Can a twin engine helicopter be ferried on one engine ?

[stilton]

Can this be done legally and / or in a tough spot at lighter weights ?

[Sikpilot]

We did it back in the 80's a few times. S58T. I'm pretty sure we got approval from the feds. Lightened the ship up a bit too if I remember correctly.

[OvertHawk]

It depends

If the weight can be sufficiently reduced

If approval from the operator and regulator is obtained

If there is a good reason

Not done it myself but i recall our company moving an S76 single engine in the UK in the late 90's.

[212man]

or in a tough spot

I think in that situation you do what is possible and sort out the legalities/paperwork later! I know an instance where an AS332L on a UN contract in Sierra Leone carried out a single engine departure from the field, with some very grateful pax who had just been chased through the bush. The crew heard their frantic radio calls and started up in readiness for their arrival, but couldn't start one engine (can't remember now whether it wouldn't start, or it was considered more prudent to just go anyway!)

[DuncanDoenitz]

In EASA-land, if its not a procedure in the AMM or MEL, you'll need approval from your Airworthiness Authority, and they are going to even consider your request without a recommendation from the Type Certificate Holder. Obviously every type (and TCH) is different.

Again, obviously, if the Red-hordes are storming the ramparts you might decide to just do it and sort out the niceties later, but make sure you've got footage of the Red-hordes.

[rudestuff]

Get a Bell 206LT, or a Gemini ST. Both certified to operate with one or two engines as required.

[DuncanDoenitz]

In EASA-land, if its not a procedure in the AMM or MEL, you'll need approval from your Airworthiness Authority, and they are going to even consider your request without a recommendation from the Type Certificate Holder. Obviously every type (and TCH) is different.

Again, obviously, if the Red-hordes are storming the ramparts you might decide to just do it and sort out the niceties later, but make sure you've got footage of the Red-hordes.

[ericferret]

We recovered a BO105 single engined.
Had an engine failure on top of a lighthouse!!!

[wrench1]

Can this be done legally and / or in a tough spot at lighter weights ?
On this side of the pond it can be done legally via a FAA Special Flight Permit (Ferry permit). But on occasion it's been known to be done without said permit especially when a category 4 hurricane is enroute and you're parked on a pad located 2 feet above sea level.

[BigMike]

Get a Bell 206LT, or a Gemini ST. Both certified to operate with one or two engines as required.

I believe the Gemini can be, but the 206LT is not certified. It's been a long time since I have flown one though.

[megan]

Oz land chief pilot ferried a 76A with the regulators approval from a off shore platform.

[albatross]

We had a 212 in Rwanda depart a very unfriendly location on one engine….the start checklist was considerably abbreviated and collective was moving up as throttle was rolled through idle to open. Fortunately they were parked on a hillside with considerable dropdown available. Second engine was started in the air. Nothing like sustained automatic weapons fire to focus the mind. Fortunately just 2 crew and light on fuel.

[Blackhawk9]

Been involved a couple of times with 212/412's flown out of not ideal places on one engine , stripped out with min fuel to be flown to a more suitable maintenance place.

[swh]

There is an STC to remove the two engines from a 212 and always operate it on one engine, saves around 300 kg.

[SASless]

Put an uprated PT6 or T-55 Lycoming in one....similar to the Bell 214....with a modern Tail Rotor and you would have a real horse.

[griffothefog]

I had a engine failure coming off Longships or Wolf rock (brain fart memory) in the Bolkow into Lands End single engine around 1990, where was you’re incident?
ericferret?

[ericferret]

I had a engine failure coming off Longships or Wolf rock (brain fart memory) in the Bolkow into Lands End single engine around 1990, where was you’re incident?
ericferret?

Couldn't tell you I'm afraid. Long time ago prior to 1986.

[ShyTorque]

I’ve done it in a military Puma from an offshore island back to the mainland.

It required a running takeoff and a running landing but was otherwise uneventful.

[stilton]

Very interesting


Thanks for the informative replies

[John Eacott]

Since there is a bit of lamp swinging going on, here's my experience.

Brent Field, far north sea and rig shuttles/bus runs carried out with our Bell 212s in the mid 1970s. Coming in to land on one of the smaller decks one of the PT6 TwinPac decided to have a significant cough,so I landed well off to one side of the (smallish) deck to leave room for a Bo105 to bring in a Ginger Beer or two to have a look. Eventually they turned up and diagnosed a power turbine departure; much discussion and I agreed to S/E ferry it back to our home platform as long as it was defuelled and we had approval from Redhill.

