Ask a helicopter pilot anything
Discussion
Can a twin engine helicopter fly on one engine safely? I guess it would not be able to take off vertically with a full load and may not be able to do a rolling take off.
If it can must Be fun, not, flying on one engine.
How do you identify the failed engine? It is as difficult as identifying a fixed wing aircraft?
Over Edinburgh at 6000’ as passenger in back and student pilot switched off wrong engine
Instructor “oh this is going to be interesting” he let the pilot sort it out, he did under guidance.
If it can must Be fun, not, flying on one engine.
How do you identify the failed engine? It is as difficult as identifying a fixed wing aircraft?
Over Edinburgh at 6000’ as passenger in back and student pilot switched off wrong engine
Instructor “oh this is going to be interesting” he let the pilot sort it out, he did under guidance.
Mercdriver said:
Can a twin engine helicopter fly on one engine safely? I guess it would not be able to take off vertically with a full load and may not be able to do a rolling take off.
If it can must Be fun, not, flying on one engine.
How do you identify the failed engine? It is as difficult as identifying a fixed wing aircraft?
Over Edinburgh at 6000’ as passenger in back and student pilot switched off wrong engine
Instructor “oh this is going to be interesting” he let the pilot sort it out, he did under guidance.
It can be horrifically complex (see the East Midlands 737 crash as just one example) to diagnose some types of failure. If an engine fails on my helicopter you’ll get an audio alert and see an “Engine 1/2 Out” caution, along with other indications such as Eng 1/2 Np dropping to zero and TGT dropping too. The good engine will arm 30second power and is relatively easy to diagnose. If you have a more complex failure, such as governor or fuel issues it can get very difficult with one engine backing off and the other overspeeding (a crap analogy sorry!) to compensate - so what type of failure do you have if you didn’t see it happen - overspeed or under speed? Generally the clue is looking at the Np gauge which should be matched to Nr (rotor speed) and if an engine Np is overspeeding it should be driving the Nr up at the same time…..but not always lol.If it can must Be fun, not, flying on one engine.
How do you identify the failed engine? It is as difficult as identifying a fixed wing aircraft?
Over Edinburgh at 6000’ as passenger in back and student pilot switched off wrong engine
Instructor “oh this is going to be interesting” he let the pilot sort it out, he did under guidance.
Yes modern helicopters can happily fly on one engine, mostly we have performance to the same standards as fixed-wing, eg performance class 1. This means if we lose a donk on takeoff prior to a defined point (TDP) we can safely land or continue after that point into the air at a set rate of climb. Offshore we fly to PC2e which is slightly different and means we have the performance to clear the deck edge on departure and not ditch. We sometimes have to restrict payload going to a low deck, eg a rig supply vessel might have a low deck of 50’ ASL and in the event of light winds/low pressures you might have to restrict max auw by 2000lbs which is nearly 10% of our max wt.
I’ve not had an engine fail for real (touches wood!) other than a wind down during a ground run which restarted without any issue….but we practice heaps of them every 6 months.
Siko said:
It can be horrifically complex (see the East Midlands 737 crash as just one example) to diagnose some types of failure. If an engine fails on my helicopter you’ll get an audio alert and see an “Engine 1/2 Out” caution, along with other indications such as Eng 1/2 Np dropping to zero and TGT dropping too. The good engine will arm 30second power and is relatively easy to diagnose. If you have a more complex failure, such as governor or fuel issues it can get very difficult with one engine backing off and the other overspeeding (a crap analogy sorry!) to compensate - so what type of failure do you have if you didn’t see it happen - overspeed or under speed? Generally the clue is looking at the Np gauge which should be matched to Nr (rotor speed) and if an engine Np is overspeeding it should be driving the Nr up at the same time…..but not always lol.
Yes modern helicopters can happily fly on one engine, mostly we have performance to the same standards as fixed-wing, eg performance class 1. This means if we lose a donk on takeoff prior to a defined point (TDP) we can safely land or continue after that point into the air at a set rate of climb. Offshore we fly to PC2e which is slightly different and means we have the performance to clear the deck edge on departure and not ditch. We sometimes have to restrict payload going to a low deck, eg a rig supply vessel might have a low deck of 50’ ASL and in the event of light winds/low pressures you might have to restrict max auw by 2000lbs which is nearly 10% of our max wt.
