Westland Lynx (Merged threads)
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Dangers of flying backwards or sideways quickly depend on the machine. It could be additional stress on the machine leading to maintenance, it could be handling difficulties which could lead to control problems (loss of control?), the aircraft attitudes may be uncomfortable or offer poor visibility, airflow around the engines may be disrupted, ...
Most of the limits are not piloting limits but rather engineering limits that may require better than average piloting. Landing on Everest is a good example.
The risk of breaking the helicopter or losing control exists, but I doubt that any serious record breakers don't carefully analyze the manoeuvres they will attempt to accomplish in order to mitigate the risks.
Matthew.
Most of the limits are not piloting limits but rather engineering limits that may require better than average piloting. Landing on Everest is a good example.
The risk of breaking the helicopter or losing control exists, but I doubt that any serious record breakers don't carefully analyze the manoeuvres they will attempt to accomplish in order to mitigate the risks.
Matthew.
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One main problem with pushing rear/side flight parameters is simply running out of either power/Tq and or control movement. And of course this all depends upon the W/V.
Airframe control surface stress has nothing to do with it. Design stress limits cannot be reached before the above factors affect you.
Airframe control surface stress has nothing to do with it. Design stress limits cannot be reached before the above factors affect you.
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Lynx is in a good class regarding tail rotor authority, also shared by most of the modern Westland and Sikorsky family, and caused by the Naval heritage, where a large tail rotor is needed.
There is no great stress on a machine in large side or rear speeds, it is a measure of the tail rotor excess thrust, mostly.
Lynx is good, but by no means the best here. The FANTAIL S-76 demonstrator regularly showed 85 knots pure side flight, and 90 degree pedal turns at 120 knots either left or right. The Comanche had virtually identical numbers. The Kamov KA-50 coaxial is reported to have similar numbers, too (why not, no tail rotor at all, right Dave Jackson?)
There is no great stress on a machine in large side or rear speeds, it is a measure of the tail rotor excess thrust, mostly.
Lynx is good, but by no means the best here. The FANTAIL S-76 demonstrator regularly showed 85 knots pure side flight, and 90 degree pedal turns at 120 knots either left or right. The Comanche had virtually identical numbers. The Kamov KA-50 coaxial is reported to have similar numbers, too (why not, no tail rotor at all, right Dave Jackson?)
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That surprises me about design limits. Are you saying that every helicopter out there given enough tail rotor power will go xx knots sideways without blowing out windows, covers, shifting transmissions beyond limits (206), ...
I have flown more than a few helicopters at a maximum sidewards/rearwards speed with plenty of power, torque and control margin remaining.
Matthew.
I have flown more than a few helicopters at a maximum sidewards/rearwards speed with plenty of power, torque and control margin remaining.
Matthew.
Below the Glidepath - not correcting
The obvious danger with going anything other than forwards at high speed (certainly when low level) is if anything unfortunate happens requiring an immediate landing. Running it on from 70 kts is fine going forwards, but if you have to turn through 180 degrees, pick your spot and then run on, while also performing the engine failure IA's, you have given yourself an interesting challenge.
Yes, in a Lynx or any other twin you have more options available, but it's not a good habit to get into unless you are prepared for such an eventuality (eg. display or test flying).
Yes, in a Lynx or any other twin you have more options available, but it's not a good habit to get into unless you are prepared for such an eventuality (eg. display or test flying).
Senis Semper Fidelis
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I seem to remember a thread similar to this one about 18 months ago re the records of the Lynx, memory chips tend to loose a little with age but I think the highest ever speed of the Lynx was alledgedly 247.9 or 249.9 mph in a straight line record attempt about 2 years ago
Vfr
PeterR-B
Vfr
PeterR-B
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The trick when flying at high speed backward is to do it downwind - for display purposes it looks better as the G/S is that much greater - but when things go wrong, the only way is up, tail first, let things sort themselves out and then land into wind. Very little pilot input required as the machine does it all quite naturally.
Flying sideways at speed is a different matter...
Flying sideways at speed is a different matter...
I assume the Lynx has set records for serviceability and mission readiness as well? How's the accident rate for the Lynx compared to other service aircraft?
I feel lucky to have survived
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While the flying capabilities of the Lynx are quite good, it is not however head and shoulders above the military helicopters in its class in any particular property, such as sideward or rearward speed.
It has one enormous achievement that overshadows this statement, however, and that is the awesome achievement of its high speed world record, where it shattered the previous record by about 20 MPH. The flight to 249 MPH is a unique achievement that has stood for decades and is not likely to be challenged for several years to come. Hats off the theWestland team that performed this tremendous feat! I have a signed print from my friends at Westland commemorating this event hanging on my study wall, the only non-Sikorsky item there, as a tribute.
It has one enormous achievement that overshadows this statement, however, and that is the awesome achievement of its high speed world record, where it shattered the previous record by about 20 MPH. The flight to 249 MPH is a unique achievement that has stood for decades and is not likely to be challenged for several years to come. Hats off the theWestland team that performed this tremendous feat! I have a signed print from my friends at Westland commemorating this event hanging on my study wall, the only non-Sikorsky item there, as a tribute.
Originally Posted by Letsby Avenue
The trick when flying at high speed backward is to do it downwind - for display purposes it looks better as the G/S is that much greater - but when things go wrong, the only way is up, tail first, let things sort themselves out and then land into wind. Very little pilot input required as the machine does it all quite naturally.
Flying sideways at speed is a different matter...
Flying sideways at speed is a different matter...
Letsby, how is flying at high speed backwards...affected by being "downwind"?? The helo doesnt know its downwind?
