HP Hermes air test after engine change

[David Rayment]

I am in the throes of writing my Father's aviation career. His last flight (ending in in the crash of Hermes G-ALDV 1/4/58) was for the purposes of an air test. The aircraft was due to fly passengers that afternoon. The take off was normal and there was no hint of trouble until the co-pilot contacted Stanstead ATC informing them that they had jammed controls, 30 seconds later the co-pilot told the ATC that they were about to crash. They did.

From the Inquest witness statements (sometimes grisly, sometimes inaccurate and occasionaly innapropriate) there is 14 minutes during which life after T/O seemed to be normal. My questions are: What would the air test entail? If you were a pilot with jammed elevators (or progressively stiffening elevators) would you turn to Stanstead with its long tempting runway (and Bishops Stortford) or would you head for the farm land in the opposite direction?

Google ICAO circular 59-AN/54

David Rayment

[staircase]

Status:



Date:

Tuesday 1 April 1958

Type:

Handley Page HP.81 Hermes IVA

Operator:

Skyways

Registration:

G-ALDV

C/n / msn:

HP.81/22

First flight:

1950

Crew:

Fatalities: 3 / Occupants: 3

Passengers:

Fatalities: 0 / Occupants: 0

Total:

Fatalities: 3 / Occupants: 3

Aircraft damage:

Damaged beyond repair

Location:

Phase:

Maneuvering (MNV)

Nature:

Test

Departure airport:

London-Stansted Airport (STN/EGSS), United Kingdom

Destination airport:

?

Narrative:
The Handley Page Hermes was on a test flight when the controls became jammed. Eyewitnesses saw the plane descending in a series of dives and climbed until it crashed and caught fire.


Probable Cause:


PROBABLE CAUSE: "The accident was caused by the elevator mechanism becoming jammed. This deprived the pilots of control of the aircraft. The jamming was due to the presence of a small extraneous object which entered the control mechanism."


Classification:

Elevator issue
Loss of control


They probably had no choice as to which direction to fly

[DaveReidUK]

I'm struggling to think what the connection might be, if any, between the engine change and the jammed elevator.

Post hoc ergo propter hoc?

[OUAQUKGF Ops]

Ray, if the accident occurred shortly after takeoff i.e in the initial 15-20 minutes of flight I would have expected the engine parameters and performance to have been closely monitored. Had your Dad had the opportunity to continue the air test he would probably have climbed to altitude, closed down the subject engine, checked the feathering and re-started it. I don't know what else would be involved. I did go as a joy-rider on one of our Vikings that was having an air test and that was what I observed. Regards Tom.

[Cornish Jack]

Somewhere in aviation archives will be a report on an incident on an RAF Hastings which suffered an elevator 'restriction' and which was recovered using trims only. The Hermes was, essentially, a Hastings converted to tricycle (nosewheel) undercarriage. Sadly, control problems of that sort, while rare, are not unique.

[David Rayment]

Hi DaveReidUK - I do not think that there was any direct connection between the jamming and the air test, although the statement "took off and climbed steeply towards the North West" appears in the accident report. Maybe that was sufficient to disturb the jamming object from its resting position. I wonder if the locking mechanism is still resident in the Duxford Hermes? I shall ask them!

[David Rayment]

Tom, thanks for that. Sometime in the 14 minutes of radio quiet they were in the 'Aviate' phase of the emergency. Difficult determine 'when' with few reliabe witnesses!
Regards Ray.

[rolling20]

Originally Posted by DaveReidUK

I'm struggling to think what the connection might be, if any, between the engine change and the jammed elevator.

Post hoc ergo propter hoc?

Just my thoughts. '....The jamming was due to the presence of a small extraneous object which entered the control mechanism'
IIRC some years ago there was a UK charter flight out of Tenerife. The crew suffered from control movement being restricted sometime after take off. I believe they could only turn one way. They eventually landed safely, I believe the captain never flew again?
Investigators found a spanner fouling the controls. An engineer had left it there during maintenance. Apparently the engineer put a notice in his crew room asking if anyone had seen it. I assume all tools are on a highlighted board, so one can see if anything is missing.
I am not suggesting the Hermes accident was similar to this incident, but the report of a extraneous object , reminded me of the incident I have described.
This is all from memory, so apologies if my account is wrong.

[David Rayment]

rolling20 - the jamming object was probably something like a 3/32" or 1/16" split pin (from the inquest)

[DaveReidUK]

Originally Posted by rolling20

Investigators found a spanner fouling the controls. An engineer had left it there during maintenance. Apparently the engineer put a notice in his crew room asking if anyone had seen it. I assume all tools are on a highlighted board, so one can see if anything is missing.

That typically only applies to special tools that an engineer wouldn't be expected to possess. Spanners, sockets, etc would typically reside in the individual's own toolbox, as was probably the case here.

[BSD]

David,

My home is near Meesden (where the Hermes came down) I've often ridden my bike, or run around the area and wondered if they were trying to make it into Nuthampstead. Though I'm not sure quite where it came down, Meesden is very close.

I believe the runways at Nuthampstead weren't broken up unitl the 60's and though I don't think it was operational in 1958, perhaps they were trying to land there. The runway (though shorter than Stansted) would have had the same alignment - 05/23.

Good luck with your writing.