I’ve not had an engine fail for real (touches wood!) other than a wind down during a ground run which restarted without any issue….but we practice heaps of them every 6 months.
You’ve probably said what you fly but if ec or airbus doesnt fadec just sort it all out During a failure? Yes modern helicopters can happily fly on one engine, mostly we have performance to the same standards as fixed-wing, eg performance class 1. This means if we lose a donk on takeoff prior to a defined point (TDP) we can safely land or continue after that point into the air at a set rate of climb. Offshore we fly to PC2e which is slightly different and means we have the performance to clear the deck edge on departure and not ditch. We sometimes have to restrict payload going to a low deck, eg a rig supply vessel might have a low deck of 50’ ASL and in the event of light winds/low pressures you might have to restrict max auw by 2000lbs which is nearly 10% of our max wt.
I’ve not had an engine fail for real (touches wood!) other than a wind down during a ground run which restarted without any issue….but we practice heaps of them every 6 months.
ghost83 said:
You’ve probably said what you fly but if ec or airbus doesnt fadec just sort it all out During a failure?
I fly Sikorsky S92A which is like a big old heavy American V8…..love it! It’s a great helicopter if a bit basc but very much 90s technology so the Fadec doesn’t sort everything out sadly 
Siko said:
I fly Sikorsky S92A which is like a big old heavy American V8…..love it! It’s a great helicopter if a bit basc but very much 90s technology so the Fadec doesn’t sort everything out sadly
Ahhh yes I know which you mean, in the more modern stuff the fadec would just sort it all out and compensate,Reading a book sea king down about sas in falklands. They set up an attack on Pucaras at pebble island.
Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick s
thouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.
Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick s
thouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.
Mercdriver said:
Reading a book sea king down about sas in falklands. They set up an attack on Pucaras at pebble island.
Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick sthouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.
There are average published weights for a soldier with different kit and these have got significantly heavier over the years, nothing to do with the size of the troops but the kit carried, body armour makes a big difference. However its not unknown to weigh everyone and kit if an accurate figure is really needed. Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick s
thouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.Mercdriver said:
Can a twin engine helicopter fly on one engine safely? I guess it would not be able to take off vertically with a full load and may not be able to do a rolling take off.
Some people say that, if you’ve got two engines you’ve got twice as much chance of having an engine failure 
Single engine pilots spend lots of training time perfecting autorotations. Twin pilots spend more of that time flying on one engine.
We’ll never know, but maybe that’s why the Clutha pilot didn’t enter an ‘auto’ immediately the engines stopped spinning
The factor that most effects performance is ‘density altitude’. Lose one engine in thin air and you may still be going down, but under manageable control
Mercdriver said:
Reading a book sea king down about sas in falklands. They set up an attack on Pucaras at pebble island.
Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick sthouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.
Helicopter about to take off, too heavy for the fuel on board, attack delayed while dumped fuel.
If you take on a section of SF with all their kit, do you know how much kit they weigh before taking off?
Knowing SF are always well equipped and carry back breaking loads surely this is taken into consideration, some of them are no lightweights either and the figure used per soldier must vary considerably.
Easy for me, a mere civvy to criticise, I got caught out one day in para aircraft, just taken on fuel, instructor and four students, they were firemen built like brick s
thouses and the aircraft was really slow to gain speed, off a short grass strip. After that I always checked out the passengers when they climbed on board for their weight, lesson learned.
