Old Aerospatiale AS350 VS new Airbus H125, main differences?

[chris pochari]

Looking at both aircraft you do not spot any major differences, my guess is the engine has been upgraded, the avionics, anything else? Is the airframe made of a new materials?

I'm doing a project comparing the innovations made in helicopters in the last 40 years.

Thanks.

[ShelbyFlyer]

Although the cover may be very similar the contents are different enough:

 

First, the Arriel 2B1 engine is more powerful in numbers and practicality. Flying an A-Star fleet that is always within 10% of max gross weight, the ease that the H125 handles load and the margin that is left over is impressive. Also with the engine is the digital engine control. Easier but not fool proof starts and additional rotor RPM if needed.

 

Second the hydraulics, while technically an option; there are no H125s being sold in America, at least the last time I was in Grand Praire, without the dual hydraulics. Not only does it give redundancy, I've seen more hydraulic failures than engine failures, it also allows approximately 300 pounds additional load (on high skids). I suppose there may be some B2s that had dual hydraulics but they'd be rare birds.

 

The VEMD is now standard. It was also on later B2s around about 2010. Just throwing it in since you were looking for advancements over the last 40 years. While Airbus' stock glass panel isn't perfect, I think it is much better than steam. Clearer indications, one limiting instrument to look at and audible tones if you get a little collective happy. We have not had an overlimit on a VEMD equipped aircraft. Unfortunately we still get them with steam gauge aircraft.

 

The basic air frame is the same. I believe all new H125s are coming with the crash/fire resistant fuel tanks.

 

I'm an instructor and check pilot with 4,900 hours in A-Stars.

[chris pochari]

Although the cover may be very similar the contents are different enough:

 

First, the Arriel 2B1 engine is more powerful in numbers and practicality. Flying an A-Star fleet that is always within 10% of max gross weight, the ease that the H125 handles load and the margin that is left over is impressive. Also with the engine is the digital engine control. Easier but not fool proof starts and additional rotor RPM if needed.

 

Second the hydraulics, while technically an option; there are no H125s being sold in America, at least the last time I was in Grand Praire, without the dual hydraulics. Not only does it give redundancy, I've seen more hydraulic failures than engine failures, it also allows approximately 300 pounds additional load (on high skids). I suppose there may be some B2s that had dual hydraulics but they'd be rare birds.

 

The VEMD is now standard. It was also on later B2s around about 2010. Just throwing it in since you were looking for advancements over the last 40 years. While Airbus' stock glass panel isn't perfect, I think it is much better than steam. Clearer indications, one limiting instrument to look at and audible tones if you get a little collective happy. We have not had an overlimit on a VEMD equipped aircraft. Unfortunately we still get them with steam gauge aircraft.

 

The basic air frame is the same. I believe all new H125s are coming with the crash/fire resistant fuel tanks.

 

I'm an instructor and check pilot with 4,900 hours in A-Stars.

Thanks, great info, BTW speaking of the dual hydraulic system, wasn't there some issue with the dual hydraulic system on the h125 that caused an accident?

[Brentd2183]

First don't be confused with AS350 vs H125, they are the same thing. What is coming off the assemble line right now is an AS350B3E, however Airbus chose to change a lot of the model names a few years ago to line them up with their airplane division. The "AS" prefix is from Aerospatiale, the original french company who designed the AS350. There have been many versions of the AS350 over the years since first released in the 1970's. AS350B, AS350BB, AS350BA, AS350B1, AS350B2, AS350B3, AS350B3-2B1, and the latest version the AS350B3E. There are other versions too but just putting the B's to keep it simple.

 

Then you had Eurocopter who was the German side of the house coming from the old MBB which designed the BO105/BK117. Now Aerospatiale and MBB together became Eurocopter and any new products designed had an EC prefix, so the EC130, EC135, EC145 etc. Once everything became Airbus Helicopters they eventually went back and changed all aircraft that had an "EC" prefix to an H. So now we have the H130, H145 etc. Anything with an "AS" was left alone and considered a legacy aircraft but eventually they decided to change the AS to an H as well for the AS350 but only for the latest version coming off the line, the AS350B3E is now called the H125. If you have an old AS350B2, it is still an AS350B2. Its all just marketing to fall in line with the airplanes which are A320, A340 etc.

 

B2's had the 1D1 engine, the B3 and B3-2B1 had the 2B and 2B1 engine which were essentially the same except for the engine control changing from a DECU to FADEC and the change of the twist grip from a manual cable to just a big switch.

 

The B3E has the 2D engine which is an absolute beast, almost 1000hp vs appx 700hp for the B2, or 847hp for the B3 and B3-2B1.

