Ask a helicopter pilot anything

[Siko]

Nurburgsingh said:

Both require the ability to move both legs and arms in a more advance “pat your head, rub your tummy” way.

Or so I’m told.

Well I’d be screwed then

[Siko]

Nova Gyna said:

Is a helicopter’s range limited to the amount of fuel it can carry, or can any of them refuel in flight?

How high can a helicopter fly, and what limits it flying higher?

Great thread OP

Thanks mate! As normal bloke shows below they can conduct aerial refuelling but it’s very much a specialist role tending to be done by elite units. On the Merlin we had aerial refuelling probes but I only ever did it in the simulator. A colleague did the trials in the aircraft which worked well apparently.

Most helicopters I’ve flown have a density altitude limit of approx 16k ft (subject to oxygen being used by the crew of course above 10k). Some smaller, lighter helicopters can get higher with the right weather conditions (cold, high pressure, strong winds etc) which is how you get stripped out AS350s (service ceiling 15k) rescuing people from Mt Everest! Other bigger helicopters with lots of power can be quite effective at high altitudes aswell such as Chinook or Mi8 Hip.

However as you get higher the air gets thinner and the amount of lift your rotors can produce decreases quite significantly, funnily enough if you’re struggling to breathe then your rotors are struggling to produce lift Also your gas turbine engines tend to run hotter (I’m sure someone can give me the technical reasons why) with altitude so the engines would be reaching their limits much quicker. As an example we flew 4 Merlins to Lisbon from the Uk, I remember as we climbed up over the Pyrenees approx 7000’ or so I started hitting the temp limits even at a very gentle rate of climb at 120kts.

[Siko]

s2kjock said:

The areas of Scotland I come from are covered by S92s from Stornoway and AW189s from Inverness. Is there a reason for the helicopter that covers the Outer Hebrides needing to be larger than the AW? ie is it for range (additional fuel load) and/or power because it covers a wider area, over water, worse weather? The Sikorsky always seems on the face of it to be oversized for lifting a couple of climbers off the Cuillins or a 4 man crew off a trawler in the Minch.

No idea sorry, both good aircraft though. Just guessing but maybe they wanted a bigger aircraft for the long range missions into the Atlantic for potentially sinking ships with lots of people on board? Just a guess though.

[Siko]

The Road Crew said:

What's the fastest speed you've flown at?

Fastest groundspeed was just under 220kts with a 70kt tailwind out of the Shetland Isles in an S92. Fastest airspeed (don’t laugh fixed-wing pilots ) was 165kts (iirc) in a Merlin. Merlin would cruise comfortably at the Vno of 148kts which is a pretty reasonable cruise speed for a helicopter.

[Siko]

take-good-care-of-the-forest-dewey said:

Being ex mountain rescue I've a bit of a love hate relationship with Helos (specially sea Kings).

The whole East Coast has gone technical when we've needed them and I've been blown into a river after being over flown when they were using their FLIR kit to look for a body at tree top height.

But... The most impressive flying I've ever seen was in the Cairngorms in 3 figure wind speeds. It was so bad one of our party was blown off their feet.

The seaking was sat in a hover max 1 rotor disc from the ridge doing a winch casevac (sadly a later fatality).

Bravest winchman flying combo I ever saw given the weather... How the hell the pilot kept it relatively stable is beyond me.

What's the scariest / bravest flying you've done. Also... That your oppos have done.

And one more... Civilian SAR... Is it as good?

Thanks for your service in the MRT…they’re amazing and real heroes. My auntie and cousin are members of one too and give up a huge amount of time to save lives. Some of the SAR rescues are just mind blowing, I have no idea how they do it but they are just incredible and I doff my hat to them all. Civilian SAR - I am in no position to judge anyone but in my opinion they are absolutely brilliant.

Bravest bit of flying I’ve done? I never served in Afghanistan so my war stories pale in comparison to what crews did there - taking RPG hits in landing sites etc etc. I guess the definition of this event is bravery, but it really pales to what crews did in Afghanistan, but I was awarded a Mention in dispatches for a mission in Northern Ireland for a massive several hour long riot I was involved in. Otherwise maybe going into a landing site in Iraq with tracer coming up at you, that was fun. Luckily 99% of the time in Iraq it was more harassing and a noise complaint than specifically trying to kill you

[Siko]

LeadFarmer said:

Are the military helicopter pilots that fly the SAS about just regular pilots that get tasked to fly them when needed, or are they the crem de la crem of pilots who are attached to them full time?

