Gipsy Queen Engines

[old,not bold]

The advice below landed in my Inbox this morning;

The CAA is advising owners of Gipsy Major engines ensure routine checks are carried out by a company/person experienced on this engine type, if low compression is noticed in the engine when turning the propeller by hand or the engine is found to be running rough. Owners are also advised to ensure they are using the most appropriate fuel at all times.

The new guidance follows an emerging trend, identified by the CAA’s Safety Performance and Risk team, of rough running engines, and engine failures, involving Gipsy Major engines.
Now, it's 52 years since I sat behind a Gipsy Queen, admittedly one with very few hours left to the next overhaul, as it rumbled away on route to Sharjah. It strikes me that it's a bit late to find out that if the prop rotates rather too freely when turning it by hand it's time to summon someone who knows what that indicates. Running rough is a rather loose term; what might sound sweet as a Gipsy Queen flies overhead sounds, I can assure you, quite rough from just behind it with another 50 miles of Mediterranean or desert to the nearest airfield. I could add the advice not to take a Gipsy Queen with you into a cloud, at least if it's installed in a Prentice, because that tends to stop the mags working perfectly (or even at all, which provides useful forced landing practice). As well as the advice not to bother with a mag check on the ground, it will fail in a tail-dragger. So long as you can get something approaching full power you take off and check the mags, if you're brave enough, at 1,000 ft. It astonishes me that there are any Gipsy Queens flying outside museums.

[dook]

The CAA advisory is about Gipsy Major engines, not Queens.

[Innominate]

It astonishes me that there are any Gipsy Queens flying outside museums. And they're unlikely to be flying INSIDE museums!

[DaveReidUK]

I recall reading recently (can't remember where) that there are still three airworthy Doves left in the world, including presumably G-DHDV (VP981) at Headcorn.

They probably account for most, if not all, of the Gipsy Queens still flying.

[sycamore]

Rapides have G-Q`s.....Comet,Mew Gull....depends on model....

[old,not bold]

The CAA advisory is about Gipsy Major engines, not QueensOh God, so it is, it's my age showing.

I wonder if my comments on the Queen also apply to the Major.

[Chris Scott]

...Running rough is a rather loose term; what might sound sweet as a Gipsy Queen flies overhead sounds, I can assure you, quite rough from just behind it with another 50 miles of Mediterranean or desert to the nearest airfield. I could add the advice not to take a Gipsy Queen with you into a cloud, at least if it's installed in a Prentice, because that tends to stop the mags working perfectly (or even at all, which provides useful forced landing practice).
Can't comment on tail-drag 'Queens, but the four on our Herrings when I was a rookie co-pilot sounded sweet enough from inside and outside. And we seemed to spend a great deal of time in cloud on our operation... Admittedly, they were the 250 HP version - a lot less powerful than the Dove's. What was it on the Prentice?

[Meikleour]

Herrings - Herons! Typo!!

[treadigraph]

Prentice and Procter both had Gipsy Queens.

Surprised to see the Dragonfly had a pair of Gipsy Majors.

[Gipsy Queen]

I recall reading recently (can't remember where) that there are still three airworthy Doves left in the world, including presumably G-DHDV (VP981) at Headcorn.

They probably account for most, if not all, of the Gipsy Queens still flying.

Hey Chaps - I've achieved fame at last!

Only three 104s still airborne? - I remember when they were just about everywhere. This rather dents visions of my continued youthfulness . . . .

My last encounter with a Queen involved a zero-houred engine which was unusually rough running and not long after installation, swallowed an exhaust valve in flight. Big arguments with Rolls Royce who by then had assumed responsibility for DH engines. My contention was that the Silphenuz (like Teflon) coating of the exhaust valve stem had lost adhesion, rolled up and jammed in the guide. There was ample evidence to support this contention but Rolls were obdurate. Later discovered that the unit had been supplied to another Dove but the Coal Board pilot had rejected it. Something a bit naughty somewhere.