HNY.
Re: LYNX Records
Although the speed record held by G-LYNX is the most well-known, I'm pretty sure that the Lynx has held one or two other records, such as the fastest flight backwards.
Your best bet would be to email or write to Westalnds direct.
If you email to [email protected] and ask for it to be passed to the Lynx Chief Designer, Alan Staples, you might get a response.
If you don't, PM me and I'll try and bend his ear for you.
VP
Your best bet would be to email or write to Westalnds direct.
If you email to [email protected] and ask for it to be passed to the Lynx Chief Designer, Alan Staples, you might get a response.
If you don't, PM me and I'll try and bend his ear for you.
VP
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Re: LYNX Records
Flying Lawyer is right, using the wind to exaggerate the groundspeed is a fine airshow trick.
However, when I showed off the Fantail at Paris, we purposely went up wind at peak speed, since 5 knots of wind is meaningless when you have 85 knots of airspeed to play with, and the professionals who were viewing would understand the conceit.
However, when I showed off the Fantail at Paris, we purposely went up wind at peak speed, since 5 knots of wind is meaningless when you have 85 knots of airspeed to play with, and the professionals who were viewing would understand the conceit.
Re: LYNX Records
N.L.:
Now THERE'S a Freudian slip of the first magnitude!
Conceit, indeed!
Flying Lawyer is right, using the wind to exaggerate the groundspeed is a fine airshow trick.
However, when I showed off the Fantail at Paris, we purposely went up wind at peak speed, since 5 knots of wind is meaningless when you have 85 knots of airspeed to play with, and the professionals who were viewing would understand the conceit.
However, when I showed off the Fantail at Paris, we purposely went up wind at peak speed, since 5 knots of wind is meaningless when you have 85 knots of airspeed to play with, and the professionals who were viewing would understand the conceit.
Conceit, indeed!
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Re: LYNX Records
To my certain knowledge, the Lynx has never officially set a rearwards flight record, though being short-coupled with relatively low directional stability, it may well be capable of such a feat. In service, it's rearwards flight envelope is limited to 40 kn for obvious stress reasons, though there is plenty of rearwards cyclic control and pedal remaining to go faster, particularly at lighter AUM.
Fast rearwards flight really serves no purpose at all (ather than the ability to hover downwind in a gale), since the pilot cannot see where he is going! The windscreen was fitted for this purpose when flying forwards! I cannot ever envisage helicopter manufacturers joining in a race to see who can fly fastest backwards .... they have enough to do to ensure that the rest of the flight envelope is safe and competititive.
Fast rearwards flight really serves no purpose at all (ather than the ability to hover downwind in a gale), since the pilot cannot see where he is going! The windscreen was fitted for this purpose when flying forwards! I cannot ever envisage helicopter manufacturers joining in a race to see who can fly fastest backwards .... they have enough to do to ensure that the rest of the flight envelope is safe and competititive.
Re: LYNX Records
During acceptance flight testing on the Lynx we did go up to about 60kts backwards as I recall, although it's 30 odd years ago now so I may have got that number slightly wrong.
As one of, if not the first, rigid rotor designs the Lynx did create a few helicopter "firsts" at the time, although I have no idea if anyone registered them as records. I can well recall other rotary wing pilots standing open-mouthed as we performed manouevres well outside the envelope of more conventional aircraft.
As I type this I'm looking at a picture on my wall of a Lynx 1 upside down at the top of a loop. I can recall being in a trials aircraft in the mid 70's that barrel rolled over the airfield on the return from a test flight sortie (I was only the humble FTE in the left seat mind). I will openly admit that fast back-flips always gave me the willies, but the TP was particularly fond of them when "demonstrating the capability of the aircraft" for some reason..............
I've no idea if the Lynx was the first helicopter capable of these manoeuvres or not, but would be interested if anyone else can confirm or deny this.
I'll lay even money that it held the record for being the most vibration riddled helicopter of it's day though. Everything you put on it broke back in the early days!
VP
As one of, if not the first, rigid rotor designs the Lynx did create a few helicopter "firsts" at the time, although I have no idea if anyone registered them as records. I can well recall other rotary wing pilots standing open-mouthed as we performed manouevres well outside the envelope of more conventional aircraft.
As I type this I'm looking at a picture on my wall of a Lynx 1 upside down at the top of a loop. I can recall being in a trials aircraft in the mid 70's that barrel rolled over the airfield on the return from a test flight sortie (I was only the humble FTE in the left seat mind). I will openly admit that fast back-flips always gave me the willies, but the TP was particularly fond of them when "demonstrating the capability of the aircraft" for some reason..............
I've no idea if the Lynx was the first helicopter capable of these manoeuvres or not, but would be interested if anyone else can confirm or deny this.
I'll lay even money that it held the record for being the most vibration riddled helicopter of it's day though. Everything you put on it broke back in the early days!
VP
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Re: LYNX Records
I agree with VP about the vibration
I had to return one to Yeovil that was way outside the acceptable limits and it was then discovered that the airframe had been used for some stress testing. It had been given a new head, gearbox and four matched rotor blades by the WHL test team just ot get it up to scratch.
It was eventually accepted into Naval Service (as it had been mostly paid for!) but went on to give enormous problems ot the Flight that took it to sea.
I had to return one to Yeovil that was way outside the acceptable limits and it was then discovered that the airframe had been used for some stress testing. It had been given a new head, gearbox and four matched rotor blades by the WHL test team just ot get it up to scratch.
It was eventually accepted into Naval Service (as it had been mostly paid for!) but went on to give enormous problems ot the Flight that took it to sea.