If at First You Don't Succeed....Try, Try Again
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If at First You Don't Succeed....Try, Try Again
From TSB...
C-GTWE, a DeHavilland DHC-8-400 aircraft being operated by WestJet Encore, was conducting
an IFR flight from Regina International Airport (CYQR), SK. to Calgary International Airport
(CYYC), AB. During the takeoff roll, the First Officer's Primary Flight Display (PFD) failed to
indicate airspeed. The takeoff was rejected with a MAYDAY declared as per company Standard
Operating Procedure (SOP). The aircraft taxied off the runway and the crew contacted the
operator's maintenance department. The flight crew was advised by maintenance to attempt
another takeoff. On the second takeoff attempt, the FO's PFD failed to indicate airspeed. The
takeoff was rejected with another MAYDAY being declared. The crew canceled MAYDAY and
returned to the gate.
The operator's maintenance department conducted an inspection of the #2 Air Data Unit (ADU)
and discovered a fitting was not fully seated. The fittings were removed and reinstalled.
Subsequent testing of the #2 ADU revealed no other faults.
C-GTWE, a DeHavilland DHC-8-400 aircraft being operated by WestJet Encore, was conducting
an IFR flight from Regina International Airport (CYQR), SK. to Calgary International Airport
(CYYC), AB. During the takeoff roll, the First Officer's Primary Flight Display (PFD) failed to
indicate airspeed. The takeoff was rejected with a MAYDAY declared as per company Standard
Operating Procedure (SOP). The aircraft taxied off the runway and the crew contacted the
operator's maintenance department. The flight crew was advised by maintenance to attempt
another takeoff. On the second takeoff attempt, the FO's PFD failed to indicate airspeed. The
takeoff was rejected with another MAYDAY being declared. The crew canceled MAYDAY and
returned to the gate.
The operator's maintenance department conducted an inspection of the #2 Air Data Unit (ADU)
and discovered a fitting was not fully seated. The fittings were removed and reinstalled.
Subsequent testing of the #2 ADU revealed no other faults.
Re: If at First You Don't Succeed....Try, Try Again
Mayday for a rejected takeoff due to cockpit instrumentation??
Re: If at First You Don't Succeed....Try, Try Again
A Mayday for an RTO for any reason is not an uncommon company policy.
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Re: If at First You Don't Succeed....Try, Try Again
"MAYDAY" Absolutely, 100%, anywhere in the world. If it offends, you, then screw you. It's how it should be done ALWAYS. I'm shutting down that runway until I can get off it safely.
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Re: If at First You Don't Succeed....Try, Try Again
Going 100+ kts down the runway and slamming on the brakes isn't a good time to be diagnosing an issue and deciding if it warrants the fire trucks. It's easier to cancel the trucks after stopping and taxi back to the gate than it is to explain why one delayed calling a Mayday after something more dangerous happened.
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Re: If at First You Don't Succeed....Try, Try Again
An ASI not working should be caught long before 100 knots, that should happen at the 'airspeed alive' call, which happens early in the roll on every machine I've ever flown. Early enough in fact, one should be able to retard the noise handles, and casually make the turn on the next exit without even touching the brakes.goingnowherefast wrote: ↑Mon Mar 24, 2025 5:01 pm Going 100+ kts down the runway and slamming on the brakes isn't a good time to be diagnosing an issue and deciding if it warrants the fire trucks. It's easier to cancel the trucks after stopping and taxi back to the gate than it is to explain why one delayed calling a Mayday after something more dangerous happened.
Re: If at First You Don't Succeed....Try, Try Again
You don't need to call mayday to occupy a runway. If you know what caused the abort and it is non life threatening, then it is abusing an emergency system by calling mayday. It's also a very lousy SOP to require this. Transport and other similar organizations should not accept SOPs like that.northernpilot2 wrote: ↑Mon Mar 24, 2025 3:44 pm"MAYDAY" Absolutely, 100%, anywhere in the world. If it offends, you, then screw you. It's how it should be done ALWAYS. I'm shutting down that runway until I can get off it safely.
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
Re: If at First You Don't Succeed....Try, Try Again
Does any other airline in Canada have this procedure?digits_ wrote: ↑Mon Mar 24, 2025 10:15 pmYou don't need to call mayday to occupy a runway. If you know what caused the abort and it is non life threatening, then it is abusing an emergency system by calling mayday. It's also a very lousy SOP to require this. Transport and other similar organizations should not accept SOPs like that.northernpilot2 wrote: ↑Mon Mar 24, 2025 3:44 pm"MAYDAY" Absolutely, 100%, anywhere in the world. If it offends, you, then screw you. It's how it should be done ALWAYS. I'm shutting down that runway until I can get off it safely.