Both requirements ticked off, hassle free flight back.

Except that in the washup it turned out that a small porky had been told, and no approval sought nor given. Lesson learned, trust but verify :=
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/796x531/g_balz_turbine_failure_6719cdc69bfe62d85b190bc82a467cd13c916 86e.jpg

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/800x507/g_balz_on_deck_02_be2a47f222a71fca0f6cf17ecd0007c5e3b8801d.j pg

[SASless]

Captain Eacott....Sir.....your yarn proves several things for sure.

The most apparent is there is Legality and there is Reality....and Forgiveness is much easier to obtain than Permission which applied to the Reality thing only gets in the way of accomplishing business.

Helicopters know naught of paperwork.

While working for Bristow I wore my Cowboy Boots as I felt they were appropriate footwear for the manner in which we operated at times.

Now back to Lamp Swinging....

I have flown many single engine flights in the Chinook A and B models.....both of which required some careful calculations to do so if starting from the ground and making a single engine takeoff.

It would have been the same for a C- model.....but the full C Model...just as in the Wessex (the twin Gnome engine version)....single engine performance was more than adequate.

We did try to have an escort for those flights in the event we were to experience a failure of the remaining engine as we were in a very inhospitable locale that more often than not was the reason for the first engine failure.

The Chinook was a pleasure to fly....and one of its characteristics was there was an airspeed that granted the best rate of climb.....and memory serves that it was 59 KTS IAS. (A Model)

A knot less.....and you went down.....a knot above....you went down.....and the key to an uneventful single engine takeoff and landing was to assess what indicated airspeed on that particular aircraft granted you the. best rate of climb and then maintain that airspeed until you were at a safe height above ground. As you burned fuel you could accelerate as you would have an increasing amount of power.

One afternoon at a place called Quang Nhai....in a B Model....I was given a demonstration of why all of the above was important.. It was a lesson that stayed with me.

I was a new Co-Pilot...new to the Chinook..new to the Unit...new to B Model....and new to flying combat missions....and upon my second session of being on a two way machine gun firing range....we had reason to land and assess damage to the aircraft to include determining why one engine was no longer running.

Decision was made to fly the machine home on a single engine....we burned off fuel to our planned minimum fuel quantity....lined up....did a hover power check and determined we did not have hover power....but were somewhat close to it.

We trundled off down the runway....at a somewhat disappointing acceleration rate (barely perceptible) but it was a longish runway......and when there was no more runway in front of us we were off in a cloud of dust with all of Quang Nhai City in. front of us.

We did great util about a hundred feet up....when the Aircraft Commander who was flying ....allowed the airspeed to decrease a few knots when we experience our first droop in Rotor RPM....at which point we were no longer climbing and in fact were losing some height.

My recollection of that moment Is triggered today whenever I see an old fashioned TV Antenna sticking up over a house....as I remember thinking that I had never seen so many of them as I did that day...looking out over the City.

We probably blew off some tin roofs and I know we hit several Antennas before getting to the countryside on the far side of Quang Nhai.

I never quite trusted that fellow after that even when we became House Mates back at Fort Rucker and wound up as Flight Instructors together teaching at the Chinook Conversion Course.

One of the Rules for the Helicopter Flight Of I adopted was....if it will not hover...do not fly it.

[Dave B]

Bristow Wessex used to ferry flight on one engine, and I had a conversation with Pip Smith (RIP) who did this a lot. He stated that he would leave the switches in position for a quick restart and would restart on approach to landing. The problem is that you could lose all the engine oil in the inoperative engine, each engine is different but on the Gnome, an inoperative engine will windmill at about 5% N1. This will be sufficient to generate oil pressure, but not enough to pressurise the bearing labyrinth seals, so all the engine oil could be lost.

[megan]

Bristow Wessex used to ferry flight on one engineIn Oz I'm told the twin Wessex used to fly enroute to the rig single engine as a fuel saving measure, a drop of some 25% in consumption I think the story went, the saved fuel being needed to cover required contingencies, flight had to be made at an altitude whereby a restart of the shut down engine could be made in the event of a failure of the one on line. I'm sure John could provide first hand info.

