1078kph in 737-800 - mach 0.xx?
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Well, those of us that do actually fly for a living use them all the time. We don't use the 3 letter codes at all.
When we talk about somewhere we say for example 'Heathrow', but for our job - flight plans, Notams, Weather, Sigmets Pireps etc, without the 4 Letter ICAO code we wouldn't get very far.
So in our world 4 letter code much better than 3 letter code.
As to the high speed 737?... Could only be a jetstream tail wind, which can be smooth or bumpy, but will give you the massive groundspeed.
When we talk about somewhere we say for example 'Heathrow', but for our job - flight plans, Notams, Weather, Sigmets Pireps etc, without the 4 Letter ICAO code we wouldn't get very far.
So in our world 4 letter code much better than 3 letter code.
As to the high speed 737?... Could only be a jetstream tail wind, which can be smooth or bumpy, but will give you the massive groundspeed.
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I did not actually mean to suggest that it was operated beyond its operational limits - rather AT these limits, it was more of a question of how one would reach such speeds (I am not familiar with high altitude air currents at all, and never exceeded 900kph on that "sector", if thats the right word, in the past), and why the plane was giving the impression of being just about to fall appart for 40 minutes or so.
It WAS also one out of two flights I've felt insecure in a plane, the other one nearly putting the aircraft upside down into terrain as the A/C flipped over (roughly 100 degrees from level) due to a strong windgust from the side on the turn to final. Approach to that airport has since been changed AFAIK.
Assuming, as always, that the flight crew on my flight were professionals, they have operated inside their limits and would have nothing to worry about should someone come across an anonymous complaining passenger on a public board. If they did not operate within their restrictions it would be better to give them a pointed finger now than waiting for something worse to happen as a result of going outside their limits again in the future. Also, I was not worried about the professionalism/airmanship of the pilots during the flight, I trusted they would keep the plane within its safety limits; it just felt unsafe to me as a passenger.
As a paying customer, I should be allowed to raise an eyebrow at a service that is perhaps not as good as one would expect. I would however ask people with more experience and knowledge about what might have happened first, rather than immediately sending a fax to Ryanair insinuating anything.
It WAS also one out of two flights I've felt insecure in a plane, the other one nearly putting the aircraft upside down into terrain as the A/C flipped over (roughly 100 degrees from level) due to a strong windgust from the side on the turn to final. Approach to that airport has since been changed AFAIK.
Assuming, as always, that the flight crew on my flight were professionals, they have operated inside their limits and would have nothing to worry about should someone come across an anonymous complaining passenger on a public board. If they did not operate within their restrictions it would be better to give them a pointed finger now than waiting for something worse to happen as a result of going outside their limits again in the future. Also, I was not worried about the professionalism/airmanship of the pilots during the flight, I trusted they would keep the plane within its safety limits; it just felt unsafe to me as a passenger.
As a paying customer, I should be allowed to raise an eyebrow at a service that is perhaps not as good as one would expect. I would however ask people with more experience and knowledge about what might have happened first, rather than immediately sending a fax to Ryanair insinuating anything.
It's at times like this that Rainboe is missed!
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Hi Arron,
Just to give you an idea. Every single one of Ryanairs aircraft is fitted with an OFDM system. This system monitors, and at the end of the day sends data to Dublin. The data that it generally monitors are exceedances of any form (including flap speed, VMO/MMO (max speeds) etc.)
The 737-800 is limited to .82, Ryanair on average flies around between .78/.79 (dependant on weight). The -800 is a fairly unstable aeroplane when it comes to flight in turbulance. As you are suggesting that it was bumpy in the cruise, it would not be a great idea for the guys to increase the speed to fly at the limit of .82 as the -800 would overspeed very easily.
If the aircraft overspeeded multiple times within one flight I can garuntee that this would be followed by tea and biscuits in Dublin. No one wants this.
Looking through the feed I would suggest that the jetstream argument is the best one and would tie in with your constant turbulance.
Just some quick numbers using the basic nasa mach calculator (doesnt take into account anything like temp. etc.
Cruise = 38000ft (guess)
Speed = 520mph = 836kph
Mach = 0.787
So that would be still air conditions.
1078kph - 836kph = 242kph
This would be the tail wind you have to get 1078kph. 242kph is just above 130kts. You may not get 130kts every day but it does happen. Just be happy it was a tailwind rather than a headwind!
Hope that makes sense, and please excuse any mistakes in my maths!
