DH Mosquito as a glider

[Laker Liker]

I have a friend who was a Mosquito pilot with 105 Squadron flying out of Bourne near Cambridge.

He mentioned yesterday that he once diverted into Manston rather than return to base on one engine. His reason for this was the understandable desire not to find himself in a situation where the other engine could have failed and the Mossie converted into a wooden glider.

His next question stumped me completely - how far did I think a Mosquito could glide in a no power situation or would it drop like a proverbial brick.

Does anyone out there have the faintest idea?

[jumpseater]

No idea but a bit of a trick question, 1st response would be, 'from what height?, and at what weight?, props feathered or in pitch?' Having said that its a commonsense choice, put it down with power asap. Being quite a slippery design with a relatively small span it probably doesnt have the best glide ratio, however the DH Mosquito museum at St Albans, may have some of the perf. data that someone could work out the answer to the question. Being right at the front in a wooden aircraft he'd be first at the scene of the accident with little substantial protection, so again a sensible choice not to ride it in. Unless he's a driver in 633 squadron during the filming........

[airborne_artist]

Assuming that the a/c is fairly empty of fuel and munitions - as it would have been on the return from a mission, I'd reckon about 5:1, so at 10,000 feet he'd get 10 miles.

Some further info. here:
http://aerodyn.org/HighLift/ld-tables.html

This (http://www.silhouet.com/motorsport/tracks/gimli.html) is also worth a read ...

[BeauMan]

Not entirely sure I'd ever want to be in that position, trying to deadstick a Mossie in.

Thing is, with the frequently lethal asymetric performance at low speeds and low altitudes, I'm really not sure I'd want to try landing it with power on just one either.

Hell of a dilemma, that... :eek:

[TheOddOne]

As seen from one of the links above, the glide angle of many a/c is quite respectable. It quotes a sub-sonic jet transport at
16-18:1. I believe the 747 that flamed-out all 4 when it flew through a volcano plume managed 20:1 during a part of the 'drift down' to re-light height of 10,000' and managed about 120 miles.

The Gimli Glider in the other link proves how efficient big jets are as gliders.

Our PA28 manages over 10:1 with a windmilling prop, I hope I never find out what it's like without a prop at all!!!!

It's a common mis-conception that powered a/c fall out of the sky when you take away the power.

Sadly, the Mossie does appear to have big asymetric power problems and I can well imagine you'd be better off reducing power on the good one. It would make an enormous difference of you could get the prop feathered on the dead side, but I can't see any reason why it shouldn't glide. After all, even the Space Shuttle is a glider (angle of 4:1).

Cheers,
TheOddOne

[jumpseater]

Asymetric problems?, I was very interested to read that, as a kid we used to got to the DeHavilland family airshow at Hatfield every year in the late 60-s and early 70's. One of the party tricks was flying the Mossie down the crowd line with one engine feathered, as well as rolls too. I cant ever remember it looping however. I'm sure there are other ex hatfielders who can probably remember it, and I know for a fact there a pic taken by my late father of it doing the 'single' pass too. I think it was Cunningham who normally flew it so obviously the skills level were 'exceptional', but it was as I say a regular feat. They then fired up the windmilled engine (starboard IIRC) and landed normally.

[treadigraph]

There was a post on a thread here on AH&N recently that concerned the sorely missed Neil Williams, a Mossie, Booker, a go around, one not picking up and a "oh dear, I think he's had it" from a very well known ex-ATA pilot. Run the bones of that through "search"; suffice to say, Williams survived that twin Merlin problem...

[henry crun]

jumpseater: The asymmetric problems would refer to the low end of the speed range.

There was a gap between liftoff and safety speed, and in the landing phase with wheels and flaps down below a certain height (600ft ?) you were committed.

[ozplane]

Bearing in mind the foregoing comments on the performance of the Mosquito on one engine, what was the attrition rate as a result of an engine failure on takeoff or approach?