[SimonK]

Not my story, but passed on as legend on my first Puma Squadron was the Flight Commander who managed to get a fairly heavy Puma into the single-engine hover one night at Bessbrook, when he was half-asleep. I gather he woke up fairly shortly afterwards and landed back on to get No2 up and running! Having woken up at 2000' and about 0400 somewhere over South Armagh, wondering where the hell I was and how I had got there, I can empathise with his alleged mistake...

[John Eacott]

In Oz I'm told the twin Wessex used to fly enroute to the rig single engine as a fuel saving measure, a drop of some 25% in consumption I think the story went, the saved fuel being needed to cover required contingencies, flight had to be made at an altitude whereby a restart of the shut down engine could be made in the event of a failure of the one on line. I'm sure John could provide first hand info.
Never heard of such a plan; drum refuelling on Browse Island was so remote that even a 25% improvement wouldn't have made any difference!

However, for many, many years we were able to plan AOS as an alternate when the forecast precluded an alternate some million miles away (1979 in the far NW of WA, flying to exploration fields somewhere off East Timor).

Until someone asked the question "where is AOS?" and was given the answer 'Any Open Space' :cool:

[172510]

My small experience tells me that most failures happen during the ferry flight to the maintenance facility. According to the tech log I mean.

[ShyTorque]

I once had a problem with an engine oil hot warning (caused by an oil cooler thermostat failure). After discussion with the maintenance organisation it asked if it was possible to run the engine long enough to get airborne on two. It was and then the affected one was shut down for ferrying to maintenance. Starting it up again for landing caused no problems. No big deal but a bit cheeky I suppose.

[ShyTorque]

Having woken up at 2000' and about 0400 somewhere over South Armagh, wondering where the hell I was and how I had got there, I can empathise with his alleged mistake...

Once, on a night call out for a casevac (I had been asleep, as we were allowed to do as standby crew) I got airborne within the required 20 minutes then on reaching the zone boundary I couldn’t remember what the pickup point was (we used a variety of landing sites). Thankfully my crewman was able to remind me!

[Lonewolf_50]

Relying on 40 year old memory here, but "yes it can" has to be balanced with "must you" and "should you".
If you look at the performance charts, you could lighten up an SH-2F (with the two T-58-GE-8F engines) sufficiently that one could, if the ship captain put enough speed on, hover single engine over the deck and then fly off to a 'feet dry' location (ostensibly to get a new engine put in and do the maintenance test flights ashore, etc).

However, one may also crane/lift an H-2 from the deck of a frigate. (And have it towed or put on a flat bed truck to a maintenance facility, yes, we once did that).

The Officer in Charge of that detachment (not mine) had proposed doing it, and was told not to, and the fact that he asked (as I understand how things panned out) took a hard bite out of a otherwise successful and promising career.

[Torquetalk]

Oz land chief pilot ferried a 76A with the regulators approval from a off shore platform.

Even light, that would have required an interesting take-off technique :ooh:

[megan]

Even light, that would have required an interesting take-off techniqueNot aware of the conditions on the day, but it was in an area where cold temps coupled with lots and lots of wind occur.

[JohnDixson]

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1539x1028/h_53_one_eng_departure_7592212c3829785784eacbe60137893fb901d 57b.jpg
Iran 1972
CH-53D with minesweeping kit. Demo in Iran completed, and weather on northbound egress was forecast light rain, which had morphed into very wet snow. The 53 guys had left us in the 67 some 100 miles south, as we did not even have inlet de-ice and the snow was piling up on our inlets. The 53 continued north, but eventually both of the EAPS ( engine air particle separator ) caution capsules illuminated. Pilots did not trust the Emergency Procedure ( which had arisen from a US Gov't agency test program, conducted by same ), so they opened only one emergency door first. Good Move! as that load of wet snow fodded the T-64 to the accompaniment of mush loud and harsh noises etc. This valley was at 6000' Hp. 53 guys hired a truck ad hoc to offload the 53 to the extent possible, got some help from the truck drivers etc to stop the traffic. Watched this from the 67 as we had been stopped 100 miles south of here, have NO inlet ice protection at all, and when the snow built up on the inlets, we landed in a mud hut village and were guarded by a spooky looking man with an 1800 vintage rusty rifle and no english. Three hours later,the snow had pretty much stopped, so we cranked up the 67 ( with an eye toward our "protector " ), and proceeded north until running into the 53 parked at the roadside truck stop.