Bit of both, there are dedicated units which are considered elite but also “regular” crews used for specific jobs too. Working with special forces is part of the day job for most crews at some stage

[Siko]

Whats on Second said:

just a cheery question

is doing a Sully possible with a complete loss of power, i.e controlling your descent, or is it curtains for all aboard in all engine failure scenarios ?

Entirely possible just difficult in a heavy helicopter. In fact I was practising them in the simulator a few weeks back. But see the Clutha crash for what can go wrong.

In a modern helicopter simultaneous double engine failures are almost impossible with the design of modern systems. Even running out of fuel you would lose the engines at different times allowing you time to setup a controlled single engine landing.

It could happen though and the aircraft can autorotate down to a safe landing, dependent on what is underneath you.

[Siko]

Pilotguy said:

I don’t know about “comfortably”. The nose down attitude to hold a steady 150kts makes it much harder to eat your bag rat. I liked the 200kts + G/Sp days on a high level transit with a tailwind though … Made it feel like a proper beast!

Fair enough, last time I flew them was 2006 so it’s been a few years! I do remember hitting 165 though racing a chinook when we were returning to base. He slowly overtook me amazingly enough, so must have been doing 170kts…..when we landed the chinook pilot told me it was shaking so badly he couldn’t see any of the cockpit instruments

Edited by Siko on Friday 1st April 06:31

Edited by Siko on Friday 1st April 06:31

Edited by Siko on Friday 1st April 06:32

[Siko]

take-good-care-of-the-forest-dewey said:

Landing under tracer

Was the cockpit sufficiently protected against lmg / hmg fire or where you just hoping fingers crossed?

We wore body armour, but the ones I flew in Iraq just had armoured seats to go with them

[Siko]

take-good-care-of-the-forest-dewey said:

It's really disappointing that the lessons learned ftom Vietnam haven't lead to better crew protection.

The collection of body armour on the floor, over the lower windows and on his seat was an image that really stood out for me in chicken hawk. That and being trapped in position when landing in a multiple helo formation. The complete lack of agency must be utterly terrifying.

Yeah it is now and armour was fitted to helicopters during my time but not when I was in Iraq, Big problem is weight to be honest and having meaningful armour limits your payload/performance/manoevrability considerably. It's not quite the golden bullet (forgive the pun) you might think it is. Something like a Chinook has such a vast reserve of power that it is no major issue for them to carry armour, but for more modestly powered helicopters (most of them to be fair) it's not quite as easy. As ever with helicopters there is a finely honed trade off between performance/manoeuvrability and payload.

[Siko]

motomk said:

Have seen this, we did tell them it had moved 30 or 40 miles away. They went to the point where it was normally attached to the gas well only to find it was missing!
The big FPSO had disconnected and cranked up the engines and moved 30 or 40 miles away to avoid the approaching cyclone.

Brilliant topic incidentally, and well done to Siko and others for answering the questions.

Thanks mate - just shows what an diverse group of people we have here

Yeah it always throws you when a ship or even better, the oil rig is not where you think it is. I know you know, but most people don't know that a lot of oil rigs can move! I've landed on an oil rig under way at about 10kts and it's a really weird experience. The ones that move (that look like regular rigs) are called semi-submersibles (also jack-ups etc) and sail to their drilling location and anchor down. They look like a James Bond baddy's lair and move when you land on them...the most I've seen on deck was a rate of climb on the vertical speed indicator of 500 ft/min

[Siko]

take-good-care-of-the-forest-dewey said:

Thanks. And thanks for starting the thread.

My pleasure - thanks for joining in

[Siko]

jamiem555 said:

Thanks Si. It’s a great thread and I’m learning things too. That’s what I love about aviation, you never stop learning. They’re such complex beasts and nearly everyday we learn something new. It would be impossible for one person to answer everything as they’re so many different specialists in each field.

Thanks Jamie - appreciate your expert input too and you're quite right about learning, every day's a schoolday!

[Siko]

IanH755 said:

The design philosophy was (and still is) "why fit armour to a helo which may only need it extremely rarely in its life, increasing the weight and decreasing performance, when we can rely on peoples own armour (crew and passenger) to do most of the work for us instead.". Also, to generally help increase performance the actual "skin" of the Merlin is extremely thin and light Aluminium composite which, as I have seen first hand, you could easily puncture with a philips screwdriver, it's that "weak" to piercing despite being very strong in compression.

