c) the visibility for the runway as observed by the pilot-in-command, if

(i) the RVR is as described in subparagraph (a) (i), (ii) or (iii), and

(ii) the ground visibility of the aerodrome is not reported as described in subparagraph (b)(ii).

Section 101 of the Air Regulations gives the following interpretation:

"ground visibility", in respect of an aerodrome, means the visibility at that aerodrome as contained in a weather observation reported by

(a) an air traffic control unit,

(b) a flight service station,

(c) a community aerodrome radio station operated under the control and supervision of the territorial government of the Northwest Territories or the Yukon Territory,

(d) a COMMET station, or

(e) a radio station that is ground based and operated by an air carrier

MANOBS, issued under the authority of the Assistant Deputy Minister, Environment Canada, includes the following definitions and procedures:

2.1.1 The visibility to be reported is the prevailing visibility observed at eye level (eye level is internationally defined at 1.8 m above the ground).

2.2 PREVAILING VISIBILITY. Is the maximum visibility value common to sectors comprising one-half or more of the horizon circle.

2.3.1 When the observed visibility in one or more sectors differs significantly from the prevailing visibility, it is sometimes necessary to record and report, not only the prevailing visibility but the variations as well ...

2.6.3 Visibility markers shall be selected with a view to choosing prominent objects so located that they may be viewed against a background of the horizon sky. One must not, for example, select a building on the side of a hill, which could be viewed with the hill as background. The distance of markers such as hills and mountains may be determined with the aid of a large scale map of the vicinity. A suitable visibility marker should subtend an angle at the observer's eye of not less than ½ degree* vertically and horizontally above the horizon. Objects such as radio masts are therefore not desirable visibility markers for daytime use. During darkness unfocussed lights of moderate intensity at known distances should be used for visibility markers.

*NOTE: ½ degree is approximately the angle subtended at the eye by a hole 8 mm in diameter punched in a card and held at arms length. Reportable Values of Visibility. The following values (in statute miles) shall be used for reporting visibility:

0, 1/8, ¼, 3/8, ½, 5/8, ¾ (increments of 1/8 mile)

10. 2.9.3 For Different Directions. If the visibility in one or more directions is half or less, or double or more the prevailing visibility, details of the visibility in such directions shall be recorded in Remarks (41).

10.3.4 Special Observations (SP). Special observations shall be taken promptly to report changes which occur between scheduled transmission times.

10.3.5 Criteria for Taking Special Observations. A special observation shall be taken whenever one or more of the elements listed in para to has changed in the amount specified. The amount of change is with reference to the preceding regular or special observation.

10. 3.5.3 Visibility. Prevailing visibility decreases to less than, or if below, increases to equal or exceed:

(a) 3 miles
(b) 1½ miles
(c) 1 mile
*(d) ¾ mile
(e) ½ mile
*(f) ¼ mile
(g) the lowest published minimum

* Criteria marked with an asterisk (*) are applicable only at aerodromes with precision approach equipment (i.e. ILS, MLS, GCA) and only down to and including the lowest published minima for these aerodromes.


A number of key points in this case have been agreed to by both parties. Mr. Muddle was the pilot-in-command of Canadian Airlines International Flight 448, a Boeing 737 serial No. 782, on February 3, 1995. During its flight that day, Canadian Flight 448 flew into and out of Rankin Inlet N.W.T. twice. On its first arrival, Flight 448 landed at 1805 UTS and subsequently departed taking off at 1908 UTS. It is that take-off which is the subject of this hearing.

It is further acknowledged by both parties that at the 1908 time of take-off the reported ground visibility at Rankin Inlet was 1/8 mile in blowing snow, as recorded in the 1900 weather report and confirmed in radio transmissions from Rankin Radio.