Re: If at First You Don't Succeed....Try, Try Again
I think the big 705s require it via their SOPs. 703 and 704 generally doesn't seem to. You always can if necessary though.pelmet wrote: ↑Tue Mar 25, 2025 5:42 amDoes any other airline in Canada have this procedure?digits_ wrote: ↑Mon Mar 24, 2025 10:15 pmYou don't need to call mayday to occupy a runway. If you know what caused the abort and it is non life threatening, then it is abusing an emergency system by calling mayday. It's also a very lousy SOP to require this. Transport and other similar organizations should not accept SOPs like that.northernpilot2 wrote: ↑Mon Mar 24, 2025 3:44 pm
"MAYDAY" Absolutely, 100%, anywhere in the world. If it offends, you, then screw you. It's how it should be done ALWAYS. I'm shutting down that runway until I can get off it safely.
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
Re: If at First You Don't Succeed....Try, Try Again
No, Jazz does not require it, in fact the SOP is to advise rejecting the take off, goes on to state if rejecting for a more serious issue then make a request for CFR.digits_ wrote: ↑Tue Mar 25, 2025 6:07 amI think the big 705s require it via their SOPs. 703 and 704 generally doesn't seem to. You always can if necessary though.pelmet wrote: ↑Tue Mar 25, 2025 5:42 amDoes any other airline in Canada have this procedure?digits_ wrote: ↑Mon Mar 24, 2025 10:15 pm
You don't need to call mayday to occupy a runway. If you know what caused the abort and it is non life threatening, then it is abusing an emergency system by calling mayday. It's also a very lousy SOP to require this. Transport and other similar organizations should not accept SOPs like that.
I agree that making a May Day call for every reject is an abuse and could be like the boy who cried wolf, if 99% of their rejects they get cancelled maybe they don’t rush so much next time.
May Day is aircraft in distress! Rejection for an airspeed that doesn’t work a second time, you’re literally expecting it and you call “May Day”, ridiculous!
Re: If at First You Don't Succeed....Try, Try Again
every large aircraft I flew had an 80 kt call. well below high speed rto
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Re: If at First You Don't Succeed....Try, Try Again
The issue is that ATC will send another plane barreling down the runway right up your chuff if they aren't paying attention. The mayday call is to get their attention in any country you may find yourself in.
Safety starts with two
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Re: If at First You Don't Succeed....Try, Try Again
This is incredibly important. I cannot talk to ATC in South America the way I talk to US and Canadian ATC.itsgrosswhatinet wrote: ↑Tue Mar 25, 2025 11:42 am The issue is that ATC will send another plane barreling down the runway right up your chuff if they aren't paying attention. The mayday call is to get their attention in any country you may find yourself in.
Re: If at First You Don't Succeed....Try, Try Again
Is anyone aware of any other airline in the world that does this? if it is so important, I wonder if British Airways, Emirates, Singapore Airlines, or any American carrier do this?
Re: If at First You Don't Succeed....Try, Try Again
Are you saying “rejecting take off” isn’t clear enough? I would think this is standard icao phraseology.Tbayer2021 wrote: ↑Tue Mar 25, 2025 12:33 pmThis is incredibly important. I cannot talk to ATC in South America the way I talk to US and Canadian ATC.itsgrosswhatinet wrote: ↑Tue Mar 25, 2025 11:42 am The issue is that ATC will send another plane barreling down the runway right up your chuff if they aren't paying attention. The mayday call is to get their attention in any country you may find yourself in.
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Re: If at First You Don't Succeed....Try, Try Again
What are you the mayday police? Rejecting a takeoff in a large aircraft can lead to brake overheating and fire. The fire trucks are ready to respond and check brake temps with infrared devices.
Safety starts with two
Re: If at First You Don't Succeed....Try, Try Again
I would still be curious to know why virtually every airline and aviation safety organization in the world has never embraced this concept. Are the policy deciders at Encore and their 0.01 percent representation of such group just more enlightened or is there something else to it.itsgrosswhatinet wrote: ↑Wed Mar 26, 2025 12:33 am What are you the mayday police? Rejecting a takeoff in a large aircraft can lead to brake overheating and fire. The fire trucks are ready to respond and check brake temps with infrared devices.
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Re: If at First You Don't Succeed....Try, Try Again
Yes you do.
You worry about that later and cancel mayday if you don't need it anymore
If that's the case, then the pilots should abuse it and I encourage it anytime something happens
Its lousy to not have SOP that requires this
Yes they should, and It should be mandatory
It looks like some of you haven't flown overseas. If you've been just buzzing around Canada/US your entire career, and if your still actively flying now, then you should start practicing standard phraseology. Eg, The next time you ask ATC for descent, say REQUEST DESCENT, not looking 4 lower. When you want to go somewhere direct, say REQUEST DIRECT POSTION _____ (waypoint), not looking 4 shortcut to ____. Its also a good idea to spell it out in case of confusion, for eg, YVR, REQUEST DIRECT POSITION YANKEE VICTOR ROMEO !!