[henry crun]

ozplane: I cannot comment on the attrition rate because that would require a knowledge of the number of hours flown/number in service etc.

My stats are brief and open to interpretation, but I reckon in the 5 years from Jan 1945 to Dec 1949 the RAF lost 62 Mossies that could be directly attributed to asymmetric problems on takeoff or landing.

The wartime losses might well have been much higher with the increased chances of losing an engine to enemy action.

[Irish Steve]

The asymmetric problems would refer to the low end of the speed range.

Nostalgia time again.

That explains why the teaching staff at the school I used to go to near Exeter used to hate the Mossie:O

In the early 60's, No 3 CAACU were still operating Mossies on target tug tasks, and at about 0905 most mornings, teaching would stop for a while as a pair of mossies would launch (in close formation) from the westerly runway (26 or 27 I can't remember what it was in those days), and depart for their task. Thing was, they'd not depart in a manner akin to fast jets, they'd get airborne, then clean up and speed up before climbing out, and the school was on the top of the hill about 1.5 miles from the western end of the runway, and almost under the centreline, so with the way that they launched, it wasn't a case of them going OVER the school, they went PAST the school, and it was a very brave (or foolish) teacher that tried to compete with 4 hard working Merlins all turning and burning at pitch fine with lots of boost, and still flying very close together.

A short while later, the Mossies were replaced with Meteors and Vampires, and while they too were classics, they didn't have the same appeal:O

[Thread drift] I can also recall one auspicious day just before one of the annual air days when I was spending more time looking out of the large facing the airport 3rd floor window than at the blackboard , and I spotted a couple of very fast moving small dots out over Woodbury Common, which I watched make a wide circuit to the North, and then come back in for a low fast run near enough along the runway line. I was one of the very few people in the room that didn't duck under the desk as 2 German Airforce Starfighters came over the top of the school at about 200 Ft, doing as close to Mach 1 as they dared, as preparation for their display at the airshow that weekend. The noise was amazing, and the view we had of them as they pulled into a vertical climb halfway across the airfield was stunning, it was a very short period before we couldn't see them. In hindsight, having spent so long at low level, that was probably the only way they could get back to where they were staging from without running out of fuel:E

They were back at the weekend, and spent a little longer over the airfield before departing in a similar manner. [/Thread drift]

[desertspytfyre]

I had to ask my father about this. He spent rather a lot of time touring the World in De Havilland products but never dead sticked a Mossie or a Hornet. His comment an asymetric landing in either, 'Bloody sight better than in a Brigand!' followed by long dicourse on idiots who insisted that asymetric landing be part of conversion programme to Brigand.:D

[spekesoftly]

As the son of another Mosquito pilot, I can remember my father relating some of his exploits in Germany on 4 Sqn with 2nd TAF, just after the end of WWII. Much of the flying was 'flag waving', and 4 Sqn specialised in Mossie formation displays, with one engine feathered. In keeping with squadron ethos, the pilots decided to attend one particular Mess function with half their moustaches shaved off ! :p

[LEVC]

As far as gliding distance is concerned, the weight makes no difference.

[jumpseater]

Weight?
So are you saying that an aircraft outbound on a mission with full fuel and bomb load, and suffering engine failure will glide the same distance as one inbound from a mission, with no munitions and light fuel load, if the failure occurred at the same speed and altitude in both cases?

[spekesoftly]

An extract from This Link (http://142.26.194.131/aerodynamics1/Performance/Page3.html) explains:-

Effect of Weight on Glide

"It is important to note that weight is not a factor in the L/D equation. Therefore, it is not a factor in how far an aircraft can glide. An aircraft always achieves maximum glide at a certain angle of attack (CL).

When gliding for maximum range we must always operate at the optimum CL which produces the maximum L/D ratio. Therefore the heavier aircraft will have to fly at a higher speed, while the lighter aircraft will fly at a slower speed. Both aircraft will be at the same angle of attack however."


Obviously force landing at the lowest speed (and therefore lower weight) and without live weapons is preferable!