[David Rayment]

BSD - An interesting theory. The crash site was : 'some 200yds South West of Manor Farm, Meesden' . The A/C crashed on a heading of 040°M, about 1 1/4 miles from Nuthamstead.
Thank You

[brakedwell]

Originally Posted by DaveReidUK

That typically only applies to special tools that an engineer wouldn't be expected to possess. Spanners, sockets, etc would typically reside in the individual's own toolbox, as was probably the case here.

I remember following a Vampire Five (in the same type) for take off at RAF Swinderby in early 1957. He lined up on the runway, accelerated and rotated normally, but then continued to climb steeply until he stalled, then crashed on the grass near the end of the runway. They found a spanner in the tail section of the wreckage, but never discovered the owner.

[WHBM]

The Hermes suffered from significant longitudinal instability from the word go - how Handley Page could get there from the aerodynamic refinement of the Halifax is difficult to see. The prototype's maiden flight got out of control on takeoff and crashed after a few miles with the loss of their two principal test pilots, right in front of all the key executives and officials assembled to watch. The production aircraft flew with such a noticeable tail-down attitude that not only did this impact drag but passing aircraft were known to enquire if everything was alright. BOAC junked them within a couple of years, although they had to make a comeback after the loss of the Comet fleet. Independent airlines such as Skyways here were told (straightforwardly, by the Ministry) to buy the aircraft secondhand, to be used on trooping flights - nothing else British made was available and no imports allowed.

[bean]

Originally Posted by WHBM

The Hermes suffered from significant longitudinal instability from the word go - how Handley Page could get there from the aerodynamic refinement of the Halifax is difficult to see. The prototype's maiden flight got out of control on takeoff and crashed after a few miles with the loss of their two principal test pilots, right in front of all the key executives and officials assembled to watch. The production aircraft flew with such a noticeable tail-down attitude that not only did this impact drag but passing aircraft were known to enquire if everything was alright. BOAC junked them within a couple of years, although they had to make a comeback after the loss of the Comet fleet. Independent airlines such as Skyways here were told (straightforwardly, by the Ministry) to buy the aircraft secondhand, to be used on trooping flights - nothing else British made was available and no imports allowed.

They werm't told to by them, they opted to buy them to try to obtain trooping contracts which were just being inttoduced
I knew a Skyways pilot who flew Hermes' and Connies for Skyways and before that Hastings for the RAF. He never complained about handling on the Hermes or Hastings and they were certified as safe by the ARB and the A&AEE.
The reason the Hermes was a disaster for BOAC was appalling payload/range particularly in tropical locations. Hence, they standardised on Argonauts and Connies.
The Skyways pilot was Dick Glading. Maybe Davids father encountered him

[WHBM]

Originally Posted by bean

They weren't told to by them, they opted to buy them to try to obtain trooping contracts which were just being introduced

I think that's rather a "Sir Humphrey" usage of the expression "they opted". The three independents who were short-listed for the trooping contracts - Airwork, Britavia and Skyways - all wanted to have DC-6s for the work, some of which were coming onto the secondhand market from early adopters in the USA. But they were "told" that such aircraft would be unacceptable, they had to be British - and that all that was available was the Hermes. The contracts were given out by the Ministry of Defence, who seem to have been at loggerheads with the Ministry of Transport, who wanted to give the work to their own BOAC.

they were certified as safe by the ARB and the A&AEE

Ah yes. Probably the same people who certified the Comet 1.

The reason the Hermes was a disaster for BOAC was appalling payload/range particularly in tropical locations.

Indeed. Gets back to the drag issue. I did a post here in ... gosh, 2008 ... about these trooping flights on the Hermes, to Singapore, describing not only all the stops needed but also the appalling catering provided :

Commentary on "The Good Old Days" of Airline Travel - Page 2 - PPRuNe Forums

[bean]

WHBM.
I think you're being unfair to thr ARB over the Comet they were the first authority in th world to try to certify a jet airliner.
You've made assertions about the Hermes pitch attitude in the cruise before. It did"nt stagger along at a noticebly high pitch attitude in level fligh, otherwise, there would have inebitabily have been stalling accidents. Never happened
.

[David Rayment]

In my researches I talked to at least a dozen pilots and none of them mentioned logitudinal instability. Underpowered yes so the a/c had to be handled carefully. The hosteses had a number of comments about the incline. A small number of engineers commented on the sitting 'backwards', but other aircraft have a similar arangement. On the positive side the comments were that it was quiet, comfortable and handled OK, one pilot even commented that it was quite 'pleasant to fly'. Looking at the accident statistics for the Hasting they seemed to have a prediliction for stalling.

The prototype crashed due to elevator overbalance.

The name Dick Gladdings dose not ring any bells - when was he with Skyways?

[WHBM]

There was a significant discussion about the Hermes here some years ago, which may be of interest :

Handley Page Hermes IV - PPRuNe Forums

[megan]

You've made assertions about the Hermes pitch attitude in the cruise before. It did"nt stagger along at a noticebly high pitch attitude in level fligh, otherwise, there would have inebitabily have been stalling accidents. Never happened

The nose up pitch attitude may have been reflective of the wing incidence being set too low, increasing the incidence would have lowered the nose attitude. Pitch attitude in such a case is no indication of relation to stalling propensity. Not the first time such an adjustment has been made. David's comment "The hosteses had a number of comments about the incline" indicate it flew in a nose high attitude. He also mentions the aircraft was under powered, once again indicative of a high pitch attitude being required for the cruise.