So with the Merlin the passenger compartment floor was self-sealling fuel tanks which "allegedly" gave protection to small arms upto Russian 7.62mmx54R AP rounds and side protection was from the passengers own body armour. The front end crew had 270' protection in their armoured seat (again proofed against Russian 7.62 AP) and then frontal protection from their own armour. The only other "armoured" part was the fuel manifold on the roof, a shoebox sized unit with Russian 7.62 AP proofed armour around it.

To be realistic this was adequate for Iraq. In fact in Iraq it was probably more dangerous for the crews to be on the ground at Basrah airfield getting rocketed/mortared daily than it was being shot at whilst flying. The rocket and mortar attacks go so bad we were pulled from Iraq for a short time so they could build revetments to protect the helos from all the shrapnel flying around.

Then came the push to get us into Afghan in 2009 and the MOD by now had practical experience of why we needed more armour for the passengers/crew so they got a civilian contractor to fit a new armoured floor which, IMHO, genuinely was capable of stopping Russian 7.62 AP, and a new side protection as they'd found that when a passenger sits in their seat, their armour only protects the top half and not the bottom half, so the armour panels (again 7.62 AP proof) were fitted to protect bums and legs.

Such was the rush to move us from Iraq to Afghan (the Army was screaming for more helos at the time) that we even took some of the civilian contractor team with us to Afghan to finish fitting the armour on IIRC 2 of the Merlins.

The loss of some performance and capacity due to the extra weight of the armour (and the additional door gunner station - 3x Afghan vs 2x Iraq) was expected and dropped the total of troops/freight we could carry so initially, despite the urgency to get us there, we were limited to mostly re-supply runs to the various FOBs but we soon found that the Merlin was literally perfect for the Counter-IED teams so that became out primary role whilst I was there, alongside the usual resupply/mail-runs etc, even though in bigger Ops like Operation Moshtarak (biggest air assault in Afghan since 2001 - over 100 ISAF helos involved) we returned to more traditional "ferrying troops into battle" role for a short time.

I've still got quite a few images from that first tour of bullet holes through tail & main blades, underneath etc and had (subsequently lost) an image from someone on a later tour of two large holes straight through the airframe left which happened as the Merlin was flying through a valley and was caused by either a RPG or horizontally fired mortar or recoilless rifle as it was around 10-ish cm across. Luckily whatever it was had whizzed through the Merlins soft skin so it hadn't detonated whereas, if it had hit the armour, it should have done, very probably losing the Merlin.

Edited by IanH755 on Friday 1st April 10:26

Great post Ian and I know exactly which photo you are referring to - it was an RPG that went straight through the Merlin without exploding.

[Siko]

Speed 3 said:

You are both right. As a nation we internationally have a duty in law to provide SAR x miles from our coastline (can't quite remember the figure, 200 rings a bell). Therefore the further away you are from the next land mass you are, the longer your missions. On the south coast you've literally got half the width of the English channel wheres NW Scotland (and Cornwall for that matter) have lots of empty sea offshore. South coast also tends to be amateur sailors getting into trouble whereas the North Atlantic is trawlers and cargo vessels.

I was involved in the original SAR-H project which transitioned away from the largely Mil provision (with me and my employer, which sounds like the current one for the OP) providing 4 bases in the far north and south. We did some very interesting modelling on the right mix of aircraft but it always came down to a mix of heavies and mediums whereas the Mil had used an all-Sea King fleet and we'd used the civilian version (S-61) at the time. That project also got the civil side into Mountain Rescue which had always been covered by the Mil prior to that.

Happy days, the helicopter business is great fun most of the time.

Thanks for your contribution Yeah I love the helicopter business too.....it's a real rollercoaster ride half the time but it is never boring

[Siko]

andy97 said:

Mention of the Clutha crash is interesting, though. Didn’t the AAIB find that the pilot ignored several (5?) warnings of low fuel? And ISTR there was a human factors aspect in that that the wrong fuel pump was switched on (or off) so no fuel got transferred at a critical moment. The inquest concluded that the pilot probably ignored the low fuel warning because he thought that he had switched the correct pumps on, and that the low fuel warnings were therefore wrong.
Mrs97 is a HF specialist who conducts fatal accident investigations (not aviation) for a living and she was astonished that the design of the fuel system allowed confusion between switches, and that the answer was to re-train pilots in the correct procedures.