sounds like they almost caught you out there! Big passengers can make a massive difference and you can occasionally get some weird centre of gravity issues at times. Quite rare but I’ve had to put the larger *ahem* passengers at the front of the cabin before as the flight planning software was showing an out of limits CofG with them spread throughout the cabin. It’s all done as part of our regular flight planning process done pre-flight on computer and signed off by the captain.Madness60 has said it already but the average weights have crept up over the years, iirc there was a Sea King accident in Iraq that was partly attributed to a much heavier payload than planned (and unfortunately downwash affected them too). The army understandably carry as much kit as they need and were normally over the standard weights. Slight digression but I was tasked to lift an underslung load one night in NI of about 1000kg. We had plenty of performance and when I pulled the lever in to lift it literally nothing happened other than the engine instruments going into the red and a lot of noise being made. I assumed it had caught on the ground and released it so we could land on again and get them to free it up. When the crewman went to investigate he found they had filled the net up with scrap metal they wanted shot of…no idea how much was there but he estimated it was 3 tonnes worth
Geneve said:
Some people say that, if you’ve got two engines you’ve got twice as much chance of having an engine failure
Single engine pilots spend lots of training time perfecting autorotations. Twin pilots spend more of that time flying on one engine.
We’ll never know, but maybe that’s why the Clutha pilot didn’t enter an ‘auto’ immediately the engines stopped spinning
The factor that most effects performance is ‘density altitude’. Lose one engine in thin air and you may still be going down, but under manageable control
Yeah quite right about DA - hot and high is massively limiting on helicopter performance. A mate of mine was flying a foreign type that has really good performance (for a helicopter Single engine pilots spend lots of training time perfecting autorotations. Twin pilots spend more of that time flying on one engine.
We’ll never know, but maybe that’s why the Clutha pilot didn’t enter an ‘auto’ immediately the engines stopped spinning
The factor that most effects performance is ‘density altitude’. Lose one engine in thin air and you may still be going down, but under manageable control
) and couldn’t get over the boundary wall in the military base he was in - he told me how he had to gently coax her into a circling transition, trying to get enough airspeed to get into translational lift, at which point he hopped over the wall and managed to fly away (just!).magpie215 said:
I was told the 2nd engine is there to get you to the crash site. Lol
Lol definitely true on some types! Merlin had a bit of a reputation of being underpowered and heavy with 3 engines and a high basic weight. I was in the sim one day and asked the instructor if we could practice some hot and high engine failures and he put me up at 16,000ft-even losing both engines it wasn’t too bad and I managed some safe-ish landings.Interesting mention of Clutha again-that was a fascinating one indeed and I think we talked about it earlier on but some very interesting human factors issues with aircraft design there, let alone the pilots reactions and decision making. No criticism implied of him - supposedly a very talented chap and I can see how he got caught out. RIP.
Siko said:
Interesting mention of Clutha again-that was a fascinating one indeed and I think we talked about it earlier on but some very interesting human factors issues with aircraft design there, let alone the pilots reactions and decision making. No criticism implied of him - supposedly a very talented chap and I can see how he got caught out. RIP.
My mate from school was playing in a band and was on stage when it happened. Pretty horrendous all round. As a pilot we often focus on the technical human nature of the events and trying to learn from them. Then we read or hear about the after effects on the passengers or people and survivors or the loved ones of the deceased and realise there’s a big responsibility flying a machine full of people or fuel around especially low over populated areas.
On a happier note.
Have you ever used your job to get girls?
My workmate was a navy helicopter pilot (we’ve got loads of ex forces pilots in my airline) and when he first joined he was always telling all the hosties he was a “naval aviator” Then one night down route in the bar he was banging on about landing on the back of a ship or something and some other bloke turned out to be ex red arrows. One of the girls then innocently asked my “naval aviator” mate if that meant Mr red arrows was a better pilot than him.
Nobody can top trump the red arrows
Siko said:
Lol definitely true on some types! Merlin had a bit of a reputation of being underpowered and heavy with 3 engines and a high basic weight. I was in the sim one day and asked the instructor if we could practice some hot and high engine failures and he put me up at 16,000ft-even losing both engines it wasn’t too bad and I managed some safe-ish landings.
Is there any truth in the theory that by using the pedals to reduce power to the tail rotor you can get extra climb performance at the expense of spinning round and making everyone dizzy?Gassing Station | Boats, Planes & Trains | Top of Page | What's New | My Stuff