 

The dual hydraulics were never an option for the B2, the hydraulic system from the AS355 was modified to go on the EC130 and then later brought over the AS350B3-2B1 line as an option. It's also the same FADEC design that came from the EC130 that made its way to the B3-2B1.

 

The VEMD was originally developed for the B3 and then eventually brought to the B2's. The first B2 with a VEMD was SN 4129 which was a 2006 AS350B2, that's when the change over occurred.

 

In the big picture the airframe has remained the same however there are always dozens and dozens of mods that are done to the airframe over the years. This year they are now being delivered with dual sliding doors standard. Before 2007 the aircraft came with no sliding doors but were options. Then the left sliding door was standard and a right slider an option for about 90-100K extra. Also the crash worth seats came in around 2007 as well. Last year there is now a new version of the crash worthy seats that has carbon fiber and new look.

 

For the dual hydraulic accidents there is a large amount of information out there you can read about but I'll give you some basics.

 

Dual hydraulic version will always keep the main rotor controls, collective and cyclic boosted. The pilot has no switch in the cockpit to turn the main rotor servos off. The cut off switch on the collective only stops hydraulic pressure flowing to the tail rotor servo which is an old school single channel servo. Guys were leaving the switch in the off position during startup/shutdown since the checklist had you turning the switch on and off to check its function. There was no indication visually in the cockpit that the switch was in the off position and pilots took off with unboosted pedals. If properly trained you can fly the aircraft with unboosted pedals without issue, however if you never had the chance to push on a flight control as hard as you have to with unboosted pedals on a B3 you would think the pedal would snap off. As a result pilot takes off, pedals are stiff, assumes its a stuck pedal and the ensuing spin ends up in a loss of control/crash.

 

They first changed the startup/shutdown checklist and moved the hydraulic check to after shutdown and removed the activation of the switch during it. Then they came out with a service bulletin, SB No. AS350-67.00.64 which added a second HYD light so HYD1 and HYD 2 and made it so that if the cut off switch is in the off position the HYD 2 would flash to let the pilot know the switch is in the wrong position. This is where we are at now with that. But ultimately poor pilot training with the hydraulic systems and then failure to follow the basic 2 step pickup which would have stopped accident chain is what happened. We teach hydraulic off training extensively and I've given the exact same failure as those three accidents to all our pilots including the smallest 115 lbs pilot we have and they have had zero issues in controlling the aircraft.

 

Any other questions you have on the AS350 series I will help you with as well.

[chris pochari]

First don't be confused with AS350 vs H125, they are the same thing. What is coming off the assemble line right now is an AS350B3E, however Airbus chose to change a lot of the model names a few years ago to line them up with their airplane division. The "AS" prefix is from Aerospatiale, the original french company who designed the AS350. There have been many versions of the AS350 over the years since first released in the 1970's. AS350B, AS350BB, AS350BA, AS350B1, AS350B2, AS350B3, AS350B3-2B1, and the latest version the AS350B3E. There are other versions too but just putting the B's to keep it simple.

 

Then you had Eurocopter who was the German side of the house coming from the old MBB which designed the BO105/BK117. Now Aerospatiale and MBB together became Eurocopter and any new products designed had an EC prefix, so the EC130, EC135, EC145 etc. Once everything became Airbus Helicopters they eventually went back and changed all aircraft that had an "EC" prefix to an H. So now we have the H130, H145 etc. Anything with an "AS" was left alone and considered a legacy aircraft but eventually they decided to change the AS to an H as well for the AS350 but only for the latest version coming off the line, the AS350B3E is now called the H125. If you have an old AS350B2, it is still an AS350B2. Its all just marketing to fall in line with the airplanes which are A320, A340 etc.

 

B2's had the 1D1 engine, the B3 and B3-2B1 had the 2B and 2B1 engine which were essentially the same except for the engine control changing from a DECU to FADEC and the change of the twist grip from a manual cable to just a big switch.

 

The B3E has the 2D engine which is an absolute beast, almost 1000hp vs appx 700hp for the B2, or 847hp for the B3 and B3-2B1.

 

The dual hydraulics were never an option for the B2, the hydraulic system from the AS355 was modified to go on the EC130 and then later brought over the AS350B3-2B1 line as an option. It's also the same FADEC design that came from the EC130 that made its way to the B3-2B1.

 

The VEMD was originally developed for the B3 and then eventually brought to the B2's. The first B2 with a VEMD was SN 4129 which was a 2006 AS350B2, that's when the change over occurred.

 

In the big picture the airframe has remained the same however there are always dozens and dozens of mods that are done to the airframe over the years. This year they are now being delivered with dual sliding doors standard. Before 2007 the aircraft came with no sliding doors but were options. Then the left sliding door was standard and a right slider an option for about 90-100K extra. Also the crash worth seats came in around 2007 as well. Last year there is now a new version of the crash worthy seats that has carbon fiber and new look.