In its application to this case, the prohibition in paragraph 555(1)(a) of the Air Regulations is clear: a take-off shall not be permitted if the take-off visibility for the runway is below the minimum visibility for the runway specified in the Canadian Airlines International OpSpec. The minimum specified in the OpSpec is a reported visibility of ¼ mile. Mr. Muddle was certified to fly in accordance with that OpSpec.

Subparagraph 555(2)(b)(ii) of the Air Regulations defines take-off visibility for a runway, applicable under the circumstances that prevailed in the subject incident, as the ground visibility of the aerodrome, provided that it is reported as set out in the definition of ground visibility. For this case that definition is the visibility at the aerodrome as contained in a weather observation reported by the Flight Service Station.

Given that the ground visibility reported by Rankin Inlet FSS at the time of Canadian Flight 448's take-off was 1/8 mile, it would seem that the contravention occurred as alleged by the Minister. In the interest of justice, however, a number of other factors must also be given consideration.

It is assumed that one purpose of section 555 of the Air Regulations, perhaps the main or only purpose, is to ensure safe air carrier operations. Specifically, its intention is to ensure that sufficient visibility prevails for the pilot to execute a safe take-off. The place where that visibility is critical is along the runway where the take-off roll is to be made. What the visibility is that prevails on the rest of the aerodrome or the surrounding environs is not relevant to a safe take-off.

Reference is made to visibility "for the runway" in a number of the applicable regulations. Specifically, subsections 555(1) and (2) of the Air Regulations refer to "take-off visibility for the runway"; the OpSpec (paragraph 2(d)) refers to "visibility for the runway to be used." Both the Canada Air Pilot and the Canadian Flight Operations Manual refer to "visibility for the runway", but only in reference to the third method (pilot's observation) of defining take-off visibility, i.e., only if neither a valid RVR report nor a valid ground visibility report are available. In subsection 555(2) of the Air Regulations the phrase "visibility for the runway" applies to all methods and does not necessarily mean visibility on or along the runway.

The first determinant for take-off visibility, a valid RVR report of visibility on the runway, is logical, as is the third determinant, the visibility for the runway observed by the pilot, presumably from the button of the runway. The second determinant, however, which takes precedence over the third, is a report on ground visibility of the aerodrome. The ground visibility to be reported is the prevailing visibility, which is "the maximum visibility value common to sectors comprising one-half or more of the horizon circle" (MANOBS 2.2).

These prioritized determinants of visibility for the runway are inconsistent – first is an electronic measurement of the visibility along the runway; second a human estimate of the prevailing ground visibility from an observation point that cannot be on the runway button; and the third is another human estimate, but observed by the pilot, who is accountable for the safe operation of the flight, along the runway to be used. Ground visibility, the second order determinant, may be different than the RVR or pilot observed visibility along the runway to be used, and therefore it is an anomaly. In addition, because the ground visibility report takes precedence over the pilot's own observation, the potential for an adversarial relationship between observer and pilot exists; such a relationship could detract from the goal of safe flight operations.

In conditions of blowing snow, visibility can vary significantly from one area to another, and the required minimum take-off visibility could be present along the runway, while the visibility at the point of observation used by the weather observer could be significantly less. On the other hand, the required minimum take-off visibility could be recorded by the observer while at the same time the visibility on the runway could be below limits. That situation is compensated for by the requirement for the pilot to ensure he has the required visibility for the runway to be used before commencing take-off (Exhibit M-6 – paragraph 2(d)). Thus, provision is made for the difference when the ground visibility is above the take-off minimum and the visibility on the runway is not, but no provision is made for the situation where the visibility at the ground observers view point is less than the minimum while the visibility on the runway as determined by the pilot's observation is at or above the minimum.

An obvious solution to this problem would be to have RVR visibility sensors on all airfields where air carrier operations take place, but that solution may not be affordable. Some other solution is needed, however, that is consistent with the Aeronautics Act definition of pilot-in-command, giving him or her the requisite authority to determine the visibility along the take-off runway by his or her own observation when a valid RVR reading is not available.