Quite a few hours with Queens; even more with the junior Gipsy III and later Major Mk10 and have to say I liked and trusted them all. Quite the opposite in the case of the dreadful Continental Tiara. I thought the Queen worked well in the Prentice but what an ugly aircraft! I seem to recall from the distant recesses of memory that the blown six also was fitted to the one and only Planet Satellite but I think Proctors might have had naturally aspirated engines. Could be wrong - probably am. It was all so long ago..

I have to say I find the CAA advice to be simplistic bordering on the stupid. If there is demonstrably low compression or unacceptable running characteristics, the power plant, (of whatever type or manufacture), is not fit to be flown. I wonder if the CAA has established a connection with the valve seat recession associated with the absence of tetra ethyl lead in automotive fuels. Of course, that's just idle musing and probably not relevant to current avgas formulation.

[Chris Scott]

Disappointed that Meikleour didn't detect my feeble attempt at flippancy. Never mind...
[...] Only three 104s still airborne? - I remember when they were just about everywhere. This rather dents visions of my continued youthfulness . . . .
Yes. Sadly, the days of rushing out into the garden in reaction to the first, distant rumblings of an approaching pair of Gipsy Queens (or, for that matter, Twin Wasps) seem to be over...
My last encounter with a Queen involved a zero-houred engine which was unusually rough running and not long after installation, swallowed an exhaust valve in flight. Big arguments with Rolls Royce who by then had assumed responsibility for DH engines. My contention was that the Silphenuz (like Teflon) coating of the exhaust valve stem had lost adhesion, rolled up and jammed in the guide. There was ample evidence to support this contention but Rolls were obdurate. Later discovered that the unit had been supplied to another Dove but the Coal Board pilot had rejected it. Something a bit naughty somewhere.
[...] I wonder if the CAA has established a connection with the valve seat recession associated with the absence of tetra ethyl lead in automotive fuels. Of course, that's just idle musing and probably not relevant to current avgas formulation.
Did Silphenuz replace the Stellite listed in Janes, or are they one and the same? (I hasten to admit knowing nothing about valve-stem coatings, except that they are relevant to the lead content of fuel.)

[treadigraph]

I got it Chris!

Very distinctive sound. I recall mentioning on here a few years ago that walking off Riddlesdown in the last glimmerings of light I'd hear a distinctive noise and seen a bright red anti collision beacon several miles away heading towards Biggin. Could only have been a Dove.

There was a Heron which arrived in the Duxford overhead several years back... beautifully quiet were those four Gipsies... I believe it's currently down but not necessarily out. Edit: has a current CofA, is it flying? Hope so...

[sycamore]

Aaaahhhh...deH.....a distant soporific mellifluent `song` of a pair.or four well synchronised Gipsies on a warm summers evening.....aahhhh.. from a Rapide,or a Herring...well synched being the operative term,as if it`s choppy or turbulent,difficult to keep it sweet...

[Chris Scott]

Yes, it was fun trying to keep the four 'Queens in synch on the Herons. They had one of those cockpit indicators with three rotating props, each showing its engine's RPM relative to the master engine - probably #1. When I went on VC10s two or three years later, I found they had the identical gauge. (Perhaps the Vanguard and Viscount had them too.)

It would be great to see and hear a Heron in the air again - not just on a pedestal outside Croydon Airport House.

[YVRLTN]

I wonder if this is as a result of preliminary investigations into the DH89 crash in YXX last month...?

[Chris Scott]

Although the DH89 has the Gipsy Six (forerunner of the Gipsy Queen?), whereas the CAA advisory relates specifically to the Gipsy Major.

[sycamore]

Chris S, drift to `Spectators`forum ,DC-8 thread.....

[DaveReidUK]

Although the DH89 has the Gipsy Six (forerunner of the Gipsy Queen?)

Yes and no.