Re: If at First You Don't Succeed....Try, Try Again
Ok. Source?
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
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Re: If at First You Don't Succeed....Try, Try Again
Why make a second take-off?The takeoff was rejected with a MAYDAY declared as per company Standard
Operating Procedure (SOP). The aircraft taxied off the runway and the crew contacted the
operator's maintenance department. The flight crew was advised by maintenance to attempt
another takeoff. On the second takeoff attempt, the FO's PFD failed to indicate airspeed. The
takeoff was rejected with another MAYDAY being declared. The crew canceled MAYDAY and
returned to the gate.
There's obviously a problem - will it somehow automatically fix itself?
Poor decision making by the crew imho.
Always fly a stable approach - it's the only stability you'll find in this business
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Re: If at First You Don't Succeed....Try, Try Again
ICAO standards don't have to be adhered to. Here is an excerpt right out of the COM section of South America in one of our manuals.cdnavater wrote: ↑Tue Mar 25, 2025 11:52 pmAre you saying “rejecting take off” isn’t clear enough? I would think this is standard icao phraseology.Tbayer2021 wrote: ↑Tue Mar 25, 2025 12:33 pmThis is incredibly important. I cannot talk to ATC in South America the way I talk to US and Canadian ATC.itsgrosswhatinet wrote: ↑Tue Mar 25, 2025 11:42 am The issue is that ATC will send another plane barreling down the runway right up your chuff if they aren't paying attention. The mayday call is to get their attention in any country you may find yourself in.
"Especially in South America all ATC controllers should be dealt with carefully. ATC is not always according to ICAO standard."
I'm having trouble finding what ATC expects pilots to say if pilots are the ones initiating a rejected take-off as per any local or international procedures. But ICAO Doc 4444 has this to say under ATC phraseologies, subsection 1.7.3.2.4 Phraseologies for Use on and in the Vicinity of the Aerodrome.
.......to top a take-off after an aircraft has commenced take-off roll
ATC: STOP IMMIDIATELY TWA123 STOP IMMIDITELY
PILOT: STOPPING
That same ICAO document makes no reference to "rejected" or "rejecting" when it comes to aborting a take-off.
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Re: If at First You Don't Succeed....Try, Try Again
I would question why maintenance would say …. Try it again. How ‘bout now …… how ‘bout now.
Successfully providing disappointment.
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Re: If at First You Don't Succeed....Try, Try Again
While that is true of a high speed reject, these were not high speed rejects. surely the crew was competent enough to realize the ASI was not functioning long before they got into a high speed situation that would require excessive braking to stop.itsgrosswhatinet wrote: ↑Wed Mar 26, 2025 12:33 am What are you the mayday police? Rejecting a takeoff in a large aircraft can lead to brake overheating and fire. The fire trucks are ready to respond and check brake temps with infrared devices.
Re: If at First You Don't Succeed....Try, Try Again
It absolutely is not clear enough for many controllers level of English in many parts of the world. I’ve been to plenty of places where if you said something the controller wasn’t 100% expecting it would go way over their head. If you go to a small airport in Cuba and say “rejecting take off”, most of the time the controllers response would be, “say again” or “issaprooof” without having any idea what you’re saying. They do understand mayday though.cdnavater wrote: ↑Tue Mar 25, 2025 11:52 pmAre you saying “rejecting take off” isn’t clear enough? I would think this is standard icao phraseology.Tbayer2021 wrote: ↑Tue Mar 25, 2025 12:33 pmThis is incredibly important. I cannot talk to ATC in South America the way I talk to US and Canadian ATC.itsgrosswhatinet wrote: ↑Tue Mar 25, 2025 11:42 am The issue is that ATC will send another plane barreling down the runway right up your chuff if they aren't paying attention. The mayday call is to get their attention in any country you may find yourself in.
Last edited by ant_321 on Wed Mar 26, 2025 9:16 am, edited 1 time in total.
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Re: If at First You Don't Succeed....Try, Try Again
You learn very quickly how laxed we are with radio procedures and phraseology when you venture outside of Canada and the US. I'll admit I got my hand slapped a few times during my first crossings.ant_321 wrote: ↑Wed Mar 26, 2025 9:00 amIt absolutely is not clear enough for many controllers level of English in many parts of the world. I’ve been to plenty of places where if you said something the controller wasn’t 100% expecting it would go way over there head. If you go to a small airport in Cuba and say “rejecting take off”, most of the time the controllers response would be, “say again” or “issaprooof” without having any idea what you’re saying. They do understand mayday though.cdnavater wrote: ↑Tue Mar 25, 2025 11:52 pmAre you saying “rejecting take off” isn’t clear enough? I would think this is standard icao phraseology.Tbayer2021 wrote: ↑Tue Mar 25, 2025 12:33 pm
This is incredibly important. I cannot talk to ATC in South America the way I talk to US and Canadian ATC.