In the subject case, the ground visibility reports give some cause for concern. The witnesses could not recall some of the dimensions, orientation or colours of those markers. The 1/8 mile and ¼ mile visibility markers used at Rankin, in their knowledge, had never been precisely measured. In addition, one of those markers, the anemometer post at ¼ mile, does not appear to meet the standard for suitable visibility markers in MANOBS 2.6.3. The criterion of a marker subtending an angle at the observer's eye of not less than ½ degree would mean the ¼ mile markers should measure at least 11.5 feet vertically and horizontally above the horizon. The single mast supporting the anemometer does not meet that criterion, and it is not large enough to be easily seen at that distance in marginal conditions. Nor does an associated nearby building meet the criterion of a suitable visibility marker as it allegedly is only six feet square in its largest dimensions.

That situation is exacerbated by the rules governing when the observer makes a special report. The MANOBS requirement to issue a special report when visibility of 1/8 mile increases to ¼ mile does not apply to Rankin Inlet, because its lowest published minimum visibility is ½ mile and it has no precision approach equipment. Thus the prevailing visibility could increase from 1/8 to ¼ mile, but a special observation at that time would not be required. Yet a valid operating minimum take-off visibility for pilots operating with the referenced OpSpec is in fact ¼ mile.

Another factor that detracts from what should be a cooperative effort between observer and pilot is the requirement for the observer to file an Aircraft Occurrence Report whenever an aircraft takes off with less than ½ mile visibility, even though a take-off with ¼ mile visibility is fully in keeping with regulations for those complying with the OpSpec authorizing the lower limit.

The situation that gave rise to the assessment of a monetary penalty against Mr. Muddle is cause for concern. The sanction is based on a ground visibility observation taken from a point away from the runway, using markers that are less than distinct and that have not been measured precisely, by observers whose guidelines ignore the fact that a legitimate minimum take-off visibility requirement may be ¼ mile rather than the published ½ mile, as it concerns reporting special observations and aircraft occurrences. At the same time, the pilot-in-command's observed visibility along the runway is deemed not to be valid. Finally, these anomalies in the regulations would seem to have some potential to undermine the desired cooperative teamwork relationship between pilot and weather observer that contributes positively to safe flight operations.


At the time of Canadian Flight 448's take-off from Rankin Inlet on February 3, 1995 at 1908 UTS, the reported ground visibility was 1/8 mile in blowing snow. That report was issued by the Rankin Inlet Flight Service Station and was based on separate observations by two fully qualified weather observers. With no RVR measuring devices at Rankin Inlet, that report was by regulation the governing measure of visibility for deciding whether or not the visibility was at or above the minimum required for take-off.

Mr. Muddle is a very experienced airline pilot with extensive arctic flying experience. The minimum visibility required by Mr. Muddle for take-off at that time was ¼ mile visibility. He stated that from the cockpit on the button of the runway he observed the visibility along the runway to be at least ¼ mile. I accept Mr. Muddle's contention that the visibility along the runway for his take-off was ¼ mile, the required minimum, and that he did not compromise flight safety.

Mr. Muddle's contention that he exercised all due diligence is not accepted. To do so, he would have complied with the existing valid regulations.

I empathize with Mr. Muddle in his frustration at not having the authority to use his own observation of visibility on the runway when it is at variance with the visibility reported by an observer at another location. It is to be hoped that section 555 of the Air Regulations will be rationalized, and that the selection and distances of the visibility markers at Rankin Inlet will be reviewed.

On the basis of that existing regulation, however, I find that Mr. Muddle did indeed unlawfully permit aircraft 782 to take off from the runway when the take-off visibility for the runway was below the minimum specified as determined in accordance with section 555 of the Air Regulations.


The Minister's allegation is confirmed but, in consideration of the circumstances prevailing at the time of the incident, the monetary penalty is reduced to $50.00.

Robert L. Mortimer
Civil Aviation Tribunal