The original DH.89 had the Gipsy Six (in fact the type was originally known as the Dragon Six), as did the civilian DH.89A, but many of the surviving Dragon Rapides are former RAF Dominies, and therefore have the Gipsy Queen 2 or 3.

[Gipsy Queen]

Yes. Sadly, the days of rushing out into the garden in reaction to the first, distant rumblings of an approaching pair of Gipsy Queens (or, for that matter, Twin Wasps) seem to be over...

Did Silphenuz replace the Stellite listed in Janes, or are they one and the same? (I hasten to admit knowing nothing about valve-stem coatings, except that they are relevant to the lead content of fuel.)

No. Stellite is a austenitic steel which is particularly effective in applications involving high mechanical loadings and elevated thermal conditions. It is a favoured material in the manufacture of exhaust valves and seats which are subjected to both these demanding conditions.

"Silphenuz" was applied by De Havilland to the exhaust valve guides/stems of some models of their aero engines but why they did this, I do not know. Evidently, this material was something like an early Teflon and suffered many of the problems which caused Du Pont to try to deny sales of their product to third parties - a court ruling barred them from restricting sales in this way. A fundamental concern with Teflon was that unless the application processes were ideal, there could be problems with adhesion of the product to the parent material and I suspect this is what happened in my case, with the stuff becoming detached, being forced into a solid mass and resultant jamming of the reciprocal parts. Fortunately, the DH104 was pretty good on one engine. I suspect that the Silphenuz was intended to provide an interface of friction resistance but from this one might suppose that there had been a history of inadequate lubrication in this area but such is not characteristic of inverted engines in general and I'm not aware of any issues in this regard specific to DH engines. In any event, one has to question the wisdom of employing this type of synthetic compound at the point of highest operating temperature of an air-cooled unit.

Because of their superior mechanical balance (120 deg crankthrows), in-line sixes naturally sound good. It could also be that any lack of engine/prop sync seems to be amplified in these engines. I wrote a post a few years ago about the soporific drone of approaching engines in the balm of a summer's evening, but in this case I was aroused from my doze by the wonderful, lumpy and unmistakable sound of a pair of ROUND ENGINES. These were attached to a Beech 18; a nice aircraft to fly and a very pretty example of the pre-War American style of twin taiidragger. However, with its wide track and short wheelbase, it could be a swine on the deck - "Ground loops, anyone?"

De Havilland could be a bit cavalier with their engine appellations. DH needed a 200hp engine so the remarkably clever Major Halford simply grafted a couple of pots onto the front of a Gipsy Major. Thus was born the Gipsy "Six" which went through much development and several production series as a naturally aspirated power plant. In 1944, The first Queen to be so styled was a RAF version of a "Six", series II and the.last of the N/A Queen series developed 250hp. In 1944, a single-stage blower was fitted to become the GQ50 at 295hp with subsequent supercharged models rising to the 380hp of the Queen 70/3 which was fitted to "my" Dove-8.

Since the "Six" and "Queen" were derived from the "Major", would it not seem reasonable to extend the CAA's waffle to the six-cylinder variants too?

[treadigraph]

Wonderful, the gentle rumble of a pair of Gipsy Queens just penetrated my thick skull... dashed outside in time to see the lovely lines of a Dove heading SW through the rain. Unfortunately lack of footwear adorning me plates means I now have wet socks!

Planefinder tells me it's G-OPLC.

[India Four Two]

Unfortunately lack of footwear adorning me plates means I now have wet socks!

Now there is the mark of a true TAP. Uncle Roger would be proud of you!

[treadigraph]

Luckily I counted not the cost and bought a spare pair of socks just in case... :)

[Four Wings]

I wonder if the CAA has established a connection with the valve seat recession associated with the absence of tetra ethyl lead in automotive fuels.

Digging back into the distant memories of my refuelling days, didn't Rapides run on unleaded 80/87 and Herons on 100/130? Given Rapides were 1930s aircraft I'm not even sure TEL had been brought in then.

Or am I dreaming?