 

For the dual hydraulic accidents there is a large amount of information out there you can read about but I'll give you some basics.

 

Dual hydraulic version will always keep the main rotor controls, collective and cyclic boosted. The pilot has no switch in the cockpit to turn the main rotor servos off. The cut off switch on the collective only stops hydraulic pressure flowing to the tail rotor servo which is an old school single channel servo. Guys were leaving the switch in the off position during startup/shutdown since the checklist had you turning the switch on and off to check its function. There was no indication visually in the cockpit that the switch was in the off position and pilots took off with unboosted pedals. If properly trained you can fly the aircraft with unboosted pedals without issue, however if you never had the chance to push on a flight control as hard as you have to with unboosted pedals on a B3 you would think the pedal would snap off. As a result pilot takes off, pedals are stiff, assumes its a stuck pedal and the ensuing spin ends up in a loss of control/crash.

 

They first changed the startup/shutdown checklist and moved the hydraulic check to after shutdown and removed the activation of the switch during it. Then they came out with a service bulletin, SB No. AS350-67.00.64 which added a second HYD light so HYD1 and HYD 2 and made it so that if the cut off switch is in the off position the HYD 2 would flash to let the pilot know the switch is in the wrong position. This is where we are at now with that. But ultimately poor pilot training with the hydraulic systems and then failure to follow the basic 2 step pickup which would have stopped accident chain is what happened. We teach hydraulic off training extensively and I've given the exact same failure as those three accidents to all our pilots including the smallest 115 lbs pilot we have and they have had zero issues in controlling the aircraft.

 

Any other questions you have on the AS350 series I will help you with as well.

Great info, I'll read this over a few times! I do have another question, was the original airframe on the aerospatiale made of aluminum or was the original made of composites?

[AS350 pilot]

The only difference between really old airframes and brand new one I've noticed (that wasn't stated above) is the nose material seems to be twice as thick....not sure why...maybe bird strike?

[Brentd2183]

Between 2012-2013 was the change in the AS350 for the canopy. They changed from the composite canopy which had been used since the original AS350 to an aluminum canopy. Its listed as mod 07-4824 "weight savings canopy." They had numerous problems over the years with cracks in the canopy, we are always doing composite repairs around the chin bubble windows or the rain gutters. I don't have the exact numbers on how much weight was saved but I will find out. With the aluminum canopy you have a removable composite nose cover, makes doing heavy avionics work easier. I've attached picture of the new canopy in the jig at Airbus and a view of what the new nose looks like.

The other change was the new "multiblock" electrical system. This replaced the SCU switch console with more reliable switches and made space for radios in the console. There was also a complete redesign of the wiring harness and the connectors involved including relays, junctions, caution warning panel, instrument lighting etc.

 

 

 

 

[chris pochari]

Between 2012-2013 was the change in the AS350 for the canopy. They changed from the composite canopy which had been used since the original AS350 to an aluminum canopy. Its listed as mod 07-4824 "weight savings canopy." They had numerous problems over the years with cracks in the canopy, we are always doing composite repairs around the chin bubble windows or the rain gutters. I don't have the exact numbers on how much weight was saved but I will find out. With the aluminum canopy you have a removable composite nose cover, makes doing heavy avionics work easier. I've attached picture of the new canopy in the jig at Airbus and a view of what the new nose looks like.

The other change was the new "multiblock" electrical system. This replaced the SCU switch console with more reliable switches and made space for radios in the console. There was also a complete redesign of the wiring harness and the connectors involved including relays, junctions, caution warning panel, instrument lighting etc.

 

 

 

IMG_3547.JPG

IMG_3548.JPG

 

 

Between 2012-2013 was the change in the AS350 for the canopy. They changed from the composite canopy which had been used since the original AS350 to an aluminum canopy. Its listed as mod 07-4824 "weight savings canopy." They had numerous problems over the years with cracks in the canopy, we are always doing composite repairs around the chin bubble windows or the rain gutters. I don't have the exact numbers on how much weight was saved but I will find out. With the aluminum canopy you have a removable composite nose cover, makes doing heavy avionics work easier. I've attached picture of the new canopy in the jig at Airbus and a view of what the new nose looks like.

The other change was the new "multiblock" electrical system. This replaced the SCU switch console with more reliable switches and made space for radios in the console. There was also a complete redesign of the wiring harness and the connectors involved including relays, junctions, caution warning panel, instrument lighting etc.

 

 

 

IMG_3547.JPG

IMG_3548.JPG

 

Again, thanks for your effort.

I wish there were more books out there on helicopters with this kind of info