Hi Andy,

That was a very sad incident indeed and I think what you say is correct. With no CVR it is almost possible to get into his decision-making loop but I think the AAIB did a good job of working it out. I didn't know the pilot but I know he was very highly regarded indeed, goes to show it can happen to anyone

Ref the Human Factors bits I couldn't agree more about the switch design, it's just nuts. When I flew the Bell 412 we had a number of overtemps on the engines when instructors were switching off the hydraulics but the engine governer switches were literally next to them and vaguely similar. Effectively rather than losing one of your hydraulic systems you suddenly dumped max fuel into an engine and got a nice afterburner effect Still amazes me that ergonomics is so bad...in mostly older aircraft to be fair.

[Siko]

TO73074E said:

Has anyone here had any experiences with the MH-53 or any of the 53 family? I always thought they were impressive looking aircraft.

Sadly not - amazing aircraft and pretty much on a par with a Chinook imho. Not long after I left the RAF an exchange post came up with the USMC and they have (or had, I don't know if it is still open) an RAF pilot flying MH53s. I would have loved that - I live close to RAF Cosford which has an MH53 on display and it is just freaking awesome.

[Siko]

tt601 said:

Feel free to not confess but two angles to the same question.

Have you ever put yourself in a situation that due to your own actions-ie no external factors have impacted-where you have thought’ why in earth did I do that and what was I thinking’!

Equally any situation you’re secretly proud of where your skills and knowledge got you out of a potentially or actually adverse situation which even today , you inwardly smile about and think ‘ yep, I did ok on that one’ .

And to echo others, well played for starting the thread and sharing. Fascinating stuff.

Thanks for your comments mate I’d agree with Madness60 in that aviation decision making and crew resource management teaches you not to get into those situations and rely on superior flying skills (sadly I only have mediocre ones to fall back on ).

To answer your first point yes I did once and was saved from certain doom by the other pilot I was flying with. I was going on leave later that day and all I could think of was getting my end away on holiday; we had one load of troops to pickup and then we were home for tea and medals. I was flogging along at low level and high speed (for a helicopter ) and saw the troops literally just go underneath us.

Funnily enough they were never easy to see I turned the helicopter on it’s side and just pulled to wash off the speed into a tight orbit back to the troops. Kind of like an airborne hand brake turn but not as cool looking (!)…as I rolled out into wind again pointing at the troops, I was desperately trying to slow the helicopter down as I was too close in. It all gets a bit complicated to explain, but essentially the rotors are trying to spin off the head in a tight turn so the engines wind down, when you have slowed the aircraft you run out of lift and suddenly need power and grab an armful of lever, which is fine in most helicopters.

Unfortunately the Puma lacked these things called anticipators which give the engines a nudge you need some power and as I pulled in the lever all that happened is we fell out of the sky like an anvil off a Cliff! There is almost nothing you can do at this stage other than hold the power (or even reduce it) and wait for the engines to kick in again. Luckily my other pilot took control and just held the controls as we plummeted earthwards from 50’, I knew we were going to crash but the engines came in again and we just about got into a hover again at barely 2-3’ above the ground. How those troops got in the helicopter after a front row seat to my fck up I have no idea, but get in they did and I learnt a very valuable lesson

To answer your second point, maybe the only time in my career I felt like I got away with something was the riot I previously mentioned a few posts back. We knew we were up against it and massively overloaded our aircraft with riot police to the stage where our crewman was lying on top of the police and his ass was touching the ceiling

The aircraft flew like an absolute pig as it was well over even our max operational overload and we broke pretty much every rule going, but overloading it with police saved lives on the ground due to the extra bodies. At the end of it all a full days flying later we went for a beer and were just utterly drained but buzzing completely that we had done it and made a difference.

[Siko]

xr287 said:

Hi Siko, occassional offshore passenger here with a few questions.

1. Do you realise how rubbish the headsets in the back normally are? Usually I can barely hear what the pilots are saying and I remember one occassion when we had to RTB with a warning light/failure although they were trying to tell us what was going on barely anyone could understand so people were a bit anxious! If I remember rightly when on the ground it was explained as a hydraulic pump failure relating to the landing gear, alledgedly 1 pump of at least 2 or 3 so no big deal but always safety first! Or is that the usual cover story to stop anyone worrying ??

2. Whenever you lift off deck you always hover for a while, feels like you are checking all the controls etc are responding ok. But interested what exactly is it you are checking before you then lift off properly?