Just to give you an idea. Every single one of Ryanairs aircraft is fitted with an OFDM system. This system monitors, and at the end of the day sends data to Dublin. The data that it generally monitors are exceedances of any form (including flap speed, VMO/MMO (max speeds) etc.)
The 737-800 is limited to .82, Ryanair on average flies around between .78/.79 (dependant on weight). The -800 is a fairly unstable aeroplane when it comes to flight in turbulance. As you are suggesting that it was bumpy in the cruise, it would not be a great idea for the guys to increase the speed to fly at the limit of .82 as the -800 would overspeed very easily.
If the aircraft overspeeded multiple times within one flight I can garuntee that this would be followed by tea and biscuits in Dublin. No one wants this.
Looking through the feed I would suggest that the jetstream argument is the best one and would tie in with your constant turbulance.
Just some quick numbers using the basic nasa mach calculator (doesnt take into account anything like temp. etc.
Cruise = 38000ft (guess)
Speed = 520mph = 836kph
Mach = 0.787
So that would be still air conditions.
1078kph - 836kph = 242kph
This would be the tail wind you have to get 1078kph. 242kph is just above 130kts. You may not get 130kts every day but it does happen. Just be happy it was a tailwind rather than a headwind!
Hope that makes sense, and please excuse any mistakes in my maths!
Last edited by Gulf Julliet Papa; 18th Mar 2010 at 14:32.
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Thank you GJP. I agree, it sounds like it was just a bad hai...wind day. I am relatively familiar with ground speed/TAS/IAS/mach, I just failed to appreciate how windy it can get up there... I know there are these jetstreams up there somewhere, but I had it in mind that they were fairly stable(reliable) things and as they had never used them before I thought there wasnt one there.
"fairly unstable" would be a way to describe the flight
Never heard of the OFDM system before now, that is interesting.
Thank you!
"fairly unstable" would be a way to describe the flight
Never heard of the OFDM system before now, that is interesting.
Thank you!
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Gulf Juliet Papa speaks the truth here. The OFDM system is very real and flight exceedances are logged electronically. Flying around at 0.81/0.82 or 340kts within turbulent air/jetstream activity/pressure waves/convective activity is going to attract the wrong sort of attention. And we are not simply talking about the crew's level of airmanship being brought into question here! An overspeed also requires the aircraft to be inspected by an engineer as it is considered an exceedance that is detrimental to the aircraft's structural integrity. This would immediately highlight that a problem has occurred long before the OFDM gets the chance to download it's data at the end of the day.
I too would concur with the fact that you probably benefited from a north/south jetstream which contributed to a considerable groundspeed. The 'flex' that you witnessed on the NGs wings is fairly usual. As you enter and exit the jetstream you will certainly witness a bit of buffet as the wind velocity begins to increase or drop off.
I too would concur with the fact that you probably benefited from a north/south jetstream which contributed to a considerable groundspeed. The 'flex' that you witnessed on the NGs wings is fairly usual. As you enter and exit the jetstream you will certainly witness a bit of buffet as the wind velocity begins to increase or drop off.
Supercharged PPRuNer
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It’s not that often we get the mighty Q400 up into a jetstream, but on the odd occasions when I have, wind speeds have been in excess of 110kts. Conditions can also be quite choppy, particularly at the jetstream boundary.
The experience you describe doesn’t sound anything special, and you can thank OFDM for the fact that very few pilots these days would want to push company limits, let alone airframe ones.
The experience you describe doesn’t sound anything special, and you can thank OFDM for the fact that very few pilots these days would want to push company limits, let alone airframe ones.
A Runyonesque Character
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I wish you could have found one on my last Q400 trip - two bloody hours (BRU-ZAG*).
Remind me again what the Q stands for?
*or if you must, EBBR - LDZA
Remind me again what the Q stands for?
*or if you must, EBBR - LDZA
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Thank you
Hint - real aviation people don't use ICAO 4-letter designators, they are for posers and wannabes
Hint - real aviation people don't use ICAO 4-letter designators, they are for posers and wannabes
Buttonpusher
After 30+ years of flying I can't decide whether I'm a poser or wannabe. Ah well, maybe I'm both.
I'd be curious to know how you estimated the angle of bank, and the subsequent procedural changes at the airport.
Not bashing you or questioning your judgment, just curious that's all.
It WAS also one out of two flights I've felt insecure in a plane, the other one nearly putting the aircraft upside down into terrain as the A/C flipped over (roughly 100 degrees from level) due to a strong windgust from the side on the turn to final. Approach to that airport has since been changed AFAIK.
Not bashing you or questioning your judgment, just curious that's all.