3. On FPSOs there's always the anxiety the morning of your day off that the helideck remains in the roll/pitch/heave limits etc and theres nothing more frustrating than watching your ride home circling waiting for things to go green. Given what I've see videos of military helicopters do, it seems our limits are hugely conservative and unless things were really bad then any good pilot especially ex military would manage to get it down ok. But how much margin is there in your opinion, maybe the ability of the S92 and the payload involved is very different to what you see in typical military videos of them landing on a ship in rough seas.

4. Another weather question, fog! Another frustrating one when you can hear the helicopter circling but you can't see it for fog and it can't land. How much visibility do you need in your opinion to land vs what the limits are set at?

5. I won't mention any names but there was an incident within the last ~15 years where a platform was on fire and a triple figure number of people were evacuated by helicopter. I believe on at least one of those flights more people were allowed on board than there were seats and were in the aisle. Sounds like the right thing to do given it was an evacuation from an incident with high escalation potential and I think was just a short flight over to another nearby platform but the story went the pilots got a roasting for this afterwards. Do you know what the official rules are for that sort of thing?

6. Nowadays we send a lot of the supply ships at reduced speed to save fuel. Are you doing anything differently nowadays to save fuel for cost or emissions savings? Also how fast is your usual cruise speed vs max speed?

You or someone made a comment about passangers being reasssured when the pilots lunch trays come out. Yes 100% accurate, when I see the pilots tucking in to their bacon sandwhichs then I am relaxed!

Brilliant questions, thank you, I’ll take them in order:

1: Yeah they aren’t great. The wonderful engineers like JamieM struggle to tweak the volume as on the 92 it distorts very quickly. There’s actually a fairly lengthy process of rectifying and checking it which I’ve been involved in before, unfortunately helicopters are bloody noisy and the 92 is one of the noisiest! I’ve had a similar incident to the one you mention and went to see the passengers afterwards to brief them in person and allow for questions. In my experience you guys are always really good and appreciate us taking the time to come speak to you. In terms of the pilots “giving you a story” it’s almost unheard of - at my company we have to give full details to the oil company and it would normally be reported to the CAA aswell, so is all open and transparent!

2. We check the engines are all fine and look at the engine torque to workout our delta torque of 18% above hover power. So if we are hovering at 72% torque, the pilot monitoring will check the engines are fine and tell the pilot flying “delta torque of 90%” which is what the pilot will then pull to (at least) for the initial vertical part of the departure.

3. The limits are conservative you’re right, but we are just taking people to work not fighting world war 3! The limits depend on the aircraft and type of installation but a 92 going to a typical FPSO/semi-sub has a limit of 3 degrees pitch and roll with a 1.3m/s heave rate. If any of those figures are out the installation has to wait 20mins for another reading (ie we can’t just land if it’s ok 2mins later). Whilst they are conservative they are safe, which is the most important thing

4. If you are in fog offshore the limit we have is 1400m for an airborne radar approach (using the weather radar to find you in a ground mapping mode). 1400m away from an oil rig in fog might sound a lot but it’s not, if we see you on the limit it looks bloody close believe me! We angle off slightly at 1.5nm to go so are pointing in a safe heading with the rig 15 degrees offset on the side of the pilot who is landing. Personally I think it’s a very sensible and safe way to do it and believe me I wouldn’t want to come any closer in fog!

5. To be honest that sort of thing is for the SAR aircraft, we are bound by the normal CAA rules that every passenger needs a seat.

6. We have trialled Sustainable fuel but whether we use it or not full time I don’t know yet as I know it costs more than regular Jet A-1. We don’t cruise at a set speed as with airspeed and altitude coupled to the autopilot and a high power setting, in the event of a down draft the aircraft could exceed the cruise torque setting which effectively breaks the aircraft. We level at altitude 3-cue, which means the aircraft controlling speed, altitude and navigation, then decouple airspeed and fly 2-cue on just altitude and navigation. We set a cruise torque of 70%, it did used to be 80% but we had an increased amount of technical issues so the lower power setting is almost as quick, more fuel efficient and better for the aircraft. Dependent on weight etc 70% to gives us approx 130-5kts if we’re at max auw or 140-50 if light.

Edited by Siko on Saturday 2nd April 15:08

[Siko]

Mercdriver said:

Thanks for book recommendation siko, low level hell is excellent could not put it down.

I think flying helicopters is demanding but doing it while under fire and protecting the grunts on the ground must be the most demanding flying there is.

Thanks for this thread, unmissable, long may it continue

Thanks buddy! I’m here as long as you guys are and believe me, when it comes to a bore-off, I win hands down